Semirecumbency among mechanically ventilated ICU patients: a multicenter observational study

Background: Preventing major morbid events such as ventilator associated pneumonia (VAP) is integral to the care of critically ill patients. Nursing patients in the semirecumbent instead of supine position is associated with lower rates of aspiration and VAP. Objective: To observe the frequency of semirecumbency amongst mechanically ventilated patients in the intensive care unit (ICU). Design: Prospective multicenter observational study. Population: Patients who were mechanically ventilated for >48 hours in four Canadian university-affiliated ICUs. Measurements: At the same time each day for 5 consecutive days, we recorded the body position of ventilated patients and categorized them into four groups: less than 15 degrees from the horizontal, 15-30 degrees, 31-45 degrees, and greater than 45 degrees. To avoid the Hawthorne effect, ICU team members were unaware of the study hypothesis. Results: We observed 61 patients age 59.3 (7.8) years, 29 (48%) female. We recorded body position for 164 patient-ventilator days. Patients were nursed at less than 15 degrees from the horizontal for a range of 15-40% of patient-ventilator days in these ICUs. The most common body position for all four ICUs was 15-30 degrees from the horizontal. Patients were observed at least 45 degrees from the horizontal for a range of only 5-22% of patient-ventilator days. Body position was unrelated to the presence of a tracheostomy and endotracheal secretion volume. Conclusions: Although randomized clinical trials suggest that the supine position is associated with higher rates of aspiration and VAP compared with the semirecumbent position, few mechanically ventilated patients were nursed in the semirecumbent position.