[Vecuronium bromide and succinylcholine procedures in medial relaxation. A comparison of electromyography and clinical findings].

UNLABELLED

Clinical and electromyographic effects of either succinylcholine (Suc) or vecuronium bromide (VEC) were compared during induction and maintenance of neuromuscular blockade for pelvic laparoscopy.

METHODS

Forty ASA class I and II patients (pat.) were studied under general anesthesia with thiopental, enflurane, and nitrous oxide. Group VEC-pat. (n = 20) received 0.015 mg/kg body wt. VEC as priming and 5 min later 0.085 mg/kg as intubation doses. Repetitive doses of 0.01 mg/kg were injected to maintain twitch depression (T1%) less than or equal to 15%. Neuromuscular block was reversed with atropine and pyridostigmine (0.01 resp. 0.1 mg/kg). In group Suc-pat. relaxation was induced with 1.5 mg/kg Suc 5 min after pretreatment with 2 mg alcuronium. Relaxation (10% less than or equal to T1% less than or equal to 15%) was prolonged using a Suc infusion. Neuromuscular blockade was assessed electromyographically (Relaxograph, Datex) using train-of-four (TOF) stimulation (2 Hz for 2 s). Intubation conditions were scored according to Fahey et al.

RESULTS

Pretreatment with 0.015 mg/kg VEC compared to 2 mg alcuronium led to a more pronounced decline in T1% and TOF-ratio (P less than 0.001). The time interval between injection of the intubation dose and complete relaxation (T1% less than or equal to 5%) was shorter in group Suc- than in VEC-pat. (P less than 0.001). Suc provides better intubation conditions than VEC (P less than 0.05). Recovery from muscle relaxation was faster in Suc- than in VEC-pat. (P less than 0.001). During Suc infusion in 8 patients a phase-II block (TOF ratio less than or equal to 30%) was observed.

DISCUSSION

Postoperative problems are often related to an unrecognized after effects of relaxants. Suc infusion leads to a remarkable number of phase-II blocks, whereas VEC can be antagonized promptly.