Continuous measurement of backrest elevation in critical care: A research strategy

Objective: To develop and test a procedure for continuous measurement of ba ckrest elevation in critical care for enhancing the precision of this measu rement for research purposes. Design: Descriptive, correlational. Setting and Measurements: Backrest elevation, defined as the height of the head of the bed in degrees of elevation above horizontal, can be continuous ly monitored by using two transducers, one attached to the bed frame lust d istal to the head of the bed gatch and another attached to the bed frame at the top of the bed. By monitoring the differential head pressure between t he two pressure channels, the height of the head of the bed can be calculat ed. A total of 30 random measurements of backrest elevation, from 0 degrees to 60 degrees, were taken by using the backrest elevation measurement on t he bed frame, a handheld protractor, acid the pressure differential between two transducers attached to the bed frame. Data collectors recorded one me asurement independent of the other measurements. All measurements were cond ucted on the same bed. Results: When the transduced method was compared with measurements by using a protractor, the Bland-Altman analysis technique yielded upper and lower limits of agreement of 8.93 degrees and -5.91 degrees, respectively. The bi as was 1.51 degrees, and the precision was 3.71 degrees. Conclusions: The measurement technique described here was developed for res earch purposes to add precision to research studies examining the appropria te height of the backrest. However, the procedure could be used in a contin uous quality improvement process to enhance compliance with patient care pr ocedures involving backrest elevation or to confirm actual nursing practice and its correlation with patient outcome. In light of the risks associated with the use of supine positioning in critically iii and mechanically Vent ilated patients, the information gained from continuous measurement of back rest position could be an extremely valuable research tool.