For decades, the prevention of pulmonary complications in immobilized patients has entailed turning them every two hours from one side to the other. However, results of research on how best to accomplish this are spotty at best. In a recent prospective, randomized trial, Ahrens and colleagues compared the use of manual turning with the use of a low-air-loss "kinetic therapy" bed, which automatically turns the patient 40[degrees] on each side, to determine which is better for reducing ventilator-associated pneumonia, lobar atelectasis, or intrapulmonary shunting or decreasing the length of ICU stay or the need for mechanical ventilation. The results were mixed in the study, funded in part by KCI USA, a manufacturer of such beds.

Patients were eligible for inclusion in the study if they had a Glasgow Coma Scale score lower than 11, needed mechanical ventilation, and had evidence of pulmonary shunting (determined by measuring the amount of arterial oxygen pressure relative to the amount of inspired oxygen). Of 255 patients in six hospitals, 118 were enrolled in the kinetic therapy group (only 97 were included in the analysis because nurses determined that 21 patients were unable to tolerate rotation for physiologic reasons or anxiety) and 137 were enrolled in the manual-turning group.

Among patients receiving kinetic therapy there were significantly fewer incidences of ventilator-associated pneumonia (14 patients [17%] in the kinetic therapy group versus 45 [49%] in the manual-turning group) and lobar atelectasis (16 patients [20%] versus 42 [44%]). There were no significant differences in terms of the incidence of pulmonary shunting, overall survival, length of ICU and hospital stays, or hospital costs.

For a number of reasons, the kinetic therapy beds in many cases weren't in operation for the 18 hours per day recommended in the study protocol. Reasons for this included the interruption of rotation for procedures, nurses' forgetting to restart rotation after procedures, and patients appearing to be uncomfortable. The authors postulate that more involvement of the nursing staff and willingness of physicians to sedate patients so that they can tolerate kinetic therapy might lead to better outcomes. They recommend another study that includes protocols for sedation and for weaning from mechanical ventilation.-Fran Mennick, BSN, RN

Ahrens T, et al. Am J Crit Care 2004;13(5):376-82.