Postoperative protein sparing with epidural analgesia and hypocaloric dextrose.
OBJECTIVE
We examined the hypothesis that epidural analgesia prevents the increase in amino acid oxidation after elective colorectal surgery in patients receiving hypocaloric infusion of dextrose.


BACKGROUND
Increased oxidative protein loss after surgery may adversely affect postoperative outcome. We have previously shown that effective segmental pain relief by epidural analgesia improves postoperative substrate utilization, resulting in less protein catabolism.


METHODS
We randomly allocated 10 patients to receive general anesthesia combined with epidural analgesia using bupivacaine/fentanyl and 10 to receive general anesthesia followed by patient-controlled analgesia with intravenous morphine. All patients received a peripheral 72-hour infusion of dextrose 10% from the day before until the second day after surgery. The dextrose infusion rate was adjusted to provide 50% of the patients' resting energy expenditure. The primary end point was whole-body leucine oxidation as determined by a stable isotope tracer technique (l-[1-C]leucine).


RESULTS
In the intravenous analgesia group, leucine oxidation increased from 19 +/- 4 to 28 +/- 6 micromol kg h after surgery. Epidural analgesia prevented this increase of leucine oxidation (preoperative 21 +/- 6 micromol kg h, postoperative 21 +/- 5 micromol kg h). This difference was statistically significant (P = 0.01; analysis of variance for repeated measures).


CONCLUSIONS
Perioperative epidural analgesia and hypocaloric dextrose infusion suppress the postoperative increase in amino acid oxidation, thereby saving more than 100 g of lean body mass per day.
Schricker
Thomas
T
Department of Anaesthesia, McGill University, Montreal, Canada. thomas.schricker@mcgill.ca
Meterissian
Sarkis
S
Wykes
Linda
L
Eberhart
Leopold
L
Lattermann
Ralph
R
Carli
Franco
F
D000368:Aged; D000596:Amino Acids / Q000378:metabolism*; D015360:Analgesia, Epidural; D016058:Analgesia, Patient-Controlled; D000768:Anesthesia, General; D018686:Anesthetics, Intravenous; D002045:Bupivacaine; D015179:Colorectal Neoplasms / Q000601:surgery*; D002149:Energy Intake; D004734:Energy Metabolism; D005260:Female; D005283:Fentanyl; D005947:Glucose / Q000008:administration & dosage* / Q000378:metabolism; D006801:Humans; D007262:Infusions, Intravenous; D007930:Leucine / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction
D000596:Amino Acids; D018686:Anesthetics, Intravenous; D007930:Leucine; D005947:Glucose; D005283:Fentanyl; D002045:Bupivacaine