Computer-Controlled Muscle Paralysis with Atracurium in the Sheep

Paralysis was maintained in sheep by computer-controlled infusion of atracurium, using the integrated electromyogram as a measure of neuromuscular transmission. A number of experiments were conducted to ascertain the average infusion rate required to achieve a given level of paralysis for one hour. Each experiment yielded a point on a plot of paralysis versus infusion rate. A dose-response curve based upon a simple model of drug receptor interaction at the neuromuscular junction was fitted to the experimental points by least squares and is able to provide a useful explanation of clinically observed behaviour. The recovery time was also measured in each experiment and plotted against both prior level of paralysis and prior average infusion rate.

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Reversal of Non-Depolarizing Block by Neostigmine

Anaesthesia and Intensive Care ◽

10.1177/0310057x8000800104 ◽

1980 ◽

Vol 8 (1) ◽

pp. 16-19 ◽

Cited By ~ 3

Author(s):

N. M. Cass ◽

W. A. Brown ◽

K. C. No ◽

D. G. Lampard

Keyword(s):

Rise Time ◽

Recovery Time ◽

Neuromuscular Transmission ◽

Integrated Electromyogram ◽

Computer Controlled

Paralysis was maintained in the sheep for 30 or 90 minutes by computer-controlled injection of gallamine, pancuronium, alcuronium or d-tubocurarine, using the integrated electromyogram as a measure of neuromuscular transmission. Neostigmine was given and the recovery time measured. In all trials the recovery rise time was no longer than two minutes, but varied between one and two minutes.

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Dosage Patterns of Non-Depolarizing Neuromuscular Blockers in the Sheep

Anaesthesia and Intensive Care ◽

10.1177/0310057x8000800103 ◽

1980 ◽

Vol 8 (1) ◽

pp. 13-15 ◽

Cited By ~ 4

Author(s):

N. Cass ◽

W. A. Brown ◽

K. C. Ng ◽

D. G. Lampard

Keyword(s):

Steady State ◽

Infusion Rate ◽

Neuromuscular Transmission ◽

Maintenance Phase ◽

Moderate Amount ◽

Neuromuscular Blockers ◽

Integrated Electromyogram ◽

Computer Controlled ◽

Onset Phase

Eighty per cent paralysis was induced and maintained for 90 minutes in the sheep by computer-controlled injection of gallamine, pancuronium, alcuronium or d-tubocurarine, using the integrated electromyogram as a measure of neuromuscular transmission. The dosage pattern consisted of a loading phase before any IEMG depression was detected, an onset phase during which a moderate amount of drug was required to achieve increasing paralysis, and a maintenance phase during which a substantially constant and relatively low infusion rate was required. The steady state rates of infusion in μg/kg/min during “maintenance” was found to be 6.0 for gallamine, 0.15 for pancuronium, 0.2 for alcuronium and 0.5 for d-tubocurarine.

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