Neonatal Apnoea and SIDS Flashcards
What factors influence breathing?
Influences from higher centres
Arterial and central chemoreceptors
Lung, airway, CV, muscle and joint reflexes
Where is the respiratory pattern generator?
Reticular formation of the medulla
Pre-Botzinger Complex
Define apnoea
20seconds or less if associated with cyanosis or bradycardia
Inverse correlation between freq apnoea and gestational age
What are the 3 types of apnoea?
1 - central
2 - obstructive = breathing effort continues but with no airflow
3 - mixed
What is the mechanism of central apnoea?
Immaturity in the chemoreceptor, mechanoreceptor or cerebral cortex pathway which feed in to the pre-Botzinger complex
Chemoreceptors show a reduced response in infants.
Mechanoreceptors (HB Reflex) depressed in prematurity
What is obstructive apnoea?
Site tends to be at laryngeal level as shown by bronchoscopy
? due to hypoxia or asynchrony of respiratory muscles (alae nasi and diaphragm)
Factors involved in apnoea?
Sleep state (> REM) Hypoxia Infection CNS disorders Environmental temp GORD Bottle feeding Anaemia Anaesthesia PDA Drugs
Rx of apnoea?
Methylxanthines
Compete with adenosine? Reduce release of GABA
Kinasthetic stimulation Tilt Position change Change environmental temperature Correct hypoxia
Do apnoeas matter?
Recurrent hypoxaemia
Redistribution of blood away from guts and kidney
Fall in anterior cerebral blood flow velocities during the apnoea
What is SIDS?
The sudden death of an infant under one year of age which remains unexplained after a thorough case investigation including a complete autopsy, examination of death scene and review of clinical history.
Risk factors for SIDS
Maternal smoking Prone and side sleeping Soft bedding and soft surfaces Warmer room temps Bed sharing Prematurity
Which areas of brain may be involved?
Arcuate nucleus - hypoplasia common, hypoplasia correlated with maternal smoking, 5-HT system and glutamate abnormalities records in AN (also systemic)
Cerebellum - abnormalities in SIDS victims, delayed maturation in SIDS, biopathological alterations in smoking mothers, prone to nicotine damage, ? effect of position on BP?
