April 2012 e-journal club

April 2012 trainees 

Greetings

We had a great traineeship week in April, with trainees from Johnson City, TN; Cary, NC; Tampa, FL and Dharan, Saudia Arabia.  The following week Carol and I traveled to Halifax, Nova Scotia for a Weekend Warrior program.  It has been great getting to know more of our peers from Canada, and I hope to travel back to the Maritimes in the future when I have more time to visit.  Our April journal article was a departure from our usual emphasis on interventional studies, but this article addresses a hot topic that may become an important aspect of enteral nutrition (EN) in the future.

April Citation:

Halmos EP, Muir JG, Barrett JS, et al.  Diarrhoea during enteral nutrition is predicted by the poorly absorbed short-chain carbohydrate (FODMAP) content of the formula.  Aliment Pharmacol Ther. 2010 Oct;32(7):925-933.

Summary: 

This was a retrospective observational study of patients that were receiving EN during 3 arbitrary time periods.  The FODMAP (fermentable oligo- di- and mono-saccharides and polyols) content of each enteral formula was determined, and univariate analysis identified factors that were associated with the appearance of diarrhea.  Multivariate analysis then identified those factors that were independently associated with diarrhea.  The definition of diarrhea used for this study was “four or more bowel actions daily and ⁄or bowel actions described as ‘loose’ or ‘ooze’ ”.

Inclusion and Exclusion Criteria were:

Inclusion criteria:

Adult patients receiving EN during three arbitrary time periods in 2003, 2005, 2007 and 2008 (28 months total time).

Exclusion criteria:

Age < 18 years, inflammatory bowel disease, receiving EN < 3 days, and postpyloric EN.

Major Results reported by authors:

The investigators reviewed records for 310 patients and found 160 patients that met the inclusion criteria, with 46 of the patients in the ICU.   The amount of FODMAPs provided via enteral formulas ranged from 10.6 g to 36.5 per 24 hours. 

Diarrhea occurred in 61% of all patients that received EN (98/160 patients).  There was no difference between the incidence of diarrhea in ICU versus other patients.  Microbiological testing of fecal specimens was conducted in only 38 of the 98 patients (38.7%) that developed diarrhea and Clostridium difficile toxin was detected in only 2 of those patients; no other infectious causes of diarrhea identified in the 38% of those checked.

In the univariate analysis, diarrhea was significantly associated with length of stay (LOS) > 21 days, receiving EN > 11 days, and antibiotics or proton pump inhibitors.  Starting the EN with the lowest FODMAP content was significantly and inversely related to diarrhea incidence.  In multivariate analysis (controlling for other factors that influence diarrhea), LOS > 21 days and EN duration > 11 days remained independently associated with diarrhea.  The use of a low FODMAP EN formula was significantly inversely related to diarrhea incidence on multivariate analysis.

Author’s Conclusions:

“Length of stay and EN duration independently predicteddiarrhoea development, while being initiated on a lower FODMAP formula reduced the likelihood of diarrhoea. As retrospective evaluation does not support a cause–effect relationship, an interventional study investigating FODMAPs in enteral formula is indicated.”

Evaluation:

The topic of the potential role of FODMAPs in IBS and other functional GI disorders is an emerging topic, but currently with a limited amount of objective data.  The concept of a potential role for FODMAPs as a contributor to GI symptoms in patients receiving EN is relatively unexplored, and is a logical extension of the research of the effects of FODMAP consumption.

The authors of this paper discuss a number of the limitations of this study, including the retrospective design, which only allows the formation of theories that need to be tested in randomized studies.  There were also a limited number of patients for a retrospective study, especially when evaluating subgroups, such as 20 patients that received the low FODMAP formula.  The definition of diarrhea used for this study is problematic because it relies on subjective assessment of what is normal versus what is “loose”.  The authors also point out the low number of patients (1/3) microbial tested for Clostridium difficile (if other microbes were tested, they were not reported) in this study.  Ultimately C. diff toxin was reported in only 5% of patients, which would be considered extraordinarily low in most hospitals in the US.  Finally, the FODMAP content was based on the daily volume of formula required to provide the RDI for micronutrients (1000mL in most circumstances), not the amount patients received (we also do not know how much of each formula each patient got, hence it is conceivable that they actually received the same amount of FODMAPS due to differences in volume of EN infused). 

One major limitation of this study not mentioned in the paper is that the investigators did not appear to account for patients that received medications as a liquid, elixir or syrup, which frequently contain the FODMAP sorbitol.  Sorbitol-containing medications have been reported to be the single most common cause of diarrhea in patients receiving EN, responsible for nearly 2/3 of all cases of diarrhea in one study.1  The lack of control for sorbitol-containing medications and not testing 2/3 of the patients for Clostridium difficile are significant limitations in a study investigating sources of diarrhea during EN.

Despite the limitations mentioned, the results of this study suggest that FODMAPS in EN formulas may contribute to diarrhea and conceivably to other GI symptoms in patients that receive EN.

Our Take Home Message (s)

EN formulas with decreased FODMAP content may be associated with a reduced incidence of diarrhea.  There is a need for a larger prospective study (studies) to investigate the role of FODMAPs in the incidence of diarrhea in patients that receive EN.  Until further data is available, clinicians may want to consider the FODMAP content of EN formulas when evaluating patients with diarrhea, AFTER the much more obvious sources of diarrhea such as laxatives, oral contrast, sorbitol or other sugar alcohol-containing medications, and Clostridium difficile infection are ruled out.

For more information of FODMAPS and fructose malabsorption check out the article in Practical Gastroenterology from August 2007 via our website:

http://www.medicine.virginia.edu/clinical/departments/medicine/divisions/digestive-health/nutrition-support-team/resources-page

Reference

1.   Edes TE, Walk BE, Austin JL.  Diarrhea in tube-fed patients: feeding formula not necessarily the cause.  Am J Med. 1990 Feb;88(2):91-3.


Other News on the UVAHS GI Nutrition Website: (www.GInutrition.virginia.edu):

The next "on the road" Weekend Warrior will take place at Duke Medical Center on June 2-3, 2012.  Click here for details.

Upcoming Webinars for Spring 2012:

--Tuesday, May 15:  Enteral Nutrition--Carol Rees Parrish, MS, RD

--Tuesday, June 12--Effectively Communicating with Physicians--Kate Willcutts, MS, RD, CNSC

Check out What’s New:

--  “Nutrition Support Blog”  

-- “ Resources for the Nutrition Support Clinician

Latest Practical Gastroenterology article:

--Gurram B, Joeckel R, Stephens M. Nutrition in Pediatric Inflammatory Bowel Disease.  Practical Gastroenterology 2012;XXXVI(4):56.

 

Joe Krenitsky MS, RD

Carol Rees Parrish MS, RD

 

PS – Please feel free to forward on to friends and colleagues.