Application Of Lung Protective Ventilation Strategy In Patients Undergoing Laparoscopic Surgery For Colorectal Cancer

Background and purpose:In recent years,laparoscopy has been widely used in many surgeries.Laparoscopic surgery has advantages of minimal invasion,small scar and shorter hospital stay.Therefore,some surgeries with great trauma,such as radical resection of colorectal cancer,is gradually transformed from laparotomy to laparoscopic surgery.However,laparoscopic surgery has some disadvantages.The artificial pneumoperitoneum often lead to the diaphragm shifted to the head,lung compliance and arterial oxygenation declined,the occurrence of atelectasis.These effects may lead to postoperative pulmonary complications and prolonged hospitalization.The establishment of artificial pneumoperitoneum and the special posture of laparoscopic colorectal surgery are the main indexes of interfering with the physiological function of patients.Therefore the difficulty of anesthesia management is increased.At present,some literatures have proved that lung protective ventilation strategy has a lung protective effect on ALI/ARDS patients.In recent years,some scholars try to apply lung protective ventilation strategy to patients without ALI/ARDS.The study confirmed that lung protective ventilation strategy is beneficial to some patients without ALI/ARDS during perioperative period.Under the condition of laparoscopic operation,even patients with normal pulmonary function can still have pulmonary compliance decrease,and the disturbance of respiratory system is obvious.The introduction of lung-protective ventilation strategy into laparoscopic surgery can theoretically improve the interference of artificial pneumoperitoneum on the respiratory system and the circulatory system.At present,some researchers have studied the application of lung protective ventilation strategy in perioperative patients with laparoscopic surgery,but the results of the study are not consistent.Therefore,pulmonary protective ventilation strategy has not been used as recommended ventilation strategy in perioperative patients undergoinglaparoscopic surgery.We know that the mechanical ventilation time is related to the degree of lung injury,short-term mechanical ventilation has little impact on the respiratory system of patients,while we know that the mechanical ventilation time is related to the degree of lung injury,and the demand of body position is not strict,it is difficult to determine whether the lung protective ventilation strategy for laparoscopic surgery is beneficial;Patients undertaken laparoscopic colorectal cancer surgery suffer with relatively long mechanical ventilation and abdominal time,higher body posture requirements,and it may interference there physiological conditions,such operations using lung protective ventilation strategy is more likely to benefit.This study attempted to compare the parameters and clinical manifestations of patients after laparoscopic surgery for colorectal cancer using traditional mechanical ventilation and pulmonary protective ventilation strategy to explore the protective effect of lung ventilation strategy in laparoscopic colorectal surgery Clinical significance.Method:This study is a prospective clinical study.A total of 60 patients undergoing laparoscopic colorectal cancer surgery in the Department of Anorectal Surgery,XXX hospital from August 2017 to January 2018 were enrolled.Including 35 males and 25females,aged 48 to 81 years,ASA grade II^III grade.Randomly divided into L group（lung protective ventilation strategy group）and C group（traditional tidal volume group）.All patients underwent laparoscopic colorectal surgery under the same surgeon,with general anesthesia.Breathing parameters were set after tracheal intubation:inhalation oxygen concentration was 100%in both groups.In group L,tidal volume was 7ml/kg,respiratory rate was 15 beats/min,PEEP was 5cmH₂O,C group set the tidal volume of 9ml/kg,respiratory rate of 12 beats/min,when P_ETCO₂>45mmHg,the feasible method of pulmonary recanalization intervention,when the patient appears to be unable to correct severe high blood carbonate,the test can be terminated.The arterial blood gas was collected before intubation,1h after pneumoperitoneum,2h after pneumoperitoneum,10 min after completion of Pneumoperitoneum and 24h after operation.The intraoperative oxygen saturation,end-tidal carbon dioxide,peak airway pressure,operation time,pneumoperitoneum time,on-machine time,postoperative ICU stay and operation-related complications were recorded.The operator’s satisfaction with the field also needs to be recorded.Follow-up of patients with pulmonary complications,and record the patient’s postoperative hospital stay.Result:（1）The baseline data of gender,age,height,weight,BMI,type of anastomosis and comorbidity between the two groups were not statistically different（P>0.05）.（2）The main ventilation indexes PaO₂,PaCO₂,pH,S_PO₂,P_PEAKEAK and P_ETCO₂ of two groups were compared at each time point:P_PEAKEAK in group L was slightly higher than that in group C at T3 and T4,P value was 0.023 at T3,P value of 0.000 at T4,there was a statistical difference;P_ETCO2 was slightly higher at T3 than in the C group,P value of0.015,with statistical differences.There is no significant difference among other ventilation parameters PaO₂,PaCO₂,pH,S_PO₂,at different time points between the two groups.（3）HR and MAP,the main circulatory indexes of two groups of patients,were compared at various time points,P>0.05,without statistical difference.（4）The main operation-related indicators of the two groups of patients were compared operation time,pneumoperitoneum time,ventilation time,ICU stay time,postoperative hospital stay,P>0.05,no significant difference.（5）There were no other surgery-related complications in both groups of patients except for postoperative pulmonary complications.（6）The two groups of patients with PPC_S level analysis P>0.05,no statistical difference.（7）The surgeon satisfaction with the surgery field is divided into three levels,satisfaction,basic satisfaction,not satisfaction,the statistical analysis,P<0.05,with statistical differences.Conclusion:For patients with laparoscopic colorectal surgery,compared with conventional ventilation strategies,the airway pressure and PaCO2 in the lung protective ventilation strategy are slightly higher,but all within the normal range,therefore,the lung protective ventilation strategy can be safely used in laparoscopic colorectal surgery.However,respiration,circulation,complication and hospitalization time in ventilation method group have no obvious advantages in addition to the higher operation satisfaction,when compared with the traditional tidal volume ventilation mode.