Application Of Positive End-expiratory Pressure Of Pulmonary Protective Ventilation Strategy In Laparoscopic Surgery In Overweight Patients

Objective:To investigate the effect of end-expiratory positive pressure of pulmonary protective ventilation strategyon in overweight patients undergoing laparoscopic surgery.Methods:Forty overweight patients,24 kg/m²?BMI<28 kg/m²,aged 20-65yr,of ASA physical status I or II,scheduled for elective laparoscopic surgery to radical resection of rectal cancer under general anesthesia,were randomly divided into 2 groups?n=20 each?using a random number table:Positive end-expiratory pressure?PEEP?group?group P?,control group?group C?.The rest of the settings in mechanical ventilation were the same in both groups,tidal volume?Vt?=6 mL/kg,initial respiration frequency?RR?=15 bpm,oxygen inhalation 100%,inspiratory expiratory time ratio?I:E?=1:2.The concentration of oxygen inhalation was 50%and respiration frequency was adjusted to maintain P_ETCO₂ 35⁴5 mmHg after endotracheal intubation.The heart rate?HR?,mean arterial pressure?MAP?,tidal volume?Vt?,airway peak pressure?Ppeak?,airway pressure platform?Pplat?were recorded,the lung dynamic compliance?Cdyn?was calculated,arterial oxygen partial pressure?PaO₂?and partial pressure of carbon dioxide in arterial blood?PaCO₂?were measured by gas analyzer,oxygenation index?OI?was calculated at the time of before induction of anesthesia?T0?,5 min after endotracheal intubation?T1?,5 min after laparoscopic pneumoperitoneum?T2?,60 min after laparoscopic pneumoperitoneum?T3?,and suturing the skin?T4?.The postoperative pulmonary complications were observed 3 days after surgery.Results:1.The two groups of patients characteristics and operative indicators was no significant difference.2.In group P,Vt was increased at 5 min after laparoscopic pneumoperitoneum compared with the preoperative data?P<0.05?.In group C,Vt was increased at 60 min after laparoscopic pneumoperitoneum compared with the preoperative data?P<0.05?.In the two group,Ppeak and Pplat were increased at T2and T3 compared with T1.Vt,Ppeak and Pplat were no significant difference between the two groups?P>0.05?.In the two groups,Cdyn were decreased at T2 and T3 compared with T1?P<0.05?.Cdyn in group P were higher than Group C?P<0.05?.3.In the two group,PaO₂ and OI were decreased at T2,T3 and T4 compared with T1?P<0.05?.In group P,PaO₂ and OI were higher than group C at T3 and T4?P<0.05?.In the two groups,PaCO₂ were higher at T2,T3 and T4 compared with T1?P<0.05?.PaCO₂ was no significant difference between the two groups?P>0.05?.4.The postoperative pulmonary complications were no significant difference between the two groups?P>0.05?.Conclusion:Positive end-expiratory pressure of protective ventilation strategy from the induction period of general anesthesia can effectively improve dynamic lung cdyniance,improve oxygenation and promote pulmonary function recovery in overweight patients undergoing laparoscopic surgery.