Effect Of Low Tidal Volume Combined With Positive End-expiratory Pressure On Respiratory Function In Infant Laparoscopic Surgery

Background and PurposeWith the improvement of medical treatment,laparoscopy has become a common surgical procedure,which is not only commonly used in adult surgery,but also more and more used in infant surgery.However,recent studies have found that high pneumoperitoneum pressure in laparoscopic surgery can increase the respiratory function of patients and postoperative pulmonary complications.Laparoscopic surgery requires tracheal intubation general anesthesia,and after general anesthesia tracheal intubation due to the disappearance of respiratory muscle tension caused by the loss of functional residual air volume,early closure of the airway,compression of the surrounding tissue,so that the lung compliance significantly decreased,prone to atelectasis.Compared with adults,infants have less lung compliance,less elastic retraction and less functional residual gas,which makes children more prone to postoperative pulmonary complications such as atelectasis.Pulmonary protective ventilation has been shown to have beneficial effects on reducing lung injury and improving prognosis in patients with acute respiratory distress syndrome and lung injury in intensive care unit.Among them,limiting tidal volume is considered to be the main intervention,while small tidal volume should be combined with appropriate positive end-expiratory pressure to improve oxygenation and reduce lung injury.So low tidal volume combined with positive end-expiratory pressure in infants and young children laparoscopic surgery,can the patient’s intraoperative lung ventilation function and ventilation function benefit,reduce pulmonary complications,accelerate the recovery of children?This study used a prospective randomized controlled study to compare the respiratory function,circulatory function and postoperative pulmonary complications of low tidal volume combined with positive end-expiratory pressure ventilation with conventional ventilation during laparoscopic surgery in infants and young children,in order to seek a more favorable lung protective ventilation anesthesia management plan for mechanical ventilation in infant laparoscopic surgery,and accelerate the postoperative recovery of the affected children.MethodsThe trial was a randomized controlled single-blind study.Including 62 children undergoing laparoscopic surgery in our hospital from january 2019 to january 2020.The children under 3 years of age.ASA grade Ⅰ～Ⅲ.The patients were randomly divided into T group and C group according to the order of admission time.Blood gas analysis and monitoring of circulatory and respiratory indexes at each moment with arterial hemodynamic analysis at 5 min(T1),laparoscopic 1 h(T2),laparoscopic 2 h(T3),and the end of the operation immediately(T4)after anesthesia,and follow up the pulmonary complications in the two groups within 5 days after operation.The two groups of ventilation modes were pressure regulated-volume control mode ventilation(PCV-VG),and the pneumoperitoneum pressure was maintained at 6～8 mmHg during the operation.The parameters of the ventilator in group T were from 6 to 8 ml/kg,and PEEP was the lowest point of the P-V curve(LIP)of 2 cmH2O.The parameters of the ventilator in group C were 10 to 12 ml/kg and 0 cmH2O for PEEP.ResultsThere was no significant difference in age,ASA and body weight between the two groups.The scores of PaO2 in T group were higher than those in C group at four times(p<0.05),the difference was statistically significant.All PA-aDO2 in T group was lower than that in C group at four moments(p<0.001),the scores of OI in T group were higher than those in C group at four times(p<0.05),.the difference was statistically significant.The PPLAT and mean pressure of group T were lower than those of group C at T1(p<0.05),the difference was statistically significant.The driving pressure of T group was lower than that of C group(p<0.001),the difference was statistically significant.The SBP,DBP and MAP of T group at T1 were lower than those of group C(p<0.05),the difference was statistically significant.There was no significant difference between the two groups on PaCO2,PH,BE,CL,HR,PPV,vasoactive drug use postoperative pulmonary complication score,pneumoperitoneum and operation time.Neither group died in hospital.ConclusionsFirstly,compared with conventional mechanical ventilation,small tidal volume combined with individualized pulmonary protection ventilation strategy with positive end-expiratory pressure can improve the ventilation function of children and improve the oxygenation index during operation for infants undergoing laparoscopic surgery.Secondly,using a small tidal volume combined with an individualized positive end-expiratory pressure pulmonary ventilation strategy can reduce the driving pressure of infants undergoing laparoscopic surgery and benefit the children’s respiratory dynamics.