British Journal of Anaesthesia, 1980, Vol. 52, No. 2 205-214
© 1980 The Board of Management and Trustees of the British Journal of Anaesthesia
research-article |
MATURATION OF NEUROMUSCULAR TRANSMISSION IN THE INFANT
Department of Anaesthesia, Harvard Medical School at the Massachusetts General Hospital Boston, Massachusetts 02114, U.S.A.
Twitch tension, train-of-four and tetanusclinical parameters of neuromuscular transmission were studied in 37 infants and children anaesthetized with halothane. The contraction time was slower in infants less than 1 month old when compared with their elder counterparts. This may indicate a possible transformation from slow to faster muscle types. The train-of-four reached 100% in most of the infants older than 2 months. The post-tetanic facilitation and the tetanus twitch ratios were significantly greater in infants older than 2 months when compared with infants less than 1 month. Post-tetamc exhaustion was seen in all the infants and children after stimulation at 100 Hz. Tetanus : twitch ratios were greater in infants more than 2 months old and in children, and the tetanic force was more marked at 50 Hz than at 20 Hz. The data indicate that maturation of neuromuscular transmission occurs in infants in and around the first 2 months of age.