Effects Of Different Levels Of Positive End-expiratory Pressure On Respiratory Function During Laparoscopic Gastric Capacity Reduction Surgery In Morbidly Obese Patients

PurposeTo study the effects of different levels of positive end-expiratory pressure?PEEP?on respiratory function in patients with morbidly obese patients during laparoscopic gastric capacity reduction surgery and to explore the more suitable PEEP level during laparoscopic gastric capacity reduction surgery in morbidly obese patients.MethodsThirty morbidly obese patients scheduled for laparoscopic gastric capacity reduction surgery at China–Japan Union Hospital of Jilin University from April 2017 to February 2018 were selected,ranging in age from 20 to 58 years,ASA grade II,with BMI of 35⁴5kg/m2.The patients were randomly divided into two groups?n=15?,Group I,PEEP=4cmH₂O;Group II,PEEP=8cmH₂O.Use pressure-controlled ventilation mode and maintain PetCO₂:35-45mmHg during the surgery.After pneumoperitoneum,do recruitment maneuver?RM?then set the PEEPwithGroupI=4cmH₂O;GroupII=8cmH₂O.Arterial partial pressure of oxygen?PaO₂?,Arterial partial pressure of carbon dioxide?PaCO₂?,End-tidal carbon dioxide partial pressure?PetCO₂?,airway peak pressure?Ppeak?and tidal volume?VT?were recorded before pneumoperitoneum?T1?,pneumoperitoneum 30min?T2?,pneumoperitoneum 60 min?T3?,10min after the end of pneumo-peritoneum?T4?.The Oxygenation index?OI?,alveolar arterial blood oxygen tension difference?A-aDO₂?,dead space ventilation?VD/VT?and pulmonary dynamic compliance?Cdyn?were calculated according to the formula.Results.[1].OI:intra-group comparison:Compared with T1 time,I group T2,T3 lower than T1,the difference was statistically significant?P<0.05?;There was no significant difference in T1³ in group II?P>0.05?,but the difference was statistically significant at T4?P<0.05?.When compared between groups,the OI of group II at T2,T3 and T4was higher than that of group I,the difference was statistically significant?P<0.05?.[2].A-aDO₂:Intra-group comparison:The T2 and T3 of group I were higher than that of T1,the difference was statistically significant?P<0.05?.Group II:no significant difference compared with each other at all time points,the difference was not statistically significant?P>0.05?.Comparison between groups:Group II T2,T3 was lower than the I group,the difference was statistically significant?P<0.05?.[3].VD/VT:intra-group comparison:I group T2,T3 higher than T1,the difference was statistically significant?P<0.05?.There were no significant differences in group II between T1,T2,T3 and T4?P>0.05?.The comparison between the two groups:Group II T2,T3,T4 lower than the I group,the difference was statistically significant?P<0.05?.[4].Cdyn:intra-group comparison:Compared with T1 time,T2 and T3 of both groups were lower than T1,the difference was statistically significant?P<0.05?.I group T4 when compared with T1,the difference was not statistically significant.T4 in group II was higher than that in T1,the difference was statistically significant?P<0.05?.Comparison between groups:Group II was greater than Group I at T2,T3 and T4,the difference was statistically significant?P<0.05?.ConclusionCompared with the use of PEEP 4cmH₂O after RM,the use of8cmH₂O PEEP after RM in the laparoscopic gastric capacity reduction surgery in patients with mobility obesity can improve intraoperative oxygenation and increase lung compliance,reduce the dead space rate.