Obstruction of the upper airway as a mechanism of sudden infant death: Evidence for a restricted nasal airway contributing to pharyngeal obstruction

Abstract

In New Zealand we have followed the English custom of referring to the sudden unexpected deaths of early infancy as 'cot deaths'. We have not in general adopted the term sudden infant death syndrome as we feel that this tends to imply a disease process and suggests a single cause. From the many case histories of deaths, and from our autopsy examinations, we think it is likely that we will find several different subgroups of cot deaths. It is widely believed that respiratory failure is the most likely cause of the majority of cot deaths (Bosma, 1975; Shannon et al., 1977). There are two types of blood oxygenation failure: (1) centrally occurring lack of respiratory center drive - or lack of activation of the muscles of respiration; and (2) inspiratory obstruction so that air does not reach the alveolae despite breathing efforts. 1. Central apneas are common in preterm babies and diminish with age, usually disappearing by 40 weeks of gestation. This type of apnea may not be related to cot death, which has the peculiar epidemiology of increasing rapidly after 1 month of age, peaking between 2 and 4 months, and then rapidly declining in frequency. 2. From the autopsy findings of petechial hemorrhages on the lung surfaces, and the frothy edema fluid in the respiratory passages, airway obstruction has long been suspected as the cause of the respiratory failure, but proof has been difficult to obtain as post-mortem changes give little clue as to the state of the upper airway at the moment of death.