A paediatric canopy system for aerosol administration and minimized environmental pollution.

Abstract

A canopy system for ribavirin aerosol administration to infants has been developed in order to improve the control of aerosol treatment, facilitate access to the infant and minimize environmental pollution. The system comprises a transparent canopy, fitted with four sealable apertures. An evacuation flow that is 3 l/min higher than the gas supply was anticipated to prevent aerosol leakage from the canopy. 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 treatment. The temperature, relative humidity and carbon dioxide concentration within the canopy were measured repeatedly to study the stability of these variables and their dependence on body weight. Infant body temperature, skin temperature and the respiratory frequency were measured. In a laboratory evaluation, aerosol leakage was studied using an ambient air admixture procedure and smoke tests. The sound level inside the canopy was measured. All physical variables inside the canopy remained stable. The sound level was 52 dBA. The carbon dioxide concentration (1000-3900 PPM) correlated with infant body weight (P < 0.001), as did canopy temperature (25.1-29.6 degrees C, P < 0.05). The relative humidity was 52-88%. Infant body temperatures were not influenced. The respiratory frequency decreased by 13% (P < 0.01). No aerosol leakage was observed. The canopy system facilitates a controlled aerosol therapy with good infant surveillance and accessibility a minimum of environmental pollution and a comfortable physical environment without apparent risks of carbon dioxide rebreathing or cooling stress at body weights of 1.8-7.1 kg.