Effect Of Different Depth Neuromuscular Blockade On Diaphragmatic Function Evaluated By Ultrasound In Elderly Patients After Laparoscopic Surgery

Objective To evaluate the effects of moderate and deep neuromuscular blockade on the function of diaphragm in elderly patients undergoing laparoscopic radical gastrectomy by using diaphragmatic ultrasound,and to compare surgical conditions,the recovery of postoperative neuromuscular blockade and pulmonary complications,to find the appropriate depth of neuromuscular blockade for this type of surgery and patients,to provide a reference for clinical muscle relaxation management.Methods Seventy elderly patients undergoing laparoscopic radical gastrectomy were recruited.They were ASA class I to III,aged 65 to 80 years,and BMI 18 to 28 kg/m².Patients with a known or suspected neuromuscular disease,suspected allergy to muscle relaxants,anesthesia,and history of abdominal surgery were excluded before surgery.Patients were divided into two groups by random number table method:moderate neuromuscular blockade group?group M,n=35?and deep neuromuscular block group?group D,n=35?.In the two groups,the depth of neuromuscular block was maintained by continuous infusion of cisatracurium under the monitoring of muscle relaxation.The target degree of neuromuscular block in group M was 1 or 2 muscle tremors after Train-of-four stimulation?TOF?,the degree of target neuromuscular blockade in group D was 1 or 2 muscle tremors after Post Tetanic Count?PTC?.During the operation,the pneumoperitoneum was maintained at 12mm Hg.The diaphragmatic motility evaluated by ultrasound in quiet breathing and deep breathing were recorded before the induction of anesthesia?T₀?,immediately after extubation?T₁?,30min?T₂?after extubation,1d?T₃?,3d?T₄?,7d?T₅?after operation.The time of anesthesia,the volume of fluid recharge,the volume of bleeding,and the amount of urine were recorded;total dosage of cisatracurium,the time of operation,the time of pneumoperitoneum,surgical condition scores,and the number of muscle relaxants required by the surgeon were recorded;the time of TOFr 0.7?time from stopping the infusion of muscle relaxant to TOFr 0.7?,the time of TOFr 0.9?time from stopping the infusion of muscle relaxant to TOFr 0.9?,the time of extubation?time from stopping the infusion of muscle relaxant to extubation?were recorded;the time of PACU,critical respiratory events,hospital length of stay,pulmonary complications postoperative 7 d were recorded.Results Four patients were excluded due to conversion to open abdomen,two patients were excluded due to postoperative VAS pain scores>3 points,two patients were excluded due to incomplete ultrasound data collection.A total of 62 patients were included,30 in group M and 32 in group D.Compared with the M group,the surgical condition score in the D group was higher?P<0.05?,the number of muscle relaxants requested by the surgeon decreased?P<0.05?.Compared with the M group,the total dose of cisatracurium in the D group increased?P<0.05?,and the time of TOFr0.7,the time of TOFr0.9,the time of extubation,and the time of PACU were prolonged?P<0.05?,the incidence of CREs were increased?P<0.05?.Differences in diaphragmatic mobility between group D and group M at deep breathing at time T₁ were statistically significant?P<0.05?,and the differences at the other time points were not statistically significant?P>0.05?.However,compared with T₀,diaphragmatic mobility of all patients decreased at T_1-5?P<0.05?.There was no significant difference in pulmonary complications and hospital length of stay between the two groups postoperative 7 days?P>0.05?.Conclusion1.Diaphragmatic ultrasound can continuously monitor the change of diaphragm function during perioperative period,which helps us to identify and screen patients with diaphragmatic injury.2.The function of diaphragm muscles of elderly patients with laparoscopic gastric cancer after radical resection were impaired varying degrees,lasting at least one week.3.The use of deep neuromuscular blockade during laparoscopic radical gastrectomy in elderly patients has the advantage of improving the operating conditions,but will cause more severe reduction of diaphragm function after extubation,prolong the postoperative respiratory function recovery time and increase the risk of PACU CREs.To assess the risks and benefits,it is more appropriate to use moderate neuromuscular blockade during laparoscopic radical gastrectomy for elderly patients.