Acute Life-Threatening Events and SIDS

Sudden infant death syndrome (SIDS) is the sudden death of an infant with no apparent pathological cause on post-mortem. It is commonly known as ‘cot death’ since typically the death occurs overnight in the baby’s cot. It is vital for the family to have a thorough investigation of the sudden death. A detailed case investigation needs a combined approach by a senior paediatrician, social services and police professionals. There is review of the history and clinical examination findings, examination of the scene of death to consider any environmental risk factors and a later meeting to review post-mortem results. It is very important to involve the family in this process to give as full an explanation as possible of the events and what can be understood about their child’s death.

Sometimes infants are found in a collapsed state, not breathing and looking grey or mottled, but can be successfully resuscitated. This is referred to as an acute life-threatening event (ALTE) or as ‘near-miss cot death’. All of these cases need careful medical and sometimes forensic investigation to try to establish a cause.

SIDS is the commonest cause of death (40%) in infants after the first week of life. The rate varies in different countries, but in the UK is currently 0.45 per 1000. The exact aetiology remains unknown and is probably multifactorial. A triple-risk model has been proposed (see box) which may explain the fact that SIDS peaks between 2 and 4 months, and 90% occur before 6 months of age.

In the UK the incidence of SIDS has fallen by over 50% as a result of the ‘Back to Sleep’ campaign (see box) which advises that babies should be put to sleep on their backs, at the foot of the cot, not overwrapped or overheated. This followed research which established that there is an eightfold increase in SIDS if the child sleeps in the prone position and a twofold risk in the side-lying position. Other risk factors include cigarette smoke in the home, parental alcohol intake and co-sleeping. There is some recent evidence that keeping the baby in the parents’ bedroom (but not bed-sharing) and the use of a dummy (pacifier) may be associated with a reduced risk of SIDS. A small number of what initially appear to be SIDS cases may be due to non-accidental injury with atypical history or abnormal findings on post-mortem. In the UK the ‘Care of the Next Infant’ (CONI) project can provide support to families who have suffered a sudden death in infancy to try to reduce the small possibility of recurrence through advice about risk factors, regular monitoring check-ups and resuscitation training. The use of breathing alarm (apnoea) monitors is controversial but some parents find them reassuring.

Sudden unexpected death in childhood (SUDIC) is a broader category where a child has died unexpectedly from any cause. It is best practice to review all such deaths (e.g. road traffic accidents, acute catastrophic infection) through a multidisciplinary approach so health protection agencies can learn lessons and also to provide as full an explanation as possible to the family.

Acute Life Threatening Events

A large number of infants are admitted to hospital following an apparent acute life-threatening event (ALTE). This may be from an obvious cause such as choking on a bottle feed to unexplained apnoeic episodes or even a ‘near-miss cot death’ where the child has been successfully resuscitated. All these infants need careful evaluation and usually a period of observation and monitoring in hospital. In difficult cases prolonged cardiac, respiratory, oxygenation and even video analysis may be necessary to establish the sequence of events. Common causes include gastro-oesphageal reflux, infection (e.g. RSV bronchiolitis) and anaemia. Inborn errors of metabolism, seizures and cardiac arrhythmias are more unusual findings.

Parental support must be offered. There is controversy over the role of apnoea monitors, but they may provide parental reassurance in selected cases.