Protective effects of different modes of ventilation on lungs on operated side during one-lung ventilation in patients undergoing thoracic surgery

Objective To evaluate the protective effects of different modes of ventilation on the lungs on the operated side during one-lung ventilation （OLV ） in patients undergoing thoracic surgery .Methods Forty-five ASA physical status Ⅰ or Ⅱ patients of both sexes ,aged 45-64 yr ,weighing 65-80 kg ,were randomly divided into 3 groups （n=15 each） using a random number table ：group A ,group B and group C .After induction of anesthesia ,the patients were intubated with double-lumen tube and OLV was performed .During OLV ,the lung on the operated side was collapsed naturally in group A ,positive pressure ventilation （FGF 2 L/min） was applied in the lung on the operated side in group B ,and high-frequency jet ventilation （frequency 100 beats/min ,driving pressure 0.5 kg/cm2 ） was used in the lung on the operated side in group C .Immediately after intubation （T0 ） , and at 1.5 h （T1 ） and 2 h （T2 ） of OLV ,blood samples were taken from the central vein and radial artery for determination of the serum interleukin-6 （IL-6 ） and IL-8 concentrations .The net release of IL-6 and IL-8 was calculated .Blood samples were taken from the radial artery at T0-2 for blood gas analysis and for determination of surfactant protein A （SP-A） concentration in the serum .Respiratory index （RI） was calculated .The non-cancer tissues 1.0 cm × 1.0 cm × 1.0 cm which were extracted from the lung cancer specimens were used for microscopic examination of the pathological changes of lungs which were scored .Results Compared with group A ,the net release of IL-6 and IL-8 ,serum SP-A concentration ,RI and pathological scores were significantly decreased at T1 ,2＆nbsp;in B and C groups （ P〈0.05） .Compared with group B ,the serum SP-A concentration and RI were significantly decreased at T1 ,2 , and the net release of IL-6 was increased at T2 in group C （ P〈 0.05 ） .Conclusion Continuous positive ventilation and high-frequency jet ventilation both can effectively protect the lungs on the operated side during OLV in patients undergoing thoracic surgery ,and the efficacy of high-frequency jet ventilation is better . Key words: Continuous positive airway pressure; High-frequency jet ventilation