Effects Of Intramuscular Injection Of Dexmedetomidine On The Recovery Quality In Patients Undergoing Tympanoplasty

Objective:To evaluate the effects of intramuscular injection of different doses of Dexmedetomidine( Dexmeditomidine, short for: DEX) on the recovery quality in patients undergone Tympanoplasty. Thus to provide clinical evidence for the application of intramuscular injection of dexmedetomidine in improving anethesia recovery.Methods:One hundred patients(Age 20-50 years,weight 50-75 kg,ASA I-II,first daily surgery, Male or female) who were scheduled for Tympanoplasty were randomly divided into five groups, 20 patients in each group: dexmedetomidine group(group D1, D2, D3, D4) and control group(group C). All the patients were not given premedication. The patients in the study were induced by midazolam 0.05-0.1mg/kg,propofol 1.5-2.5mg/kg, fentanyl 2.0-3.0μg/kg, rocuronium 0.6-1.0mg/kg, then tracheal intubation was performed and the patients were allowed to mechanical ventilation.Anesthesia was maintained with propofol 4-8mg/kg/h, Atracurium 0.5-0.7mg/kg/h,remifentanil 0.1-0.3μg/kg/min. At 15 minutes before the end of surgery,patients in D1,D2, D3 groups received 1.0,1.5,2.0μg/kg of dexmedetomidine( DEX)intramuscularly at the deltoid muscle respectively, while patients in D4 group received 0.5ug/kg dexmedetomidine intravenously, the same volume of normal saline was given in C group. SBP, DBP, HR, SPO2 were recorded at T0(before operation),T1(before given DEX), T2(5 min after given DEX), T3(10 min after given DEX),T4(15 min after given DEX), T5(at extubation), T6(5 min after extubation), T7(15min after extubation), T8(30 min after extubation). The duration from the termination of anesthesia to full recovery of spontaneously breathing, eye opening response to instruction and tracheal extubation were recorded. Sedation score and analog score at the time point of T6, T7, T8 were recorded, the number of people who has complications was also recorded. Venous blood sample were collected to measure theplasma concentrations of cortisol(COR) at T1, T3, T5, T6, T7.Results:1.The basic conditions of the five groups’ patients have no statistically signficant difference(P>0.05).2.There was no statistically significant differences between five groups of patients’ SBP, DBP, HR, SpO2, COR at T0(P>0.05).3.In the group D1, patients’ SBP, DBP and HR at T5 is higher than T0, and has no obviously difference compared with group C at the same time point. At the time point of T5, the SBP, DBP and HR in group D2, D3, D4 are lower than group C, and the patients’ SBP, DBP and HR at T5 have no significantly difference compared with T0 in the same group, patients’ SBP,DBP and HR gradually recover after extubation,but still lower than the lever at T0. There was no significantly differences between five groups of patients’ SPO2 at different time points(P>0.05).4.The spontaneous breathing recovery time, wake- up time and extubation time in all patients of the D1, D2, D3, D4 groups, only group D3 prolonged compared with group C(P<0.05).5.The incidence of agitation, Beckoning tachycardia, hypertension in group D2,D3, D4 were significantly lower than group C(P<0.05). There was no difference in the incidence of agitation, Beckoning tachycardia, hypertension between group D1 and group C. Also there was no difference in the incidence of Nausea, vomiting,Beckoning bradycardia, hypotension between the five groups(P>0.05).6. The score of Ramsay, VAS of patients in group D2、D3、D4 at T6、T7、T8 have significantly difference compared with group C(P<0.05), and the score of Ramsay of patients in group D3 at T8 is significantly larger than group C(P<0.05).7. Plasma cortisol of patients in group D2、D3、D4 such as T5 compared with T1 in the same group has obviously declined, the plasma cortisol at T5 in group D2, D3,D4 were lower than group C, the difference has statistical significance(P<0.05).Conclusions:Both intramuscular injection of 1.5μg/kg and intravenous infusion of 0.5μg/kg dexmedetomidine can provide more stable haemodynamics and relieve stressresponse in the recovery periods, They can effectively improve the quality of anesthesia recovery in patients undergoing tympanoplasty.