Differential ventilation with low-flow CPAP and CPPV in the treatment of unilateral chest trauma

A case of severe unilateral chest trauma with bronchopleural fistula is presented. Ventilatory therapy consisted of asynchronous independent lung ventilation (AILV). The injured lung was ventilated with intermittent positive pressure ventilation (IPPV) [tidal volume (TV) = 200 ml, f = 25/min, I:E = 0.5, minute volume (MV) = 5.0 l/min, FiO2 = 0.4], and the unaffected lung was ventilated with continuous positive pressure ventilation (CPPV) (TV = 600 ml, f = 12/min, I:E = 0.5, MV = 7.2 l/min, PEEP = 0.5 kPa, FiO2 = 0.4). Adequate gas exchange was obtained (PaO2 = 14.5 +/- 2.3 kPa, PaCO2 = 5.5 +/- 0.7 kPa), but high air leakage volumes persisted. Thus, differential low-flow CPAP (V = 5.0-7.5 l/min, PEEP = 0.5 kPa, FiO2 = 0.4) of the injured lung and CPPV (TV = 600 ml, f = 12/min, MV = 7.2 l/min, I:E = 0.5, PEEP = 0.5 kPa, FiO2 = 0.4) of the unaffected lung was applied for 36 hours. Further deterioration of pulmonary function was prevented, and the bronchopleural fistula closed after several hours. After another period of AILV the patient was treated with conventional mechanical ventilation, and finally weaned with high-flow CPAP.