A 3-month-old boy is discovered not breathing in his crib this morning. Cardiopulmonary resuscitation was begun by the parents and was continued by paramedics en route to the hospital. You continue to try to revive the child in the emergency center, but pronounce him dead after 20 minutes of resuscitation. You review the history with the family and examine the child, but you are unable to detect a cause of death.
How should you manage this situation in the emergency department?
What is the most likely diagnosis?
What is the next step in the evaluation?
ANSWERS TO CASE 23: Sudden Infant Death Syndrome
Summary: A 3-month-old boy discovered not breathing by his parents.
• First step: Tell the boy’s parents that despite everyone’s best efforts, their son has died. Ask the parents if they would like you to call a friend, family member, religious leader, or other support person. Provide them with a quiet room where they can be left alone.
• Most likely diagnosis: Sudden infant death syndrome (SIDS) is the most likely diagnosis, assuming that the parents’ story is true. Infanticide must be considered, as well as the possibility of an underlying congenital or metabolic disorder.
• Next step: Discuss with the parents that routine protocol is followed after an unexplained infant death. A coroner will perform an autopsy and police investigators will examine the parents’ home for clues related to the death. Emphasize that these measures can help to bring closure for the family and may yield important information for preventing future child deaths should the couple have more children.
1. Know the definition of SIDS.
2. Know the factors that are associated with SIDS.
3. Know how to counsel parents about SIDS risk–reducing measures.
Sudden infant death syndrome is one of the most tragic and frustrating medical diagnoses. When the family is in the emergency center, other possible causes of death (eg, child abuse or inherited disorders) cannot be excluded. Your role is to remain objective about these other possibilities yet sympathetic to the parents’ grieving. As always, meticulous documentation of the history and physical examination findings is imperative.
Sudden Infant Death Syndrome
APPARENT LIFE-THREATENING EVENT (ALTE): Observations and events perceived by a caregiver as life-threatening. By definition, the event is observed. Myriad conditions may be responsible, including cardiac, respiratory, central nervous system (CNS), metabolic, infectious, and gastrointestinal causes. In approximately 50% of cases a cause is never known.
APNEA:Cessation of breathing for at least 20 seconds that may be accompanied by bradycardia or cyanosis. Recurrent episodes of apnea related to immaturity may occur in premature infants, but usually resolve by 37 weeks postgestational age.
SUDDEN INFANT DEATH SYNDROME (SIDS): The sudden death of an infant that cannot be explained by results of a postmortem examination, death scene investigation, and historical information.
Sudden infant death syndrome is the most common cause of death in infants between the ages of 1 week and 1 year. The majority of SIDS deaths occur between 1 and 5 months of age, with a peak incidence between 2 and 4 months of age; it is more common in winter. SIDS is more common among African-American and Native-American infants; whether these latter associations result from ethnicity or reflect other environmental factors is unclear.
No cause of SIDS has been identified. Epidemiologic studies suggest that the following are independent SIDS risk factors: prone or side sleep position, sleeping on a soft surface, bed sharing, pre- and postnatal exposure to tobacco smoke, maternal prenatal use of opiates, over-heating, late or no prenatal care, young maternal age, prematurity and/or low birth weight, and male gender. The incidence of SIDS has decreased dramatically in areas with public education campaigns targeted at limiting prone sleep positioning. The investigation of the unexpected infant death includes a clinical history, a postmortem examination, and a death scene investigation. In some infants, autopsy reveals mild pulmonary edema and scattered intrathoracic petechiae; these findings are supportive but not diagnostic of SIDS.
Explainable causes of sudden infant death can be divided into congenital and acquired conditions. Congenital conditions include cardiac anomalies (arrhythmia, congenital heart disease), metabolic disorders, and CNS etiologies. Acquired causes include infection and both accidental and intentional trauma. Infants who have experienced an ALTE may be at risk for sudden death. The evaluation of an ALTE infant is guided by the history and physical examination. A report of feeding difficulties or emesis leads to consideration of swallowing studies, whereas unusual posturing or movements leads to an electroencephalogram. A complete blood count and serum bicarbonate level obtained close to the time of the event may help to uncover an infectious or metabolic etiology. An electrocardiogram may be considered to look for prolonged QT syndrome or other cardiac anomaly. Documented cardiorespiratory monitoring and polysomnography can be helpful in some cases.
In the past, infants with a history of apnea were thought to be at risk for SIDS, but more recent epidemiologic research has refuted this hypothesis. Siblings of infants who have died of SIDS have been reported to potentially be at increased risk of SIDS themselves, but the role of a possible genetic susceptibility versus environmental factors and unrecognized infanticide in these cases is unclear.
23.1 Which of the following infants most warrants home cardiorespiratory monitoring?
A. A healthy 3-month-old infant, born at term, whose weight is at the 5th percentile
B. A healthy infant, born at 29 weeks’ gestation, whose weight is at the 50th percentile
C. A 5-month-old infant with a history of recurrent bouts of wheezing
D. A premature infant with recurrent apnea and bradycardia
E. A healthy term infant whose older sibling died of SIDS
23.2 A pregnant woman comes to you for a prenatal visit. As her family pediatrician, your advice to her should include which of the following statements about reducing the risk of SIDS?
A. Reduce the infant’s exposure to tobacco smoke, and always place the baby in the supine position when she sleeps.
B. Always keep the baby in the prone position, even while awake.
C. Administer supplemental infant vitamins.
D. Attempt to make breast milk the infant’s primary source of nutrition.
E. Protect the infant from people who are ill.
23.3 Which of the following statements about the environment to reduce SIDS is accurate?
A. Infants should sleep in the same bed as the parent or on their chest so they can be closely monitored for apnea.
B. Infants should sleep on a firm mattress with no accompanying soft bedding or objects, including no devices advertised to maintain the sleep position.
C. Pacifiers should be avoided as they can obstruct the baby’s airflow during respiration.
D. Infants placed to sleep on their backs will have more episodes of plagiocephaly, reflux, choking, and ALTEs.
E. Infants should be given acetaminophen before their scheduled vaccines in order to prevent an undetected febrile seizure and resulting SIDS.
23.4 The investigation of an unexpected infant death includes a history, a postmortem examination, and which of the following?
A. DNA studies
B. An arterial blood gas measurement
C. A venous blood gas measurement
D. A death scene investigation
E. Stool studies
23.1 D. Home cardiorespiratory monitoring has not been shown to decrease the incidence of SIDS. Monitoring is recommended for symptomatic premature infants (ie, those with apnea and bradycardia), but can safely be discontinued by 43 weeks postgestational age in most cases. Monitoring may also be warranted for children with certain underlying chronic conditions, such as those with chronic lung disease. It is not recommended for the infants in choices A, B, or C. The occurrence of a genetic susceptibility to SIDS within a family is thought to be exceedingly rare.
23.2 A. Although your advice to this woman might also include choices C, D, and E, these measures have not been shown to reduce the infant’s risk of SIDS.
23.3 B. The decline in SIDS from 20 years ago has been attributed to the change in sleep position. Recently, pacifier use has been identified as a protective measure. Infants who have died of SIDS have been less likely to have been immunized. While there has been an increase in positional plagiocephaly since the Back to Sleep campaign, it can be avoided with adequate tummy time, frequent upright holding, and alternating the crib orientation. The other events have not occurred with increased incidence.
23.4 D. A death scene investigation is crucial to rule out trauma, both intentional and accidental.
Sudden infant death syndrome (SIDS) is a diagnosis of exclusion assigned only after the postmortem investigation, postnatal history, and crime scene investigation fail to yield another explanation.
Prone sleep position and exposure to cigarette smoke are significant risk factors for SIDS.
Apparent life-threatening events (ALTE) are observed occurrences that can be caused by myriad etiologies.
Apnea of prematurity is not a risk factor for SIDS.
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