摘要
背景为了缓解焦虑、提高患儿配合度,临床上常在麻醉前给患儿服用咪达唑仑。然而咪达唑仑的肌肉松弛作用具有影响患儿呼吸功能的潜在风险。我们分别评估患儿清醒时以及手术前口服咪达唑仑(0.3mg/kg)20分钟后的功能残气量(functionalresidualcapacity,FRC)、通气协调性和呼吸力学特征,其中通气协调性以肺清除率指数(1ungclearanceindex,LCI)加以评价。方法18例3—8岁患儿口服咪达唑仑前后,采用六氰化硫(SF6)多次呼吸洗脱技术测定FRC和LCI,通过振荡技术获得输入阻抗,测定呼吸系统阻力与肺弹性阻力。结果麻醉前给予咪达唑仑导致患儿FRC均值降低6.5%,从25.0ml/kg降低至23.4ml/垤,该差异虽小但具有显著统计学意义,同时LCI由6.4增加至6.9,提高7.8%,这些都显示患儿的通气不协调性增加。此外,咪达唑仑导致患儿呼吸系统阻力增加了7.4%(从3.38±0.6到3.62±0.6cmH,0S/L,P〈0.001).呼吸弹性阻力增加9.2%(48.8到52.9cmH2OS/L,P〈0.001)。FRC、LCI、肺阻力和弹性阻力等指标的变化具有显著相关性(P〈0.001)。结论手术前,给肺功能正常的患儿小剂量的咪达唑仑,短时间内呼吸参数改变较小。然而,麻醉医生应该意识到,对于存在呼吸系统并发症的高危患儿,咪达唑仑可能会明显抑制其呼吸功能。
BACKGROUND: Premedication with midazolam is commonly used in children to reduce anxiety and im- prove cooperation before anesthesia. However, it has the potential to alter respiratory function because of its musde relaxant properties. We assessed functional residual capacity (FRC), ventilation homogeneity, using a lung clearance index (LCI), and respiratory mechanics in children awake and 20 min after oral premedication with midazolam (0.3 mg/kg). METHODS: FRC and LCI were measured using a SF6 multibreath washout technique while respiratory resistance and elastance were extracted from the input impedance obtained by forced oscillation technique in 18 children (3 -8 yr) before and after oral premedica- don with midazolam. RESULTS: Premedication led to a small (6.5%) but statistically significant decrease in group mean FRC from 25.0 (sd 1.4) to 23.4 (1.9) ml/kg and an associated increase in LCI by 7.8% from 6.4 (0.4) to 6.9 (0. 4), indica- ting increased ventilation inhomogeneities. Furthermore, midazolam resulted in a statistically significant increase in respirato- ry resistance by 7.4% from 3.38 (0. 6) to 3.62 (0. 6) cm H2O s/L (P 〈 0. 001 ) and in respiratory elastance by 9.2% from 48.8 to 52.9 cm H20 s/L (P 〈 0. 001 ). The changes in FRC, LCI, resistance and elastance were significantly correlated (P 〈 0. 001 ). CONCLUSIONS: In children with normal lungs, premedication with a relatively small-dose of midazolam led to mild changes in respiratory variables shortly after its administration. However, the anesthesiologist should be aware that using mi- dazolam in children at high risk of respiratory complications under anesthesia might lead to a greater decrease in respiratory function.
出处
《麻醉与镇痛》
2011年第6期38-43,共6页
Anesthesia & Analgesia