Abnormal Exercise Responses in Survivors of Acute Lung Injury During Cardiopulmonary Exercise Testing: AN OBSERVATIONAL STUDY.

Abstract

This study compared exercise responses in individuals who had recently survived an admission to the intensive care unit for acute lung injury (ALI) with healthy controls. Ten patients with ALI were recruited at 2 Australian hospitals. Six weeks after hospital discharge, participants completed lung function measures and a laboratory-based cardiopulmonary exercise test. Identical measures were collected in 21 healthy participants of similar age and gender distribution. Compared with the healthy participants, the ALI participants were similar in age (51 ± 14 vs 50 ± 16 yr), with a lower peak oxygen uptake ((Equation is included in full-text article.)O2) (median [interquartile range], 31.80 [26.60-41.73] vs 17.80 [14.85-20.85] mL/kg/min; P < .01) and higher ventilatory equivalent for carbon dioxide ((Equation is included in full-text article.)E/(Equation is included in full-text article.)CO2) at anaerobic threshold (mean ± SD, 25.7 ± 2.5 vs 35.2 ± 4.1; P < .01). Analysis of individual ALI participant responses showed that 8 participants had a decreased peak (Equation is included in full-text article.)O2 and anaerobic threshold. All ALI participants were limited by leg fatigue. Abnormalities of pulmonary gas exchange were present in 7 participants. Evidence of cardiac ischemia was present in 2 participants. Compared with healthy controls, ALI participants had reduced exercise capacity, mainly due to profound deconditioning. Exercise training to optimize aerobic capacity would appear to be a rehabilitation priority in this population.