Restrictive pulmonary dysfunction caused by the grafted chest and abdominal burn.

We report on the effect of the excised and grafted chest and abdominal burn on lung function. Six consecutive patients with 3 degree burns to the entire chest and abdomen (72 +/- 10% total body surface area 3 degree burns) were studied. A severe restrictive lung dysfunction due to the noncompliant nature of the excised and grafted chest and abdominal wound was identified; this was most evident when inspiratory pressure (IP) was even modestly impaired with general anesthetics. Measured vital capacity (VC) was 12 to 14 ml/kg at 6 to 8 wk postburn, in the absence of any significant parenchymal injury. The measured VC was identical to the tidal volume (VT) used during the extended period of mechanical ventilatory support. Dynamic compliance (or characteristic) (Cdyn) decreased dramatically from 35 +/- 8 to 15 +/- 9 ml/cm H2O when the positive pressure VT was increased by as little as 100 ml above prior VT settings, indicating the noncompliant nature of the combined chest and abdominal excised and grafted burn. Major cardiopulmonary complications developed in the first two patients after onset of the restrictive process when general anesthesia was used for grafting procedures (n = 8) and the limits of chest wall excursion were unrecognized. Patients received only continuous positive airway pressure preoperatively. A modest but significant decrease in IP from -45 +/- 8 to -33 +/- 5 cm H2O and 30% decrease in spontaneous VT were noted in the early postoperative period. These changes, however, resulted in a dramatic decrease in pulmonary function leading to hypercarbia, PCO2 greater than 50 torr.(ABSTRACT TRUNCATED AT 250 WORDS)