A PEDIATRIC CANOPY SYSTEM FOR AEROSOL ADMINISTRATION AND MINIMIZED ENVIRONMENTAL-POLLUTION

Background: A canopy system for ribavirin aerosol administration to in fants has been developed in order to improve the control of aerosol tr eatment, facilitate access to the infant and minimize environmental po llution. The system comprises a transparent canopy, fitted with four s ealable apertures. An evacuation flow that is 3 l/min higher than the gas supply was anticipated to prevent aerosol leakage from the canopy. Method: In a clinical evaluation, 10 infants with body weights of 1.8 -7.1 kg were placed inside the canopy during 1 hour of simulated treat ment. The temperature, relative humidity and carbon dioxide concentrat ion within the canopy were measured repeatedly to study the stability of these variables and their dependence on body weight. Infant body te mperature, skin temperature and the respiratory frequency were measure d. In a laboratory evaluation, aerosol leakage was studied using an am bient air admixture procedure and smoke tests. The sound level inside the canopy was measured. Results: All physical variables inside the ca nopy remained stable. The sound level was 52 dBA. The carbon dioxide c oncentration (1000-3900 PPM) correlated with infant body weight (P<0.0 01), as did canopy temperature (25.1-29.6 degrees C, P<0.05). The rela tive humidity was 52-88%. Infant body temperatures were not influenced . The respiratory frequency decreased by 13% (P<0.01). No aerosol leak age was observed. Conclusion: The canopy system facilitates a controll ed aerosol therapy with good infant surveillance and accessibility, a minimum of environmental pollution and a comfortable physical environm ent without apparent risks of carbon dioxide rebreathing or cooling st ress at body weights of 1.8-7.1 kg.