Aerosol Therapy with Valved Holding Chambers in Young Children, Importance of a Face Mask Seal

Abstract

Purpose of the Study. The purpose of this study was to determine the relative ability of 3 different spacers with masks to obtain a tight seal. The Nebuchamber (Astra Draco AB, Lund, Sweden), the AeroChamber (Trudell Medical, London, Ontario, Canada), and the Babyhaler (Glaxo GmbH, Germany) were compared with the Hans Rudolph anesthesia mask in infants and young children. Masks are viewed as a critical interface between the valved holding chamber and the small child for providing aerosol treatments.Study Population. The study population included 30 children with a mean age of 3.2 years with asthma or wheezing. These children were required to have used a spacer with mask continuously for at least 1 month after appropriate instruction. Instruction was provided in 1-on-1 educational session provided by a respiratory nurse or pediatric pulmonologist.Methods. Face mask leak was investigated for the Nebuchamber, AeroChamber, Babyhaler and Hans Rudolph mask by measuring ventilation with an inline pneumotachograph with the face mask maintained in place by the parent. Parents were asked to document how they deliver medication to their children without any additional instruction. The first 10 patients performed the test with full repeat studies with each mask, and then again within 1 month. On the second occasion, the parents were coached throughout the maneuver, encouraged to maintain the mask tightly applied to the child’s face.Results. The AeroChamber and Hans Rudolph mask were assessed to have the best seal as determined by the magnitude of ventilation that was measured. The Nebuchamber provided the poorest seal, with 45% less ventilation than the AeroChamber and Hans Rudolph (Hans Rudolph, Inc, Kansas City, MO) mask. Additionally, there was considerable intraindividual variability (24%–48%) for all masks; however, the variability of the Nebuchamber was twofold greater than the other masks. During the coached sessions, all ventilatory volumes were significantly increased compared with the uncoached session. Variability during the coached session was considerably less except for the Babyhaler, which was unchanged.Conclusions. The authors concluded that spacers with mask designed for use in small children may provide an inadequate seal to the face that leads to reduced or more variable dose delivery. The face mask seal is critical to deliver adequate aerosol to infants and young children, and this should be emphasized to parents.Reviewer’s Comments. Additional prospective studies with larger groups of children in different demographic settings would be meaningful to determine if the variability and the efficiency of the seal, that the AeroChamber is superior to the other spacers. Clearly, spacer technique should be taught to health care providers and in turn taught and reiterated to parents on return visits to office or clinic.