SIDS, also known as crib death or cot death, is the most common cause of death in the post-neonatal period. As many as 1 in 10 Neonatal Intensive Care Unit patients with the diagnosis of chronic lung disease, with or without a tracheostomy, when discharged may die suddenly at home without apparent reason, only some of which are appropriately classified as SIDS.

Vulnerable Infant

Generally, the "vulnerable infant" is born to young, single, uneducated and socially deprived parents with or without a family history of SIDS, and is suffering from a mild upper airway infection. Then this infant is exposed to a "vulnerable environment", which initiates the brain stem abnormality and dysfunction Evidence now suggests that smoking, not only by the mother during and after pregnancy but also by members of the household increases the risk for SIDS.

Vulnerable Environment

Irritants in the child's environment that cause airway swelling are a critical factor. Smoke (cigarette, wood burning stove), dust, dander, and hair are some of the agents that are responsible for airway hyperactivity and increased secretions. Sleeping in a prone position probably compounds the obstructive and mixed apneas with which these infants are faced. The Canadian Pediatric Society and the American Academy of Pediatrics now recognize this and are endeavoring to encourage parents to position their newborn babies on their side or back for sleeping.

Unsafe Sleeping Environments

Soft, loosely filled cushions, water beds, and bean bags that can conform to the infant's body and head are especially dangerous. Infants lying face down are vulnerable to re-breathing expelled air. In addition, an obstruction results from pushing the mandible and tongue posteriorly, thereby further aggravating obstructive apnea. In spite of Federal guidelines and warning labels, there still are older, unsafe cribs and mattresses in use. An adult lying on the child has been cited as a cause of sudden infant death since the time of King Solomon and, therefore, co­sleeping should be discouraged. Regurgitated materials and feces on the bedding can cause increased growth of microbials that may adversely affect the infant.

The temperature in the baby's immediate environment is a critical factor. Over-wrapping and exposure to direct heat cause hyperthermia, which is known to induce abnormalities of ventilatory control and brain stem dysfunction. Sweat glands are active in the baby's scalp and scalp sweating can be used as a clinical indicator. Primary care givers should routinely ask parents regarding scalp sweating.

Vulnerable Brain Stem

An abnormality of brain stem maturation and cardiorespiratory control continues to be one of the most compelling hypotheses for the occurrence of SIDS. The clinical presentation of an abnormal brain stem function is the occurrence of repetitive central, obstructive, and/or mixed apneas. A deficit of the arousal and gasping mechanism follows the brain stem dysfunction. This is not an absolute requirement for SIDS.

Unique Pediatric Airways and Sleep States

It is well recognized that pediatric upper airways are narrower than adults. Swelling of the airway mucosa frequently occurs from irritation and infection. Rapid eye movement sleep (REM) in this age group induces irregular breathing patterns and apneas, which makes the airways even more vulnerable. The inhibition of monosynaptic reflexes during REM cause laxity of upper airways, which in turn aggravate the apneic states. These events produce varying degrees of hypoxia and desaturation during sleep.

Support and Treatment for the Family

SIDS is an extraordinarily devastating experience that occurs with no warning. The family is left in a state of shock. The medical community's approach has changed dramatically over the years and now has become more compassionate and caring, with a better understanding of grief reactions and the differences in grieving that exist within the family. The father may react differently from the mother, and there may be divergent responses to the possibility of subsequent children. Appropriate supportive and counseling services for individuals, the family and the community are essential. An autopsy should be performed in all cases of sudden unexplained death and the results made available to the primary care physicians so they can review the autopsy findings with the family and help them. A follow up system should be in place to help the family adjust and cope.