Despite advances in mechanical ventilation and critical care, the mortality rate for acute respiratory distress syndrome (ARDS) remains over 40%. In addition to mortality, health-related quality of life (HRQL) is also thought to be impacted negatively. Prone positioning has been used in ARDS to attenuate lung injury and to provide a more homogeneous distribution of stress and strain in the injured lung. In this month’s issue of Intensive Care Medicine, Chiumello et al published an observational prospective study to evaluate the quality of life and pulmonary function in patients ventilated with prone versus supine positioning. 

Twenty-six patients were evaluated from five Italian hospitals (n= 13 prone; n=13 supine). HRQL was assessed with the SF-36 instrument. Prone vs. supine patients were similar in terms of age and severity. Pulmonary function tests, gas exchange, and DLCO were evaluated at 12 months.

Several other outcome measures were also assessed. There were no significant differences between the prone and supine patient groups in terms of pulmonary function tests, days of mechanical ventilation (p = 0.22), and intensive care unit length of stay (p=0.15). The mortality rate was 64.1% in the prone group vs. 56.8% in the supine group. Arterial oxygenation, and the percent of well-aerated lung tissue, was slightly higher in the supine group.
There were no statistically significant differences in SF-36 scores between the groups.

While this study consisted of a very small number of patients, only a few studies have examined long-term outcomes for ARDS patients. Importantly, despite recommendations in 1994 suggesting that HRQL be considered for future outcomes studies, this study is one of the few critical care studies attempting to measure it. The results from this study showed that the mortality rate for ARDS was high at one year and that lung function — as well as HRQL — was not statistically different among patients ventilated in the supine vs. prone position. While the results from this study may not be particularly robust based on the small sample size, the methods stand as an example of how future critical care outcomes studies might be conducted.

Concise Critical Appraisal is a regular feature authored by SCCM member Samuel M. Galvagno Jr., DO. Each installment highlights journal articles most relevant to the critical care practitioner.