Effect Of 30 Degree Reserve Trendelenburg Position On Respiratory Function In Obese Patients Undergoing Laparoscopic Gastric Volume Reduction Surgery

Background and purposeThe special respiratory physiology of obese patients poses a serious challenge for anesthesia and surgeons.How to improve the respiratory function of perioperative obese patients and reduce the intraoperative and postoperative complications of obese patients are issues that anesthesia and surgeons should pay attention to.To observe and compare the effects of 30°reserve Trendelenburg position lying position on the respiratory function of obese patients,so as to provide a better basis for improving respiratory function and preventing respiratory adverse events during and after operation in obese patients.Methods15 obese patients with ASAI-II,BMI≥30kg/m²,undergoing laparoscopic sleeve gastrectomy in our hospital from June 20 to January2019,observed supine position（SP）And the 30°reserve Trendelenburg position（30°RTP）two indicators of position.The arterial blood gas partial pressure（PaO₂）,oxygenation index（OI）,and alveolar arterial oxygen pressure difference(P_A-aO₂)were recorded after the patient was inoculated with oxygen for 10 minutes（before operation,BO）.Arterial blood gas partial pressure（PaO₂）,oxygenation index（OI）,lung static compliance（Cstat）,intrapulmonary shunt rate（Qs/Qt）,and different body position after mechanical ventilation（MV）Alveolar arterial oxygen pressure difference(P_A-aO₂).10 min（after operation,AO）pulse blood oxygen partial pressure（PaO₂）,oxygenation index（OI）,alveolar arterial oxygen pressure difference(P_A-aO₂)and intrapulmonary shunt rate（Qs/Qt）.Results1)Compared with SP:At BO,30%RTP PaO₂,OI increased（P<0.05）P_A-aO₂ decreased（P<0.05）;in MV,30°RTP PaO₂,OI,Cstat increased（P<0.01）P_A-aO₂ decreased（P<0.05）,Qs/Qt showed a downward trend（P>0.05）;at AO,30°RTP PaO₂ and OI increased（P>0.05）,P_A-aO₂decreased（P>0.05）and Qs/Qt decreased significantly（P<0.01）.2)Compared with BO:PaO₂ and OI decreased significantly in the two positions,about 30%（P<0.01）,P_A-aO₂ increased significantly（P<0.01）;PaO₂ in two positions under AO OI decreased significantly by about 50%（P<0.01）and P_A-aO₂ increased significantly（P<0.01）.ConclusionThe alveolar-arterial oxygen pressure difference and intrapulmonary shunt rate of obese patients are significantly higher than those of normal weight,and the oxygenation index of the postoperative tube state is about30%lower than that before surgery,but after extubation It is about 50%lower than before surgery.Obese patients at 30°RTP can improve lung static compliance,reduce intrapulmonary shunt rate,reduce alveolar arterial oxygen pressure difference,increase arterial oxygen partial pressure,improve oxygenation.