The primary aim of the research reported in this thesis was
to study breathing patterns during sleep in a) apparently
normal symptom-free full-term infants, b) infants admitted
to hospital during and following recovery from relatively
minor illnesses, and c] infants thought to be at increased
risk for Sudden Infant Death Syndrome CSIDS) - siblings of
previous SIDS victims, and 'near-miss' for SIDS cases, to
quantify apnoea (central and obstructive] and observe its
effect on heart rate and transcutaneous oxygen tension, PtcO₂.
Secondary aims were to study gross body movements (as an
indicator of arousal], and to assess whether infants at
'increased risk' for SIDS were chronicallyhypoxaemic during
the early months of life. Polysomniographic studies lasting
three to five hours during the night recorded eye movements,
digastric muscle tone, electrocardiogram^, electroencephalogram, airflow, chest and
abdominal movements and PtcO₂ in 86 index cases and 11 healthy
controls studied on 176 and 31 occasions respectively.
The results were as follows:
1. The 11 normal healthy infants did not have episodes of obstructive
or prolonged (^-15 seconds] central apnoea during sleep.
2. 33 'symptomatic' infants revealed:
a] Bronchiolitis - apnoeic pauses were shorter than 15 seconds.
Indices of central apnoea were increased significantly
in quiet sleep during the index illness. Prolonged (≥
6 seconds) obstructive apnoea was uncommon;