Impact of burn contractures of chest wall and their surgical release on pulmonary function

Extensive burn scars and contractures are likely to restrict the movements of the chest wall which may affect the pulmonary ventilation by restricting its expansion during inspiration. We designed this study to evaluate the effect of burn contractures of chest wall on pulmonary function and to estimate the effect of contracture release on pulmonary functions in patients with compromised PFT.

Pulmonary function tests (PFT) of 20 patients having chest wall contractures involving more than 50% of the chest circumference were studied. Restrictive lung disease was defined as forced vital capacity (FVC) value less than 80% of predicted normal for the age, weight, and height of that patient. Patients with a restrictive pattern on PFT were subjected to the surgical release of the contracture. PFT was repeated one month after the surgery which was compared with the initial report.

Of the 20 patients included in the study, 5 (25%) patients had a restriction pattern on PFT. 1 patient had a mild restriction, 2 patients had moderate restriction and 2 patients had a severe restriction of pulmonary function. The mean duration of contracture was 58.2±15.75months in patients with a pulmonary restriction as compared to 29.87±6.21months in patients with a normal PFT (p=0.001). All patients having a restrictive pattern on PFT had contracture involvement of >75% of the chest wall circumference (p=0.0036). The mean forced vital capacity (FVC) increased from 1.94L preoperatively to 2.11L after surgical release of the contracture (p=0.047). However, the restriction pattern in PFT did remain.

Long standing chest wall contractures and contractures involving >75% of the chest circumference are likely to cause a restrictive pattern on PFT. Any significant improvement of pulmonary function after surgical release of the contracture is unlikely.