Effect Of Different Ventilation Modes On The Function Of Diaphragmatic Muscle By Bedside Ultrasound

Objective: To measure the diaphragm thickness(Tdi)and diaphragm displacement(DE),and to calculate the diaphragm thickening fraction(TFdi)of A/C group and PSV group patients by bedside ultrasound,which will help monitor the diaphragmatic activity and found diaphragmatic atrophy,and thus compare the effects of two different ventilation modes on diaphragmatic function.The changes of diaphragmatic morphology after A/C and PSV ventilation for 12 hours were investigated respectively.Method: A prospective randomized controlled study was conducted,consecutive patients admitted to the ICU department of Qingdao University Affiliated Hospital after elective general anesthesia surgery between January 1 2016 and June 31 2016 were enrolled.After about 30 minutes,the patient was in a relatively stable state(t0)as the starting point of the study,after each ventilation for 12 hours(t12)as the end of the study.In this study,71 cases met the inclusion criteria and exclusion criteria,The patients were randomly assigned to the A/C group or the PSV group according to the random number table method computer generated,in the course of the study,not meet the conditions to be eliminated,and ultimately a total of 56 cases were selected,There were 29 cases in the A/C group,and 27 cases in the PSV group.To measure diaphragm thickness in the end inspiratory(Tdi-ei)and in the end expiratory(Tdi-ee)and DE by bedside ultrasound at t0 and t12 respectively,and calculate the TFdi.SPSS 19 software was used to analyze the experimental data.Results: 1.Comparison between groups: compared with PSV group,the Tdi-ei,Tdi-ee,DE and TFdi of diagram in A/C group on the end of the study(t12)were significantly lower,the differences were statistically significant,respectively(t= 2.395?2.038?3.235?2.891,p=0.020?0.043?0.002?0.005).2.Comparison within each group: in A/C group patients,compared with t0,the Tdi-ei,Tdi-ee,DE and TFdi of diagram at t12 were significantly lower,the differences were statistically significant,respectively(t=17.048?9.715?3.380?2.077,p=0.000?0.000?0.002?0.010);In PSV group patients,compared with t0,the Tdi-ei,Tdi-ee,DE and TFdi of diagram at t12 were slightly lower,there is not statistically significant,respectively(t= 1.724?0.686?1.962?1.807,p=0.097?0.499?0.061?0.082).3.Effects of PEEP on the diaphragm thickness and thickening fraction: no relationship was found between diaphragm thickness at end-expiration and the level of PEEP,respectively(t0:A/C:R =-0.021,p = 0.922,PSV:R=0.096,p=0.294;t12:A/C:R =-0.097,p = 0.668,PSV:R = 0.033,p = 0.875).Similarly,no relationship was found between diaphragm thickness at end-expiration and the level of PEEP,respectively(t0:A/C:R=0.168,p =0.422,PSV:R=0.057,p=0.359;t12:A/C:R =0.254,p =0.253,PSV:R= 0.031,p =0.884).Conclusions: 1.Compared with the pressure support ventilation mode,because the disuse degree of diaphragm is more serious,it might be more likely to lead to thinning,atrophy,contraction and dysfunction of diaphragm.2.Assist control ventilation mode can cause the diaphragm to become thinner,atrophy and decrease in activity in a short period of time(12 hours).On the contrary,the change of the thickness and activity of the diaphragm was not caused by the pressure support ventilation in 12 fashion.