RESUMO
Objective To evaluate the effect of intraoperative mechanical ventilation on alveolar gas exchange in patients with type 2 diabetes mellitus.Methods Thirty ASA Ⅰor Ⅱpatients with type 2 diabetes mellitus aged 46-64 yr weighing 47-78 kg undergoing total gastrectomy under general anesthesia were divided into 2groups according to preoperative glycolated hemoglobin level(HbA1c)(n=15 each):group B HbA1c/Hb=6.6%-10.4%and group C HbA1c/Hb＞10.4%.Another 15 non-diabetic patients with comparable demographic data were included in this study as control group(group A).Radial artery and right internal jugular vein were cannulated.The patients were intubated after induction of anesthesia and mechanically ventilated(VT 8 ml/kg,RR 12-lected from artery before induction of anesthesia(To,baseline)and at 30,60,90 and 120 min of mechanical ventilation(T1-4)for blood gas analysis and determination of plasma SOD activity and MDA,'TNF-α,IL-6,IL-10 concentrations.PA-aDO2 was calculated.Results PA-aDO2 was significantly increased during mechanical ventilation at T1-4 as compared with the baseline at T0 in diabetic patients and were significantly higher than in non-diabetic patients.The plasma SOD activity was significantly decreased at T1-4 as compared with the baseline at T0 in diabetic patients and was significantly lower than in non-diabetic patients.While the plasma MDA,TNF-α,IL-6 and IL-10concentrations were significantly increased at T1-4 compared with the baseline at T0 in diabetic patients and were significantly higher than in non-diabetic patients.The PA-aDO2,plasma MDA,TNF-α,IL-6 and IL-10 concentrations were significantly higher and plasma SOD activity lower in gorup C than in group B.Conclusion Intraoperative mechanical ventilation can decrease alveolar gas exchange by inducing inflammatory response in patients with type 2 diabetes mellitus.The changes are correlated with severity of diabetes.