Effects of intravenous anesthetics on the human radial artery used as a coronary artery bypass graft.
OBJECTIVE
Intravenous anesthetics are often used for anesthesia, sedation, and analgesia in the intraoperative and postoperative periods of coronary artery bypass graft (CABG) surgery. This study was designed to investigate the direct effects of intravenous anesthetics on the human radial artery (RA).


METHODS
In vitro, prospective with repeated measures.


METHODS
University research laboratory.


METHODS
RA segments (n = 20) were obtained from CABG surgery patients and were divided into 3- to 4-mm vascular rings.


METHODS
Using the organ bath technique, the endothelium-independent vasodilatation function was tested in vitro by the addition of cumulative concentrations of thiopental, ketamine, etomidate, and propofol after vasocontraction by phenylephrine in the presence of N(G)-nitro-L-arginine methyl ester (L-NAME) and indomethacin.


RESULTS
Thiopental (10(-8) to 10(-4) mol/L), ketamine(10(-8) to 10(-4) mol/L), propofol (10(-8) to 3 x 10(-4) mol/L), and etomidate (10(-8) to 3 x 10(-4) mol/L) caused concentration-dependent vasorelaxation in human RA rings precontracted with phenylephrine in the presence of L-NAME and indomethacin (n = 20, for each drug). The pEC(50) and maximum relaxant effect values of thiopental and ketamine were significantly higher than for etomidate and propofol (p < 0.05).


CONCLUSIONS
These findings indicate that thiopental, ketamine, etomidate, and propofol produce concentration-dependent relaxation on RA rings from humans. Thiopental and ketamine are more potent relaxant agents than etomidate and propofol. Intravenous anesthetics may be effective as alternative vasodilators for treatment of intraoperative and postoperative spasm of coronary artery grafts.
Gursoy
Sinan
S
Department of Anesthesiology, Cumhuriyet University School of Medicine, Sivas, Turkey.
Berkan
Ocal
O
Bagcivan
Ihsan
I
Kaya
Tijen
T
Yildirim
Kemal
K
Mimaroglu
Caner
C
D000700:Analgesics / Q000494:pharmacology; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage; D001026:Coronary Artery Bypass; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000008:administration & dosage; D005045:Etomidate / Q000494:pharmacology; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007213:Indomethacin / Q000008:administration & dosage; D007649:Ketamine / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D019331:NG-Nitroarginine Methyl Ester / Q000008:administration & dosage; D010656:Phenylephrine / Q000008:administration & dosage; D015742:Propofol / Q000494:pharmacology; D011446:Prospective Studies; D017534:Radial Artery / Q000187:drug effects*; D013874:Thiopental / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000008:administration & dosage; D014664:Vasodilation / Q000187:drug effects*
D000700:Analgesics; D018686:Anesthetics, Intravenous; D000894:Anti-Inflammatory Agents, Non-Steroidal; D004791:Enzyme Inhibitors; D014662:Vasoconstrictor Agents; D010656:Phenylephrine; D007649:Ketamine; D013874:Thiopental; D019331:NG-Nitroarginine Methyl Ester; D007213:Indomethacin; D015742:Propofol; D005045:Etomidate