High thoracic epidural blockade increases myocardial oxygen availability in coronary surgery patients.
BACKGROUND
High thoracic epidural techniques are increasingly being used in patients scheduled for cardiothoracic surgery, including coronary artery bypass grafting. In the present study, we evaluated the acute effects of the epidural blockade on myocardial oxygen availability by means of tissue oxygen pressure monitoring in patients submitted for surgical revascularization.


METHODS
Fifty adult patients were included in a prospective, randomized, double-blind study. After placement of an epidural catheter in thoracic space T1-T2, and under general anesthesia, 5-10 ml of either normal saline or 0.3% ropivacaine was injected through the epidural catheter. Hemodynamic parameters and the intramyocardial oxygen partial pressure were recorded before and 20 min after the epidural injection.


RESULTS
There were no demographic or hemodynamic differences between the groups before intervention. A significant increase in intramyocardial partial oxygen pressure was observed in the ropivacaine group (14.6 mmHg vs. 25.1 mmHg, P < 0.0005).


CONCLUSIONS
High thoracic epidural blockade with 5-10 ml of 0.3% ropivacaine increases myocardial oxygen availability in coronary diseased patients prior to surgical revascularization without deleterious hemodynamic disturbances.
Lagunilla
J
J
Department of Anesthesiology and Postoperative Intensive Care Unit, Hospital Clinico Universitario, University of Santiago de Compostela School of Medicine, 15706 Santiago de Compostela, Spain.
García-Bengochea
J B
JB
Fernández
A L
AL
Alvarez
J
J
Rubio
J
J
Rodríguez
J
J
Veiras
S
S
D000368:Aged; D000577:Amides; D015360:Analgesia, Epidural; D000767:Anesthesia, Epidural; D000779:Anesthetics, Local; D001026:Coronary Artery Bypass; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010313:Partial Pressure; D000077212:Ropivacaine
D000577:Amides; D000779:Anesthetics, Local; D000077212:Ropivacaine; D010100:Oxygen