Reversal of profound paralysis: use of large doses of edrophonium to antagonize vecuronium and pancuronium induced neuromuscular blockade

Central neural influences on neuromuscular transmission may explain the frequent failure of evoked electromyographic (EEMG) responses to return to control values during offset of neuromuscular block. This study, performed in conscious subjects, did not demonstrate any change in EEMG response of either the first dorsal interosseous muscle during onset of ulnar nerve block or the flexor hallucis brevis during onset of subarachnoid block. It is concluded that central enhancement of EEMG response via a neural mechanism does not explain the observed failure of EEMG monitoring of neuromuscular block.

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confidence: 99%

“…This hypothesis has not been subject to experimental validation, in spite of its potential importance. Central enhancement of EEMG has been quoted as an explanation for die failure of EEMG monitoring [2,3], although the neuroanatomical basis for the effect has not been defined.…”

mentioning

confidence: 99%

Central Enhancement of Evoked Electromyographic Monitoring of Neuromuscular Function †

Smith

1991

“…Evoked electromyographic (EEMG) monitoring of neuromuscular function is unreliable in 5-42% of patients because the first response (Tl) to train-offour (TOF) stimulation does not return to the preblock baseline value during the offset of neuromuscular block [1][2][3]. A decrease in the Tl response of the EEMG also occurs during the first 15-20 min of general anaesthesia without neuromuscular blocking agents [4][5][6], but not in awake volunteers [7].…”

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confidence: 99%

Influence of serum concentrations of catecholamines and i.v. or volatile anaesthesia on evoked electromyography in the hand

Smith

Hope

1994

We have examined the correlation between serum concentrations of catecholamines and the evoked electromyographic (EEMG) response from the first dorsal interosseous muscle of the hand in 20 patients during minor surgery under propofol or enflurane anaesthesia without neuromuscular blocking drugs. The supinated forearm, with the wrist fully extended, was strapped firmly to an armboard and immobilized with adhesive tape. In the propofol group, the mean EEMG response to the first stimulus in the train-of-four (T1) decreased to 83.0% (95% confidence intervals (CI) 78.7-87.3%) of baseline, while in the enflurane group the mean EEMG T1 response decreased to 84.0% (95% CI 81.6-86.4%) of baseline. The decrease in the EEMG response occurred over 20 min and did not correlate with plasma concentrations of adrenaline or noradrenaline (correlation coefficients all < 0.26). We conclude that the decrease in EEMG response during the first 30 min of anaesthesia occurred during both i.v. and inhalation anaesthesia, and that changes in plasma concentrations of catecholamines did not cause the decrease in the EEMG response.

“…Its potential advantages include a faster onset of action (which, unlike neostigmine, makes it feasible to titrate dose to effect) and a lower requirement for anticholinergic drugs [1,2]. In the presence of profound neuromuscular block (single twitch height < 10 % of control height) these advantages appear to be offset by the inadequacy of the degree of recovery [3].…”

mentioning

confidence: 99%

Neostigmine and Edrophonium Antagonism of Moderate Neuromuscular Block Induced by Pancuronium or Tubocurarine

Shorten¹,

Ali²,

Goudsouzian³

1993

Edrophonium and neostigmine are anticholinesterase drugs used commonly to antagonize competitive neuromuscular block. Although it has a faster onset of action than neostigmine, edrophonium is unreliable when used to antagonize deep neuromuscular block. We have compared the antagonist characteristics of these two drugs when used to antagonize a moderate degree of pancuronium- or tubocurarine-induced neuromuscular block. Forty ASA I or II patients undergoing surgical procedures were allocated randomly to receive either pancuronium 70 micrograms kg-1 or tubocurarine 0.5 mg kg-1, and to receive either edrophonium 0.5 mg kg-1 or neostigmine 0.05 mg kg-1. Antagonism was attempted when the first response to train-of-four (TOF) stimulation recovered spontaneously to 25% of the control height. Neuromuscular function was monitored using the evoked integrated electromyogram of the first dorsal interosseous muscle of the hand. Adequate recovery was defined as the achievement of a TOF ratio of 0.70 or greater. Only seven of 20 patients who received edrophonium demonstrated adequate recovery 30 min after antagonism. Under the conditions described in this study, edrophonium 0.5 mg kg-1 was less effective as an antagonist than neostigmine 0.05 mg kg-1.