经食管超声心动图测量右美托咪定对不同年龄段患者心输出量的影响

Effects of different ages of dexmedetomidine on cardiac output measuring by transesophageal echocardiography

目的：通过食管超声心动图测定右美托咪定对不同年龄段患者心输出量的影响。方法：择期全麻患者60例,年龄20-75岁,ASA分级I或II级,无心血管系统基础疾病,将患者按年龄分成三组每组20例：A组（20-35岁）、B组（36-55岁）、C组（56-75岁）,每组患者在麻醉诱导后静脉泵注右美托咪定0.6μg·kg-1·h-1维持30min,分别在麻醉诱导后泵注右美托咪定前（T0）、泵注右美托咪定10min（T1）、泵注右美托咪定20min（T2）、泵注右美托咪定30min（T3）各时点记录心率（HR）、平均动脉压（MAP）,通过食管超声心动图测定各时点每搏量（SV）,计算心输出量（CO）。结果：A组和B组患者在T3时刻MAP、HR和CO较基础值降低（P〈0.05）,C组在MAP、HR在T2、T3时刻降低（P〈0.05）,CO在T1、T2、T3时刻降低（P〈0.05）,且HR和CO与A组比较有明显下降（P〈0.05）,但SV变化不明显（P〉0.05）。结论：静脉泵注右美托咪定0.6μg·kg-1·h-1时间〉30min时,HR有一定程度的减慢,CO轻度降低,这种变化在老年患者出现的更早,变化更明显,但SV不受影响。

Objective： To determine the effect of dexmedetomidine on cardiac output in patients of different age periods using transesophageal echocardiography. Methods： Sixty elective general anesthesia patients,between 20 to 75 years old,ASA grade I - II level,and had no underlying cardiovascular system disease,The patients were divided into 3 groups according to age（ n = 20） ： group A（ 20 - 35 years old）,group B（ 36 - 55 years old）,group C（ 56 - 75 years old）,for patients in each group,dexmedetomidine 0. 6μg·kg- 1·h- 1was administrated by intravenous infusion after anesthesia induction and maintained for 30 minutes,HR and MAP were recorded at the time points： before dexmedetomidine infusion（ T0）,10 minutes of dexmedetomidine infusion（ T1）,20 minutes of dexmedetomidine infusion（ T2）,30 minutes of dexmedetomidine infusion（ T3） after anesthesia induction; SV were measured at each time point by transesophageal echocardiography; and CO were calculated. Results： In group A and group B,MAP,HR and CO were lower than baseline at T3（ P〈0. 05）,while in group C,MAP,HR reduced at T2 and T3,but CO reduced at T1,T2 and T3（ P〈0. 05）;additionally HR and CO were significantly lower than group A（ P〈0. 05） but SV did not significantly changed（ P〈0. 05）. Conclusion： When intravenous infusion of dexmedetomidine 0. 6μg·kg- 1·h- 1were more than 30 minutes,HR showed slower to some extent,CO slightly reduced,which occurred earlier,more significant in aged patients,but SV was not affected.