Distribution of expired air in carry cots--a possible explanation for some sudden infant deaths.

A possible explanation for the cause of some cot deaths is examined by placing an appropriate cot death model on a cold wet sheet so that its "breath" is directed downwards across the sheet, thereby being cooled and becoming heavy enough to stay trapped in the hollow of the mattress. The breath is then available for rebreathing by the model. The level of carbon dioxide (CO2) "inhaled" is showed to be lower in nostril breathers, singletons and in bassinets and higher with mouth breathing models, in "twins", and in carry cots, especially if the model's head is accidentally covered. Under these conditions a living infant would become progressively acidotic due to inability to adequately excrete its metabolic CO2. This must inevitably be accompanied by increasing hypoxia. If left undisturbed in this predicament, it would rebreathe its own breath for the period of time between feeds and develop increasing degrees of asphyxia, depending on the circumstances outlined.