“To Die, To Sleep ...” A Discussion on SIDS COL H. Joel Schmidt Pediatric Pulmonology SIDS - outline ALTE not “near-miss SIDS” SIDS background definition etiology controlof breathing epidemiology avoidable risk factors ALTE definition frightening to the observer characterized by some combination of apnea colorchange marked change in muscle tone choking gagging (involves vigorous stimulation or resuscitation) Factoids prevalence from 0.05% to 6.0% most with ALTE do not die of SIDS combinedprevalence of SIDS among other family members of infants w/ ALTE = 11% most with SIDS have never had ALTE 73 - 96% w/o ALTE median age at presentation = 2 months slight male predominance Causes GE Reflux 28% Neurologic problems 12% Infection 6% Upper Airway Obstruction 2% Metabolic problems 2% Cardiac problems 1% Idiopathic 47% Work-Up History History History History History History History Home Monitor? 1986 NIH Consensus Conference on Infantile Apnea and Home Monitoring definitely indicated – severe ALTE – tracheostomy <18 months old – ISAM‟s – twin of SIDS victim not indicated – normal infant – asymptomatic premature infant Questionable Risk Group Sib of SIDS moderate ALTE decision based benefits, liabilities, and limitations risks, parent - provider decision Monitor Requirements home telephone basic infant CPR instruction for all caregivers use and trouble shooting of monitor for all caregivers 24‟ medical and technical back-up SIDS background decreasing infant mortality this century one category of infant death not decreasing 1969 - “SIDS” title given Steinschneider A: Prolonged apnea and the sudden infant death syndrome. Pediatrics 1972; 50 (4): 646. 1991 - definition expanded by NICHD causes of infant death <1 year old, 1992 maternal complications RDS prematurity birth defects other Unknown 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 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 AAP Addition to Evaluation Exam of the dead infant at a hospital ED by a child maltreatment specialist 1-5% of SIDS may be infanticide clues to infanticide – > 6 months old – previous unexpected or unexplained sib death – simultaneous death of twins etiology - broad no common etiology- multifactorial final common pathway may be: failure to arouse to cope w/ homeostatic challenge abnormal development of the control of cardiorespiratory systems maldevelopment of fetal to newborn transition mechanism etiology - focused developing nervous system developing immune system inherited metabolic disease changes in cardiac conduction system changes in respiratory control non-accidental trauma Baruch‟s Observation “If all you have is a hammer, everything looks like a nail.” CNS autopsy findings increased gliosis increased brainstem dendritic spine density delayed myelin maturation epidemiologic studies NICHD Cooperative Epidemiologic Study of SIDS Risk Factors New Zealand Cot Death Study Avon Infant Mortality Study King County Washington SIDS Study NICHD SIDS Study Oct „78 - Dec '79 multicenter, population based, case controlled 838 SIDS 1676 controls age-matched living - randomly selected age-matched living - matched for race and low birth weight 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.” NICHD SIDS Study - results maternal factors inadequate prenatal care smoking anemia ISAM VD UTI NICHD SIDS Study - results other factors low birth weight inadequate post-natal care lack of breast feeding GI infections NICHD SIDS Study - results non-factors URI‟s apnea of prematurity New Zealand Cot Death Study 1987 - 1990 multicenter, prospective, case- controlled covered 78% of all births 485 cot deaths 1800 random controls - matched for post-natal age New Zealand Study - results significant avoidable risks prone sleeping position co-sleeping not breast fed maternal smoking Avon Infant Mortality Study 1984 - 1992 Avon County in SW England pop. 940,000 with 13,000 births/year 1 coroner, 1 Peds Path, 3 OB units all unexpected deaths detailed history and conditions collection of bact, and virology specimens 2 controls/death matched for age, Hx, exam, and home Avon Study - results significant avoidable risks prone sleeping position thermal environment role of infection parental smoking avoidable SIDS risk factors prone sleeping position thermal environment parental smoking co-sleeping? studies of infant sleep position > 20 retrospective studies odds ratio 1.9 - 12.7 ? recall bias 1 prospective study in high risk infants 15SIDS, 116 controls odds ratio 3.92 x‟s higher 2 intervention studies 1 U.S. study Infant Sleeping Position and SIDS Rate - Netherlands 70 1.75 SIDS rate % infants prone sleep 60 1.5 SIDS rate 50 1.25 40 1.0 30 0.75 20 0.5 10 0.25 0 0 1965 1970 1975 1980 1985 1988 1990 Infant Sleeping Position and SIDS Rate - Avon England 70 4.0 SIDS rate % infants 60 prone sleep 3.4 50 SIDS rate 2.9 40 2.3 30 1.7 20 1.1 10 0.6 0 0 1987 1988 1989 1990 1991 1992 Infant Sleeping Position and SIDS Rate - King County Washington population based, case-controlled study Nov. 1992 - Oct. 1994 47 SIDS, 142 matched controls 57.4% of SIDS cases usually slept prone vs./ 24.6% of controls adjusted odds ratio = 3.12 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.” US SIDS Rate 1991 - „99 year % prone rate deaths „91 1.30 5349 „92 70 1.20 4891 „93 59 1.17 4669 „94 43 1.03 4073 „95 29 0.87 3396 „99 0.68 2648 US SIDS Rate 1980 - „99 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 '80 '82 '84 '86 '88 '90 '92 '94 '96 '98 adverse effects of supine sleep airway obstruction Pierre Robin syndrome RDS choking/aspiration not a problem Czech & Hong Kong data Netherlands interventional study data 750 newborn deaths reviewed – only lethal episodes of aspiration occurred in neurologically impaired (all were prone) thermal environment well known association of SIDS & cold suggests hypothermia no data showing low temp or less insulation are risk factors 2 controlled studies investigating tog Avon Tasmania thermal environment - studies Avon (risk increases 1.14/tog if > 8 tog) SIDS slightly more heavily wrapped SIDS more likely have heating left on 25% SIDS found with head covered (no controls) >10 tog + URI increased odds ratio to 51.5 thermal environment - studies Tasmania (28 SIDS c/w 54 controls) mean insulation for SIDS was 1.3 tog > controls o mean ambient temp was 1.5 C > controls SIDS more likely to have home heating thermal environment - pathophysiologic mechanisms birth to 3 months metabolic rate increases by 50% SQ fat increases peripheral vasomotor control becomes more effective > 3 mo. metabolic rate markedly increases with virus < 3 mo. metabolic rate decreases or remains the same with virus increased temp causes hypoventilation smoking & SIDS prospective cohort studies highly significant + correlation between parental smoking and SIDS (odds ratio >2) dose effect retrospective case controls odds ratio for maternal smoking = 1.68 odds ratio for paternal smoking = 1.39 odds ratio if both smoke = 3.46 “And this woman‟s son died in the night because she lay on it.” 1 Kings 3:19 co-sleeping infants and children sleeping in contact or close proximity to their parents same bed rocked or held while sleeping parent & child close enough to hear feel or smell one another common in: pre-industrial societies Far, Near, & Middle East La Leche League discouraged in Euro./Western society co sleeping & SIDS sleep data demonstrate overlapping, partner induced arousals ? fosters development of optimal sleep pattern ? gives infants practice arousing New Zealand cot death study increased in Maori Indians – also highest poverty, drug use, smoking ?evolved with & to offset neurologic immaturity co sleeping & SIDS Questions breastfeeding and co-sleeping relation infant safety (fall) adult sleeping surfaces (waterbed, soft mattress) 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. 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. The recommendations are for healthy infants only. Some medical problems may prompt a pediatrician to recommend prone sleep. AAP Recommendations: revised 12/96 The recommendations are for sleeping babies. Some “tummy time” while the baby is awake and observed is recommended.