RESIDUAL GASTRIC VOLUME IN MORBIDLY OBESE DIABETICS AFTER AN OVERNIGHT FASTING OR 3 HOURS OF A CARBOHYDRATE-ENRICHED SUPPLEMENT: A RANDOMIZED CROSSOVER PILOT STUDY.

BACKGROUND: To reduce the risk of regurgitation during anesthesia for elective procedures, residual gastric volumes (RGV) have traditionally been minimized by overnight fasting. Prolonged preoperative fasting presents some adverse consequences and has been abandoned for most surgical procedures, except for obese and/or diabetic patients.

AIMS: The aim of this study was to assess the RGV in morbidly obese diabetic patients after traditional or abbreviated fasting.

METHODS: This study was approved by the Ethics Committee for Research with Human Beings from the Federal University of Mato Grosso, under number 179.017/2012. This is a prospective, randomized, and crossover design study in eight morbidly obese type II diabetic patients. RGV was measured endoscopically after either traditional overnight fasting of at least 8 hours, or after abbreviated fasting of 6 hours for solids and 3 hours for a drink containing water plus 25 g (12.5%) of maltodextrin. Data were expressed as mean and range and differences were compared with paired t-tests at p<0.05.

RESULTS: The study population had a mean age of 41.5 years (28-53), weight of 135 kg (113-196), body mass index of 48.2 kg/m2 (40-62.4), and type II diabetes for 4.5 years (1-10). The RGV after abbreviated fasting was 21.5 ml (5-40) vs 26.3 ml (7-65) after traditional fasting. This difference was not significant (p=0.82).

CONCLUSIONS: Gastric emptying in morbidly obese diabetic patients is similar after either traditional or abbreviated fasting with a carbohydrate drink.