Pectoralis muscle area in the follow-up of Acute Respiratory Distress Syndrome

Background: Acute respiratory distress syndrome (ARDS) survivors are at risk to a wide variety of disabilities, including physical dysfunction. Aim: Our aim was to quantify pectoralis muscle area (PMA) in ARDS survivors and evaluate the impact of PMA in lung function and quality of life after 6 months. Methods: We conducted a cohort study of 22 survivors of moderate-severe ARDS, recruited in Sao Paulo, Brazil. High-resolution CT (HRCT) scan of the lungs were performed after 1 and 6 months. If present, a HRCT obtained in ICU was also evaluated. At 6 months a pulmonary function test and a quality of life questionnaire (SF-36) were performed. PMA area was assessed using image J software. Results: 22 patients were followed-up for 6 months. 17 presented a HRCT at 1 and 6 months and were included. There was a reduction in PMA after 1 month compared with ICU (40.6 cm2 vs 30.4 cm2, p = 0.01), with an improvement after 6 months compared to 1 month (30.4 vs 35.1, p = 0.001). PMA at 6 months was related to age (r = -0.46, p=0.03), predicted body weight (r = 0.53, p = 0.03) and mechanical ventilation time (r = -0.44, p=0.04). There was a functional impact of PMA, with a correlation between PMA and residual volume/pulmonary total capacity at 6 months (r = -0.65, p=0.002), as well as an impact in quality of life, with PMA related to vitality dimension in SF-36 (r=0.72, p=0.02). Conclusions: There was a reduction in PMA 1 month after ARDS with recovery in 6 months. The analysis of PMA could be an easy and available tool to estimate sarcopenia in ARDS patients, but further study should evaluate the relationship with functional deficits and late outcomes.