The Effects of High Frequency Jet Ventilation to the Collapsed Lung on Systemic Oxygenation during One Lung Ventilation

Noh, Gyu Jeong; Jeon, Woo Jae

Abstract

BACKGROUND: In some cases of one-lung ventilation (OLV), hypoxemia may occur secondarily to the obligatory right to left transpulmonary shunt through the collapsed lung. We investigated the efficacy of high frequency jet ventilation (HFJV) to the non-dependent lung which rendered to be manually collapsed by surgeon and not to be reinflated, in improving systemic oxygenation and ventilation during OLV while ventilating the dependent lung with intermittent positive pressure ventilation.
METHODS
Investigation was carried out on 20 ASA 2 or 3 patients who underwent thoracotomy in lateral decubitus position. The patients were randomly allocated into HFJV group (n = 11) or CPAP group (n = 9). In HFJV group, 20 minutes after OLV began, HFJV with driving pressure 1.0 bar, Ti 30%, and frequency 150 cycles/min, was applied to the non-dependent lung. In CPAP group, 5 cmH2O of CPAP was applied to the non-dependent lung without re-inflation. We compared the changes of PaO2, PaCO2, AaDO2 and pulmonary shunt, before and after HFJV or CPAP was applied to the non-dependent lung during OLV.
RESULTS
AaDO2 and pulmonary shunt were decreased significantly and therefore, PaO2 was increased significantly when HFJV was applied to the non-dependent lung (P < 0.05, respectively). PaO2, AaDO2 and pulmonary shunt were not improved after 5 cmH2O of CPAP was applied to the non-dependent lung without re-inflation. In HFJV group, PaCO2 measured after HFJV was not decreased significantly compared with that before HFJV.
CONCLUSIONS
HFJV to the non-dependent lung during OLV improved systemic oxygenation, even after the non-dependent lung collapsed completely but did not enhance CO2 elimination. 5 cmH2O of CPAP to the non-dependent lung, which was completely collapsed and not re-inflated, did not improve systemic oxygenation.