RT Journal Article SR Electronic T1 Mechanical model testing of rebreathing potential in infant bedding materials JF Archives of Disease in Childhood JO Arch Dis Child FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP 323 OP 328 DO 10.1136/adc.78.4.323 VO 78 IS 4 A1 James N Carleton A1 Ann M Donoghue A1 Warren K Porter YR 1998 UL http://adc.bmj.com/content/78/4/323.abstract AB Rebreathing of expired air may be a lethal hazard for prone sleeping infants. This paper describes a mechanical model to simulate infant breathing, and examines the effects of bedding on exhaled air retention. Under simulated rebreathing conditions, the model allows the monitoring of raised carbon dioxide (CO2) inside an artificial lung–trachea system. Resulting levels of CO2(although probably exaggerated in the mechanical model compared with an infant, due to the model’s fixed breathing rate and volume) suggest that common bedding materials vary widely in inherent rebreathing potential. In face down tests, maximum airway CO2 ranged from less than 5% on sheets and waterproof mattresses to over 25% on sheepskins, bean bag cushions, and some pillows and comforters. Concentrations of CO2 decreased with increasing head angle of the doll, away from the face down position. Recreations of 29 infant death scenes also showed large CO2 increases on some bedding materials, suggesting these infants could have died while rebreathing.