Anesthesia and analgesia
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Anesthesia and analgesia · Apr 1985
Vecuronium infusion dose requirements during fentanyl and halothane anesthesia in humans.
Steady-state infusion rate requirements of vecuronium were determined in 29 patients during either halothane-nitrous oxide or fentanyl-nitrous oxide anesthesia at different levels of neuromuscular block. During N2O-halothane anesthesia (end-tidal concentration, 0.5%), the infusion rate necessary for a steady-state (defined as unchanging twitch height and infusion rate for at least 20 min) 50% depression of twitch force was 28.8 +/- 5.4 (mean +/- SD) (n = 8) and 47.6 +/- 9.7 micrograms . kg-1 . hr-1 (n = 6) at 90% reduction of twitch force. ⋯ The variances of vecuronium steady-state infusion dose requirements were smaller in the halothane groups than in the fentanyl anesthesia groups. The steady-state vecuronium infusion dose requirements during fentanyl anesthesia were greater than the mean infusion dose requirements during halothane anesthesia at equivalent levels of twitch depression.
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The safety of etomidate for induction of anesthesia in malignant hyperthermia-susceptible (MHS) pigs was evaluated in a two-phase experiment. Two litters of Purebred Poland China pigs, one MHS (n = 4) and the other malignant hyperthermia-resistant (MHR) (n = 4) were used. Phase I compared MHS vs MHR animals in terms of cardiovascular, metabolic, and skeletal muscle rigidity responses to etomidate and fentanyl anesthesia and to a subsequent malignant hyperthermia (MH) challenge with halothane-succinylcholine. ⋯ Heart rate and bicarbonate levels were lower in MHS than in MHR pigs during etomidate infusion. With discontinuation of etomidate and a subsequent challenge with halothane-succinylcholine, all four pigs developed the MH syndrome within 15-30 min. Thiopental replacement of etomidate in the phase II experiment resulted in a twofold greater time (45-75 min) for halothane-succinylcholine to trigger MH in the susceptible pigs.(ABSTRACT TRUNCATED AT 250 WORDS)