Eltanolone for induction of anaesthesia in the surgical patient. A comparison of dose requirements in young and elderly patients.

BACKGROUND

The relative potency of the steroid anaesthetic agent eltanolone has been compared with respect to induction of anaesthesia in ASA I and II young (18-40 years) and elderly (> 65 years) patients.

METHOD: 113 temazepam premedicated patients (60 elderly) were evaluated in an open randomised study. They were allocated to receive doses between 0.05 and 0.75 mg/kg given i.v. over 30 s. The first 33 patients formed a pilot phase; the formal study comprised 80 patients. The primary efficacy variable was loss of verbal contact within 120 s and an effect lasting more than 4 min. All patients breathed 100% oxygen throughout the study period. Safety data (heart rate, blood pressure, respiratory apnoea, involuntary movements, hypertonus and other adverse effects) were noted.

RESULTS

Anaesthesia was adequately induced in 12/40 elderly and 7/40 young patients. The lowest effective induction dose was 0.2 mg/kg in elderly and 0.3 mg/kg in young patients. This gave a relative potency of 0.28 (95% CI 0.12-0.52; P = 0.0039). The cardiovascular effects associated with induction were small; other side-effects included involuntary movement and hypertonus, and respiratory upsets (apnoea, hiccups and coughing).

CONCLUSION

The effective induction dose of eltanolone was significantly lower in the elderly patients; but the drug safety profile was similar in both age groups of patients.