Dose-dependent hemodynamic effects of propofol induction following brotizolam premedication in hypertensive patients taking angiotensin-converting enzyme inhibitors.
OBJECTIVE
To determine a propofol dose that minimizes hemodynamic changes on induction of anesthesia in patients chronically taking angiotensin-converting enzyme inhibitors (ACEIs).


METHODS
Prospective, randomized trial.


METHODS
Operating room of a university-affiliated general hospital.


METHODS
88 ASA physical status II and II hypertensive patients chronically taking ACEIs, scheduled for elective abdominal surgery with general anesthesia.


METHODS
Patients were premedicated with brotizolam and anesthesia was induced with propofol, fentanyl, and rocuronium; anesthesia was then maintained with isoflurane. Patients were randomly assigned to undergo anesthetic induction with propofol in doses of 1.3, 1.6, 2.0, or 2.3 mg/kg.


METHODS
Oscillometric blood pressure and heart rate were evaluated at one-minute intervals during the first 10 minutes of anesthesia. End-tidal isoflurane concentrations were also recorded. Episodes of hypertension, tachycardia, bradycardia, or hypotension (defined as > 30% of baseline values) were managed per protocol with esmolol, atropine, phenylephrine, or ephedrine. Administration of any of these drugs was considered a pharmacological intervention.


RESULTS
After adjusting for covariables in a model assuming a linear relationship between dose and log-response, each propofol dose increase of 0.3 mg/kg was associated with a 31% increase in mean number of hypotensive/bradycardic episodes requiring interventions (95% confidence intervals of +5% and +65%; P = 0.018). Based on our model, a dose of 1.3 mg/kg resulted in the fewest number of pharmacological interventions.


CONCLUSIONS
In patients chronically taking ACEIs, low doses of propofol reduce hemodynamic instability.
Weisenberg
Marian
M
Department of Anesthesia, Edith Wolfson Medical Center, Holon, Israel.
Sessler
Daniel I
DI
Tavdi
Monica
M
Gleb
Muzikant
M
Ezri
Tiberiu
T
Dalton
Jarrod E
JE
Protianov
Michael
M
Zimlichmann
Reuven
R
D000328:Adult; D000368:Aged; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage*; D001381:Azepines / Q000008:administration & dosage*; D001794:Blood Pressure / Q000187:drug effects; D001919:Bradycardia / Q000188:drug therapy; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D006993:Hypnotics and Sedatives / Q000008:administration & dosage*; D007022:Hypotension / Q000188:drug therapy; D008875:Middle Aged; D011229:Preanesthetic Medication; D015742:Propofol / Q000008:administration & dosage*; D011446:Prospective Studies; D013610:Tachycardia / Q000188:drug therapy
D018686:Anesthetics, Intravenous; D000806:Angiotensin-Converting Enzyme Inhibitors; D001381:Azepines; D006993:Hypnotics and Sedatives; C020960:brotizolam; D015742:Propofol