A Comparison Between Two Lung Ventilation With CO₂ Artificial Pneumothorax And One Lung Ventilation On Early Postoperative Cognition In Elderly Patients Undergoing Minimally Invasive Radical Esophagectomy

ObjectiveIt is unclear whether two lung ventilation with carbon dioxide（CO₂）artificial pneumothorax influences the incidence of delayed neurocognitive recovery（DNR）in elderly patients undergoing minimally invasive radical esophagectomy.This prospective study aimed to compare the effects of two lung ventilation with CO₂ artificial pneumothorax and one lung ventilation on regional cerebral oxygen saturation（rSO₂）,S100βprotein,neuron-specific enolization（NSE）,and early postoperative cognitive function in elderly patients undergoing minimally invasive radical esophagectomy.Methods58 elderly patients undergoing minimally invasive radical esophagectomy were selected and randomly divided into two lung ventilation with CO₂ artificial pneumothorax group（T group）and endobronchial blocker one lung ventilation group（O group）,with28 cases in each group.During the thoracoscopic procedure,CO₂ was filled to establish artificial pneumothorax（pressure 8mm Hg,flow rate 8L/min）in the T group,and an endobronchial blocker was used for one lung ventilation in the O group.The intraoperative rSO₂ were recorded before the thoracoscopic procedure（T1）,30min（T2）,60min（T3）after the thoracoscopic procedure started,the end of the thoracoscopic procedure（T4）,15min after the end of the thoracoscopic procedure（T5）,and the end of surgery（T6）.The minimum values of rSO₂ during the thoracoscopic procedure were recorded.The values of rSO₂at T1 were defined as the baseline line.The minimum value of rSO₂ decreased by more than 20%of the baseline line was defined as cerebral oxygen desaturation,and the occurrence of cerebral oxygen desaturation was recorded.The MAP、HR、SpO₂、CVP、Pplat were also recorded and arterial blood gas analysis was performed at the time point from T1 to T6.The serum S100βand NSE concentrations taken from central venous blood were calculated by the enzyme-linked immunosorbent assay（ELISA）before the start of the operation,at the end of the operation,and on the first day after the operation.Neuropsychological tests were used to evaluate the occurrence of DNR in patients 1 day before the operation and 7 days after the operation.Postoperative complications were also recorded.ResultsA total of 54 cases were included in the analysis.No significant difference was found in general information and surgical-related data between the two groups（P>0.05）.The incidence of DNR on the 7th day after surgery was 11 cases（40.7%）in the O group,and4 cases（14.8%）in the T group.The difference between the two groups was statistically significant（P=0.033）.Compared with T1,there was no significant change in rSO₂ from T2 to T6 in the T group（P>0.05）.The rSO₂ from T2 to T4 was significantly lower than that in T1（P<0.05）in the O group.The rSO₂ of the T group from T2 to T4 was significantly higher than that of the O group（P<0.05）.There were 3 cases（11.1%）with cerebral oxygen desaturation in group T,and 13 cases（48.1%）with cerebral oxygen desaturation in group O.The difference was statistically significant（P<0.05）.The differences of MAP and Hb between the T group and the O group at each time point were not statistically significant（P>0.05）.HR,SpO₂,CVP,Pplat,PaO₂,and PaCO₂of the T group at T2 to T4 was higher than that in the O group（P<0.05）.The value of pH in the T group at T2 to T4 was lower than that in the O group（P<0.05）.The serum S100βand NSE concentrations at the end of the operation and the first day after the operation were higher in the two groups than that before the operation（P<0.05）.But the serum S100βand NSE concentrations in the T group increased than that in the O group at the end of the operation and the first day after the operation（P<0.05）.There was no statistical difference in other postoperative complications between the two groups（P>0.05）.ConclusionCompared with one lung ventilation,two lung ventilation with CO₂ artificial pneumothorax had a lower incidence of DNR and lower serum S100βand NSE levels in elderly patients undergoing minimally invasive radical esophagectomy.It may be related to decrease the incidence of intraoperative decerebral oxygen saturation during two lung ventilation with CO₂ artificial pneumothorax.