Infant Asphyxia, Soft Mattresses, and the "Trough" Effect

Abstract

Although unexpected infant death in a cot has traditionally been attributed to sudden infant death syndrome, careful evaluation of death scenes and sleeping environments has increasingly identified deaths due to accidental asphyxia from so-called sleeping accidents. The case of a 5-month-old infant boy who was found facedown and unresponsive in a wooden portable cot with a sagging canvas base is reported to illustrate another potentially lethal situation. Although the autopsy revealed no specific findings, examination of the cot showed a significant depression caused by the sagging canvas base that was exacerbated by a soft-foam mattress and layers of bedding. Once in the trough, the infant would not have been able to extricate himself. Death was therefore attributed to accidental suffocation due to the infant's position resulting in contact of the mouth and face with soft bedding. In addition to again demonstrating the potential dangers of using old second-hand cots, this case clearly shows the problems that may exist when soft and sagging bedding forms a central trough that may entrap an infant. Death scene investigators should specifically comment on the presence of such troughs and measure of depth of the trough and/or cot base to provide some quantification of the degree of concavity present.

Infant gender, shared sleeping and sudden death

“…The formation of a trough between the parent and mattress also presents a potentially dangerous situation, particularly for young infants. Splinting of the infant chest may also be a contributing factor 11 …”

Application of a classification system focusing on potential asphyxia for cases of sudden unexpected infant death

“…We were unable to demonstrate any meaningful differences in classification assignment between the five reviewers. One forensic (13)(14)(15)(16)(17)(18)(19) pathologist and the pediatric pathologist were slightly less inclined to designate SIDS than the remaining two forensic pathologists. The rate that the pathology resident used SIDS as a cause of death fell between these two groups.…”

“…Their classification resulted from recognition by scene investigators that an asphyxial sleep environment is the most commonly encountered contributing factor or actual cause of death; factors predisposing to asphyxia included prone sleep position, soft bedding, especially those that allow creation of a trough from the weight of the baby [15], bed sharing, bed covers, and devices designed to prevent prone sleeping [16]. We recognize that established criteria for possible asphyxia do not exist in SUID.…”

Sudden Unexpected Death in Infancy (SUDI) — The Role of the Pathologist

“…Identification of unsafe practices may include the assessment of specific types of sleeping environments, feeding patterns, or household activities such as bathing [85][86][87][88][89]. Publicizing such deaths may lead to the recall or modification of defective products.…”