Effect of intravenous nitroglycerin on cerebral saturation in high-risk cardiac surgery.
OBJECTIVE
To determine whether or not intravenous nitroglycerin (IV NTG) can prevent a decrease in near-infrared spectroscopy (NIRS) values during cardiopulmonary bypass (CPB).


METHODS
We conducted a randomized double-blinded study in a tertiary academic center including 30 patients with a Parsonnet score>or=15 scheduled for a high-risk cardiac surgery. The patients were randomized to receive either IV NTG (initial dose of 0.05 microg.kg(-1).min(-1), followed by 0.1 microg.kg(-1).min(-1)) or placebo after anesthetic induction until the end of CPB. The primary outcome was a decrease of 10% in NIRS values during CPB.


RESULTS
Despite the absence of between-group difference in the mean cerebral oxygen saturation during CPB, there was a significant decrease in NIRS values during CPB in the placebo group, whereas mean NIRS values were maintained in the IV NTG group (-16.7% vs 2.3% in the NTG, P=0.019). Major hemodynamic variables were similar at corresponding time periods in both groups, while patients in the IV NTG group had higher CK-MB values and experienced greater blood loss during the first 24 hr postoperatively.


CONCLUSIONS
Intravenous nitroglycerin administration before and during CPB may prevent a decrease in NIRS values associated with CPB in high-risk cardiac surgery. Further studies are warranted to determine the efficacy and the risks associated with IV NTG infusion for this indication during CPB in high-risk patients.
Piquette
Dominique
D
Department of Anesthesiology and Research Center, Montreal Heart Institute and Université de Montréal, 5000 Bélanger Street, Montréal, Québec H1T 1C8, Canada.
Deschamps
Alain
A
Bélisle
Sylvain
S
Pellerin
Michel
M
Levesque
Sylvie
S
Tardif
Jean-Claude
JC
Denault
André Y
AY
D000368:Aged; D000369:Aged, 80 and over; D000768:Anesthesia, General; D001794:Blood Pressure / Q000187:drug effects; D001921:Brain / Q000098:blood supply / Q000378:metabolism*; D002315:Cardiopulmonary Bypass; D004311:Double-Blind Method; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D016343:Monitoring, Intraoperative; D005996:Nitroglycerin / Q000008:administration & dosage*; D010100:Oxygen / Q000032:analysis; D019265:Spectroscopy, Near-Infrared; D016896:Treatment Outcome; D014662:Vasoconstrictor Agents / Q000008:administration & dosage; D014665:Vasodilator Agents / Q000008:administration & dosage*
D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D005996:Nitroglycerin; D010100:Oxygen