Etomidate and thiopental-based anesthetic induction: comparisons between different titrated levels of electrophysiologic cortical depression and response to laryngoscopy.
OBJECTIVE
To determine whether etomidate-based induction can provide better hemodynamics than a standard thiopental sodium-based anesthetic induction.


METHODS
Prospective, single-blind clinical trial.


METHODS
Multicenter university neurosurgical operating room.


METHODS
66 ASA physical status II and III inpatients undergoing neurosurgical procedures for intracranial tumor or other pathology.


METHODS
Patients were divided into two groups for anesthetic induction. The first group (control) was divided into two subgroups, with the first subgroup receiving "low-dose" etomidate (LET) 0.4 to 0.6 mg/kg titrated to an electroencephalographic (EEG) spectral edge frequency (SEF) of 10 to 12 Hz. The second subgroup received thiopental sodium (THIO) 3 to 6 mg/kg titrated to the same EEG endpoint. The study group was given high-dose etomidate (HET) 0.5 to 1.7 mg/kg titrated to an early burst suppression pattern.


RESULTS
Baseline (awake) measurements of mean arterial pressure (MAP) heart rate (HR), and SEF were obtained prior to anesthetic induction that was accomplished using a small bolus plus an infusion of the induction drug titrated to the EEG target. MAP, HR, and SEF were recorded just prior to laryngoscopy and intubation (T1), 30 seconds after laryngoscopy and intubation (T2), and 90 seconds after (T3) laryngoscopy and intubation. Times to reach EEG endpoint, along with total dose of anesthetic given, were also recorded. Compared with baseline values, the THIO group had the highest increase in both HR (22.9 +/- 4.4 bpm.) and MAP (16.8 +/- 4.2 mmHg) (P < 0.05) after laryngoscopy and intubation. The LET group also had significant increases compared with the HET group that demonstrated the least hemodynamic variability. No correlations could be made between age and dose of induction drug.


CONCLUSIONS
Etomidate-based anesthetic induction, titrated to EEG burst suppression, produced stable hemodynamics during laryngoscopy and intubation as compared with lower dose, more "classic" inductions with etomidate or thiopental.
Jellish
W S
WS
Department of Anesthesiology, Loyola University Medical Center, Maywood, IL, USA.
Riche
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Salord
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Ravussin
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Tempelhoff
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D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000771:Anesthesia, Intravenous; D018686:Anesthetics, Intravenous; D001794:Blood Pressure / Q000187:drug effects; D004569:Electroencephalography / Q000187:drug effects*; D005045:Etomidate / Q000009:adverse effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007442:Intubation, Intratracheal; D007828:Laryngoscopy; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016037:Single-Blind Method; D013874:Thiopental / Q000009:adverse effects
D018686:Anesthetics, Intravenous; D013874:Thiopental; D005045:Etomidate