EFFECT ON CO₂ DISPERSAL RATE OF COMMERCIAL PRODUCTS MARKETED TO REDUCE SUDDEN INFANT DEATH SYNDROME RISK

¹Pediatrics, Children’s Hospitals and Clinics- Minneapolis, MN; ²Dept. of Pediatrics, Saint Louis University, St. Louis, MO

Background: Less prone sleeping has been accompanied by lower SIDS rates. One explanation may be that non-prone infants are not rebreathing exhaled air from underlying bedding. Despite this risk, many infants still sleep prone. New products claim to reduce rebreathing risk for prone infants.

Methods: 5 commercial sleep products were studied. "Active" systems: Halo Sleep Systems™, Sleep Guardian™; "Passive" systems: Breathe Easy™, Bumpa Bed™, Kid Safe Baby Air™. Products were tested for their ability to hasten CO₂ dispersal using a biomechanical model of a mannequin placed face-down on the test surface and "ventilated" with a syringe containing 5% CO₂ (J Appl Physiol 78 p 740). The t½ for CO₂ dispersal from the mannequin-bedding ensemble quantitates rebreathing potential of the bedding. Face-down studies were compared to conventional bedding and to a control with the mannequin face-to-side. Each product was tested with the face down and underlying cover 1)taut, 2)wrinkled, and 3)taut but mannequin arm at side of head. Ten repetitions of the CO₂ washout were done with each product under each of the three simulations.

Results: t½ differed among products for all three simulations (ANOVA; all p<0.0001). All sleep systems caused significant increases in t½ compared to the control system except for the Halo System (sheet taut and sheet wrinkled). In many instances, t½ exceeded thresholds associated with a rise in PaCO₂ (³ 21.1 s) or lethality (>24.0 s). All systems exceeded thresholds under one or more simulations except the Halo System.

Conclusions: 1)Standard, firm bedding and most items said to prevent rebreathing, do little to reduce, or may worsen, CO₂ trapping. 2)Most cannot be recommended for infants who might turn their face down. 3)No product completely prevented rebreathing, but the Halo Sleep System maintained CO₂ dispersal at rates preventing increases in PaCO₂. 4)Industry standards for rebreathing based on biomechanical models should be developed.

t½ as seconds (mean + SD)

* denotes statistically significant difference at p<0.0005 when compared to control t½ (unpaired t test)