The effects of bolus and continuous nasogastric feeding on gastro-oesophageal reflux and gastric emptying in healthy volunteers: A randomised three-way crossover pilot study

Background & aims: Nasogastric feeding may result in gastro-oesophageal reflux and, therefore, increase the risk of aspiration. This may be greater when feeds are administered via a bolus than by infusion. We aimed to measure gastric emptying time and quantify gastrooesophageal reflux in healthy volunteers given a liquid feed via an oral bolus (OB), a nasogastric tube bolus (TB) and a nasogastric tube drip (TD). Methods: Twelve mate volunteers participated in three separate studies (OB, TB and TD) in random order, each 3 days apart. The feed consisted of 220 ml Ensure Plus (1.5 kcal/ml), labelled with 12 MBq Tc-99m DTPA. The OB and TB were given over 5 min and the infusion rate for the TD was 55 ml/h. Gastric emptying time was measured using gamma scintigraphy. Gastro-oesophageal reflux was observed continuously until the stomach was empty, using a multichannel intraluminal impedance catheter. Results: Mean (95% CI) T-50 gastric emptying times for the OB and TB studies were 41.3 (36.5-46.2) min and 36.2 (30.6-41.8) min respectively (p = 0.19). The stomach emptied at a rate equal to the infusion rate in the TD studies. Median (IQR) number of reflux episodes for the OB, TB and TD studies were 4.5 (2.0-6.0), 3.0 (2.0-4.75) and 2.0 (0.25-6.25) respectively. Median (IQR) total duration of reflux for the OB, TB and TD studies were 38 (20-242), 49 (17-71) and 36 (1-125) s respectively (p = NS). Conclusions: The tack of difference in gastro-oesophageal reflux between bolus and continuous feeding indicates that in healthy volunteers both methods are equally safe with respect to the risk of aspiration. (C) 2008 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.