Effects of desflurane and isoflurane on systemic vascular resistance during hypothermic cardiopulmonary bypass.
OBJECTIVE
The objective of this study was to examine the dose-related effects of desflurane and isoflurane on systemic vascular resistance during hypothermic cardiopulmonary bypass.


METHODS
Randomized, prospective trial.


METHODS
University hospital.


METHODS
Sixty consenting patients, 65 years of age or older, scheduled for elective coronary artery surgery.


METHODS
Patients were randomly allocated to one of five groups to receive 0.5 or 1.0 minimum alveolar concentration (MAC) (exhaust gas concentration) desflurane or 0.5 or 1.0 MAC isoflurane during hypothermic (32 degrees to 33 degrees C) nonpulsatile cardiopulmonary bypass or to a control group that did not receive any anesthetic agent. Systemic vascular resistance index was recorded at baseline, every 2 minutes for the first 10 minutes during initial administration and every 5 minutes for another 15 minutes during maintenance of anesthesia.


RESULTS
In patients receiving 0.5 MAC desflurane and isoflurane, there were significant differences in systemic vascular resistance index only at 20 and 25 minutes compared with control values. In the desflurane 1.0 MAC group, significant decreases were observed at 15, 20, and 25 minutes compared with controls. In the 1 MAC isoflurane group, the 10-, 15-, 20-, and 25-minute value differed significantly from the control. There were significant decreases in systemic vascular resistance index in the 1.0 MAC groups at 20 and 25 minutes compared with 0.5 MAC values, as well.


CONCLUSIONS
Equi-MAC concentrations of desflurane and isoflurane had similar effects on systemic vascular resistance; 0.5 MAC maintained systemic vascular resistance; 1.0 MAC decreased systemic vascular resistance during hypothermic cardiopulmonary bypass.
Rödig
G
G
Department of Anesthesiology, University Hospital, Regensburg, Germany.
Wild
K
K
Behr
R
R
Hobbhahn
J
J
D000368:Aged; D000369:Aged, 80 and over; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D000077335:Desflurane; D006801:Humans; D007036:Hypothermia, Induced; D007530:Isoflurane / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D013997:Time Factors; D014655:Vascular Resistance / Q000187:drug effects*
D018685:Anesthetics, Inhalation; D000077335:Desflurane; D007530:Isoflurane