Cardiovascular responses to propofol and etomidate in long-term instrumented rhesus monkeys (Macaca mulatta).
OBJECTIVE
Cardiac and arterial responses to prescribed doses of propofol and etomidate in rhesus monkeys were compared.


METHODS
Intravenously administered induction doses of propofol (2 mg/kg of body weight) or etomidate (1 mg/kg) followed by continuous intravenous infusions of propofol (200 microg/kg/min) or etomidate (100 microg/kg/min) were administered. Left ventricular and right atrial access catheters were implanted for long-term use, along with a transit-time flow probe on the ascending aorta, and pericardial electrocardiogram leads. A dual sensor 3-F micromanometer was used to measure left ventricular pressure and aortic pressure, and an active redirectional transit-time probe measured aortic flow. Noordergraaf's four-element model was used to estimate total peripheral resistance and systemic arterial compliance.


RESULTS
Significant (P < 0.01) decreases in mean arterial pressure, heart rate, and myocardial contractility were accompanied by an increase in systemic arterial compliance associated with propofol and etomidate. Only minimal changes in left ventricular diastolic pressure, cardiac output, stroke volume, and total peripheral resistance were found for both drugs. The changes associated with propofol are comparable to results in human beings, whereas the changes associated with etomidate did not agree with results of published human studies.


CONCLUSIONS
The significant cardiovascular alterations associated with both agents were attributed to reductions in heart rate, although the possibility exists that negative inotropic effects may have had a role.
Fanton
J W
JW
Oregon Regional Primate Research Center, Beaverton 97006, USA.
Zarr
S R
SR
Ewert
D L
DL
Woods
R W
RW
Koenig
S C
SC
D018686:Anesthetics, Intravenous / Q000009:adverse effects*; D000818:Animals; D001011:Aorta / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002319:Cardiovascular System / Q000187:drug effects*; D005045:Etomidate / Q000009:adverse effects*; D006339:Heart Rate / Q000187:drug effects; D007700:Kinetics; D008253:Macaca mulatta; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D015742:Propofol / Q000009:adverse effects*; D016277:Ventricular Function, Left / Q000187:drug effects
D018686:Anesthetics, Intravenous; D015742:Propofol; D005045:Etomidate