Prevention of lung-to-lung aspiration during emergency thoracic surgery: an experimental study

Background Lung separation is essential for an emergency thoracic surgery for massive hemoptysis. When using a double lumen tube (DLT), a commonly adopted lung separation device during thoracic surgery, a water-tight seal of endobronchial cuff is crucial to prevent lung-to-lung aspiration of blood. In this study, we investigated the fluid sealing characteristics of the endobronchial cuff of a DLT and examined the effect of gel lubrication on the fluid leakage beyond the endobronchial cuff of DLT. Methods An artificial tracheobronchial tree was intubated with a DLT. In the first phase of the study, the intra-cuff pressure of endobronchial cuff of DLT was set to 25, 50, or 100 cmH2O (n = 7, each), and the non-dependent bronchus was filled with 5 ml of water. Fluid leakage to the dependent bronchus beyond the endobronchial cuff was collected for 6 h. The time until leakage was first detected and the time until 100% leakage occurred were measured. In the second phase, the endobronchial cuff was coated with either saline (group C, n = 10) or lubricant gel (group GEL, n = 10), and the same parameters were measured. Results In the first phase of the study, the times to first leakage and 100% leakage at an intra-cuff pressure of 25 cmH2O were 21.0 (7.0 - 59.0) sec and 3.0 (2.0 - 4.0) min, respectively. Higher intra-cuff (50 and 100 cmH2O) resulted in longer time for the first leakage and 100% leakage, but the duration was not long enough for clinical purpose. In the second phase, all the DLTs in group C showed 100% fluid leakage during the 6-hour period. In contrast, in group GEL, fluid leakage beyond the endobronchial cuff was detected only in 50% of the DLTs and none of the DLT showed 100% fluid leakage during the study. Among the DLTs which exhibited fluid leakage, the time to first leakage was 252.0 (171.0-305.0) min and the leakage volume at the end of the study period was 0.3〔0.0-1.8〕ml. Conclusions Endobronchial cuff of DLT cannot prevent fluid leakage beyond the endobronchial cuff, but lubricant gel coating on the endobronchial cuff can effectively reduce the lung-to-lung aspiration