title: Rebreathing expired gases from bedding: a cause of cot death?
abstract: The reported association of cot death and sleeping prone could be due to rebreathing of expired gases. A mechanical model simulating the respiratory system of an infant, exhaling warm humidified air with an end tidal carbon dioxide of 5%, has been used to investigate this. Some commonly used bedding materials caused an accumulation of carbon dioxide of 7% to over 10% with the model lying face down. This phenomenon persisted even with the head inclined at 45 degrees, but only on very soft materials, and could be a cause of cot death in a baby unresponsive to asphyxial blood gas changes. A coir fibre mattress allowed complete dispersal of exhalate as did a rubber sheet between any mattress and the covering sheet.
authors.affiliation: Department of Physiology, University of Otago Medical School, Dunedin, New Zealand.
authors.forename: D P
authors.initials: DP
authors.lastname: Bolton
authors.forename: B J
authors.initials: BJ
authors.lastname: Taylor
authors.forename: A J
authors.initials: AJ
authors.lastname: Campbell
authors.forename: B C
authors.initials: BC
authors.lastname: Galland
authors.forename: C
authors.initials: C
authors.lastname: Cresswell
mesh_terms: D001237:Asphyxia / Q000150:complications*; D001512:Bedding and Linens; D003625:Data Collection / Q000379:methods; D006801:Humans; D007223:Infant; D008954:Models, Biological; D016684:Prone Position; D012119:Respiration / Q000502:physiology*; D013398:Sudden Infant Death / Q000209:etiology*