Effect of face mask design on inhaled mass of nebulized albuterol, using a pediatric breathing model

BACKGROUND: Aerosol face mask design and the distance at which the face mask is held from the face affect the delivery of nebulized medication to pediatric patients. OBJECTIVE: To measure the inhaled mass of nebulized albuterol with 3 types of pediatric face mask, at 3 different distances from the face, with a model of a spontaneously breathing infant. METHODS: We compared a standard pediatric face mask and 2 proprietary pediatric face masks (one shaped to resemble a dragon face, the other shaped to resemble a fish face). The albuterol was nebulized with a widely used jet nebulizer. Aerosol delivery with each type of mask was measured with the mask at 0 cm (ie, mask directly applied to the mannequin face), 1 cm, and 2 cm from the mannequin face. In each test the nebulizer was filled with a 3-mL unit dose of albuterol sulfate and powered by oxygen at 8 L/min, with a total nebulization time of 5 min. The mannequin face was connected to a lung simulator that simulated a spontaneously breathing infant. We measured inhaled mass by collecting the aerosol on a 2-way anesthesia filter that was attached to the back of the mannequin's oral opening via a 15-mm silicon adapter. We also measured residual drug left in the nebulizer, and estimated the drug lost to the atmosphere. RESULTS: The mean ± SD inhaled percentage of the nominal dose values at 0 cm, 1 cm, and 2 cm, respectively, were 2.18 ± 0.53%, 1.45 ± 0.46%, and 0.92 ± 0.51% with the standard mask; 2.65 ± 0.55%, 1.7 ± 0.38%, and 1.3 ± 0.37% with the dragon mask; and 3.67 ± 0.8%, 2.92 ± 0.4%, and 2.26 ± 0.56% with the fish mask. With all 3 masks there was a statistically significant difference (p < 0.001) in inhaled mass between the 0 cm and 2 cm distance. The fish mask had a significantly higher (p < 0.001) inhaled mass than the dragon mask or the standard mask, at all 3 distances. CONCLUSIONS: The inhaled mass of albuterol is significantly reduced when the mask is moved away from the face. The fish mask had significantly higher inhaled mass than the standard mask or the dragon mask, under the conditions we studied. Mask design may affect nebulized albuterol delivery to pediatric patients.