A sleep position-dependent mechanism for infant death on sheepskins

J. S. Kemp and B. T. Thach
Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St Louis, MO 63110.

OBJECTIVE--To determine whether rebreathing of expired air is a plausible lethal mechanism of sudden death in infants sleeping face down on sheepskins. DESIGN--Case reports of infants who died on sheepskins combined with a controlled study of effects of their respiratory microenvironment at death. SETTING--Research laboratory. MATERIALS--Rabbits used experimentally to assist in simulation of an infant's respiratory microenvironment. Rabbits breathed into sheepskin through the airway of an infant mannequin. INTERVENTION--None. MEASUREMENTS/MAIN RESULTS--Rebreathing of expired air was documented by carbon dioxide analysis of airway gas. Arterial blood gas analysis showed hypoxemia, hypercarbia, and acidosis in all experimental rabbits but not in controls. Rebreathing expired air was lethal for three of four experimental rabbits. CONCLUSIONS--Infants sleeping prone on a sheepskin, with their faces straight down, experience potentially lethal rebreathing of expired air. Avoidance of the prone position would markedly reduce the risk of rebreathing expired air. The pronounced decrease in sudden infant death syndrome in southern New Zealand that followed a campaign to eliminate prone sleeping may have been attributable to reduced fatal rebreathing, as deaths of infants sleeping face down on sheepskins were common before the campaign.

THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES

Inspired CO2 and O2 in sleeping infants rebreathing from bedding: relevance for sudden infant death syndrome
Patel et al.
J. Appl. Physiol. 2001;91:2537-2545.
ABSTRACT | FULL TEXT  

Effects of the supine and prone position on diaphragm thickness in healthy term infants
Rehan et al.
Arch. Dis. Child. 2000;83:234-238.
ABSTRACT | FULL TEXT  

Changing Concepts of Sudden Infant Death Syndrome: Implications for Infant Sleeping Environment and Sleep Position
Task Force on Infant Sleep Position and Sudden Inf
Pediatrics 2000;105:650-656.
ABSTRACT | FULL TEXT  

Changing Infants' Sleep Position Increases Risk of Sudden Infant Death Syndrome
Mitchell et al.
Arch Pediatr Adolesc Med 1999;153:1136-1141.
ABSTRACT | FULL TEXT  

Influence of core temperature on autoresuscitation during repeated exposure to hypoxia in normal rat pups
Serdarevich and Fewell
J. Appl. Physiol. 1999;87:1346-1353.
ABSTRACT | FULL TEXT  

Mechanical model testing of rebreathing potential in infant bedding materials
Carleton et al.
Arch. Dis. Child. 1998;78:323-328.
ABSTRACT | FULL TEXT  

Consequences of Getting the Head Covered During Sleep in Infancy
Skadberg and Markestad
Pediatrics 1997;100:e6-e6.
ABSTRACT | FULL TEXT  

Infant Sleep Position and the Sudden Infant Death Syndrome: A Survey of Pediatric Recommendations
Carolan et al.
CLIN PEDIATR 1995;34:402-409.
ABSTRACT  

The Risk of Sudden Infant Death
Cohle et al.
NEJM 1994;330:63-64.
FULL TEXT