Effects Of Inverse Ratio Ventilation On Oxygen Metabolism And Pulmonary Function In Infants With Thoracoscopic One-Lung Ventilation

Objective:To study the effects of inverse ratio ventilation（IRV）on oxygen metabolism and pulmonary function in infants with one-lung ventilation.Methods:A total of 60 infants（n=60）who underwent right thoracoscopic pulmonary cystadenoma or isolated pneumonectomy during December 2019 to March 2021 were（x±s）selected and divided into group C（conventional ventilation group:aspiration/aspiration ratio:1:1.5）and group IRV（inverse ratio ventilation group:aspiration/aspiration ratio:1.5:1）according to random number table method,with 30cases in each group.The venous blood of the radial artery and right cervical artery were collected at TLV15 min（T1）,OLV30min（T2）,OLV60min（T3）,and TLV15min（T4）for blood gas analysis.Hemodynamic parameters,respiratory parameters,and blood gas analysis results were recorded at each time point,and pulmonary dynamic compliance（Cdyn）,oxygen delivery（DO₂）,oxygen consumption（oxygen consumption）were calculated,and pulmonary dynamic compliance（Cdyn）and oxygen delivery（DO₂）were calculated（VO₂）,the oxygen uptake rate（ERO₂）and other oxygen metabolism indicators;For Capillary refill time,observe the Capillary refill time（CRT）,Temperature gradients central-to-peripheral（d TC-P）and Skin mottling score（SMS）.The occurrence of postoperative pulmonary complications（PCC）within 7 days after surgery,operative time,single lung ventilation time,extubation time,and postoperative postoperative pulmonary complications（PCC）were recorded.Results:Compared with C group,the peak airway Pressure（Ppeak）,oxygen uptake rate（ERO₂）and Oxygenation index（OI）were decreased at T2 and T3 in the group.Arterial partial pressure of oxygen,arterial partial pressure of oxygen,arterial blood pressure,arterial blood pressure,arterial blood pressure,arterial blood pressure,arterial blood pressure,arterial blood pressure,arterial blood pressure,arterial blood pressure（Pa O₂）,Arterial oxygen saturation（Sa O₂）,Central venous partial pressure of oxygen,Pcv O₂),Central venous oxygen saturation（Scv O₂）,oxygen supply（DO₂）were increased（P<0.05）.Compared with T1,Ppeak,Pmean and ERO₂ were increased at T2 and T3,while Cdyn,Pa O₂,Sa O₂,Pcv O₂,Scv O₂and DO₂ were decreased（P<0.05）.During one-lung ventilation,there was a positive correlation between oxygen supply and oxygen consumption in group C（r=0.5117 at T2,r=0.6125 at T3）（P<0.05）,while there was no correlation between oxygen supply and oxygen consumption in group IRV（r=0.3589 at T2,r=0.3039 at T3）（P>0.05）.There was no significant correlation between oxygen supply and lactic acid during one-lung ventilation in the two groups（P>0.05）.There were no statistically significant differences in heart rate,mean arterial pressure,cardiac output,arterial blood lactic acid,nasopharyngeal temperature,peripheral clinical evaluation,blood loss and urine volume between the two groups at different time points.There were no statistically significant differences in postoperative extubation time,hospital stay and postoperative respiratory complications（PCC）between the two groups（P>0.05）.Conclusion:The strategy of inverse ratio ventilation during thoracoscopic one-lung ventilation in infants can reduce peak airway pressure,improve lung compliance,increase oxygen supply and improve oxygen metabolism,and has a higher safety boundary.