The performance of four pleural drainage systems in an animal model of bronchopleural fistula.

In order to compare the performance of four pleural drainage units (PDU [Emerson Post-Operative Pump, Pleur-Evac, Sentinel Seal, Thora-Klex]), we created an animal model of bronchopleural fistula that simulated the type of air leak seen clinically (mean maximal flow = 5 L/min). The PDU were tested at 0 cm (water seal), -20 cm and -40 cmH2O suction. Compared to water seal, -20 cmH2O suction significantly increased the ability of all four PDU to evacuate air via the chest tube and abolished small differences in chest tube air leak seen among the PDU at water seal. An increase in suction to -40 cmH2O did not significantly alter flow via the chest tube. Previously demonstrated differences among the PDU in handling large air flows were not seen in this lower flow model of bronchopleural fistula. However, because of their higher resistance, use of the Sentinel Seal and of the Thora-Klex was technically impractical even at air leaks of 4 to 5 L/min.