Canadian Journal of Anesthesia, Vol 9, 306-311, Copyright © 1962 by Canadian Anesthesiologists' Society

Intramuscular Succinylcholine for Endotracheal Intubation in Infants and Children. II

¹ Hôpital Maisonneuve, Montreal, Quebec

In a period of three years over 400 children and infants of the age of a few hours to 10 years were intubated after being given succinylcholine chloride in a 10 per cent solution intramuscularly. The smaller the child the faster the full relaxation took place after the injection, i.e., in a period of time that varies between 1 minute or less to 3 minutes. The dosage of the succinylcholine was: 1 mg. per pound of body weight in patients the age of 3 years and younger and 2 mg. per pound in patients 4 years and older.

The advantages of this method were:

1. Smooth and short induction of anaesthesia.

2. It was considered good for bad risk cardiac patients as any straining and crying could be avoided.

The main objections were:

1. That an infant or child may be difficult or impossible to intubate even if a relaxant was given, and therefore it was considered unsafe to give a relaxant to an infant or child prior to intubation. The author of this article did not find any difficulties in intubation in his series, but considers that a recession of the chin or protrusion of maxilla (Pierre-Robin syndrome), which can be detected prior to the induction of anaesthesia, is a contraindication for giving a relaxant prior to intubation. Cleft palate and lip was not considered a contraindication for the method.

2. That it is difficult to keep the natural airway patent during the period of partial paralysis until the drug is fully effective. We think that this difficulty may be caused by breathholding and straining of the patient if controlled respiration, instead of assisted, is attempted before the patient is fully relaxed.

3. That injection of succinylcholine in an infant or child may cause a marked bradycardia. The injection of the above-mentioned dosage of succinylcholine i.m. does not seem to cause a slowing of the heart.

4. That the pulmonary inflation or intubation of a very lightly anaesthetized patient may cause a slowing of the heart and sinus arrhythmias due to parasympathetic stimulation. To avoid this I consider that the use of atropine in premedication is essential.