The ST Segment Analysis And Hemodynamic Effects Of Different Anesthesia Methods In Elderly Patients With Silent Myocardial Ischemia (SMI)

Objective:To observe the ST segment changes and hemodynamic effects of combined spinal epidural anesthesia or general anesthesia in elderly patients with silent myocardial ischemia(SMI) or myocardial strain during great saphenous varicose operation.Methods:Sixty consecutive patients, aged 65-75 years old with SMI or myocardial strain but without chest distress 、 constriction in front heart area 、 short of breath 、 fatigue, ASA class Ⅱ or Ⅲ,waiting for great saphenous varicose operation were randomly divided into combined spinal epidural anesthesia(A)group and general anesthesia(B) group. Group A :epidural L3-4 puncture,slowly inject with 0.5% bupivacaine,if the block level couldn’t meet the requirements of the operation,2% lidocaine single dose added through epidural catheter, level of anesthesia should located T10 below. Group B:after sufficient oxygenation,tracheal cannula induced by 0.04mg/kg midazolam,0.3-0.5mg/kg etomidate,0.5ug/kg sufentanil,0.2mg/kg cisatracurium; 2% sevoflurane for maintenance of anesthesia.12 hours ECG monitor after surgery were proformed for all the patients,hemodynamics and ST-T changes were measured respectively at different time and cardiovascular events after surgery were also observed for comparison about the influence on hemodynamics among old patients with SMI or myocardial strain between the 2 groups.Results:All the patients of two groups were linked to SMI or myocardial strain.Hemodynamic changes during operation:(1)intra-group comparison:the blood pressure of patients in group A decreased significantly at 20 min post-anesthesia、30min post-anesthesia compared with pre-anesthesia(P<0.05),the blood pressure of patients in group B decreased significantly at 10 min post-anesthesia、20min post-anesthesia、30min post-anesthesia compared with pre-anesthesia(P<0.05);the heartreat of patients in group A decreased significantly at 10 min post-anesthesia 、 30 min post-anesthesia compared with pre-anesthesia(P<0.05),the heartreat of patients in group B decreased significantly at 10 min post-anesthesia 、20min post-anesthesia 、 30 min post-anesthesia compared with pre-anesthesia(P<0.05);the pulse oxygen saturation of patients in group B at 30 min post-anesthesia and the time when leaving the operating room are statistically significant compared with pre-anesthesia( P <0.05).(2)comparison between groups:there was no significant difference of mean arterial pressure、heart rate、oxygen saturation and ST-T changes between the two groups at the same time(P>0.05),Cardiovascular accidents occurs in neither of the group and there was no significant difference in hemodynamics between the two groups according to12 hours after surgery ECG monitor results, 12 hours after surgery ECG monitor showed that the incidence of myocardial ischemia and arrhymia in group A was significantly lower than which in group B(P < 0.05):2 cases of sinus bradycardia,4 cases of paroxysmal supraventricular tachycardia,2 cases of atrioventricular block in group A;5 cases of sinus arrhythmia,3 cases of PSVT( Paroxysmal Supra Ventricular Tachycardia),5 cases of atrioventricular block,5 cases of ventricular premature beat.Conclution:For elderly patients with SMI or myocardial strain,combined spinal epidural anesthesia and general anesthesia have the same impact on circulatory system during operation,but according to 12 hours ECG monitor after surgery:compared with general anesthesia,it occurs lower rate of SMI or arrhythmia when applying combined spinal epidural anesthesia,which has more benefits for stabilization of hemodynamics after surgery.