Postoperative myocardial ischemia: epidural versus intravenous patient-controlled analgesia. A pilot project.
OBJECTIVE
Continuous postoperative epidural analgesia with bupivacaine (BUP) and morphine (MS) may be associated with a decreased incidence of postoperative myocardial ischemia (ISCH) and infarction (MI). This study evaluated the incidence of ISCH and MI in patients with two or more risk factors for coronary artery disease (CAD) who were admitted to the ICU after upper abdominal surgery for cancer.


METHODS
During a 1-year period, 198 patients were studied for the incidence of ISCH and MI in a prospective, nonrandomized fashion. The epidural group (EPI, n = 110) received continuous epidural anesthesia by injection at the T7-9 interspaces with 0.5% BUP/0.013% MS and light general anesthesia followed by 0.1% BUP/0.01% MS epidural analgesia for 5-7 days. The general anesthesia group (GEN, n = 88) received a balanced technique followed by intravenous patient-controlled analgesia with 0.1% MS for 5-7 days. All patients had preoperative and postoperative 12 lead ECGs every 6 hours on the first 3 postoperative days. Patients with ECG changes consistent with myocardial ischemia had creatine kinase levels with isoenzymes drawn every 8 hours.


RESULTS
There were no differences in age, sex, number of cardiac risk factors, number taking anti-anginal medication, preoperative heart rate (75 +/- 5 [EPI] vs. 73 +/- 4 [GEN]), and incidence of preoperative or intraoperative ischemia between the two groups. All patients had adequate analgesia. Postoperatively, patients in the EPI group had a lower incidence of tachycardia (15 [14%] vs. 58 [65%], P < .00001), ischemia (5 [5%] vs. 15 [17%], P < .004), and infarction (0 vs. 3 [20% of patients with ischemia]). All episodes of ischemia were silent and occurred more frequently during the first 36 hours postoperatively (14 episodes or 72%). Overall 60% of the ISCH episodes were associated with tachycardia (5/5 in the EPI group and 7/15 in the GEN group). There were no deaths in either group.


CONCLUSIONS
These preliminary results suggest that epidural anesthesia and analgesia may decrease the incidence of postoperative tachycardia, ischemia, and possibly infarction in patients undergoing upper abdominal procedures.
de Leon-Casasola
O A
OA
Department of Anesthesiology, Pain and Critical Care Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263, USA.
Lema
M J
MJ
Karabella
D
D
Harrison
P
P
D000005:Abdomen / Q000601:surgery; D000368:Aged; D015360:Analgesia, Epidural; D016058:Analgesia, Patient-Controlled; D002045:Bupivacaine; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D009020:Morphine; D009203:Myocardial Infarction / Q000209:etiology / Q000503:physiopathology; D017202:Myocardial Ischemia / Q000209:etiology* / Q000503:physiopathology; D010865:Pilot Projects; D011183:Postoperative Complications / Q000503:physiopathology*; D011446:Prospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
D009020:Morphine; D002045:Bupivacaine