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Gastric Versus Jejunal Feeding: Evidence Or Emotion?

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Gastric Versus Jejunal Feeding: Evidence Or Emotion? NUTRITION ISSUES IN GASTROENTEROLOGY, SERIES #42 Carol Rees Parrish, R.D., M.S., Series Editor Gastric versus Jejunal Feeding: Evidence or Emotion? Joe Krenitsky Delivery of enteral feeding into the small bowel has been suggested as a strategy to reduce the risk of aspiration pneumonia and improve the delivery of nutrition. However, randomized studies of gastric versus enteric small bowel feeding have been inconclusive, in part due to the methodological limitations and small number of patients in each study. The conclusions of three different meta-analysis were inconsistent; the efficacy of small bowel feedings to reduce pneumonia incidence or improve delivery of nutrition remains an area of persistent debate. The goal of this article is to critically evaluate the literature available on gastric versus small bowel feedings so that rational and safe feeding proto - cols can be developed that are based on the best available evidence. INTRODUCTION that have been challenged in recent investigations. For n patients that require nutrition support, enteral nutri - example, research demonstrating successful EN in tion (EN) results in reduced infectious complications, severe pancreatitis, hypotension with pressors, and I immediately after bowel anastomosis, all highlight the and is more cost effective compared to parenteral nutrition (PN) (1). The knowledge of the benefits of EN feasibility of EN in settings that may have previously has led to increasing acceptance and use of enteral feed - been considered a contraindication to EN (2–6). ing, especially in critically ill patients. However, there It is true, however, that many critically ill patients remains a substantial reluctance to utilize enteral feed - exhibit delayed gastric emptying and have multiple risk ings in some clinical situations due to concerns of feed - factors for aspiration pneumonia (7). The acquisition of ing intolerance and aspiration risk. It is clear that some nosocomial pneumonia portends a more complicated of these concerns are perceptions of feeding intolerance hospitalization with increased length of stay, hospital costs, and mortality (8). Clinicians have searched for a means to retain the advantage of EN while reducing the Joe Krenitsky, M.S., R.D., Nutrition Support Special - risks of feeding intolerance and aspiration. Strategies ist, Digestive Health Center of Excellence, University such as the use of prokinetic medications, elevation of of Virginia Health System, Charlottesville, VA. (continued on page 49) 46 PRACTICAL GASTROENTEROLOGY • SEPTEMBER 2006 Gastric versus Jejunal Feeding NUTRITION ISSUES IN GASTROENTEROLOGY, SERIES #42 (continued from page 46) the head-of-bed and placing the feeding tube beyond These trials have been conducted in a variety of patient the pylorus, have all been suggested as possible ways to populations including medical, surgical, neurological reduce the risk of aspiration. and trauma ICU patients, as well as non-ICU patients. Placement of the feeding tube beyond the pylorus There are important methodological differences between may appear to be an obvious choice to reduce aspiration the studies that make direct comparison difficult. One of risk, and intuitively, would not appear to have any clin - the most evident differences between the studies is the ical drawbacks. However, like many other intuitive position of the tip of the feeding tube. Five studies strategies applied to the critical care setting, controlled intended to place the feeding tube into the duodenum trials have yielded unexpected results. There are over 10 (12–16), while 3 studies attempted to place the feeding controlled trials that have investigated gastric versus tube into the jejunum (17–19). Two studies did not state small bowel feeding and the risk of aspiration, and no the precise location of the tube (20–21). It is important to study has demonstrated a significant reduction in pneu - note the position of the feeding tubes, both in interpreta - monia incidence or mortality with small bowel feedings. tion of the significance of the study results, as well as in Although some studies have suggested that small bowel the clinical implementation of feeding protocols. Reflux feeding allows improved feeding tolerance and nutrition occurs commonly from the proximal small bowel provision, other studies have reported no significant dif - (15,22) and feedings must be infused beyond the liga - ference in feeding tolerance between groups. The indi - ment of Treiz to minimize the possibility of reflux (23). vidual studies of gastric versus small bowel feeding Heyland reported that as the feeding tube was placed in have all been hampered by a small sample size. In an a more distal position there were less episodes of gas - attempt to overcome the limitation of small sample size, troesophageal regurgitation (15). However, some at least 3 meta-analyses of these studies have been pub - reviews and practice guidelines do not differentiate lished (9–11). However, due to limitations in the indi - between “post-pyloric” or “small bowel” placement vidual studies and different conclusions of each meta- (which could mean proximal duodenum) versus jejunal analysis, there is a lack of consensus among experts placement of feeding tubes. In this review, the author regarding the role of post-pyloric feeding in reducing will use the terms small bowel or post-pyloric as a aspiration risk, pneumonia incidence, or improving generic term and for studies that do not specify location feeding tolerance and delivery. This qualitative review of the tube beyond the stomach; the term “jejunal” will will discuss the implications of the available research only be used when studies have specified placement dis - and review the findings of the 3 available meta-analysis tal to the duodenum. Another important consideration in terms of aspiration risk, incidence of pneumonia and that is not equally controlled for in each study is the pos - feeding tolerance. It will focus on those studies that sible displacement of feeding tubes during the study. Fre - have randomized patients to gastric versus small bowel quent displacement of post-pyloric feeding tubes has feedings that investigated reflux, aspiration, pneumonia, been described in some settings. At least one study or feeding adequacy. Research designed to investigate reported that 13% of the jejunal group had to be crossed- gastric versus small bowel feeding in the setting of pan - over to the gastric group due to tube displacement during creatitis has been excluded because research into the the study (17). If a small bore nasogastric (NG) or oro - safety of gastric feedings in pancreatitis is ongoing, gastric (OG) tube is used, it is also possible that some of inconclusive and the details of that topic would fill an the gastric feeding groups actually received small bowel entire article by itself. feedings during the study. A number of studies do not report if tube position was reconfirmed during the study period (13,14,17,19,21). CLINICAL TRIALS—STUDY DESIGN Location of the Feeding Ports Concurrent Gastric Decompression There are at least 10 randomized studies that have inves - An additional aspect that varies in some of the studies tigated gastric versus small bowel feeding (Table 1). was the decision to suction gastric secretions in the PRACTICAL GASTROENTEROLOGY • SEPTEMBER 2006 49 Gastric versus Jejunal Feeding NUTRITION ISSUES IN GASTROENTEROLOGY, SERIES #42 Table 1 Gastric vs Jejunal Feeding Trials Tube Position Gastric Study Patients Tube Position Rechecked Prokinetics Suctioning Montecalvo et al. 38 surgical and Endoscopically Not reported Not used No 1992 medical ICU placed Strong et al. 33 malnourished Second portion Every 3 days Not reported No 1992 hospitalized duodenum – patients various methods Kortbeek et al. 80 trauma ICU Fluoro placed Not reported Prokinetics used No 1999 patients duodenum after 24 hours. Kearns et al. 44 medical ICU Blind or Not reported 1 dose with tube No 2000 fluoroscopic placement only placement into duodenum Esparza et al. 54 mixed ICU Transpyloric – Continuous Prokinetics used No 2001 patients not specified monitoring "as required" (see paper) Heyland et al. 39 medical/surgical Blind or Position reconfirmed Prokinetics used Yes 2001 ICU patients endoscopically only when suspicion "as required" into duodenum of displacement Day et al. 25 Neurological Blind-placement Not reported Not used No 2001 ICU to duodenum Neumann et al. 60 general ICU Not specified Not specified Not used No 2002 Davies et al 66 Mixed ICU Endoscopic Every 3 days Not used Yes 2002 placed nasojejunal Montejo et al. 110 mixed ICU Dual-lumen Not specified Not used yes 2002 patients naso G-J Used with permission from the University of Virginia Health System Nutrition Support Traineeship Syllabus (53) small bowel feeding group. Three of the studies placed other studies relied on various clinical diagnoses of a nasogastric tube to suction or drainage in all patients pneumonia. Clinical diagnosis of pneumonia has been with small bowel feeding (15,18,19), while the other criticized as non-specific in some patient populations seven studies did not. (24). Some components of clinical diagnosis rely on subjective interpretation that can be a source of signif - icant bias (especially in those studies that are not dou - Defining Pneumonia ble-blind). Only 2 studies reported a double-blind pro - The method of diagnosing pneumonia also differed tocol, that is, those involved in the diagnosis of pneu - between the various studies. Two of the
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