Dr Simon GabeRichard Brady, ESCP Communications Committee, was delighted to speak with consultant gastroenterologist Dr Simon Gabe about the management of high output stoma as part of our focus on Intestinal Failure throughout the month of December.

Dr Gabe is a consultant gastroenterologist at St Mark’s hospital. He started as a consultant in 2000 subspecialising in nutrition and intestinal failure and now co-chairs the Lennard Jones Intestinal failure unit. In addition, Dr Gabe is President of BAPEN (British Association for Parenteral and Enteral Nutrition) and developed the NASIT (National Adult Small Intestinal Transplant) Forum together with Dr Steve Middleton from Addenbrooke’s hospital. Dr Gabe is also on the ESPEN (European Society for Parenteral and Enteral Nutrition) Acute intestinal Failure Special Interest Group and has been on the Colorectal Clinical Reference Group.

Dr Gabe, thank you for providing us time during this month of ESCP’s focus on Intestinal Failure to discuss a very challenging issue for most colorectal surgeons; management of the high output stoma.

Can you tell us a little about the clinical service that is offered at your unit at St Mark's and what are the most common types of patients you see with high output stoma?

We see so many patients with a high output stoma. As a tertiary referral centre this is usually as a result of having a short bowel, occurring in patients with a jejunostomy. Patients with a high output fistula should also be considered in the same way as those with a high output stoma as most of the treatment approaches are the same. We see many patients with fistulae as well.

At St Mark’s we see patients with a high output in order to optimise their management and establish them on intravenous nutrition or intravenous electrolytes if required. We ensure that the short bowel regime that is used in these patients is done properly with a true MDT approach. Patients get consistent advice on a short bowel regime from physicians, surgeons, nurses, dietitians, pharmacists and even from other patients on the ward! So often the short bowel regime is not working as it is not being done consistently by patients. Patients do come to us expecting to need intravenous nutrition support but sometimes we can get them home without any formal of intravenous support, but just by getting them onto an optimal short bowel regime.

What is a high output stoma? Why do people get it?

A high output stoma is an output that results in a net negative balance for patients. This is generally when the output is greater than 1.5L/day. It is often missed for a number of reasons. Firstly fluid balance charts are haphazard in hospitals at the best of times. Secondly, a patients output often gets overlooked and people are more concerned as to whether it is working or not. Thirdly, the consequences can be missed if the patient is given IV fluids.

What are the key questions you ask from patients when you meet them?

The key questions to ask include:

  • Is the output from your stoma (or fistula) is high or very watery?
  • Is your urine dark in colour? Are you passing much urine?
  • Do you feel dry? Are you thirsty?
  • What is happening to your weight?

These questions give you a good idea as to whether the output is high causing intravascular depletion to some extent. If the output is only a little bit higher than it should be then there will not be much in the way of signs when examining the patient but these questions do give you a good clue as to whether you should assess if the principles of a short bowel regime should be used for that patient

Can I ask about the work-up process that you would employ when evaluating patients with high output stoma – what are the key tests or investigations that determine your subsequent approach?

Patients will normally have had some blood tests which will have included renal function (urea and creatinine). However, these only become abnormal when there is >5-10% dehydration. It is important to be able to pick this up earlier and the key test for this is a urine sodium. If the urine sodium is <20 mmol/L then the patient is dry. It is a good test but as a spot urine sodium you do have to bear in mind if the patient has had IV fluids before the sample was taken.

Another key test that is often overlooked is a serum magnesium. In patients with a high output this tends to be low. If left uncorrected then the patients develop cramps and then tetany. The serum calcium will tend to fall when the magnesium gets very low.

It is also very important to try and work out why the patient has a high output. If the patient is known to have a short bowel then this can be obviously the cause. However, sometimes patients can have a stricture within the small bowel which paradoxically can cause a high output. A barium follow-through or axial imaging (CT/MRI) can be performed to assess this. This is also useful if there is any possibility of intra-abdominal sepsis, which does drive a high output state. In addition, bacterial overgrowth can be contributing to a high output. Often a glucose hydrogen breath test is performed to assess this but this is not necessary. That test is only really meant for patients who have a colon in situ. Usually the best test for this is a trial of antibiotics.

It is important also to exclude coeliac disease as well as infective causes. Very occasionally Clostridium difficile can affect the small bowel causing a high output.

Do you have a clear management process for all patients or rather are there points that you cover with every case?

There is a very clear short bowel regime that we do use for patients with a high output stoma due to a short bowel. We give them an information booklet as well as dietary advice, advice about drinking (hypotonic fluid & an electrolyte mix), anti-motility agents (loperamide & codeine phosphate), antisecretory agents (proton pump inhibitors). They get advice about the timing of their medication and eating as well as being told not to eat and drink fluid at the same time.

However, not all patients have a high output due to a short bowel. Nevertheless, the management is very similar but it may not be quite so extreme. Low doses of medications I used, for example.

All cases are assessed on requirements all the management is tailored according to need.

What should we be careful not to miss?

The patient that gets missed is a patient who has only a slightly high stoma output. These patients usually get sent home but return a few weeks later with renal failure. Around 10-20% of patients with a newly formed ileostomy can have a high output stoma. See the information below:

High output stoma information sheet

Are there common mistakes you see people making in the management high output stoma?

The commonest mistake is telling patients to drink more. This only worsens the problem, increasing their output and making them thirstier and more dehydrated.

The correct approach is tell them to drink less, even though it seems like the wrong thing to do. It is important to correct any dehydration with intravenous fluids and that will help to decrease the driving the first that patients can often experience.

What do you think is the most important principle you employ when treating such patients?

Telling patients to drink less when their output is high. Also understanding the principles of a short bowel regime so that they know how to correct the problem.

What are your thoughts on long term diet/nutrition for such patients - which foods/drinks are good/bad/to avoid?

In general patients should be on a low fibre high salt diet. In addition, this is generally a high-energy diet but this can depend upon their nutritional state. It will be very important for them to see an experienced dietician in order to get the correct advice.

Regarding drinks, I tend to allow them to drink 1 L of hypotonic fluids (coffee, tea, water, juice) and 1 L of an electrolyte mix. Fizzy drinks are best avoided as they also increase output. For an electrolyte mix at St Mark's we tend to use the one often called the St Mark's electrolyte mix. This is made up from glucose, salt, sodium bicarbonate and water. However, commercial electrolyte mixes can be used as well. It is important to look at the sodium concentration within these as generally the sodium concentration is around 60 mmol/L. This is not high enough and we will generally advise that these are made up double strength. An example would be Dioralyte and we will tell them to use double strength Dioralyte. There is one word of caution, however, in that Dioralyte contains potassium and double strength Dioralyte contains 40 mmol of potassium. Generally this is not a problem but if patients have renal dysfunction then it does need to be thought about.

Are there any new therapies or drugs which you are aware of which may be in development or help?

It is really important to remember the basics. People do tend to get excited about new therapies but at the same time they will forget about the basics. The basics are all the elements of a short bowel regime.

The new therapy that is around the corner is teduglutide. This is a growth factor that increases the surface area of the bowel. It is licensed for patients with short bowel but its use is limited at the moment due to its cost, which is exceptional. In time, other growth factors will become available and I am sure these will have a useful role.

Another key point to remember is whether patients have got some bowel that is out of continuity. If that is the case then it will be important that there is a plan to bring this back into continuity if at all possible. Sometimes we will feed patients in distal parts of the bowel that are not connected - this is called enteroclysis.

In your view has management of high output stoma changed in the last 5 years? Are we getting better or worse at it?

This is a difficult question for me to answer. In my job I tend to see patients who have had problems and do not see the whole spectrum. The impression that I get from my colleagues is that this is a continuing problem and something that is often very much overlooked. I do not get the impression that more or less patients are being managed correctly over the past 5-10 years. I think there is a good role for education of doctors, surgeons, nurses who care for patients with stomas. The dieticians are very well aware of these problems but are not seeing the patients initially. Stoma care nurses are more aware of these patients but often do not get involved until the output is particularly high or they are getting leakage which is causing a problem.

Where should surgeons go to find out more about managing high output stoma - can you recommend any key resources or courses?

The St Mark’s intestinal failure and intestinal rehabilitation course is, of course, outstanding! It does cover this area in detail and is on 12/13 December. In addition, the book 'Intestinal failure' edited by Dr Jeremy Nightingale is excellent.

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