Control of ventilation in subsequent siblings of victims of sudden infant death syndrome

To learn whether the ventilatory responses to hypoxia (17% O 2) and hypercapnea (4% CO 2) differ in the subsequent siblings of sudden infant death victims (SIDS), we studied seven normal control infants, nine infants who had had a prolonged apneic spell (apneic infants), and 10 subsequent siblings of SIDS (mean ages 10.4 weeks, 15 weeks, and 10 weeks, respectively). With inhalation of 17% O 2, one of seven controls, two of nine apneic infants, and seven of 10 siblings of SIDS breathed periodically (controls vs siblings, p