For both ages and body positions, covering the head resulted in significant CO2 accumulation around the face, fewer apneas (3 to 10 seconds), shorter duration of apneas after sighs, higher heart and respiratory rates, and peripheral skin temperature. Differences were generally greater at 21/2 than at 5 months. While covered, the prone position was associated with higher CO2 levels close to the face, slightly higher transcutaneous PCO2, and higher heart rates and peripheral skin temperatures than the supine position. In the supine position 23% were able to remove the cover from the head at 21/2 and 60% at 5 months, whereas only 1 infant of 5 months managed to remove the cover when prone.
CONCLUSIONS:
The observed responses are consistent with a potential for distress when the head is covered, particularly when placed prone. Probably most important with respect to sudden infant death syndrome is the infants' inability to remove the bedding from the head upon awakening from prone sleep.