Guidelines recommending head of bed (HOB) elevation greater than 30º to prevent ventilator-associated pneumonia conflict with guidelines to prevent pressure ulcers, which recommend HOB elevation less than 30º.


To examine the feasibility of 45º HOB elevation and describe and compare the occurrence of reflux, aspiration, and pressure ulcer development at 30º and 45º HOB elevation.


A randomized 2-day crossover trial was conducted. HOB angle was measured every 30 seconds. Oral and tracheal secretions were analyzed for pepsin presence. Skin was assessed for pressure ulcers. Wilcoxon signed rank tests and Kendall τ correlations were conducted.


Fifteen patients were enrolled; 11 completed both days. Patients were maintained at 30º (mean, 30º) for 96% of minutes and at 45º (mean, 39º) for 77% of minutes. No patients showed signs of pressure ulcers. A total of 188 oral secretions were obtained, 82 (44%) were pepsin-positive; 174 tracheal secretions were obtained, 108 (62%) were pepsin-positive. The median percentage of pepsin-positive oral secretions was not significantly higher (P = .11) at 30º elevation (54%) than at 45º elevation (20%). The median percentage of pepsin-positive tracheal secretions was not significantly higher (P = .37) at 30º elevation (71%) than 45º elevation (67%). Deeper sedation correlated with increased reflux (P = .03).


HOB elevation greater than 30º is feasible and preferred to 30º for reducing oral secretion volume, reflux, and aspiration without pressure ulcer development in gastric-fed patients receiving mechanical ventilation. More deeply sedated patients may benefit from higher HOB elevations.

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