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Thread: Preventing Urinary Catheter Blockages

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    Preventing Urinary Catheter Blockages

    PREVENTING URINARY CATHETER BLOCKAGES

    BARRY SIMPSON

    According to theusers' information leaflet, Nitrofurantoin (also known as Macrobid, Macrodantin or Genfura) is used 1) to cureurinary infections and 2) to prevent them. It is proved below that if used to prevent urinary infections, in mycase it also prevented catheterblockages. I do not know for how manyother people with catheter blockages it would be effective. It would be unlikely to work for those whohave blockages caused by kidney stones or bladder stones.
    The normal dose forpreventing urinary infections is 50 or 100mg daily at night. Having taken 50mg per day for 30 days, thiswas reduced to 50mg 3 or 4 times per week and then to just nights when I wasfeeling feverish as might warn of a urinary infection or when there was aconsiderable amount of sediment in my catheter. That worked for me, but others might needdifferent doses. Like other medications,Nitrofurantoin comes with many cautions and possible side-effects, listed in theusers' information leaflet, but I have not had any at these doses.
    As well as takingNitrofurantoin I also repositioned my catheter by pulling it forwardimmediately after going to bed to prevent the intake being obstructed bypressing up against my bladder wall and, as far as possible, assisted drainageby gravity by placing my catheter flat on the bed rather than strapped to myleg.
    I have also usedseveral supporting methods to keep my catheter clear. These are listed below.


    WHAT CAUSED THE BLOCKAGES?

    From January to July 2016the misery of my spinal injury was aggravated by the torment of catheter blockages. Here are a few observations to help identifywhat had been causing them:

    1 My suprapubiccatheter was installed in May 2013, about 4 months after my spinal injury. Ihad no blockage during the first two years and eight months but I had 23between 17/1/16 and 24/7/16. Towards the end of that period, they becamemore frequent.

    2 All the blockages occurred soon after changing positions from sitting uprightin my wheelchair to lying flat on my back in bed. On every occasion Ihave wakened up sweating and trembling with exceptionally violent spasms, usuallybetween midnight and 1am. There is ahighly significant relationship between time and occurrence of blockages. If we use simple dichotomy that blockages could occur at either day or night, ifthere were no relationship between time of blockage and occurrence, theprobability of any one blockage occurring at night would be 0.5. The probability of all 23 blockages occurringat night would be 0.523 = 0.000000119 or a little over 1 chance inten million.
    http://www.rapidtables.com/calc/math/Exponent_Calculator.htm
    The base is 0.5 and theexponent is 23.
    The binomial distribution can also be used with the sameresult:

    http://www.vassarstats.net/textbook/ch5apx.html

    where N = 23, k = 23, p = 0.5 and the answer is p(k outof N)

    The multinomial distribution can be used too:

    https://www.easycalculation.com/statistics/multinomial-distribution.php
    where the number ofoutcomes is 2 (night/day), the number of occurrences 23 and 0, p = 0.5 for eachoutcome.
    Sitting is a wheelchair,my catheter is usually strapped to the upper side of my left leg. If left there when lying flat in bed, thispart of my catheter might be at a higher level than the intake, impeding flowby gravity. I have noticed that sweatinghas on a few occasions been stopped by unstrapping my catheter from my leg andlaying it at a lower level on the bed. Now I always have it unstrapped when in bed.

    3 Thenurse has never taken more than a few minutes to unblock the obstruction. It takes about 10 minutes for the sweatingand spasms to subside enough to be clearly noticeable and a further 10 minutesfor the sweating to have gone and the spasms returned to their normal level. In perhaps 8 or 10 of my 23 cases of blockage,it was uncertain why the blockage had cleared. Sometimes there was insufficient sediment for that to be a likely cause. Movement of the catheter in some cases seemedto be sufficient to make the urine to flow. Unblocking the catheter did not in every case cause a sudden, clearlyvisible flow of urine.

    4 Onlyonce has a blockage recurred during the same night. On this occasion, twonurses arrived at 10.50pm and replaced my catheter which was choked with'sludge'. At 2.40am I woke sweating again. The same nursesreturned. This time the blockage was 'positional'.

    5 There were at least two causes of the blockages - bacterial and physicalobstruction.

    BACTERIAL BLOCKAGES

    6 For abouthalf of the blockages, the nurse mentioned sediment and/or 'pus' as the likelycause. On some occasions, including the most recent, only 36 hours aftera bladder wash-out, the nurse said there was no sediment.

    7 My leg bagis supposed to be changed weekly. On 3 or 4 occasions, the nurse hasmentioned a dirty leg bag, when the carers (and me) had forgotten about it orwhen we had run out of them.

    8 Onthe morning following several of the blockages I have had a bout of sweatingwhich has always been stopped by taking Nitrofurantoin. This seems toindicate that I had a urinary infection, and that the infection was caused bybacteria which also caused the blockage the night before. A urine sample has never beentaken at the time of a blockage or soon after. However, it seems likely that the bacteria killed by Nitrofurantoincreated the sediment which resulted in most of the blockages.
    I do not have a goodexplanation as to why I had no blockages between installation of my catheter inMay 2013 and 17/1/16 despite having more than a dozen urinary infections duringthis period. I can only state theobvious that whatever bacteria were causing these infections did not producesufficient sediment to cause a blockage but there was a change in January2016. Before July 2016 I tookNitrofurantoin only occasionally to cure urinary infections.
    When Nitrofurantoin stoppedmy blockages it also removed the additional spasms accompanying the infectionand the blockage. So Nitrofurantoin achievefour results for me: i) it cured urinary infections; ii) it prevented urinary infections; iii) it preventedblockages; iv) it cured/prevented additional spasms resulting from infectionsand blockages.

    BLOCKAGES BY PHYSICAL OBSTRUCTION

    9 Weeklybladder wash-outs were started soon after the blockages began. I havenever had a blockage on the following night, but I have had them soonafter.

    10 Forabout half the blockages, the nurse mentioned a physical obstruction, such as acollapsed tube. I do not know why physical obstructions were absent fromMay 2013 until January 2016. Maybe there was a change in type orbrand of catheter in December 2015 or January 2016?

    11 Forthe most recent blockage, the nurse offered the following explanation: theend of the catheter tube might be pressing up against my bladder wall, soobstructing the intake. This fits well with what two or three othernurses have said: 'I'm not sure what caused the blockage but wiggling thecatheter where it enters the bladder seemed to unblock it'.

    AN INITIAL TRIAL: 15th JULY - 12th AUGUST 2016
    From 17/1/16 to 24/7/16 Ihad 23 blockages, including 6 from 15 - 24/7/16. It seemed thatinfections by bacteria were responsible for the majority of the blockages(point 8 above) and the position of my catheter for the others (point11). It is likely that someblockages were caused by a combination of the two: a constriction not severeenough to block the flow of urine caused sediment to collect on the upstreamside and this caused a blockage.
    So it is very likely thatchanging positions from wheelchair to bed triggered nearly all the blockages,most of which were caused by sediment in the catheter. Why might changing positions cause anaccumulation of sediment in my catheter? Gravity would probably act more weakly in bed; sediment in my bladdermight change position on going to bed and obstruct the intake of my catheter. These are possible explanations as to whychanging positions from wheelchair to lying flat in bed seemed to triggerblockages but I do not have a convincing answer.
    Since 24/7/16 I have taken 50mgNitrofurantoin each day at about 8pm to allow time for it to take effectbefore moving from wheelchair to bed (point 8) and pulled my catheterforward away from the bladder wall immediately after going to bed (point11). From 24/7/16 - 12/8/16 I had no blockage in 20 nights.

    So WITHOUT Nitrofurantoinand catheter repositioning: 10 nights, 6 blockages;
    WITH Nitrofurantoin and catheter repositioning: 20nights, no blockage.

    It looks obvious that there is a connection betweenNitrofurantion/catheter repositioning and stopping blockages. The strength of the evidence can be measuredlike this:

    what are the chances of having 6 blockages on the first 10nights (without Nitrofurantoin) and none on the following 20 (withNitrofurantoin) if Nitrofurantoin and catheter repositioning had no effect?

    That can be calculated like this:

    if there had been just one blockage, the chances of itbeing in the first 10 nights would have been 10 divided by the total number ofnights (30) = 0.3333;

    if there had been two blockages the chances of both of thembeing in the first 10 nights would have been 0.3333 multiplied by 0.3333 =0.1111 and so on ...... until

    the chances of 6 blockages all being in the first 10 nightsis 0.3333 multiplied by itself five times or 0.33336 = 0.0014, thatis 14 chances in 10,000 or 1 chance in 714 (10,000 is the number that 0.0014would have to be multiplied by to get 14). So the probability of there being no association between takingNitrofurantoin/catheter repositioning is low, therefore the probability thatthere is an association is high. It is 1- p = 0.9986 = 9,986 chances in 10,000 =9,986/(10,000 - 9,986) chances in 10,000/(10,000-9,986) = 713 chances in 714.
    .

    The probability of there being no association betweentaking Nitrofurantoin/catheter repositioning and the occurrence of catheterblockages can also be calculated using the binomial distribution where theprobability of success for a single trial is again 10/30 = 0.3333, the numberof trials is 6 (the number of blockages on all 30 nights) and the number ofsuccesses (hardly the right word for a catheter blockage - the number ofblockages during the first 10 nights) is also 6.

    http://stattrek.com/online-calculator/binomial.aspx
    The probability justcalculated is 'if there is no association between Nitrofurantoin and catheterblockages, what are the chances of getting 6 blockages in the 10 nights withoutNitrofurantoin?' It can also be calculated the other way round: what arethe chances of there being no blockage in 20 nights with Nitrofurantoin if lackof blockages is not associated with it? In this case, theprobability of success for a single trial is 20/30 = 0.6667 the number oftrials is 6 (the number of blockages on all 30 nights) and the number ofsuccesses (the number of blockages on the last 20 nights) is 0. Theanswer is the same, that is, probability = 0.0014.

    Themultinomial distribution can also be used with 2 outcomes (blockage/ noblockage) probability of outcome 1 (blockage) is 10/30 = 0.3333; frequency ofoutcome 1 (number of blockages when not taking Nitrofurantoin) = 6; probabilityof outcome 2 (no blockage) is 20/30 = 0.6667; frequency of outcome 2 is 0 (thenumber of blockages when taking Nitrofurantoin). The answer is the sameas before (p = 0.0014).

    http://stattrek.com/online-calculator/multinomial.aspx

    This too can be calculated theother way round: outcome 1 (no blockage, probability 0.6667, frequency 0);outcome 2 (blockage, probability 0.3333, frequency 6) with the same result.

    So for the 30 nights of the trial, it is possible to saythat taking Nitrofurantoin and catheter repositioning were associated withstopping my catheter blockages with only a very small chance of beingwrong (probability 0.0014) which is 1 chance in 714.

    That was the situation on 13/8/16. It is changingevery day. If I have a blockage, the chances of the statement being wrongwill increase. If I do not have ablockage, the chances of the statement being wrong will become even smaller; forexample when the number of nights without a blockage reached 50 (12thSeptember), the probability became (10/60)6 = 0.16676 = 0.000021, that is 21 chancesin a million or 1 in 47,619 (one million is the number that 0.000021 would haveto be multiplied by to get 21).

    Such probabilities as p = 0.0014 or p = 0.000021 do notpredict the frequency with which I can expect a blockage; neither do theypredict the proportion of patients with a condition the same as mine havingtheir blockages stopped. All theymean is that in my case, it is almost certain that taking Nitrofurantoin andrepositioning my catheter have reduced the chances of getting a blockage: p = 0.000021 (the probability of there not being an association) or 1-p =0.999979 (the probability of there being an association) are measures ofthe chance that Nitrofurantoin and catheter repositioning are associated withcatheter blocking; they are not measures of what that association is, thatis, how much they reduce the chancesof a blockage.

    So for patients with a condition the same as mine, the treatment can be expected to reduce the frequency ofblockages for almost all of them.

    It could be argued that although what has been calculatedshow a very strong correlation between taking Nitrofurantoin/catheterrepositioning and the absence of blockages, demonstrating correlation is notthe same as demonstrating cause: something else might have happened on 24thJuly 2016 when I started taking Nitrofurantoin regularly and it was this'something else' which stopped my blockages. This is true, but I am not aware of anything happening on that day orsoon after, and which has continued to be effective since then, which could bethis 'something else'.

    It is possible to predict the number of blockages withinany specified period using the Poisson probability distribution:

    http://stattrek.com/online-calculator/poisson.aspx.

    For example, suppose we wish to predict the chance of 1blockage in a period of 7 days, the Poisson random variable would be 1. The average rate of success is the average numberof blockages which in the past have occurred in 7 days (number ofblockages/number of days in observation period x 7). To predict the chance of 2blockages in 28 days, the Poisson random variable would be 2 and the averagerate of success would be the average number of blockages in 28 days. As long as there are no blockages on nightsfollowing taking Nitrofurantoin, the average number of blockages for any periodis 0: so until there is a blockage, theprediction of future blockages for any period is zero.


    NITROFURANTOIN AND BLOCKAGES 16th January 2016 to 16th January 2017

    My first blockage occurred on the night of 16/17th January2016.

    There were 23 blockages in the first 190 days, none in thefollowing 176.
    If Nitrofurantoin and catheter repositioning had no effect,the probability of having 23 blockages in 190 days followed by no blockage in176 days is (190/(190+176))23 or 0.519123 = 0.0000002823 which is less than 3 chances in10 million (ten million is the number that 0.0000002823 would have to bemultiplied by to get 2.823).

    http://www.rapidtables.com/calc/math/Exponent_Calculator.htm
    The base is 0.5191 andthe exponent is 23.

    The probability of Nitrofurantoin having had no effect isbecoming even smaller every day I do not have a blockage.

    The binomial distribution can also be used with the sameresult:

    http://www.vassarstats.net/textbook/ch5apx.html

    where N = 23, k = 23, p = 0.5191 and the answer is p(kout of N)

    The multinomial distribution can be used too:

    https://www.easycalculation.com/statistics/multinomial-distribution.php
    where the number of outcomesis 2 (night/day), the number of occurrences 23 and 0, p = 0.5191 and 1- 0.5191= 0.4809.
    .


    DOSAGE OF NITROFURANTOIN

    Side-effects and build-up of bacterial resistance areconcerns about antibiotics generally. Although there are no indications that I have had either so far, I amnow trying to determine the minimum effective dose of Nitrofurantoin.

    Having taken 50mg every day from 24th July until 22ndAugust (30 days), this was reduced to 3 or 4 times per week and then to justnights when I was feeling feverish as might warn of a urinary infection or whenthere was a considerable amount of sediment in my catheter:
    August 24, 25, 26, 28, 29, 30;
    September 1, 2, 4, 7, 8, 10, 13, 16, 18, 19, 22, 25;
    October 1, 5, 6, 7, 11, 14, 15, 17, 20 (100mg), 21, 22, 23,25, 29, 31;
    November 4, 5, 7, 10, 13, 16, 19, 22, 24, 26, 28;
    December 1, 3, 5, 8, 11, 12, 17, 22, 31;
    January 8, 16, 18, 22;
    February 5, 13, 16, 20, 25;
    March 11,


    CONCERNS ABOUT TAKING NITROFURANTOIN LONG-TERM

    The Users' Information Leaflets issued by Dr Reddy'sLaboratories and Genfura recommend 50 or 100mg four times per day for sevendays for treatment of bacterial infections of the liver, bladder and otherparts of the urinary tract and 50mg or 100mg once per day at night for theprevention of further infections but do not say for how long. The connection between preventing infectionsand preventing catheter blockages is not mentioned. The leaflets list many possibleside-effects. So far, I have notexperienced any but others do; see for example:

    http://www.webmd.com/drugs/drugreview-14274-Nitrofurantoin+Oral

    https://www.drugs.com/comments/nitrofurantoin/

    Will it cease to be effective after a while? So far it hasn't. It has already provided me with a very welcomerelief from the misery of regular catheter blockages, possibly preventedinternal damage and saved a significant amount of nurses' time.

    Brumfitt and Hamilton-Miller support the use ofNitrofurantoin for long-term (12 months) prevention of urinary infections:

    http://jac.oxfordjournals.org/content/42/3/363.full.pdf;see also

    https://www.medicines.org.uk/emc/medicine/22540 and

    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3228625/


    CATHETERS

    Has the catheter had any influence on the occurrence ofblockages? There is a widely-held viewthat catheter production has lagged a long way behind the technology availableand is failing patients badly. See forexample:

    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4673556/

    http://www.bbc.co.uk/news/health-33270030

    http://www.medicalplasticsnews.com/news/opinion/why-criticise-catheters/

    I can refer only to the catheters I have had. My indwelling suprapubic catheter waspresented to me in hospital in May 2013 as being better than the intermittenturethral catheter used between January and May 2013. This would have been impossible on returninghome because I live alone and have very little movement in my hands. The indwelling urinary catheter via theurethra was not mentioned to me, presumably because the hospital consultantsthought it would be less suitable than the type I have got.

    In my case, my present type of catheter is the onlypractical one I was offered. The threatof urinary infection is always with me. Hotand cold sweats occur most days. My armsare often stinging with cold while the rest of me, where I have sensation, isoverheating. It is possible that bettercatheters would render blockages something of the past, which would be welcomerelief for more than 200,000 people in the UK with long-term catheters and severaltimes as many when shorter-term users are included.

    http://www.healthtalk.org/files/nursing_times_living-with-an-indwelling-urinary-catheter.pdf

    We may wonder why the enormous buying power of the NHSresults in some not-very-good equipment and medications at high cost while inthe commercial world, large organisations are able to use their buying power tosecure what the customer wants at competitive prices. An Internet search on NHS overcharged (1/2/17)revealed about 190,000 results for drugs:

    https://www.google.co.uk/?gws_rd=cr&ei=q-uRWNXPOYuxa5HQh5AG#q=nhs+overcharged+for+drugs

    and 143,000 for equipment:

    https://www.google.co.uk/?gws_rd=cr&ei=qSqSWO6ICIb8aaGalagC#q=NHS+overcharg ed+equipment

    The standard period between changes of catheter has been 12weeks (5 weeks in hospital) but there have been some variations. It was changed shortly before 11pm on 23/7/16by a night nurse attending a blockage and was followed less than 4 hours later bya blockage of the new catheter, described by the nurse as 'positional'. The catheter that was replaced coincided with more blockages thanany other I have had. I had no furtherblockage with the new catheter which was replaced on 18/10/16. In my case so far, there is no substantial evidenceconnecting blockages with particular catheters or with the period of time sinceinstallation ..... but absence of evidence is not evidence ofabsence.


    SUPPORTING METHODS TO REDUCE CATHETER BLOCKAGES

    Although Nitrofurantoin and catheter repositioning haveeliminated blockages so far, often there is sediment in my catheter: sosupporting methods are used to keep it clear:

    1 High waterintake: widely recommended to wash out loose sediment and to dilute urine andbacterial concentration: possibly a necessary but not sufficient method toprevent blockages. It certainly did notcause the sudden cessation of blockages from 24/7/16.

    2 Bladderwash-outs: I have never had a blockage on the night immediately following awash-out but I have had at least one on the night after that: they reduce butdo not eliminate blockages.

    3 Loosening anysediment in the catheter by rolling it between the hands.

    4 Adding vinegarto food seems to be followed by a clearer catheter (by lowering urine pH andacting as an antibiotic). There are manyother natural antibiotics which might help:

    http://cincovidas.com/foods-that-act-as-natural-antibiotics/

    Drinking lemon tea has been followed by a clearer catheter. To make lemon tea, I simply cut an unpeeledlemon in half, slice or chop one half into pieces and pour hot water ontoit. In a small cup (200ml.) this can betopped up with hot water several times, squashing the lemon with a spoon.

    It looks possible that the sediment was caused by reducingthe amount of Nitrofurantoin below 50mg per day and that the supporting methodsmight be alternatives to higher doses. Nitrofurantoin does appear to clear sedimentfrom the catheter not much longer than an hour after taking it - as would beexpected from its property of preventing blockages.

    BACTERIA CAUSING CATHETER BLOCKAGES
    It seems likely that the bacteria killed by Nitrofurantoincreated the sediment which resulted in most of the blockages. Samples of the contents of the catheter atthe times of blockages would have been useful to test this.
    Nitrofurantoin has been shown tobe effective against: Citrobacterspecies, Coagulasenegative staphylococci, E. coli, Enterococcusfaecalis, Klebsiellaspecies, Staphylococcusaureus, Staphylococcussaprophyticus, Streptococcusagalactiae
    Observations point to one or more ofthese bacteria as the likely cause of perhaps three-quarters of my blockages (the other quarter being the result ofphysical obstructions). Without knowingwhich of these bacteria caused the blockages, we can not be sure thatNitrofurantoin is the most selective antibiotic to deal with them or what otherantibiotics would also work. Also, wedo not know at what pH the blockages occurred.
    Many or all strains of the followinggenera are resistant to Nitrofurantoin: Enterobacter, Klebsiella, Proteus, Pseudomonas
    https://en.wikipedia.org/wiki/Nitrofurantoin


    BLADDER STONES AND CATHETER BLOCKAGES

    The methods explained in this paper will be effective onlyfor blockages caused by certain types of bacteria or certain catheterpositions. It remains to be seen to whatproportion of catheter blockages these conditions apply. In July 2016, before taking Nitrofurantoin aspart of this treatment, a rehabilitation consultant suggested to me that kidneystones might be the cause of my blockages. Bits breaking off the stones would block the catheter. In the absence of any samples from mycatheter having been taken at the time of a blockage, this seemed a reasonablepossibility, but now that the blockages have been demonstrated to bebacteriological (otherwise they would not have been stopped by Nitrofurantoin)it looks unlikely in my case - but not necessarily in others.

    After reading an earlier version ofthis paper in November 2016, a urology consultant suggested to me that mine mightbe a case of bladder stones because these can cause re-infection. Repeated infections, might in some cases, beprevented by removal of bladder stones.

    The following are commonly mentionedsymptoms of bladder stones, not necessarily soon after their formation:
    1 lower abdominal pain, 2 pain or discomfort when urinating, 3 difficultywhen starting or a stop-start in urinating, 4 cloudy or dark-colouredurine, 5 discomfort or pain in the penis, 6 urinating more frequently, especially at night, 7 bloodin the urine.
    http://www.nhs.uk/conditions/bladder-stones/pages/introduction.aspx
    http://www.medicalnewstoday.com/articles/184998.php

    Spinal injury and consequent loss ofsensation and use of a catheter might reduceawareness of some of these symptoms. Cloudy urine is commonly mentioned but not sediment which would beneeded to cause a catheter blockage. Darkening of urine is also a usual consequence of taking Nitrofurantoin.

    Anyone with persistent catheterblockages might be recommended by their medical practitioner to have acystoscopy, an examination of the bladder with a fine telescope, to detectwhether there are any stones. Stickler and Feneley suggest that Proteus mirabilis produced by bladder stones is a likely cause ofcatheter blockages:
    http://www.nature.com/sc/journal/v48/n11/full/sc201032a.html
    However, Nitrofurantoin is noteffective against most strains of Proteus. See also

    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3228625/

    So Nitrofurantoin is unlikely to prevent blockages caused by bladderstones.


    ATITUDES TOWARDS CATHETER BLOCKAGES

    The nurses, particularly the nightnurses, have left me with the impression that catheter blockages are much morecommon than they need to be. Often, theyleft me with a cheery 'See you again soon'. The prevailing attitude in both the medical and nursing professions thatthey are an inevitable consequence of having a catheter should bequestioned.

    In November 2016 I 'phoned the night nurses to thank them for coming to unblock mycatheter on 23 nights between January and July, to explain why I have notcalled them out since July, and to offer to send them a copy of this paper: 'Wedon't give out e-mail addresses over the phone'.
    Meanwhile, patients wake in theearly hours of the morning, sweating profusely, trembling with massive shocksof spasms, resulting in urine being forced back to the kidneys and in extremecases, autonomic dysreflexia, internal damage and death. Night nurses rushbetween patients to unblock catheters which do not need to be blocked.Sometimes they have taken over 2 hours to reach me (although the average isabout 1 hour 20 minutes), explaining that they have had a lot of patients withblocked catheters that night.
    Recently, a nurse from the localhealth authority called to assess my condition. A friend who was with mementioned my catheter blockages and offered her this paper: no thanks. 'It'ssomething they can live with'.
    Although I have not heard anyone elsesay so explicitly, 'something they can live with' reflects the prevailingattitude of others connected to the nursing and medical professions. With a few exceptions, no-one wants to knowand the few who do want to know are not in positions to persuade the medicaland nursing professions to listen to a patient.
    Such has been the resistance to anapproved dose of an approved medication. How much greater can we expect the difficulties of improvement in themedications available for spasms for example, or equipment such as catheters,when those needing them have been conditioned to expect nothing better thanwhat they are given, when manufacturers are allowed to happily continue to sellthe same old products. I must say I amleft wondering whether the brick wall of complacency about catheter blockagesalso applies to other treatments and equipment that those with spinal injuriesneed - including treating the injury itself - and beyond spinal injuries.

    This, of course, is my ownstory. My need for a catheter was causedby breaking my neck at C4/5 with consequent spinal damage and paralysis belowmy shoulders. I do not know for how manyothers the treatment would be effective but I have no reason to believe thatit would not work for some of those -male or female - with catheters for other reasons. Other people might need different doses ofNitrofurantoin. If you have persistentblockages or know someone who has, do consider showing this paper to a medicalpractitioner.



    P.S. Still no blockage since the night of 23rd / 24th July.

    20th March 2017

  2. #2
    ONE YEAR LATER

    I have still not had a catheter blockage since the night of 23/24th July 2016.

    Neither have I had a urinary tract infection, at least not one sufficiently serious to be recognisable without bacterial analysis.

    I have had a few occasions when I have had a limited amount of overheating which might have been minor urinary tract infections. I have treated these by taking just one 50mg tablet of Nitrofurantoin, or for very minor overheating, lemon tea and vinegar on food. It appears that they have allowed a reduction in the dose, but in the amounts I have been taking (1/2 lemon and 30ml. vinegar per day) they would probably not be sufficient alone. For example, on the evening of 9th February 2018 after consuming the usual amounts of lemon and vinegar, my catheter had a large amount of sediment in it: so I took 50mg. Nitrofurantoin: the following morning it was clear.

    There is usually some sediment in my catheter. Usually I loosen this when going to bed by manipulating and bending the catheter, or if there is an amount which looks sufficient to threaten a blockage, I take 50mg Nitrofurantoin.

    There has been little reaction from the medical and nursing professions. Where a blockage is sedimentary, there remains a need to carry out bacterial analyses of catheters at the time of blockage so that an appropriate antibiotic can be used as a prophylactic.

    SUMMARY OF METHODS TO PREVENT URINARY TRACT INFECTIONS AND CATHETER BLOCKAGES

    May 2013 to 15th January 2016: no blockage; Nitrofurantoin taken occasionally to cure urinary infections.

    16/17th January 2016 to 23/24th July 2016: 23 blockages; Nitrofurantoin taken occasionally to cure urinary infections.

    Since March 2016: weekly bladder wash-outs.

    Since 24th July 2016: no blockage;

    50mg Nitrofurantoin taken on these evenings to prevent infections and blockages:

    2016
    July 24-31;
    August 1-22, 24, 25, 26, 28, 29, 30;
    September 1, 2, 4, 7, 8, 10, 13, 16, 18, 19, 22, 25;
    October 1, 5, 6, 7, 11, 14, 15, 17, 20(100mg), 21, 22, 23, 25, 29, 31;
    November 4, 5, 7, 10, 13, 16, 19, 22, 24, 26, 28;
    December 1, 3, 5, 8, 11, 12, 17, 22, 31.
    Total for July - December 2016: 84x50mg

    2017
    January 8, 16, 18, 22;
    February 5, 13, 16, 20, 25;
    March 11, 25;
    April 2, 8, 13, 22, 28;
    May 1, 12, 19;
    June 3, 13, 18;
    July 2, 10, 23;
    August 14, 15;
    September 17, 18;
    October 11, 17;
    November 2, 14;
    December - none.
    Total for 2017: 33x50mg

    2018
    January 5, 22, 31;
    February 9, 15;
    March 2, 9, 10, 17

    Catheter repositioning to prevent non-sedimentary blockages.

    Since January 2017: rolling catheter between hands and consumption of natural antibiotics: lemon tea (half a lemon), 30ml. vinegar on food.


    20th March 2018

  3. #3
    Senior Member alan's Avatar
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    This is a very interesting read. Thank you for your diligence. I'll mention this to my urologist-I'd like to be able to prevent my Foley blockages.
    Alan

    Proofread carefully to see if you any words out.

  4. #4
    Macrodantin has been used in many places with some success. It is different for everyone. I think that if it works for you that is great. And it is something that others should know. That being said, it is not the panacea for all.

    ckf
    The SCI-Nurses are advanced practice nurses specializing in SCI/D care. They are available to answer questions, provide education, and make suggestions which you should always discuss with your physician/primary health care provider before implementing. Medical diagnosis is not provided, nor do the SCI-Nurses provide nursing or medical care through their responses on the CareCure forums.

  5. #5
    I have had to change my suprapubic catheter on a fairly regular basis for the last two or three years. Normally, I can go anywhere between two and four weeks without having problems. However, recently I had an infection which turned my urine almost black, it was quite scary to be honest. I took an antibiotic which cleared the problem up and catheter when nearly 7 weeks. I had it changed, although it was still okay. Then the one they put in lasted a week and I had to have it changed again. Now this is what is puzzling, nine times out of 10 the catheter doesn't actually completely block. What normally happens is I will go to bed and then start bypassing naturally. So I've taken to wearing an external catheter whilst in bed. However, most of the time I will still be draining through the catheter, doesn't completely block. It's really frustrating because I really don't know where I stand..

  6. #6
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    In the past I have had this problem. In 2013 I was having blockages in my Foley catheter. The urologist suggested I go from a 16 F to an 18 F. This only temporarily solve the problem. I was at the point of having to change my catheter every 2 or 3 days. We tried using a saline flush which really did not help much. The urologist then scoped my urinary bladder and used a laser. He found only 2 small stones. After healing period of several weeks the problem return. After much discussion with my family we began using the predecessor to Microcyn AH. We tried several dilutions, length of time of irrigation and frequency of use. We settled on about 75% Microcyn and 25% sterile saline irrigation for between 5 and 10 minutes. Currently I am irrigating once per day for 6 minutes with 15-20 mL of diluted Microcyn. This topic has been discussed frequently by this group and there are others here reading this forum with much more expertise than I have.

    Bob

  7. #7
    Quote Originally Posted by RLP22 View Post
    In the past I have had this problem. In 2013 I was having blockages in my Foley catheter. The urologist suggested I go from a 16 F to an 18 F. This only temporarily solve the problem. I was at the point of having to change my catheter every 2 or 3 days. We tried using a saline flush which really did not help much. The urologist then scoped my urinary bladder and used a laser. He found only 2 small stones. After healing period of several weeks the problem return. After much discussion with my family we began using the predecessor to Microcyn AH. We tried several dilutions, length of time of irrigation and frequency of use. We settled on about 75% Microcyn and 25% sterile saline irrigation for between 5 and 10 minutes. Currently I am irrigating once per day for 6 minutes with 15-20 mL of diluted Microcyn. This topic has been discussed frequently by this group and there are others here reading this forum with much more expertise than I have.

    Bob
    Glad you have had success with this technology. Here are a couple threads the original poster may want to read. I understand the first thread I've referenced is nearly 10 years old. But, the information is still relevant. The first thread is also very long, but there is a lot of good information in all of those posts to help you decide upon your own process. The second thread is newer and has some particularly interesting information on a product that is sold in New Zealand and Australia. The product is called Microdox UTI, which uses Microcyn Technology. I have posted information on post number 90 that shows the label and usage information card for Microdox UTI. The usage card has three usage levels for Microdox UTI: Acute Treatment, Post-Acute Treatment and Prophylaxis.

    I don't advocate the use of Microcyn Technology to "cure" a urinary tract infection and it shouldn't be used in lieu of antibiotics prescribed by your doctor after a uninalysis (UA) and a culture & sensitivity (C&S) lab tests. But, a number of us have found that Microcyn Technology helps to prevent urinary tract infections, reduce biofilm occurrences and biofilm recurrences. Used prophylactically (instillation every day or every other day), Microcyn has helped to reduce the cloudy appearance, odor, and sediment in urine.

    http://sci.rutgers.edu/forum/showthr...light=microcyn

    http://sci.rutgers.edu/forum/showthr...light=microcyn

  8. #8
    UPDATE 24th July 2019
    I have still had no catheter blockage and only a few minor urinary tract infections since the night of 23rd/24th July 2016.

    Dosage of Nitrofurantoin
    This has remained similar after initial reduction early in 2017 - as and when there appears to be a UTI. The indicators I use for a possible UTI are 1) sweating not explicable by other causes such as leg bag being full or simply wearing too much clothing and 2) excessive cloudiness (E. coli) or sediment (Staphylococcus saprophyticus) in my catheter. I took 33x50mg tablets in 2017, 33 in 2018 and 10 so far this year. Since my last post on 20th March 2018 I have taken 50mg Nitrofurantoin on these evenings:
    2018
    April 8,9,23,29; May 12; June 11,16; July 1,16,29; August 2,13,17; September 3, 10; October 7,8,16(100mg), 17,29; November 5; December 15,26
    2019
    January none; February 12,18; March 1(100mg),2; April 6,13; May 24(100mg); June 17

    Lack of bacterial resistance to Nitrofurantoin
    The bacteria involved in my UTIs and catheter blockages - E. coli and Staphylococcus saprophyticus, have shown no indication of developing immunity to Nitrofurantoin: it is just as effective in knocking them out as it was three years ago when I started using it to prevent infections and blockages.

    Changing suprapubic catheter has opened up the site and caused UTIs
    The bacteria causing UTIs have been entering via catheter site. Early in January 2019 my catheter site became healed with no leakage for the first time that I can remember. I had no infection in January and took no Nitrofurantoin. My catheter was changed at the normal 12-week interval on 5th February. This was followed by two minor infections, soon cleared with Nitrofurantoin. Catheter changes increase leakage around the site and appear to be liable to increase the entry of bacteria with consequent infections. The next change of catheter, due on 30th April, was postponed. On 23rd May, my catheter was left with insufficient slackness. It pulled and began to leak around the site. I had a minor infection on 24th May. As the leakage around the catheter site had started, the reason for not changing my catheter had gone and it was changed on 27th May, a day short of 16 weeks after the previous change. It has not been changed since then. Since the third week in June, my catheter site has been healed. I have had no UTIs.

  9. #9
    Senior Member alan's Avatar
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    I'm taking Amoxicillin nightly as a prophylactic to prevent the bacteria which cause my bladder sediment from taking hold.
    Alan

    Proofread carefully to see if you any words out.

  10. #10

    Preventing Urinary Tract Infections and Catheter Blockages

    PREVENTING URINARY TRACT INFECTIONS
    AND CATHETER BLOCKAGES

    BARRY SIMPSON


    CONTENTS
    Abstract
    Summary of methods to prevent urinary tract infections and catheter blockages.
    An overnight catheter blockage.
    Blockages: causes and remedies - Nitrofurantoin and catheter repositioning; sedimentary and positional blockages.
    Supporting methods to prevent catheter blockages.
    Could the blockages have been stopped by something else or by chance? In my case it is extremely unlikely that cessation of blockages was not associated with taking Nitrofurantoin as a prophylactic.
    Predicting future blockages.
    Nitrofurantoin and catheter repositioning stopped my blockages but what started them? Three steps to identify the bacteria responsible if this had not been done at the time of blockage. Where did the bacteria come from?
    For how many people might the methods described be effective? What you could try if Nitrofurantoin does not work for you or if it has undesirable side-effects?
    How serious are urinary catheter blockages?
    Attitudes towards catheter blockages
    A few reflections; deficiencies in current practice.

    ABSTRACT
    Between January and July 2016 I had 23 catheter blockages. Even without testing the contents of my catheter, after a while it began to look as though most of them were associated with urinary tract infections: so if my infections could be stopped, so too would the blockages. I started using Nitrofurantoin to prevent rather than to cure infections on 24th July 2016. I have had no blockage since. I took 50mg each evening for 30 days; then I gradually reduced it, and from the beginning of 2017, partially replaced it with natural antibiotics.
    My catheter blockages were being caused by urinary tract infections of Staphylococcus saprophyticus and E. coli; these caused the sediment which led to the blockages. Using Nitrofurantoin as a prophylactic has controlled the bacteria and so the production of sediment to levels below that needed to cause a blockage. Although originally intended to prevent catheter blockages, it is likely that the method can also be used to control UTIs in those who do not have blockages, or even a catheter.
    I have had a few occasions when I have had a limited amount of overheating which might have been minor urinary tract infections. These were accompanied by sediment in my catheter. As well as loosening the sediment by manipulating and bending my catheter, I have treated these by taking 50mg Nitrofurantoin, or for very minor overheating, lemon tea and vinegar on food. It appears that they have allowed a reduction in the dose, but in the amounts I have been taking (1/2 lemon and 30ml. vinegar per day) they would probably not be sufficient alone.
    I do not know for how many others it would be suitable. If others try these methods without success, it is likely to be because their blockage was caused by a different bacterium not on the Nitrofurantoin hit-list. In such a case, it would be advisable to request an analysis of the catheter contents at the time of the blockage and then use a different antibiotic to control it.
    SUMMARY OF METHODS TO PREVENT URINARY TRACT INFECTIONS AND CATHETER BLOCKAGES
    Since May 2013: catheter changed every 5 weeks to July 2013 in hospital, then every 12 weeks.
    May 2013 to 15th January 2016: no blockage; Nitrofurantoin taken occasionally to cure urinary infections.
    16/17th January 2016 to 23/24th July 2016: 23 blockages; Nitrofurantoin taken occasionally to cure urinary infections.
    Since March 2016: weekly bladder wash-outs.

    Since 24th July 2016: no blockage;
    50mg Nitrofurantoin taken on these evenings to prevent infections and blockages:

    2016 July 24-31, August 1-22, 24-26, 28, 29, 30; September 1, 2, 4, 7, 8, 10, 13,16, 18, 19, 22, 25; October 1, 5, 6, 7, 11, 14, 15, 17,20(100mg), 21, 22, 23, 25, 29, 31; November 4, 5, 7, 10, 13, 16, 19, 22, 24, 26, 28; December 1, 3, 5, 8, 11, 12, 17, 22, 31. TOTAL 84x50mg.

    2017 January 8, 16, 18, 22; February 5, 13, 16, 20, 25; March 11,25; April 2, 8, 13, 22, 28; May 1, 12,19; June 3, 13, 18; July 2, 10, 23; August 14, 15; September 17, 18; October 11, 17; November 2, 14; December none; TOTAL 33x50mg.

    2018 January 5, 22, 31; February 9, 15; March 2, 9, 10, 17; April 8, 9, 23, 29; May 12; June 11,16; July 1, 16, 29; August 2, 13, 17; September 3, 10; October 7, 8, 16(100mg), 17, 29; November 5; December 15, 26. TOTAL 33x50mg.

    2019 January none; February 12, 18; March 1(100mg), 2; April 6, 13; May 24(100mg); June 17; July 28.

    Catheter repositioning to prevent non-sedimentary blockages.

    Since January 2017: rolling catheter between hands and consumption of natural antibiotics: lemon tea (half a lemon), 30ml. vinegar on food.

    AN OVERNIGHT CATHETER BLOCKAGE
    It's coming up to 1'o clock in the morning. I waken up sweating profusely. I'm getting tremendous shocks of spasms. I have an overwhelming urge to move my legs but I can't. I can't move: following a spinal injury in 2013, I have been paralysed from the shoulders down. I fumble round the bed to find the 'phone. Eventually I find it, despite very little movement or sensation in my hands, now clawed up like an animal's paws. With my knuckles and a protruding little finger, I 'phone for a nurse, desperately trying to hold the 'phone to my ear. Fortunately a kind and thoughtful nurse had previously given me their direct number so that I don't have to endure the 111 service. The spasms and sweating are becoming even more severe. By the time she arrives, which can be over two hours later, the bedsheets are wet with sweat. 'Sorry I took so long. I've had a lot of catheter blockages tonight'.
    Another one: between the nights of 16/17th January and 23/24th July 2016 I had 23 like that, typically between about midnight and 1am - long enough for urine to build up if my catheter had actually become blocked immediately after going to bed.
    BLOCKAGES: CAUSES AND REMEDIES - NITROFURANTOIN AND CATHETER REPOSITIONING
    I had a suprapubic catheter installed in May 2013. I had no blockage for the first two years and eight months.
    At least two-thirds, but not all of my blockages were accompanied by sediment in my catheter. The last two blockages both occurred on the night of 23/24th July 2016. My catheter was replaced after the first of these. The second blockage was described by the nurse as 'positional'. Attending an earlier blockage, a different nurse had suggested that a possible cause was the catheter intake pressing against my bladder wall. So there seemed to be at least two causes of the blockages: by sediment and by the position of the catheter.
    Why were all my blockages shortly after changing positions from sitting in my wheelchair to lying flat in bed? That is a better question than is my answer to it. The positional blockages were likely to have been caused by my catheter coming up against my bladder wall or the intake becoming too low for drainage of urine by gravity. The sedimentary blockages might have resulted from the catheter moving to a lower part of my bladder where sediment had collected.
    The penny drops
    Late on the morning of 24th July 2016 I began sweating heavily and my spasms became more severe. Having had two blockages the previous night, I thought this might be another one: so I called for a district nurse. When she came, she assured me that there was no blockage and 'phoned for medical advice. I could hear her part of the conversation. As soon as her conversation had finished, she told me that I had a suspected septicemia and that she would 'phone for an ambulance for immediate admission to hospital. I was surprised because I had none of the symptoms such as chills, high temperature, fast breathing or high pulse rate; indeed, her telephone conversation had made no reference to any of these symptoms.
    http://www.healthline.com/health/septicemia#overview1
    The nurse left and the ambulance soon arrived. The two paramedics took the standard readings such as pulse, breathing and temperature: everything was normal. I declined the invitation to go to hospital and assured the paramedics that I would take some Nitrofurantoin: my urinary tract infection was soon cleared.
    This was not the first time that symptoms of an infection followed a blockage: the bacteria causing the infections were also creating the sediment which caused most of the blockages: so using Nitrofurantoin to prevent infections (rather than to cure them) in my case, also prevented catheter blockages. From the evening of 24th July I started taking 50mg Nitrofurantoin each day at about 8pm. I have had no blockage since.
    In these circumstances, I try to maintain an awareness of the symptoms of septicaemia, the infection, and sepsis, the body's inflammatory reaction to it and to be aware that urinary infections can develop into septicaemia and sepsis; and because I have a spinal injury, also autonomic dysreflexia:
    http://www.webmd.com/hypertension-hi...topic-overview

    What about the blockages not caused by sediment - the 'positional' blockages? To prevent these I simply gently pull my catheter forward each night immediately after going to bed to pull it away from my bladder wall. At the same time I also unstrap the catheter and leg bag from my leg and lay it flat on the bed to help gravity by ensuring that as much of my catheter as possible is at a lower level than the intake.
    In the afternoon of 1st March 2019 I began sweating or no obvious reason other than a minor urinary tract infection. I took 50mg Nitrofurantoin late in the afternoon and a further 50mg about 8pm. The infection seemed to be cleared until about 4pm on the following day when some sweating returned. I took 50mg Nitrofurantoin at 7.30pm. The sweating became more severe. After repositioning my catheter about 9.30pm my sweating subsided: it appears that my sweating on 2nd March was a result of a constriction of my catheter, possibly by it pressing up against my bladder wall.

    The Users' Information Leaflet says that the normal dose of Nitrofurantoin for preventing infections is 50mg or 100mg daily at night but does not say for how long. On the principle that it is best not to take more medication than necessary, after 30 days taking 50mg, I began tentatively to omit it on a few nights and risk the horror of a blockage. For about 3 months I took 50mg on 3-4 nights per week and then reduced it further to only nights when I had a considerable amount of sediment in my catheter or sweating which could warn of a urinary infection.
    (From January to August 2013 I was in a specialist spinal injuries hospital. Overheating of patients, including me, was very common. The solution was to train a fan on the patient. I was never offered Nitrofurantoin for this or for diagnosed urinary infections which were treated with other antibiotics via drips.)

    SUPPORTING METHODS TO PREVENT CATHETER BLOCKAGES
    The district nurses started giving me weekly bladder wash-outs soon after my blockages started: so the first few nights I omitted Nitrofurantoin were wash-out days. Wash-outs probably reduced the number of blockages but did not eliminate them. Not long after I reduced Nitrofurantoin to less than every night, I did begin to get sediment in my catheter. This seems to have been kept in amounts insufficient to cause a blockage by carers rolling the catheter between their hands to disturb it and by consuming natural antibiotics, including adding vinegar to food and drinking lemon tea (not surprising - the bladder wash-out solution contains citric acid). To make lemon tea, I simply cut an unpeeled lemon in half, cut up the half into pieces or slices put in a cup and add hot water, topping up several times and squeezing the lemon with a spoon. Lemons can be used in many other ways too:
    http://www.healthextremist.com/lemon...at-lemon-peel/
    There are many web sites which offer advice on preventing urinary tract infections without antibiotics on prescription, such as:
    https://draxe.com/home-remedies-for-uti/
    https://www.healthline.com/health/wo...-antibiotics#6
    Such sites have much in common with each other, which adds to the likelihood of them being useful. D-Mannose (a sugar contained in several fruits including cranberries, apples, oranges, peaches and pineapples) garlic, vitamin C, apple cider vinegar and cranberry juice are commonly recommended.
    I will never know whether rolling my catheter and taking natural antibiotics would have been sufficient to stop the blockages without Nitrofurantoin. I started them in January 2017, six months after my blockages had been stopped. It does appear that they have allowed a reduction in the dose, but in the amounts I have been taking (1/2 lemon and 30ml. vinegar per day) they would probably not be sufficient alone. For example, on the evening of 9th February 2018 after consuming the usual amounts of lemon and vinegar, my catheter had a large amount of sediment in it: so I took 50mg. Nitrofurantoin: the following morning it was clear.

    COULD THE BLOCKAGES HAVE BEEN STOPPED BY SOMETHING ELSE OR BY CHANCE?
    Could something else have stopped my blockages immediately, completely and for such a long time? All I can say is that I am not aware of doing anything else on and immediately following 24th July that could be expected to stop blockages other than taking Nitrofurantoin and catheter repositioning.
    Although I have had no blockage since the night of 23/24th July 2016, often I have sediment in my catheter. When this looks sufficiently severe to risk a blockage, I take 50mg Nitrofurantoin about 8pm. Within an hour or two, the sediment is reduced or has gone completely.
    I had 23 blockages in a period of 190 days from 16th January to 24th July 2016, no blockage since (365 days up to 24th July 2017). The probability of Nitrofurantoin and catheter repositioning having had no effect can be calculated as the probability of 23 random occurrences in a period of 190+365 days all being in the first 190 days.
    The probability of any one of them being in the first 190 days is 190/(190+365) = 0.3423;
    considering any two of the blockages, the probability of both of them being in the first 190 days would be 0.3423 x 0.3423 and so on until .....
    the probability of all 23 being in the first 190 days is 0.3423 multiplied by itself 22 times = 1.95595e-11 = 0.0000000000195595 which is a little less than 2 chances in a hundred thousand million (a hundred thousand million is the number that 0.0000000000195595 would have to be multiplied by to get 1.95595).
    http://www.rapidtables.com/calc/math...Calculator.htm
    The base is 0.3423 and the exponent is 23.
    So the probability that Nitrofurantoin and catheter positioning were not associated with stopping blockages is 0.0000000000195595; therefore the probability that they have been associated with stopping blockages is 1 - 0.0000000000195595 = 0.9999999999804405 where absolute certainty equals 1.
    The binomial distribution can also be used with the same result:

    http://www.vassarstats.net/textbook/ch5apx.html

    where N = 23, k = 23, p = 0.3423 and the answer is p(k out of N)

    The multinomial distribution can be used too:

    https://www.easycalculation.com/stat...stribution.php
    where the number of outcomes is 2 (blockage on a day in first 190 days /blockage a day in following 365 days), the number of occurrences 23 and 0, p = 0.3423 and 1-0.3423 = 0.6577.
    Similarly, after 3 years without a blockage, all the above probabilities could be re-calculated by substituting 190/(190+(3x365)) = 0.1479 for 0.3423: so the probability of there being no association between taking Nitrofurantoin and catheter positioning stopping my blockages becomes 8.1146e-20.
    These calculations are based on cautious assumptions. The probability of there being no association between taking Nitrofurantoin and the absence of blockages is likely to be even smaller than the very small probability of 1.95595e-11. On about 10 of the 190-day period with blockages I took Nitrofurantoin to cure urinary infections. I had no blockage on these days. So there is a case for reducing the period to 180 days, or fewer if the effect of Nitrofurantoin lasted for more than one day, and adding 10 or more days to the blockage-free period. If the period were reduced to 180 days, the probability of all 23 blockages being in the first 180 days would become (180/(180+375))23 = 0.324323 = 5.6465e-12.
    There is no practical difference between using a period of 190 days, 180 days or fewer. In all cases the probability of all 23 blockages being in this period by chance is so small as to be negligible. This very small probability means that it is practically certain that Nitrofurantoin and catheter repositioning were associated with stopping my blockages; it is not the probability of having a blockage tonight; nor is it a prediction of when a blockage can be expected.
    PREDICTING FUTURE BLOCKAGES

    Prediction methods rely on making inferences from the past: so while the treatment is never followed by a blockage, the prediction will remain zero for any period into the future.

    However, where treatment sometimes fails, any of several methods can be used to estimate when future failures will occur.

    If I were to have a blockage, the negative binomial distribution, also known as the Pascal distribution, could be used to predict the probability of a further blockage on each of the days following.

    http://stattrek.com/online-calculato...-binomial.aspx

    The number of trials is the number of days after the first blockage, the number of successes is the number of blockages to be predicted (1 if the next blockage is to be predicted, 2 if it is to be the blockage after that and so on), probability of success on a single trial would be 1 divided by the number of days between the start of my blockage-free period and the first blockage and the negative binomial probability is the probability of the chosen blockage (1st, 2nd or whatever was chosen) occurring on the chosen number of days after the first blockage.

    A cumulative version, which can make some calculations less laborious, is available at:

    http://calculator.vhex.net/post/calc...e-distribution

    The geometric distribution is a particular case of the negative binomial distribution where the number of successes, in my case, blockages, is equal to 1: so if the timing of only the next blockage is to be estimated, it can be used instead of the negative binomial distribution.

    http://www.calcul.com/show/calculato...ax=7&k=6&p=0.5

    Here, the number of successes is the number of days without a blockage before the next one occurs, the probability of success is as for the negative binomial distribution and the maximum number of trials is the number of days for which you require the probability to be calculated. This calculator can save time by using the probability mass function, which shows the probabilities of a blockage on the days leading up to the day chosen.

    It is possible to predict the number of blockages within any specified period using the Poisson probability distribution:

    http://stattrek.com/online-calculator/poisson.aspx.

    For example, suppose we wish to predict the chance of 1 blockage in a period of 7 days, the Poisson random variable would be 1. The average rate of success is the average number of blockages which in the past have occurred in 7 days (number of blockages/number of days in observation period x 7). To predict the chance of 2 blockages in 28 days, the Poisson random variable would be 2 and the average rate of success would be the average number of blockages in 28 days. As long as there are no blockages on nights following taking Nitrofurantoin, the average number of blockages for any period is 0: so until there is a blockage, the prediction of future blockages for any period is zero.

    The negative binomial distribution, the geometric distribution and the Poisson probability distribution rely on the events (blockages in this case) being independent - not connected to each other, even indirectly by a common cause - and randomly distributed. This is liable to introduce inaccuracies into the predictions if the connections are not taken into account. On the other hand, if predictions from these techniques do not fit observations, that will be evidence that there are connections between the events (blockages) and that there is likely to be a common cause.

    It might seem inconsistent that the effectiveness of Nitrofurantoin and catheter repositioning was demonstrated by the lack of randomness in the distribution of the 23 blockages between the 190 days without the treatment and the 365 days with it, while the techniques for predicting future blockages rely on them being randomly distributed. Not necessarily so; the predictive techniques would be used only in the period when the treatment is taking place.


    NITROFURANTOIN AND CATHETER REPOSITIONING STOPPED MY BLOCKAGES BUT WHAT STARTED THEM?
    I do not have a good answer to this. I had my catheter for 2 years and 8 months before I had a blockage. This period included about a dozen urinary infections.
    On the evening of 16th January 2016 I was overheating so I took 500mg Paracetamol. That was the first time I had taken any since my catheter was installed. A few hours later I had my first blockage. The coincidence looked too close to believe that the Paracetamol had not played a part. I took no more Paracetamol but continued to have blockages about a week or ten days apart. After a few of these I convinced myself that they had nothing to do with Paracetamol: on 16th January I had a urinary infection and should have taken Nitrofurantoin instead of Paracetamol. So I left this out of the earlier paper:
    http://static.smallworldlabs.com/spi...-blockages.doc
    http://sci.rutgers.edu/forum/showthread.php?258431-Preventing-Urinary-Catheter-Blockages
    Nevertheless, I have taken no more Paracetamol.

    Even without an analysis of the contents of my catheter at the time of a blockage, it is possible, by using a filtering process and information from the Internet, to identify the most likely bacterial culprits for my blockages. This might be important in identifying what other antibiotics are likely to be effective in preventing blockages for those who have an adverse reaction to Nitrofurantoin.
    The filtering process comprises three stages:
    1 Against what bacteria is Nitrofurantoin effective?
    Before the blockages started I had more than a dozen urinary infections, readily stopped by Nitrofurantoin.
    Nitrofurantoin has been shown to be effective against the following bacteria:
    Citrobacter species, Coagulase negative staphylococci, E. coli, Enterococcus faecalis, Klebsiella species, Staphylococcus aureus, Staphylococcus saprophyticus, Streptococcus agalactiae
    Many or all strains of the following genera are resistant to Nitrofurantoin: Enterobacter, Klebsiella, Proteus, Pseudomonas
    https://en.wikipedia.org/wiki/Nitrofurantoin

    Obviously, whatever bacteria caused the pre-blockage infections did not create enough sediment to cause a blockage. These bacteria must be on the Nitrofurantoin hit list; so too must those that did cause blockages, but they were not necessarily the same ones or in the same concentrations as those that did not cause a blockage.


    2 It has been established that most of my blockages were associated with urinary infections, so which of these bacteria cause urinary infections?

    E. Coli and Proteus mirabilis are often the cause of urinary infections:

    https://www.google.co.uk/?gws_rd=cr&...+users&spf=395

    http://www.msdmanuals.com/profession...nfections-utis

    'Escherichia coli or E. coli, is responsible for more than 85 percent of all UTIs, according to a 2012 report in the journal Emerging Infectious Diseases.
    Several other common bacteria also cause UTIs, including Staphylococcus saprophyticus, Pseudomonas aeruginosa and Klebsiella pneumonia.'
    http://www.everydayhealth.com/e-coli...act-infection/
    Pseudomonas, Klebsiella and Proteus are on the list for which Nitrofurantoin is not likely to be effective: so that leaves us with E. Coli and Staphylococcus saprophyticus.

    3 Which of these bacteria cause sediment which could block a catheter?
    Cloudy urine, but not sediment, is mentioned as a consequence of E. coli.
    http://www.everydayhealth.com/e-coli...act-infection/

    Sediment is associated with Staphylococcus saprophyticus:

    https://www.ncbi.nlm.nih.gov/pubmed/6377440


    That leaves Staphylococcus saprophyticus and E. coli as the prime suspects. Although Staphylococcus saprophyticus is the better fit to the information I have been able to find, E. coli is a much more common cause of urinary infections. Without any analyses of the contents of my catheter at the times of infections with or without blockages, it is not possible to be sure.

    Because Nitrofurantoin is effective against some of the bacteria which cause urinary infections and which also create sediment in urine, it should not come as a surprise that it prevents some blockages associated with urinary infections.

    I can only guess how many of my blockages could have been avoided if taking a sample of the contents of catheters were standard practice when a blockage occurs.
    There might have been other mechanisms starting the blockages: an increase in urine pH, a change in brand of catheter .....
    Why did I get infections from time to time after installation of my suprapubic catheter in May 2013 but no blockages until January 2016? Without analysis of my catheter contents it is only possible to speculate on a possible explanation: until January 2016 my infections were caused by E.coli which did not cause sufficient sediment to cause blockages. Then in January 2016, Staphylococcus saprophyticus arrived and this caused the blockages.
    This would also explain why it took so long to recognise the connection between infections and blockages (23 infections spread over a period of six months): some of the infections were caused by E. coli with little or no Staphylococcus saprophyticus so there was no blockage; some of the blockages were caused by Staphylococcus saprophyticus with only subdued symptoms of infection.
    Where did the bacteria come from?
    Early in January 2019 the site where my suprapubic catheter enters into me healed more fully than I had ever noticed previously. Until then, there had always been a small amount of weeping around the site. I had no minor overheating as usually accompanies an infection after the weeping stopped until 12/2/19. My catheter was changed on 5/2/19, re-opening the wound and causing the weeping to resume. By mid March the catheter site had almost stopped weeping. Infections too had stopped: it is beginning to look as though my catheter entry point has been an entry point for the bacteria causing urinary tract infections. The next change of catheter, due on 30th April, was postponed. On 23rd May, my catheter was left with insufficient slackness. It pulled and began to leak around the site. I had a minor infection on 24th May. As the leakage around the catheter site had started, the reason for not changing my catheter had gone and it was changed on 27/5/19, a day short of 16 weeks after the previous change. It has not been changed since then. Since the third week in June, my catheter site has been healed. I have had no UTIs.
    https://livingwithacatheter.com/foru...loggedout=true

    FOR HOW MANY PEOPLE MIGHT THE METHODS DESCRIBED BE EFFECTIVE?
    What I have reported is, of course, my own story. I do not know for how many other people it might be effective but there seems to be a reasonable expectation that it might work for others - male or female - whose catheters are being blocked by sediment created by bacteria for which Nitrofurantoin is effective.

    So it seems that blockages caused by bladder stones would not be prevented by Nitrofurantoin because the bacterium involved is Proteus mirabilis:
    http://www.nature.com/sc/journal/v48...sc201032a.html

    Nitrofurantoin will not be suitable for everyone. The Users' Information Leaflet lists many precautions and possible side effects.

    It might aggravate some conditions, possibly including Parkinson's disease:
    http://www.ehealthme.com/ds/nitrofur...se-aggravated/

    Patients' reviews of the effectiveness and side-effects of Nitrofurantoin are mixed, for example

    https://www.drugs.com/comments/nitrofurantoin/

    https://healthunlocked.com/pmrgcauk/...nitrofurantoin

    One of the reasons that I set out in detail above the dosage I have been taking is that it is much lower than that usually recommended and does not follow the usual 'finish the course' advice to keep on taking it after the infection appears to have been cleared.

    This became increasingly controversial following a study reported in the British Medical Journal in July 2017:

    https://www.bmj.com/content/358/bmj.j3418

    This was widely reported, including The Telegraph of 27th July 2017:

    https://www.telegraph.co.uk/science/...tibiotics-say/

    Not surprisingly, the study ruffled a few feathers among the professions involved:

    https://www.nhs.uk/news/medication/q...f-antibiotics/
    I have not had any side effects at the doses explained but others might. Nitrofurantoin was used to stop the bacterial blockages simply because it was the only antibiotic I had. If Nitrofurantoin does not stop your infections and blockages as it did for me, it might be because yours are being caused by a different bacterium from mine. A sample of the contents of your catheter at the time of a blockage would enable the bacterium responsible to be identified and an appropriate antibiotic might be chosen to use instead of Nitrofurantoin.
    Some web sites suggesting other antibiotics for Staphylococcus saprophyticus, E. coli and other bacteria causing urinary tract infections are as follows:
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC183755/
    http://www.webmd.com/drugs/condition...Infection.aspx

    https://www.google.co.uk/?gws_rd=cr&...ctions&spf=396

    HOW SERIOUS ARE URINARY CATHETER BLOCKAGES?
    Catheter blockages are at least distressing, especially if experienced help is not quickly available. Uncertainty about when help will arrive adds to the distress. I had to wait between about 40 minutes and 2 hours 15 minutes with the sweating and spasms progressively becoming more severe.
    Is there likely to be any lasting or permanent damage? I am not aware of having any myself but serious kidney and bloodstream infections, septicaemia and autonomic dysreflexia have been experienced by others:
    http://www.healthtalk.org/peoples-ex...eter/blockages
    How many deaths result from catheter blockages? We are not likely to get an accurate estimate because some of them are liable to be recorded as autonomic dysreflexia, sepsis or something else. Recorded deaths from sepsis are many and increasing:
    https://www.nigms.nih.gov/education/...et_sepsis.aspx
    http://www.world-sepsis-day.org/CONT...ctSheet_DE.pdf
    It has been estimated that about 2,100 deaths per year result from the Foley catheter (but not all resulting from blockages?):
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4673556/
    https://www.elsevier.com/connect/ear...ing-infections
    About 450,000 people in the UK have permanent catheters and as many as a half of these experience 'recurrent infections with blockages and leakages':
    http://www.healthtalk.org/files/nurs...y-catheter.pdf
    The same paper quotes that 'In the UK, permanent catheters are used by 3% of people living in the community and 13% of care home residents'.


    ATITUDES TOWARDS CATHETER BLOCKAGES

    The nurses, particularly the night nurses, have left me with the impression that catheter blockages are much more common than they need to be. Often, they left me with a cheery 'See you again soon'. The prevailing attitude in both the medical and nursing professions that they are an inevitable consequence of having a catheter should be questioned.

    In November 2016 I 'phoned the night nurses to thank them for coming to unblock my catheter on 23 nights between January and July, to explain why I have not called them out since July, and to offer to send them a copy of an earlier version of this paper: 'We don't give out e-mail addresses over the phone'. This was particularly disappointing because their own records of nursing call-outs will confirm the data on which this paper is based.

    Meanwhile, patients wake in the early hours of the morning, sweating profusely, trembling with massive shocks of spasms, resulting in urine being forced back to the kidneys and in extreme cases, autonomic dysreflexia, internal damage and death. Night nurses rush between patients to unblock catheters which do not need to be blocked. Sometimes they have taken over 2 hours to reach me (although the average is about 1 hour 20 minutes).

    A nurse from the local health authority once called to assess my condition. A friend who was with me mentioned my catheter blockages and offered her this paper: no thanks. 'It's something they can live with'.

    During the course of preparing this paper I have had correspondence with many people connected to the medical or nursing professions. Although no-one else has used those exact words, 'something they can live with' sounds chillingly close to the attitude to so many of the responses (or lack of responses). Charities and other organisations that I have contacted appear to be content to work with the treatments and equipment that is available rather than to represent patients to get improvements.

    Such has been the resistance to an approved dose of an approved medication. How much greater can we expect the difficulties of improvement in the medications available for spasms for example, or equipment such as catheters, when those needing them have been conditioned to expect nothing better than what they are given, when manufacturers are allowed to happily continue to sell the same old products. I must say I am left wondering whether the brick wall of complacency about catheter blockages also applies to other treatments and equipment that those with spinal injuries need - including treating the injury itself - and beyond spinal injuries.
    http://www.dailymail.co.uk/health/ar...omplaints.html
    Surgeon who 'blew whistle' was posted a dead animal. The Times 25th August 2018 p7.
    https://www.thetimes.co.uk/article/j...ital-wrlphv50h

    A FEW REFLECTIONS

    1 Catheter blockages are not something to accept as inevitable. Some of them are preventable.

    2 Greater priority should be given to prevention in order to reduce the need for firefighting.

    3 A small amount of resources devoted to preventing catheter blockages seems likely to result in a handsome pay-off in terms of savings in time spent unblocking catheters and unnecessary hospital appointments.

    4 They are much more serious than is sometimes recognised among both the medical and nursing professions.

    5 Prevention of catheter blockages has not had the priority it merits. Nurses could advise patients on preventing those caused by physical obstruction.

    6 The method outlined worked for me but might not be so successful for some others. Nitrofurantoin can not be expected to prevent blockages caused by bladder stones for example, because it would not be effective against Proteus mirabilis, the bacterium involved.

    7 Nitrofurantoin might have unacceptable side-effects for others as set out in the Users' Information Leaflet.

    8 Samples of catheter contents should be taken when there is a blockage to identify what bacteria or other causes were responsible. This should lead to much earlier and more accurate diagnosis of the cause and what action to take. It can also be expected to reduce the suffering and damage to patients, waste of nursing time unblocking catheters which do not need to have been blocked and unnecessary hospital appointments resulting from wrongly guessing the causes of blockages in the absence of evidence. During this study three hospital consultants have been involved in guessing the cause of my blockages: bladder stones (2), kidney stones (1). All recommended that I should have hospital tests. Together with the locum who diagnosed emergency admission for suspected septicaemia, that makes four medical practitioners willing to guess a diagnosis in the absence of evidence, all of them wrong. I contacted one of them and sent him an earlier version of this paper: he showed no interest. The other three were surrounded by gatekeepers and means of preventing patients making contact.

    9 The methods which worked for me could be offered to others with catheter blockages if there is no reason to believe that Nitrofurantoin would be unsuitable for them, particularly if samples of catheter contents have been analysed and found to contain bacteria against which Nitrofurantoin is effective, such as Staphylococcus saprophyticus or E. coli.

    10 Depending on the results of analysis of samples from catheters at the time of blockage, it would be worthwhile to investigate the possibilities of using other antibiotics for those for whom Nitrofurantoin has undesirable side-effects or whose catheters have been blocked by sediment created by bacteria not on the Nitrofurantoin hit-list.
    11 Blocked catheters are at least traumatic, at worst they are killers, they are expensive in terms of nursing and other medical staff time and resources and occur on a scale which makes them one of the most common healthcare problems. Some of the papers quoted in the previous section make the often-heard call for better catheters, which would empty the bladder completely and so reduce infections and blockages. Sadly, it is no surprise to read this, but until they are available, there remains a need for preventing blockages in the catheters which we have.
    12 At the end of July 2017, there was conflicting advice on whether patients should finish courses of antibiotics:
    http://www.telegraph.co.uk/science/2...tibiotics-say/
    So far I have not found any decrease in the effectiveness of Nitrofurantoin with continued use or with irregular dosage. This is closer to the new advice than the more traditional recommendations.
    13 In the nursing profession and in medicine, there is a tendency to standardise rather than to use discretion. Some examples are to change catheters at a fixed interval, in my case 12 weeks; weekly bladder wash-outs rather than when there was evidence that these needed to be done. Taking Nitrofurantoin at the doses and intervals in this study goes against the conventional practices. Standardisation requires much less interpretation and judgement than discretion; it is more defendable if something goes wrong.
    14 Some significant questions remain not fully answered:
    Why did I get no catheter blockages between May 2013, when my catheter was installed, and January 2016? I had more than a dozen urinary tract infections during this period, some of them more serious than those between January and July 2016 which were associated with blockages. Were the bacteria causing the infections different before January 2016?
    Why did all my blockages occur at approximately the same time of day, when going to bed?
    15 Nitrofurantoin has succeeded in at least two ways which are not mentioned in the Users' Information Leaflet. As well as its use as a prophylactic to prevent catheter blockages, it has reduced spasticity by removing that accompanying urinary tract infections.
    16 Could anything have been done better? It looks likely that the dosage of Nitrofurantoin could have been reduced earlier if I had started taking lemon tea and vinegar earlier than January 2017. It is possible that if I had taken larger amounts of lemon tea and vinegar before my infections and blockages started, they would have never started.

    P.S. Still no blockage since the night of 23rd/24th July 2016.
    1st August 2019

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