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Spontaneous versus edrophonium-induced recovery from paralysis with mivacurium
B W Brandom1, O O Taiwo, S K Woelfel
1Department of Anesthesiology, Children's Hospital of Pittsburgh, PA 15213-2583, USA.
Abstract:
This study compared spontaneous with edrophonium-induced recovery of neuromuscular transmission (NMT) after mivacurium infusion. During nitrous oxide-narcotic-propofol anesthesia, the electromyogram (EMG) of the adductor pollicis (AP) was recorded and the movement of the first toe in response to stimulation of the posterior tibial nerve was noted. Mivacurium infusion was titrated to produce posttetanic count of 1-5 at the toe and absence of NMT at the AP. Thirty children were assigned to three groups on the basis of age. Edrophonium, 1 mg/kg, with atropine 10 micrograms/kg, was given after the mivacurium infusion when NMT of the AP was 1% or 10% of baseline. In the third group, spontaneous recovery was observed. Edrophonium given when NMT was 11% +/- 1% SEM produced the most rapid recovery, 7.5 +/- 0.6 min to a train-of-four (TOF) ratio (T4/T1) of 0.9 and the shortest interval from T4/T1 of 0.4-0.9, when residual block was likely to be underestimated, 4.8 +/- 0.6 min. Edrophonium given when block was greater produced recovery of the T4/T1 to 0.4 in 2.8 +/- 0.7 min, but the time from then to T4/T1 = 0.9 was 7.9 +/- 1.1 min, as long as during spontaneous recovery. Spontaneous recovery to T4/T1 = 0.9 occurred 12.9 +/- 0.7 min after the first measurable AP EMG. There was no significant relationship between duration of infusion, which ranged from 16 to 135 min, and time to appearance of AP EMG after the infusion, which averaged 3.1 +/- 0.5 min. We recommend that administration of edrophonium to induce reversal of mivacurium be delayed until two responses to a TOF stimuli are observed because this will produce the most rapid recovery and decrease the interval in which residual block may be underestimated.
Insights
Administering edrophonium for mivacurium reversal is most effective when neuromuscular transmission shows two responses to train-of-four stimulation. This approach ensures the quickest recovery and minimizes the risk of underestimating residual neuromuscular block.
Area of Science:
- Anesthesiology
- Pharmacology
Background:
- Neuromuscular transmission (NMT) monitoring is crucial during anesthesia.
- Mivacurium is a neuromuscular blocking agent used in anesthesia.
- Assessing recovery from neuromuscular blockade is essential for patient safety.
Purpose of the Study:
- To compare spontaneous recovery of NMT with edrophonium-induced recovery after mivacurium infusion.
- To determine the optimal timing for edrophonium administration to reverse mivacurium-induced blockade.
- To evaluate the impact of block depth on the efficacy of edrophonium reversal.
Main Methods:
- Electromyogram (EMG) of the adductor pollicis and toe movement were recorded.
- Mivacurium infusion was used to induce neuromuscular blockade.
- Edrophonium was administered at different levels of residual blockade, or spontaneous recovery was observed.
Main Results:
- Edrophonium administration when NMT was 11% of baseline resulted in the fastest recovery to a train-of-four (TOF) ratio of 0.9 (7.5 min).
- Delayed edrophonium administration led to prolonged recovery times, similar to spontaneous recovery.
- Spontaneous recovery to a TOF ratio of 0.9 took 12.9 min after the first measurable EMG response.
Conclusions:
- Edrophonium is most effective for mivacurium reversal when administered after at least two responses to TOF stimulation are observed.
- Delaying edrophonium until two TOF responses appear optimizes recovery speed and reduces the risk of underestimating residual block.
- Current practice of early edrophonium administration may not provide the most rapid or complete reversal.