Study On The Relationship Between The Pressure Volume Loop And The Degree Of Muscle Relaxation In The Laparoscopic Surgery

Objective:Laparoscopic surgery requires sufficient muscle relaxation to meet the surgical field,but residual muscle relaxation may increase the incidence of postoperative adverse events.Different skeletal muscles have different reaction and sensitivity to muscle relaxants,When the muscle relaxation of the diaphragm is restored to spontaneous breathing,the recovery of the limb muscles is still weak which will not cause the body to move.There is no method to monitor the muscle relaxation of diaphragm directly in the clinic.The changes of the pressure volume loop can reflect the activity of the diaphragm,The surgical position is an important factor affecting the compliance of chest and lung.We observed the muscle relaxation values at the time notch of P-V ring in patients with head low and head high laparoscopic surgery as the critical value of muscle relaxation during operation.It provides a basis for more accurate adjustment of muscle relaxation in laparoscopic surgery,which can not only meet the surgical field of vision,but also avoid the postoperative residual muscle relaxationMethods:Patients with gynecological laparoscopic surgery and general surgery 30 cases each were divided into two groups,the American Society of anesthesiologists?ASA?classification.The T1 value of adductor pollicis muscle?AP?was recorded by TOF monitoring at the time when the first notch of the pressure volume loop?P-V?appeared,as well as when the P-V ring notch appeared again after the addition of the muscle relaxants.The respiratory dynamic indexes including tidal volume?VT?,minute volume?MV?,inspiratory plateau pressure?Pplat?,mean airway pressure?Pmean?,positive end expiratory pressure?PEEP?,peak inspiratory pressure?Ppeak?,peak inspiratory flow?FImax?,peak expiratory flow?FEmax?,end tidal carbon dioxide partial pressure?PetCO₂?was recorded at four time points,such as,immediately after the pneumoperitoneum was established and pressure stabilized?T0?,T1recovery time T1=1?T1?,T1=10?T2?as well as the first notch of P-V ring?P-V1?appeared.Pulmonary dynamic compliance?Cdyn?and static compliance?Cst?was calculated.The doctor's satisfaction with the field of surgery was recorded meanwhile.RESULTS:T1 value when the first notch of P-V ring appeared:Gynecological surgery group data 30,mean value of 24.3,the maximum value of 33,the minimum value of 17.The fifth percentile was 18.1.Department of general surgery data 30,mean value of 22.5,the maximum value of 32,the minimum value of 16.The fifth percentile was 16.6.Datas are accorded with normal distribution.Within the same group,there is no significant statistical difference of T1 value between the first notch of P-V ring and the second notch of P-V ring.Also,there is no significant statistical difference of T1 value of the first notch of P-V ring between two groups.In the same group,Ppeak,Pplateau,Pmean and PetCO2 were significantly increased with the prolongation of operation time,while FImax,FEmax,Cdyn,Cst were significantly decreased.The comparison between the two groups,the Ppeak,Pplateau numerical head high group at each time point was significantly lower than the head low group.Pmean value was not statistically significant.The notch of P-V ring is associated with the satisfaction of the doctor's surgical field.The doctor's satisfaction with the field of surgery decreased when the notch of P-V ring appeared.Conclusion:The satisfaction degree of surgical field was significantly decreased after the notch of P-V ring.If the degree of muscle relaxation at this time as a critical value to meet the needs of surgery field.In head low group of laparoscopic surgery,the mean value of T1 is 24.3,fifth percentile is 18.1.In head high group of laparoscopic surgery,the mean value of T1 is 22.5,fifth percentile is 16.6.There was no significant difference between the two postures.