Effects of different modes of one-lung ventilation on hemodynamics in patients undergoing thoracic operation

Abstract

Objective To investigate the effects of different modes of one-lung ventilation (OLV) on hemodynamies in the patients undergoing thoracic operation.Methods Forty-five adult patients undergoing thoracic surgery,were randomly allocated into 3 groups based on the modes of OLV used ( n =15 each):intermittent positive pressure ventilation ( IPPV,VT 6-8 ml/kg,RR 10-14 bpm,I:E 1:2) group,IPPV + positive end-expiratory pressure (PEEP) group and IPPV + continuous positive airway pressure (CPAP) group.Double-lumen tube was inserted.Conrrect positioning was verified by fiberoptic bronchoscopy.The patients were mechanically ventilated.PETCO2 was maintained at 35-45 mm Hg.In group IPPV + PEEP,OLV was performed for 30 min with PEEP of 5 cm H2O and then for another 30 min with PEEP of 10 cm H2O.In group IPPV + CPAP,OLV was performed with IPPV in the lung on the ventilated side and with CPAP of 5 cm H2O in the lung on the operated side (for 1 h).MAP,HR,cardiac output (CO),cardiac index ( CI),stroke volume (SV),and stnoke volume index (SVI) were recorded before induction of anesthesia,at 10 min after intubation,at 30 min of two-lung ventilation,at 30 min and 1 h of OLV,and at the end of operation ( T1-6 ).Arterial blood samples were taken at T1,2,4-6 for blood gas analysis.The levels of blood glucose and lactate were measured.Oxygen delivery ( DO2 ) and DO2 index ( DO2I) were calculated.Results Compared with IPPV group,SV,SVI,CO,CI,DO2 and DO2I were significantly decreased at T4,5 ( P ＜ 0.05),and no significant change was found in the levels of blood glucose and lactate in group IPPV + PEEP,and no significant change was found in the parameters mentioned above in group IPPV + CPAP ( P ＞ 0.05).Compared with IPPV + PEEP group,SV,SVI,CO,CI,DO2 and DO2I were significantly increased at T4,5 ( P ＜ 0.05),and no significant change was found in the levels of blood glucose and lactate in group IPPV + CPAP ( P ＞ 0.05).Conclusion It exerts no influence on hemodynamics using OLV with IPPV in the lung on the ventilated side and with CPAP of 5 cm H2O in the lung on the operated side,however,OLV with IPPV + PEEP can result in hemodynamic fluctuation,but the degree of fluctuation is lesser and DO2 can be maintained in the patients undergoing thoracic operation. Key words: Intermittent positive-pressure ventilation; Continuous positive airway pressure; Positive-pressure respiration; Hemodynamics