[Long-lasting neuromuscular effects of non-depolarizing muscle relaxants, as measured by tetanic stimulation (author's transl)].

Spontaneous decurarization after single doses of tubocurarine (d-Tc) 0.44+/-0.04 mg/kg, pancuronium (PANC) 0.093+/-0.013 mg/kg, gallamine (GALL) 1.69+/-0.31 mg/kg and alcuronium (ALC) 0.193+/-0.02 mg/kg b.w. was investigated by means of tetanic stimulation of the ulnar nerve in 37 routinely anaesthesized adults of either sex. Tetani of 4-5 s and 30-400 Hz were sustained prior to muscle relaxation during light anaesthesia. After the injection of muscle relaxants the frequency of incomplete myographic black-out revealed slight underestimation of the doses of both GALL and ALC. However, no significant differences could be found between the drugs investigated, as far as latency of recovery is concerned. Recovery time to 30 Hz (=75-80% receptor occlusion) was 110+/-37, 109+/-66, 92+/-25 and 90+/-35 minutes for d-Tc, GALL, PANC and ALC, respectively. Up to 100 Hz (=50% receptor occlusion) it was 328+/-69, 327+/-83, 282+/-88 and 218+/-66 minutes for d-Tc, ALC, GALL and PANC, respectively. Myographic recurarization rather frequently occurred with ALC, GALL and d-Tc. The use of antidotes seems urgently to be indicated whenever non-depolarizing muscle relaxants have been applied in the above mentioned range of dosage.