不同浓度七氟醚麻醉对老年患者左心室功能的影响

Influence of different concentrations of sevoflurane during anesthesia induction on left ventricular function in elderly patients

目的：评价超声心动图下不同浓度七氟醚麻醉对老年患者左心室功能的影响。方法选择全麻下择期手术患者120例,男59例,女61例,年龄65~69岁,ASA Ⅰ或Ⅱ级,采用随机数字表法按最低肺泡有效浓度（MAC）将患者随机分为四组,每组30例。分别维持呼气末 MAC 值为1.0（S1组）、1.5（S2组）、2.0（S3组）、2.5（S4组）,维持上述预定值10 min 后静脉注射芬太尼、琥珀胆碱快速诱导气管插管,机械通气,调整吸入浓度。于麻醉诱导前即刻（T0）、呼气末七氟醚浓度达到并维持在预定值3 min（T1）、5 min（T2）、8 min（T3）、10 min（T4）时采用心动超声记录左心室舒张末期内径（LVEDD）、左心室收缩末期内径（LVESD）、左心室射血分数（LVEF）、左心室内径缩短率（LVFS）、心输出量（CO）。同时记录 SBP、DBP、HR 及吸入七氟醚期间心血管不良事件的发生情况。结果与 T0时比较,T1~T4时四组 SBP 和 DBP 明显降低,T2~T4时 S2、S3、S4组 LVEF、LVFS 和CO 明显降低,S3、S4组 LVESD 明显升高（P 〈0.05）。T2~T4时 S2、S3、S4组 LVEF、LVFS 和 CO明显低于 S1组,S3、S4组 LVESD 明显高于 S1组（P 〈0.05）。T2时 S3、S4组 LVESD 明显高于 S2组（P 〈0.05）。S1、S2组无一例低血压发生,S3、S4组分别发生6例（20%）和9例（30%）低血压,S3、S4组低血压发生率明显高于 S1、S2组（P 〈0.05）。结论低浓度七氟醚麻醉对老年患者左心室功能无明显影响,而高浓度七氟醚麻醉对左心室收缩功能有明显抑制作用,但对舒张功能无明显影响。

Objective To evaluate effects of different concentration of sevoflurane anesthesia on left ventricular function in elderly patients by cardiac ultrasound.Methods One hundred and twenty patients （59 males,61 females,aged 65-69 years,ASA gradeⅠor Ⅱ）undergoing elective surgery having general anesthesia were divided into 4 groups according to minimum alveolar concentration （MAC）using random number table method,30 in each.To maintain the MAC at 1.0,1.5,2.0,2.5,fentanyl and suc-cinylcholine were used for rapid induction,followed by endotracheal intubation.Mechanical ventilation was maintained at the preset value for 10 minutes,then the concentration of sevoflurane was adjusted.Left ven-tricular end-diastolic diameter （LVEDD）,left ventricular end-systolic diameter （LVESD）,left ventricular ejection fraction （LVEF）,left interior diameter shortening rate （LVFS）,cardiac output by cardiac ultra-sound,noninvasive arterial systolic pressure,diastolic pressure,heart rate were recorded prior to the induc-tion （T0 ）and after 3 min （T1 ）,5 min （T2 ）,8 min （T3 ）,10 min （T4 ）of reaching the target concentra-tion.Cardiovascular event was also documented if there was any during the study.Results Compared with T0 ,the systolic pressure and diastolic pressure of 4 groups decreased at T1-T4 time point,LVEF,LVFS and cardiac output of group S2,S3,S4 decreased at T2-T4 time point,LVESD of group S3 and S4 increased at T2-T4 time point,with significant differences （P 〈0.05）.Compared with group S1,group S2,S3 and S4 at T2-T4 time point,LVEF,LVFS and cardiac output decreased,LVESD of group S3 and S4 increased, the difference being statistically significant （P 〈0.05）.Compared with group S2,LVESD of group S3 and S4 increased with significant difference （P 〈0.05）.No hypotension occurred in group S1 and S2.Hypoten-sion in group S3 and S4 occurred in a rate of 20% and 30% respectively.Compared with group S1 and S2, the incidence of hypotension of group S3 and S4 increased （P 〈0.05）.Conclusion Low concentration of sevoflurane anesthesia exerts no obvious effect on left ventricular function of elderly patients,however high concentration of sevoflurane anesthesia has obvious inhibition on left ventricular systolic function,but had no＆nbsp;effect on left ventricular diastolic function.