Carbon dioxide rebreathing induced by crib bumpers and mesh liners using an infant manikin

OBJECTIVES: Quantify impaired respiration in currently marketed crib bumpers (CBs), mesh liners (MLs) and alternative products (ALTs) used to attenuate the interaction between the baby and the crib sides and elucidate the relationship between impaired respiration and permeability. METHODS: We experimentally quantified carbon dioxide rebreathing (CO(2)RB) via an infant manikin and air permeability via previously published test protocols, in commercially available CBs, MLs and ALTs. RESULTS: Differences in CO(2)RB in ML (median [m]=8.2%, 25th percentile [P25]=6.8, 75th percentile [P75]=8.6), ALT (m=10.5%, P25=9.8, P75=10.7) and CB (m=11.6%, P25=10.2, P75=14.3) were significant (p<0.0001). For comparison, manikin tests with a pacifier yielded CO(2)RB of 5.6%–5.9%, blanket draped over the face/torso yielded CO(2)RB of 7.7%–8.6% and stuffed animal in various positions yielded CO(2)RB from 6.1% to 16.1%. Differences in permeability between ML (m=529.5 cubic feet per minute [CFM], P25=460, P75=747.5), ALT (m=29.0 CFM, P25=27.7, P75=37.7) and CB (m=46.6 CFM, P25=30.1, P75=58.7) groups were significant (p<0.0001). CO(2)RB was poorly correlated with air permeability (max R(2)=0.36). In a subset of tests, CB CO(2)RB increased by 50%–80% with increasing penetration force, whereas the ML CO(2)RB was nominally unchanged. CONCLUSIONS: Government agencies and standards organisations are presently considering regulation of bedding including CBs. As paediatricians are consulted in the development of such regulations, our findings that permeability by itself was a poor predictor of CO(2)RB should be considered.