Abstrakt: |
In an evaluation of the clinical effectiveness of pyridostigmine as an antagonist of d-tubocurarine-induced and pancuronium-induced neuromuscular blockade in patients anesthetized with a neurolept-nitrous oxide (N2O) technic, 60 adults received either d-tubocurarine (dTc) (N equals 30) or pancuronium (N equals 30). The pancuronium-dTc potency ratio with neurolept-N2O anesthesia is 4.85:1. The mean doses of pyridostigmine necessary for 50 percent recovery of control twitch height and sustained tetanus were 5.72 plus or minus 0.45 (S.E.) mg. and 11.6 plus or minus 0.88 mg., respectively, for dTc, and 4.05 plus or minus 0.24 mg. and 8.27 plus or minus 0.41 mg., respectively, for pancuronium. There was no correlation between the amount of pyridostigmine necessary for relaxant antagonism and the total dose of relaxant used. In 24 patients, neuromuscular blockade was reversed by an intravenous injection of pyridostigmine and either 0.6 mg. or 1 mg. of atropine. Within 2 minutes, patients given 1 mg. of atropine had a significantly faster heart rate than those given 0.6 mg of atropine (p smaller than 0.0001). There was no correlation between control heart rate and maximum changes in heart rate. No cardiac arrhythmia or bronchospasm was observed in patients with either pancuronium or dTc following atropine-pyridostigmine mixtures. The cardiac muscarinic effects of pyridostigmine could be modified by simultaneous administration of 1 mg. of atropine. |