Effect Of Injection Of Normal Saline At The Junction Of Brachial Plexus And Anterior Oblique Muscle Combined With Small Dose Of Local Anesthetics On Phrenic Nerve Motor Function Of Patients

Objective:Objective to evaluate the effect of injection of normal saline at the junction of brachial plexus and anterior oblique muscle combined with low-dose local anesthetics on phrenic nerve motor function Methods:Sixty patients(34 males and 26 females,aged 18-65 years old,BMI 18-32 kg /m2,ASA Ⅰ or Ⅱ)undergoing interscalene brachial plexus block were randomly divided into two groups with 30 cases in each group: Group E(injected with normal saline at the junction of brachial plexus and anterior scalenus),group C(injected without normal saline).All patients received interscalene brachial plexus block before operation,and diaphragmatic thickness index was defined as expiratory thickness /inspiratory thickness.The diaphragmatic thickness index(D1)was recorded before the interscalene brachial plexus block,and the diaphragmatic thickness index(D2)was recorded 20 minutes after the interscalene brachial plexus block;During the operation,the patients were monitored by electrocardiography,and the pulse oxygen was used.The adverse events such as nausea,vomiting,dizziness,chest tightness and oxygen saturation decrease were recorded without oxygen inhalation.When the adverse reactions were found,the patients were given low flow oxygen inhalation in time;the thickness index(D3)was recorded befor operation is over;the visual analogue scale(VAS)was recorded at 2 h,4 h,6 h,12 h,24 h,48 h after the operation.Results::The number of D2 and D3 less than 1.2 in Group E was significantly less than that in group C(P < 0.05)(P < 0.05);the incidence of nausea and vomiting,dizziness,decreased pleural and oxygen saturation in Group E were significantly lower than those in group C(P < 0.05);there was no significant difference in the incidence of skin pruritus and incomplete block between the two groups(P > 0.05);the VAS scores at 4H and 6h in Group E were higher than those in group C(P < 0.05);there was no significant difference in the scores at 2h,12 h and 24 h in Group E(P > 0.05).Conclusion:Injection of normal saline at the junction of brachial plexus and anterior oblique muscle combined with low-dose local anesthetics can protect phrenic nerve motor function,but can shorten postoperative analgesia and block time.