Predictors of backrest elevation in critical care

Low backrest and supine positions are associated with increased mortality and ventilator associated pneumonia (VAP). Data are not available across ICU settings about the level of backrest position used and its relationship to enteral feeding and hemodynamic status. The purpose of this descriptive study was to document the level of backrest elevation and position and identify factors associated with and predict positioning in a medical, surgical and neuroscience intensive care unit. Data were collected randomly in each unit over a 6-week period, resulting in 506 observations for 170 patients. Backrest elevation was determined by electronic bed read-out or bed frame elevation gauge. BP, HR and enteral feeding status were retrieved from the medical record. Results showed that mean backrest elevation was 19.2° and 70% of subjects were supine. No difference in backrest elevation among units was found. Significant correlations between backrest elevation and systolic BP (r= 0.15, P= 0.006); and backrest and diastolic BP (r= 0.13, P= 0.02) were found. There was no difference in backrest elevation between patients being fed and not being fed. Differences in backrest elevation for intubated versus nonintubated patients approached significance (P=0.07) with intubated patients at lower backrest elevations. In summary, use of higher backrest elevations (>30°) is minimal, is not related to feeding and minimally related to hemodynamic status. Strategies to meet published recommendations for backrest elevation (30-45°) must include repeated feedback about nurse's use of backrest elevation and estimates of elevation.