Reflux during nasojejeunal feeding

Comments

Although some duodenogastric reflux occurs during nasojejunal feeding abactericidal pH in the stomach remains. However reflux may become moresignificant during long-term feeding and large numbers will be required todiscover whether the proposed benefits of nasojejunal feeding have anyeffect on outcome.

Introduction

It is accepted that early enteral feeding in the intensive care unit (ICU) patientis important, but frequently gastric stasis prevents feeding via thenasogastric tube. Feeding via a nasojejeunal feed may improve the abilityto deliver calories and overcome the danger of aspiration of stagnantgastric contents. It may also prevent gastric bacterial overgrowth, whichhas been implicated in aspiration pneumonia, by conserving gastric acidity.The aims of this study were to assess whether these benefits hold true fornasojejeunal feeding.

Aims

To investigate the effect on gastric pH and incidence ofduodenogastric reflux during nasojejeunal feeding in critically illpatients.

Methods

A total of 21 patients being mechanically ventilated on the ICU and requiringenteral feeding over a 6 month period (1995/1996) were studied. Medicationsaffecting gastric motility and/or gastric acid production were discontinuedfor the period of the study. A double-lumen nasogastrojejunal feeding tubewas passed under X-ray control, and continuous intragastric pH measurementswere taken during fasting (240 min) and a subsequent period of feeding witha standard liquid diet (240 min). In addition, 11 patients had the feed labelledwith ¹¹¹In DTPA and gastric aspirates taken every 30 min; subsequently measurements of volume, glucose, bile acid and radioactivity were made.

Results

Median pH during fasting was 1.59 which rose to 2.33 duringnasojejunal feeding (P = 0.013), and the duration of time recorded with a pH ≥4 also rose from 1 to 9 min (P = 0.026) over the two periods.A total of 10 out of 11 patients showed a significant rise in radioactivity ofaspirates during feeding and bile acid concentration rose in all 11 patientsfrom 392 μmol/l during fasting to 1446 μmol/l during nasojejeunal feeding(P = 0.01). Glucose concentrations and gastric aspirate volumes rose duringfeeding although the volume change was not statistically significant.

Discussion

Nasogastric feeding may put the critically ill patient at riskfrom ventilator associated pneumonia through aspiration of contents.Nasogastric feed may also promote gastric colonisation since gastric pH israised. It has been suggested that nasojejunal feeding may therefore offercertain advantages. However this study shows that there is significantduodenogastric reflux during nasojejunal feeding and that biliary secretionis not inhibited even though food is delivered beyond the duodenum. Howevergastric pH remained acidic during feeding and previous studies have shownthat a pH<4 is bactericidal. Duodenogastric reflux is a physiologicalphenomenon and may have been worsened by the presence of a tube through thepyloric sphincter.