预注小剂量甲氧明和麻黄碱对老年患者无痛胃肠镜麻醉诱导后循环动力学的影响

The Effects of Pre-Injection of Low-Dose Methoxamine and Ephedrine on Circulatory Dynamics after Anesthesia Induction in Elderly Patients Undergoing Painless Gastrointestinal Endoscopy

摘要: 目的：观察预注小剂量麻黄碱、甲氧明对老年无痛胃肠镜检查患者麻醉诱导后低血压的防治效果。方法：选择60例接受无痛胃肠镜检查患者(≥60岁；ASA分级为I~II级)，并按照随机数字表法随机分为三组(每组20例)，A组(生理盐水2 ml)，B组(麻黄碱5 mg)，C组(甲氧明1 mg)。记录麻醉前(T0)、麻醉药物推注后即刻(T1)、麻醉药物推注后3 min (T2)、麻醉药物推注后5 min (T3)各个时间点的收缩压(SBP)、舒张压(DBP)、平均压(MAP)、心率(HR)、脉搏血氧饱和度(SPO₂)。记录低血压(SBP < 90 mmHg)、心动过缓(HR < 60次/分)、麻醉苏醒后恶心呕吐等不良反应。结果：三组基线血压和心率无统计学差异(p > 0.05)。麻醉诱导后，A组诱导后SBP下降大于B、C组(p < 0.05)。与B组比较，A组T1、T2的DBP、MAP、HR降低程度更明显(p < 0.05)。与C组比较，A组诱导后T1时的DBP、T1~T3时的MAP、T2时的HR降低更明显(p < 0.05)。B、C两组相比较，血压及心率变化无显著性差异(p > 0.05)。三组低血压和心动过缓等不良事件发生率无统计学差异(p > 0.05)。结论：麻醉前预注小剂量麻黄碱或甲氧明可有效维持老年无痛胃肠镜检查患者的血流动力学稳定，减少血压波动。

Abstract: Objective: To observe the effect of pre-injection of low-dose ephedrine and methoxamine on hypotension after anesthesia induction in elderly patients undergoing painless gastrointestinal endoscopy. Methods: Sixty elderly patients (≥60 years old; ASA class I~II) scheduled for painless gastrointestinal endoscopy were randomly divided into three groups (n = 20 each) using a random number table: Group A (normal saline 2 mL), Group B (ephedrine 5 mg), and Group C (methoxamine 1 mg). Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), and pulse oxygen saturation (SpO₂) were recorded at baseline (T0), immediately after anesthesia induction (T1), 3 minutes after induction (T2), and 5 minutes after induction (T3). Adverse events, including hypotension (SBP < 90 mmHg), bradycardia (HR < 60 bpm), and postoperative nausea and vomiting, were recorded. Results: There were no significant differences in baseline blood pressure or HR among the three groups (p > 0.05). After anesthesia induction, the decrease in SBP was more significant in Group A compared to Groups B and C (p < 0.05). Compared with Group B, Group A showed greater reductions in DBP, MAP, and HR at T1 and T2 (p < 0.05). Compared with Group C, Group A exhibited more pronounced decreases in DBP at T1, MAP at T1~T3, and HR at T2 (p < 0.05). No significant differences in blood pressure or HR changes were observed between Groups B and C (p > 0.05). The incidence of adverse events (hypotension and bradycardia) did not differ significantly among the three groups (p > 0.05). Conclusion: Pre-injection of low-dose ephedrine or methoxamine before anesthesia can effectively maintain hemodynamic stability and reduce blood pressure fluctuations in elderly patients undergoing painless gastrointestinal endoscopy.