Effect of rotational therapy on aspiration risk of enteral feeds

Enteral nutrition has been demonstrated to reduce ventilator days and the incidence of pneumonia, but the safest route for providing enteral nutrition to mechanically ventilated patients is unclear. Our objective was to determine if there is a difference between the incidences of microaspiration of gastric secretions in patients fed via a nasogastric tube vs a postpyloric tube while undergoing rotational therapy for acute respiratory distress syndrome (ARDS).

Institutional review board approval was obtained for this prospective, randomized study. Patients were randomized to gastric or postpyloric enteral feedings. Daily tracheal secretion samples were collected, and we used an immunoassay to detect pepsin. Using the data for aspiration and tube type, a univariate unadjusted odds ratio was calculated to assess the risk of aspiration between the 2 tube types. An independent samples t test was used to analyze the hypothesis that microaspiration significantly affects lung recovery from ARDS.

Of the 20 study patients, 9 (45%) received nasogastric feeds and 11 (55%) received postpyloric feeds. Western blot analysis for the presence of pepsin in each tracheal aspirate revealed microaspiration in 2 nasogastric (22%) and 2 (18%) postpyloric patients. The nasogastric tube provided a protective effect for aspirating with an odds ratio of .778 (95% confidence interval, .09-6.98). An independent samples t test was used and showed no significant change in PaO(2):FiO(2) ratio in the aspirating vs nonaspirating group (P = .552).

The results of this study indicate that enteral nutrition should not be delayed or stopped to position the tube in patients with ARDS on rotational therapy.