Sudden Infant Death Syndrome

CONTINUITY CLINIC Objectives Describe possible etiologic mechanisms for sudden infant death syndrome (SIDS). Describe possible etiologic mechanisms for sudden infant death syndrome (SIDS). Identify the risk factors for SIDS. Identify the risk factors for SIDS. Understand the relationship between apnea and SIDS. Understand the relationship between apnea and SIDS.

CONTINUITY CLINIC ALTE definition frightening to the observer frightening to the observer characterized by some combination of characterized by some combination of apnea apnea color change color change marked change in muscle tone marked change in muscle tone choking choking gagging gagging Often elicits vigorous stimulation or resuscitation Often elicits vigorous stimulation or resuscitation

CONTINUITY CLINIC Factoids prevalence from 0.05% to 6.0% prevalence from 0.05% to 6.0% most with ALTE do not die of SIDS most with ALTE do not die of SIDS combined prevalence of SIDS among other family members of infants w/ ALTE = 11% combined prevalence of SIDS among other family members of infants w/ ALTE = 11% most with SIDS have never had ALTE most with SIDS have never had ALTE % w/o ALTE % w/o ALTE median age at presentation = 2 months median age at presentation = 2 months slight male predominance slight male predominance

CONTINUITY CLINIC Causes GE Reflux28% GE Reflux28% Neurologic problems12% Neurologic problems12% Infection 6% Infection 6% Upper Airway Obstruction 2% Upper Airway Obstruction 2% Metabolic problems 2% Metabolic problems 2% Cardiac problems 1% Cardiac problems 1% Idiopathic47% Idiopathic47%

CONTINUITY CLINIC Work-Up HISTORY

CONTINUITY CLINIC Home Monitor? 1986 NIH Consensus Conference on Infantile Apnea and Home Monitoring 1986 NIH Consensus Conference on Infantile Apnea and Home Monitoring definitely indicated for: definitely indicated for: severe ALTE severe ALTE tracheostomy <18 months old tracheostomy <18 months old ISAM’s (infants of substance abusing mothers) ISAM’s (infants of substance abusing mothers) twin of SIDS victim twin of SIDS victim not indicated not indicated normal infant normal infant asymptomatic premature infant asymptomatic premature infant

CONTINUITY CLINIC Questionable Risk Group Sibling of SIDS Sibling of SIDS Moderate ALTE – what are the criteria for this…….not clear Moderate ALTE – what are the criteria for this…….not clear decision based decision based risks, benefits, liabilities, and limitations risks, benefits, liabilities, and limitations parent - provider decision parent - provider decision

CONTINUITY CLINIC Monitor Requirements home telephone home telephone basic infant CPR instruction for all caregivers basic infant CPR instruction for all caregivers use and trouble shooting of monitor for all caregivers use and trouble shooting of monitor for all caregivers 24’ medical and technical back-up 24’ medical and technical back-up

CONTINUITY CLINIC SIDS background decreasing infant mortality this century decreasing infant mortality this century one category of infant death not decreasing one category of infant death not decreasing “SIDS” title given “SIDS” title given Steinschneider A: Prolonged apnea and the sudden infant death syndrome. Pediatrics 1972; 50 (4): 646. Steinschneider A: Prolonged apnea and the sudden infant death syndrome. Pediatrics 1972; 50 (4): definition expanded by NICHD definition expanded by NICHD

CONTINUITY CLINIC causes of infant death <1 year old, 1992

CONTINUITY CLINIC Definition of SIDS Sudden death of an infant under 1 year old that can not be explained despite: autopsy within 24’ incl. skeletal survey, tox and metabolic screens autopsy within 24’ incl. skeletal survey, tox and metabolic screens prompt examination of the death scene including interviews of household members by knowledgeable indevidual prompt examination of the death scene including interviews of household members by knowledgeable indevidual review of the clinical history from caretaker, key medical providers and medical records review of the clinical history from caretaker, key medical providers and medical records

CONTINUITY CLINIC AAP Addition to Evaluation Exam of the dead infant at a hospital ED by a child maltreatment specialist Exam of the dead infant at a hospital ED by a child maltreatment specialist 1-5% of SIDS may be infanticide 1-5% of SIDS may be infanticide clues to infanticide clues to infanticide > 6 months old > 6 months old previous unexpected or unexplained sibling death previous unexpected or unexplained sibling death simultaneous death of twins simultaneous death of twins

CONTINUITY CLINIC Etiology - broad no common etiology- multifactorial no common etiology- multifactorial final common pathway may be: final common pathway may be: failure to arouse to cope w/ homeostatic challenge failure to arouse to cope w/ homeostatic challenge abnormal development of the control of cardiorespiratory systems abnormal development of the control of cardiorespiratory systems maldevelopment of fetal to newborn transition mechanism maldevelopment of fetal to newborn transition mechanism

CONTINUITY CLINIC Etiology - focused developing nervous system developing nervous system developing immune system developing immune system inherited metabolic disease inherited metabolic disease changes in cardiac conduction system changes in cardiac conduction system changes in respiratory control changes in respiratory control non-accidental trauma non-accidental trauma

CONTINUITY CLINIC Baruch’s Observation “If all you have is a hammer, everything looks like a nail.”

CONTINUITY CLINIC Epidemiologic studies NICHD Cooperative Epidemiologic Study of SIDS Risk Factors NICHD Cooperative Epidemiologic Study of SIDS Risk Factors New Zealand Cot Death Study New Zealand Cot Death Study Avon Infant Mortality Study Avon Infant Mortality Study King County Washington SIDS Study King County Washington SIDS Study

CONTINUITY CLINIC NICHD SIDS Study Oct ‘78 - Dec '79 Oct ‘78 - Dec '79 multicenter, population based, case controlled multicenter, population based, case controlled 838 SIDS 838 SIDS 1676 controls 1676 controls age-matched living - randomly selected age-matched living - randomly selected age-matched living - matched for race and low birth weight age-matched living - matched for race and low birth weight

CONTINUITY CLINIC NICHD Study - conclusion “None of the risk factors documented are of sufficient strength to enable identification of SIDS infants prior to their death. Instead a descriptive profile has emerged that associates several maternal, neonatal, and postnatal factors with increased SIDS risk.” “None of the risk factors documented are of sufficient strength to enable identification of SIDS infants prior to their death. Instead a descriptive profile has emerged that associates several maternal, neonatal, and postnatal factors with increased SIDS risk.”

CONTINUITY CLINIC NICHD SIDS Study - results maternal factors inadequate prenatal care inadequate prenatal care smoking smoking anemia anemia ISAM ISAM VD VD UTI UTI

CONTINUITY CLINIC NICHD SIDS Study - results other factors low birth weight low birth weight inadequate post-natal care inadequate post-natal care lack of breast feeding lack of breast feeding GI infections GI infections

CONTINUITY CLINIC NICHD SIDS Study - results non-factors URI’s URI’s apnea of prematurity apnea of prematurity

CONTINUITY CLINIC New Zealand Cot Death Study multicenter, prospective, case-controlled multicenter, prospective, case-controlled covered 78% of all births covered 78% of all births 485 cot deaths 485 cot deaths 1800 random controls - matched for post-natal age 1800 random controls - matched for post-natal age

CONTINUITY CLINIC New Zealand Study - results significant avoidable risks prone sleeping position prone sleeping position co-sleeping co-sleeping not breast fed not breast fed maternal smoking maternal smoking

CONTINUITY CLINIC Avon Infant Mortality Study Avon County in SW England Avon County in SW England pop. 940,000 with 13,000 births/year pop. 940,000 with 13,000 births/year 1 coroner, 1 Peds Path, 3 OB units 1 coroner, 1 Peds Path, 3 OB units all unexpected deaths all unexpected deaths detailed history and conditions detailed history and conditions collection of bact, and virology specimens collection of bact, and virology specimens 2 controls/death matched for age, Hx, exam, and home 2 controls/death matched for age, Hx, exam, and home

CONTINUITY CLINIC Avon Study - results significant avoidable risks prone sleeping position prone sleeping position thermal environment thermal environment role of infection role of infection parental smoking parental smoking

CONTINUITY CLINIC Avoidable SIDS risk factors prone sleeping position prone sleeping position thermal environment thermal environment parental smoking parental smoking co-sleeping? co-sleeping?

CONTINUITY CLINIC studies of infant sleep position > 20 retrospective studies > 20 retrospective studies odds ratio odds ratio ? recall bias ? recall bias 1 prospective study in high risk infants 1 prospective study in high risk infants 15 SIDS, 116 controls 15 SIDS, 116 controls odds ratio 3.92 x’s higher odds ratio 3.92 x’s higher 2 intervention studies 2 intervention studies 1 U.S. study 1 U.S. study

CONTINUITY CLINIC Infant Sleeping Position and SIDS Rate - Netherlands SIDS rate

CONTINUITY CLINIC Infant Sleeping Position and SIDS Rate - Avon England SIDS rate

CONTINUITY CLINIC Infant Sleeping Position and SIDS Rate - King County Washington population based, case-controlled study population based, case-controlled study Nov Oct Nov Oct SIDS, 142 matched controls 47 SIDS, 142 matched controls 57.4% of SIDS cases usually slept prone vs./ 24.6% of controls 57.4% of SIDS cases usually slept prone vs./ 24.6% of controls adjusted odds ratio = 3.12 adjusted odds ratio = 3.12

CONTINUITY CLINIC Infant Sleeping Position and SIDS Rate - King County Washington Conclusion: “Prone sleep position was significantly associated with an increased risk of SIDS among a group of American infants.” “Prone sleep position was significantly associated with an increased risk of SIDS among a group of American infants.”

CONTINUITY CLINIC US SIDS Rate ‘99

CONTINUITY CLINIC US SIDS Rate ‘99

CONTINUITY CLINIC Adverse effects of supine sleep airway obstruction airway obstruction Pierre Robin syndrome Pierre Robin syndrome choking/aspiration not a problem choking/aspiration not a problem Czech & Hong Kong data Czech & Hong Kong data Netherlands interventional study data Netherlands interventional study data 750 newborn deaths reviewed 750 newborn deaths reviewed only lethal episodes of aspiration occurred in neurologically impaired (all were prone) only lethal episodes of aspiration occurred in neurologically impaired (all were prone)

CONTINUITY CLINIC Thermal environment well known association of SIDS & cold well known association of SIDS & cold suggests hypothermia suggests hypothermia no data showing low temp or less insulation are risk factors no data showing low temp or less insulation are risk factors 2 controlled studies investigating tog 2 controlled studies investigating tog Avon Avon Tasmania Tasmania

CONTINUITY CLINIC Thermal environment - studies Avon (risk increases 1.14/tog if > 8 tog) SIDS slightly more heavily wrapped SIDS slightly more heavily wrapped SIDS more likely have heating left on SIDS more likely have heating left on 25% SIDS found with head covered (no controls) 25% SIDS found with head covered (no controls) >10 tog + URI increased odds ratio to 51.5 >10 tog + URI increased odds ratio to 51.5

CONTINUITY CLINIC Thermal environment - studies Tasmania (28 SIDS c/w 54 controls) mean insulation for SIDS was 1.3 tog > controls mean insulation for SIDS was 1.3 tog > controls mean ambient temp was 1.5 o C > controls mean ambient temp was 1.5 o C > controls SIDS more likely to have home heating SIDS more likely to have home heating

CONTINUITY CLINIC Thermal environment - pathophysiologic mechanisms birth to 3 months birth to 3 months metabolic rate increases by 50% metabolic rate increases by 50% SQ fat increases SQ fat increases peripheral vasomotor control becomes more effective peripheral vasomotor control becomes more effective > 3 mo. metabolic rate markedly increases with virus > 3 mo. metabolic rate markedly increases with virus < 3 mo. metabolic rate decreases or remains the same with virus < 3 mo. metabolic rate decreases or remains the same with virus increased temp causes hypoventilation increased temp causes hypoventilation

CONTINUITY CLINIC Smoking & SIDS prospective cohort studies prospective cohort studies highly significant + correlation between parental smoking and SIDS (odds ratio >2) highly significant + correlation between parental smoking and SIDS (odds ratio >2) dose effect dose effect retrospective case controls retrospective case controls odds ratio for maternal smoking = 1.68 odds ratio for maternal smoking = 1.68 odds ratio for paternal smoking = 1.39 odds ratio for paternal smoking = 1.39 odds ratio if both smoke = 3.46 odds ratio if both smoke = 3.46

CONTINUITY CLINIC Co-sleeping infants and children sleeping in contact or close proximity to their parents infants and children sleeping in contact or close proximity to their parents same bed same bed rocked or held while sleeping rocked or held while sleeping parent & child close enough to hear feel or smell one another parent & child close enough to hear feel or smell one another common in: common in: pre-industrial societies pre-industrial societies Far, Near, & Middle East Far, Near, & Middle East La Leche League La Leche League discouraged in Euro./Western society discouraged in Euro./Western society

CONTINUITY CLINIC Co-sleeping & SIDS sleep data demonstrate overlapping, partner induced arousals sleep data demonstrate overlapping, partner induced arousals ? fosters development of optimal sleep pattern ? fosters development of optimal sleep pattern ? gives infants practice arousing ? gives infants practice arousing New Zealand cot death study New Zealand cot death study increased in Maori Indians increased in Maori Indians also highest poverty, drug use, smoking also highest poverty, drug use, smoking ?evolved with & to offset neurologic immaturity ?evolved with & to offset neurologic immaturity

CONTINUITY CLINIC Co-sleeping & SIDS Questions Questions breastfeeding and co-sleeping relation breastfeeding and co-sleeping relation infant safety (fall) infant safety (fall) adult sleeping surfaces (waterbed, soft mattress) adult sleeping surfaces (waterbed, soft mattress)

CONTINUITY CLINIC AAP Recommendations: revised 12/96 Placing infants to sleep supine carries the lowest risk of SIDS and is preferred. However, a side position carries a significantly lower risk than a prone position. If a side position is used, place the lower arm forward to reduce the risk of the infant rolling onto his or her stomach. Placing infants to sleep supine carries the lowest risk of SIDS and is preferred. However, a side position carries a significantly lower risk than a prone position. If a side position is used, place the lower arm forward to reduce the risk of the infant rolling onto his or her stomach.

CONTINUITY CLINIC AAP Recommendations: revised 12/96 Soft surfaces and gas trapping objects should be avoided in the crib or other sleeping surfaces. In particular, pillows or quilts should not be placed beneath a sleeping infant. Soft surfaces and gas trapping objects should be avoided in the crib or other sleeping surfaces. In particular, pillows or quilts should not be placed beneath a sleeping infant. The recommendations are for healthy infants only. Some medical problems may prompt a pediatrician to recommend prone sleep. The recommendations are for healthy infants only. Some medical problems may prompt a pediatrician to recommend prone sleep.

CONTINUITY CLINIC