预注小剂量甲氧明防治老年患者腰硬联合麻醉后低血压的效果

摘要

Objective The study aims to evaluate the clinical effect of low dose prophylactic methoxamine infusion in preventing and treatment of hypotension in combined spinal and epidural anesthesia in elderly patients. Methods Sixty elderly patients who received operations of lower extremities under combined spinal and epidural anesthesia were randomly divided to two groups,the prophylactic methoxamine group(group M)and the supplemental methoxamine group(group N). Methoxamine were diluted to 0.5mg/ml with normal saline. Combined spinal epidural anesthesia was achieved at L2-3 or L3-4. Doses of methoxamine(1mg)were injected slowly(30s)in group M simultaneously as local anesthetics were given,while in group N methoxamine(1mg)would only be injected when blood pressure dropped by more than 15％ than baseline or SBP dropped below 90mmHg. Systolic blood pressure(SBP),diastolic blood pressure(DBP)and heart rate(HR)before anesthesia(T0),5 min after anesthesia(T1),10 min after anesthesia(T2),and 15 min after anesthesia(T3),and at the end of surgery(T4)of the two groups were recorded. Adverse events were compared between the two groups. Results In both groups,SBP and DBP valves at T1- T3 decreased significantly compared to T0. In M group, SBP,DBP at T1,T2 were significantly higher than that of N group(P<0.05).HR of two groups at T1-T3 was significantly decreased compared to T0,but there was no significant difference in and between groups(P>0.05). No significant difference of SBP,DBP and HR at T0 and T4 between the groups was observed(P>0.05).Incidence rate of nausea,vomiting,hypotension,bradycardia and palpitations in group M was significantly less than that in group N(P<0.05). Conclusion Low dose prophylactic methoxamine infusion can effectively prevent hypotension after combined spinal and epidural anesthesia in elderly patients,and maintain stable circulation during operation.%目的 观察静脉预注小剂量甲氧明防治老年患者腰硬联合麻醉后低血压的效果.方法 将拟行腰硬联合麻醉下骨科下肢手术的老年患者60例按随机数字表法分为两组,预注甲氧明组(M组)和补救静脉注射甲氧明组(N组),每组各30例.甲氧明预先用生理盐水稀释为0.5mg/ml.采取L2-3或L3-4腰硬联合麻醉穿刺成功,注入局部麻醉药即刻,M组缓慢(30s)静脉注射甲氧明1 mg,N组注入麻醉药后即刻不给予甲氧明,当患者出现血压下降幅度>15％或SBP<90mmhg时给予静注甲氧明1mg.记录两组麻醉前(T0)、麻醉后5 min(T1)、麻醉后10 min(T2)及麻醉后15 min(T3)、手术结束时(T4)两组患者的收缩压(SBP)、舒张压(DBP)、心率(HR)变化情况.比较两组术中不良反应发生情况.结果 与T0比较,T1～T3时两组的SBP、DBP均显著下降,且T1、T2时点M组患者的SBP、DBP明显高于N组,差异有统计学意义(P<0.05);两组T1～T3时的HR与T0比较有所下降,但组内及组间比较差异无统计学意义(P>0.05);T0和T4时点两组SBP、DBP和HR差异无统计学意义(P>0.05).M组恶心呕吐、低血压、心动过缓、心悸发生率明显少于N组,差异有统计学意义(P<0.05).结论 静脉预注小剂量甲氧明能有效防治老年患者腰硬联合麻醉后低血压的发生,维持术中循环稳定.