Detecting wakefulness in anaesthetised children

To investigate the suitability of the isolated forearm technique in detecting wakefulness in children aged 8 to 16 yr. Forty-one healthy English speaking children were enrolled. Following intravenous induction of anaesthesia with 5-7 mg.kg-1 thiopentone iv, but before administration of 1-1.5 mg.kg-1 succinylcholine a pneumatic tourniquet was inflated to 50 mmHg above systolic pressure in order to isolate the non-cannulated forearm. Thereafter, anaesthesia was maintained with halothane 1.5-2.5% in nitrous oxide and oxygen. Following the muscle relaxant the patient was instructed to move the unparalyzed arm. Movement was checked at 30 sec intervals and if present on command, identified as wakefulness. Movement of the isolated forearm to command was observed in 19.5% of children. The youngest child to respond was five years old. The isolated forearm technique can be used to detect wakefulness during and immediately following tracheal intubation in children from the age of five years.