Effects of Central Apneas on Transcutaneous Po₂ in Control Subjects, Siblings of Victims of Sudden Infant Death Syndrome, and Near Miss Infants

Abstract

A total of 75 polysomnograms recorded during night sessions in 25 control subjects, 25 siblings of sudden infant death syndrome victims, and 25 near miss infants were studied in order to correlate the duration of central apnea to the decrease in transcutaneous oxygen pressure (tcPo₂). A total of 1,650 central apneas were recorded. The three groups of infants presented the same tendency for a lower tcPo₂ in indeterminate and active sleep as in quiet sleep (P > .10). The apneas were not preceded by a decrease in tcPo₂, but were followed by a decrease in tcPo₂, directly proportional to the duration of apnea. The correlation was measured in each infant individually, and proved to be significant in all cases, and comparable in the three groups. The longest apneas (greater than ten seconds) were followed by the greatest decrease in tcPo₂, and were restricted to the near miss group. Apart from this observation, the near miss and sibling infants did not show lower tcPo₂ than the control subjects, at any time, during sleep.