ABSTRACT
Objective To explore the effect of dexmedetomidine on hemodynamics in hypertensive patients undergoing thyroid surgery with local anesthesia.Methods Sixty patients with preoperatively diagnosed class Ⅰ to Ⅱ hypertension undergoing selective thyroidectomy were randomly divided into D (dexmedetomidine) and M (midazolam) groups (30 patients in each group).Doses of dexmedetomidine 0.5 μg/kg were finished in 20 minutes injection in patients of D group before the start of the surgery,then sequentially maintained at the rate of 0.1 ～ 0.5 μg/ (kg · h) with decreasing speed of 0.1 μg/(kg · h) when systolic pressure kept down to 110 mmHg or heart rare down to 60 bpm or Ramsay score of 3 points.The patients in M group were injected with midazolam 0.04 mg/kg 20 minutes before the start of surgery,then maintained at the rate of 0.02 ～ 0.05 mg/(kg · h),decreasing speed of 0.1 mg/(kg · h) to keep Ramsay score of 3 points if necessary.Two groups of patients with Ramsay score of 3 points but a high blood pressure (higher than 30％ of basic level) or heart rate (more than 100 bpm) were treated with drugs during operation.Record the systolic pressure,diastolic pressure,heart rate and Ramsay score at the time of before medication (T0),the injection of local anesthetics (T1),the start of surgery (T2),pain compliments required additional local anesthetics (T3),dealing with gland (T4) and the end of surgery,VAS in 8 h after operation and adverse reaction were recorded.Results In D group,the dosages of urapidil and esmolol [(10 ±5)mg and (0 ±0)mg] were significantly less than those in patients of M group [(60 ± 10) mg and (80 ±5) mg,t =14.82,t =19.78,P ＜ 0.05].Blood pressure and heart rate were all significantly decreased at the time of T1,T2 and T5 when comparing with T0(P ＜0.05 orP ＜0.01),and only heart rate was significantly decreased at the time of T3 and T4 (P ＜ 0.05).While in M group,blood pressure and heart rate were higher than basic levels at the time of T3 and T4 (P ＜ 0.05).Besides,lower blood pressure and heart rate were less than those in M group at all observed time expect T0 (P ＜ 0.05).Conclusions Good sedation effects can be produced by both dexmedetomidine and midazolam in hypertensive patients undergoing thyroid surgery with local anesthesia,but dexmedetomidine was determined more suitable in sedation and anti-hypertension in patients with light to moderate hypertension for better hemodynamic stability effect with local anesthesia.