Incidence of gastroesophageal reflux and aspiration in mechanically ventilated patients using small-bore nasogastric tubes

Background. Use of a large-bore nasogastric tube (NGT) and patient position are considered key factors in promoting gastroesophageal reflux (GER) and pulmonary aspiration in critically ill patients. The objective of this stud y was to determine the incidence of CER and pulmonary aspiration of gastric contents in mechanically ventilated (MV) patients using small-bore NGTs. M ethods: We studied 30 patients on mechanical ventilation for acute respirat ory failure who tolerated enteral nutrition through a small-bore NGT. Patie nts were randomly assigned to a group with (n = 16) or without (n = 14) a s mall-bore NGT and were maintained in a semirecumbent position during the st udy. GER and aspiration of gastric contents were assessed by a radioisotopi c technique. Scans were done 24 hours after technetium-99m administration ( n = 30). In 9 patients a dynamic scintigraphy was performed immediately aft er colloid administration, and samples of blood and tracheal and oropharyng eal secretions were obtained basally, 30 minutes, and 24 hours after techne tium administration and analyzed for radioactivity using a gamma counter. R esults: Both groups were similar in age, underlying diagnosis, number of da ys of mechanical ventilation at the day of study, and mortality. There were no GER reaching the oropharynx and aspiration of gastric contents in both groups. Conclusions: GER and aspiration of gastric contents were not detect ed in MV patients using small-bore NGTs and may be a simple measure to prev ent ventilator-associated pneumonia.