Open Access

Benefit of prokinetics during enteral nutrition: still searching for a piece of evidence

Critical Care201620:341

https://doi.org/10.1186/s13054-016-1502-3

Published: 26 October 2016

The original article was published in Critical Care 2016 20:259

I read with interest the article by Lewis et al. [1] who presents a review and meta-analysis of randomized controlled trials (RCTs) examining the benefit and harms of prokinetics in patients receiving enteral nutrition. They used the Grading of recommendation, assessment, development, and evaluation (GRADE) method to assess the quality of evidence for various clinical outcomes including feeding tolerance, success of postpyloric placement tubes, pneumonia, mortality, vomiting, and diarrhoea.

It is important to note that this meta-analysis excluded studies comparing prokinetics to each other, and those assessing gastric emptying by pharmacokinetic (acetaminophen absorption) or isotopic methods. This may lead to important consequences.

Firstly, all the meta-analysed studies used gastric residual volume (GRV) as a marker of feeding (in)tolerance, with threshold values of 150 to 250 ml for the definition of intolerance. This may be considered obsolete since we know nowadays that GRV is a poor marker of gastric emptying, and the use of GRV for monitoring enteral nutrition was therefore recently challenged [2]. Taking this into consideration means that many patients included in this meta-analysis were falsely considered intolerant to enteral feeding. This does not contradict the main conclusions of the article, but instead it further weakens the already “moderate quality of evidence” that prokinetic agents are effective in improving feeding intolerance.

Another consequence of the study selection criteria is the relatively poor number of patients we are left with. Indeed, after separation of the articles assessing success of postpyloric tube placement or incidence of pneumonia, we are left with only five eligible RCTs and a total of 227 patients for evaluation of other major clinical outcomes including “feeding tolerance”, GRV, vomiting, and diarrhoea. Therefore, caution should be taken when interpreting the results. In particular, the increased rate of diarrhoea did not reach statistical significance, although the incidence of diarrhoea almost doubled in patients under prokinetic therapy in the two eligible studies. This is in accordance with a 40 % (single prokinetic) to 49 % (double prokinetic therapy) incidence of diarrhoea that was reported in patients fed enterally [3], suggesting the presence of digestive malabsorption aggravated by prokinetics in the critically ill. For intensive care unit (ICU) practitioners, “enteral feeding tolerance” is often assimilated to “adequate gastric emptying”. Although proper gastric emptying is a prerequisite for efficient enteral nutrition, the ultimate goal is to get the nutrients absorbed. In this regard, we may further question the place of prokinetics, as these may alter intestinal absorption through poorly adapted gut motility [4].

Notes

Abbreviations

GRADE: 

Grading of recommendation, assessment, development, and evaluation

GRV: 

Gastric residual volume

ICU: 

Intensive care unit

RCT: 

Randomized, controlled trial

Declarations

Funding

This work is unfunded.

Author’s contributions

AD designed and wrote the manuscript as the sole author.

Competing interests

The author declares that he has no competing interests.

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Authors’ Affiliations

(1)
Department of Intensive Care, Louvain School of Medicine, CHU UCL Namur

References

  1. Lewis K, Alqahtani Z, McIntyre L, Almenawer S, Alshamsi F, Rhodes A, Evans L, Angus DC, Alhazzani W. The efficacy and safety of prokinetic agents in critically ill patients receiving enteral nutrition: a systematic review and meta-analysis of randomized trials. Crit Care. 2016;20:259.View ArticlePubMedPubMed CentralGoogle Scholar
  2. Elke G, Felbinger TW, Heyland DK. Gastric residual volume in critically ill patients: a dead marker or still alive? Nutr Clin Pract. 2015;30:59–71.View ArticlePubMedGoogle Scholar
  3. Nguyen NQ, Ching K, Fraser RJ, Chapman MJ, Holloway RH. Risk of clostridium difficile diarrhoea in critically ill patients treated with erythromycin-based prokinetic therapy for feed intolerance. Intensive Care Med. 2008;34:169–73.View ArticlePubMedGoogle Scholar
  4. Deane A, Wong G, Horowitz M, Zaknic A, Summers M, Di Bartolomeo A, Sim J, Maddox A, Bellon M, Rayner C, Chapman M, Fraser R. Randomized double-blind crossover study to determine the effects of erythromycin on small intestinal nutrient absorption and transit in the critically ill. Am J Nutr. 2012;95:1396–402.View ArticleGoogle Scholar

Copyright

© The Author(s). 2016

Advertisement