SUDDEN INFANT DEATHS - SOME CURRENT RESEARCH STRATEGIES

Some 45 scientists from Australia and New Zealand participated in a workshop on sudden infant death syndrome (SIDS) research. The pathologists emphasized the need for a cooperative effort to assemble control material, since accidental deaths are rare in he SIDS age range. Animal experiments on respiratory and circulatory factors in the genesis of intrathoracic petechiae were presented. Acute asphyxial factors in SIDS were accepted, but further work was recommended on evidence currently attributed to chronic hypoxia. The physiologists focused their discussions on breathing mechanisms in the fetus and newborn, on apnoea and states of depressed arousal, and on the problems of home-monitoring. Sleep apnoea and 'near-miss' SIDS syndromes were related to the loss of muscle tone in the upper airway during REM-sleep, to the possible enlargement of the tongue with artificial feeding, and to laryngeal obstructions from vagal damage or temporal lobe seizures. The biochemists discussed 'sudden' death syndromes of poultry associated with hypoglycaemia, the effects of hypoglycaemia on disturbances of breathing, and the mechanism of fatal apnoea induced by chlormethiazole ('half' thiamine). Veterinary models were discussed for postnatal deaths during minor stress, and from preceding occult damage to the nervous system (after prenatal hyperthermia in the guinea-pigs, in foals from working-mixtures which damaged the recurrent laryngeal nerves, and in newborn foxes from thiamine deficiency). Epidemiological clues from SIDS infants included depressed reaction to needle prick, excessive sweating, fatigue and stress, and possible uneven geographical distributions.