Sudden Unexpected Death in Babies

Dr L du Toit-PrinslooUniversity of Pretoria

Department of Forensic Medicine

Definitions

• Unexpected death: – Not anticipated as significant possibility 24

hours before the death

• Sudden Unexpected Death in Infancy (SUDI):– Unexpected deaths of infants up to 1 year in

age at the point of presentation

• Sudden Infant Death Syndrome:– To follow…

Natural causes of unexpected childhood deaths

Infections

• Meningococcal / pneumococcal• Myocarditis• URTI• Respiratory infections• Meningitis• Septicamia• Enteroviruses

Cardiovascular system

• Congenital abnormalities• Cardiomyopathy• Endocardial fibroelastosis• Dysrhytmias

– WPW– LQTS– Brugada– ARVD

Gastrointestinal

• Fulminant gastroenteritis– Dehydration– Electrolyte disturbances

• Intestinal obstruction

Metabolic disorders

• Inborn errors of metabolism– Medium chain acyl CoA dehydrogenase

deficiency

Central nervous system

• Sudden Unexpected Death in Epilepsy (SUDEP)

• Status epilepticus

Respiratory system

• Sudden death in Asthma

Non-natural causes of death

Trauma

• Non-accidental Injury Syndrome• Head injury• Asphyxia• Accidental

– MVA– Drowning– Poisoning

Sudden Infant Death Syndrome

“SIDS is perhaps the greatest single medical mystery confronting scientists”.

Dr Cyril H. Wecht

Coroner of Allegheny County, PittsburghJnl of the American Medical Association, Jan 1996

Definition

• San Diego 2004• Sudden unexpected death• Infant < I year• Remains unexplained after thorough investigation

» Post mortem» Scene investigation» Review of the clinical history

Epidemiology

• Most common cause of death ages 1mo – 1yr• 50% of deaths 2 – 4 mo (Western societies)• Incidence 1-3/1000 live births• American Indians 6/1000; UK 2/1000; SA = ?• NB!! - abnormal as a group

»? not a single entity»sleeping position

• Factors: BABY / MOTHER / ENVIRONMENT

Table 13Number of registered infant deaths, South Africa, 1997 - 2002

6,52 887 654186 9262 13787 41697 373Total

7,3499 26836 60338217 15119 0702002

6,8451 93630 75031414 48115 9552001

7,4413 96930 43236914 25615 8072000

7,9381 90230 35946414 24215 6531999

8,6367 68931 73837614 72316 6391998

8,5318 28727 04423212 56314 2491997

TotalUnspecifiedFemalesMales

Infant deaths as percent of total deaths

Total deaths

Infant deaths under age one yearYear

Critical development

StressorVulnerable infant

Triple risk model – Kinney and Filiano

• Critical development period– 1st 6 months

• Stressor– Prone sleeping position– Soft bedding– Overheating

• Vulnerable infant– Brainstem abnormalities in protective

mechanisms against homeostatic challenges

Etiology/pathophysiology

• Chronic hypoxia / hypoxaemia• Brain stem immaturity• Neurochemical deficiency

• Respiratory / cardiac arrest

• Prone sleeping position• Airway obstruction• Cardiovascular failure (vertebral circulation)

• Cardiac remodelling / conduction (LQTS)

• Infection• Allergic• Immunisation• Cardiac• Neurological• Respiratory – central apnoea• Serotonin• Multifactorial

Pathology

• No pathognomonic lesion• Diagnosis of exclusion• Macroscopic findings:

– Petechial haemorrhages– Pulmonary edema and/or congestion– Cerebral edema and/or congestion

• Microscopic findings:– Signs indicative of chronic hypoxia/hypoxaemia

In 15% of infants who present clinically as SIDS, an adequate cause of death can

ultimately be demonstrated, with thorough investigation

The remaining 85% remain obscure and are confirmed as SIDS

Differential Diagnosis

• 1. Cardiac: Congenital valve lesions etc., Myocarditis, fibro-elastosis etc.

• 2. Pulmonary: Pneumonitis, bronchiolitis etc.• 3. Brain: Meningitis, encephalitis, A-V malform. • 4. Other:

• Trauma - NB!• Poisoning• Hepatitis• Enterocolitis• Sepsis (fulminant)• Aspiration• Heat illness / hyperthermia

Preventative measures

• No smoking

• Safe sleep environment

• No overheating

• Dummy

• Monitoring?

Medical practitioner’s role

• Appropriate attention: parental and legal perspectives

• Visit scene of death

• Review case history• No death certificate of natural causes• Autopsy:

– Thorough and complete– Histology– Toxicology– Virus and/or bacterial cultures

• Formulation of cause of death: ( = Diagnosis of exclusion)“Consistent with Sudden Infant Death Syndrome”

“In the present state of knowledge, it seems that SIDS is the final common pathway that leads to death in infants who have been compromised by a number of deleterious factors, which have to come together in one baby at one time in order to summate to a final outcome.”

Knight’s Forensic Pathology – P Saukko B Knight

Supporting families

Family support

• Set the right scene• Parents• Grandparents• Other siblings• Multi-team approach

Literature references• SIDS and Near-SIDS (Shannon) (NEJM, Vol. 306, No 16 +17, 1982)• Child Abuse, Sudden Infant Death Syndrome and Unexpected Infant

Death (Emery) (Am J Dis Ch – vol 147, October 1993)• Non-natural Death Masquerading as SIDS (Perrot) (Am J Forens

Med Pathol vol 9. No 2. 1988)• The value of a thorough protocol in the investigation of sudden infant

deaths (Sadler) (J Clin Path 1998; 51:695–699)• Finding the failure mechanism in Sudden Infant Death Syndrome

(Harper) (Nature Medicine, Vol 4, Number 2, February 1998)• Unexpected Death in Childhood – A handbook for Practitioners

Peter Sidebotham and Peter Fleming• www.sidsinternational.minerva.com.au• www.sids.org.uk