Ventilator-associated pneumonia remains a common problem with attributable morbidity and mortality. Several preventive strategies are recommended including semi-recumbent positioning (head of bed angle at 30 degrees or above) in the absence of contraindications. Most studies that describe this practice, however, assess head of bed (HOB) position infrequently (i.e., often just once per day). As such, the data provided may not be reflective of what is occurring over longer time intervals. We sought to determine the angle of the HOB once per minute in patients receiving mechanical ventilation.
The HOB angle was measured using an inclinometer (Rieker, Inc.; Folcroft, PA) and the information was stored in a data logger (Onset Computers; Bourne, MA) until it was downloaded. The inclinometer-logger system was housed in a box which attached to the undersurface of the head of the bed. Calibration curves for each of six inclinometer-logger boxes was obtained between 0 to 60 degrees at 5 degree intervals. Each morning during the week a box was placed under the head of the bed of an intubated patient if the clinical team expected the patient to remain intubated at least for that day. Data was collected until the patient was extubated.
30 intubated patients were evaluated over a two month period. The median time of intubation was 47 hours (range 2-340 hours). The mean HOB angle for each of the 30 patients ranged from 0-27 degrees (median 21 degrees). The median percentage of time spent at or above a 30 degree angle was 3% (range 0-62%). The median percentage of time spent at or above a 45 degree angle was 0% (range 0-2%).
This study indicates that semi-recubancy is rarely achieved in patients receiving mechanical ventilation. We have developed a tool which allows for continuous measurement of HOB angle. This method of monitoring shows promise as an assessment tool to improve patient care and provide feedback to the healthcare team.
There is much room for improvement in pneumonia prevention.
Boaz Markewitz, None.