PHYSIOLOGICAL MANAGEMENT COMPARED WITH PHARMACOLOGICAL AND ELECTRICAL STIMULATION IN BARBITURATE POISONING

¹ Division of Neurology, Department of Medicine, University of Washington School of Medicine, Seattle

Experimental barbiturate poisoning was produced in 61 cats and 8 dogs by pentobarbital sodium given intravenously at a rate of 10 mgm./kgm. every five minutes.

The respiratory arrest dose (RAD) of pentobarbital sodium in cats given no specific treatment was 69 mgm./kgm. Artificial respiration supported life in animals until doses of barbiturate averaging 4.3 times the RAD had been given. Treatment with neosynephrine in addition to artificial ventilation sustained life until doses of barbiturate averaging 6.7 times the RAD had been given.

Picrotoxin reinstated spontaneous respiration in animals which had received pentobarbital dosages up to, but not beyond, 2.0 times the RAD. Cardiac arrhythmias appeared during administration of picrotoxin in three-fifths of the animals who remained apneic. Convulsions were frequent with picrotoxin treament.

Mikedimide reinstated spontaneous respiration in animals which had received pentobarbital dosages up to, but not beyond, 1.4 times the RAD. Cardiac arrhythmias appeared during drug administration in one-fifth of all animals treated with Mikedimide. Generalized convulsions appeared in two-thirds of the animals who remained apneic.

Non-convulsive electrical stimulation (ES) failed to initiate respiration in any animal who had been poisoned with 1.28 times the RAD of pentobarbital sodium. No pressor response was observed even when convulsive amperages were employed.