Analysis of cardiovascular changes and arterial blood gases in patients resistant to methohexital anesthesia.

Two studies were done to evaluate the patient who appears to be clinically resistant to incremental methohexital infusion for general anesthesia. A retrospective study revealed that 9% of the 513 patients developed resistance to methohexital maintenance and required a volatile inhalation anesthetic supplement. The cardiovascular and arterial blood gas analysis in a prospective study failed to disclose any gross changes that would explain the physiology associated with patients resistant to methohexital anesthesia. To maintain adequate anesthesia depth, doses of methohexital ranged from .07 to .12 mg/kg/min or 4.1 to 8.2 mg/min.