Anesthetic Induction with Fentanyl

Park, Jin Woo

Abstract

We evaluated the efficacy as an anesthetic induction agent and cardiovascular effects of fentanyl in sixty patients with myocardial ischemia on electrocardiogram, who were scheduled for elective operations of more than two-hour duration. In addition, the effects of pretreatment with pancuronium and/or lorazepam prior to anesthetic induction were evaluated on the induction speed, the incidence and severity of skeletal muscle rigity, heart rate, and systolic blood pressure. All the patients were given 30ug/kg of fentanyl and divided into four equal groups of fifteen patients according to pretreatment drugs administered before fentanyl. The results were as follows: 1) Eighty-seven percent of the patients in control group (pretreated with saline)were rendered unconscious during or one minute after infusion of 30ug/kg of fentanyl. 2) Pretreatment with lorazepam before fentanyl significant#ly increased the induction speed (p<0, 025), but was not significantly correlated with the incidence and severity of skeletal muscle rigidity. Pancuronium pretreatment significantly decreased the incidence and severity of skeletal muscle rigidity (p<0.01) but was not significantly correlated with the induction speed, Pretreatment with lorazepam plus pancuronium significantly increased the induction speed (p<0.025) and significantly decreased the incidence and severity of skeletal muscle rigidity (p<0.01). 3) Saline pretreatment and pancuronium pretreatment did not significantly change heart rate or systolic blood pressure, but both lorazepam poretreatment and lorazepam-pancuronium pretreatment decreased heart rate or systolic blood pressure (p<0.05), which were within thirty percent of preanesthetic values. 4) All the patients did not exhibit significant changes in heart rate or systolic blood pressure immediately after, in comparison to, immediately before tracheal intubation or skin incision (p> 0.05). From the above results, it is concluded that anesthetic induction with 30 ug/kg of fentanyl produces profound analgesia and amnesia, stable cardiovascular dynamics, and a minimum of problems, and pretreatment with small doses of lorazepam and pancuronium before fentanyl facilitates not only a rapid loss of consciousness but also a reduction in the incidence and severity of fentanyl-induced rigidity.