Variation in Pediatric Aerosol Delivery: Importance of Facemask

Abstract

We have quantified in vitro the influence of the facemask on the amount of drug delivered (e.g., inhaled mass) by jet nebulizer and pressurized metered dose inhaler (pMDI) valved holding chamber (VHC) combinations (non-detergent-coated and detergent-coated). Pediatric breathing patterns were used with a breathing simulator, which was connected to a face onto which each device was positioned. An inhaled mass filter interposed between the simulator and the face captured the aerosolized drug. Budesonide inhalation suspension (0.25 mg) was used with the jet nebulizers and fluticasone propionate (220 microg) pMDI with the VHCs. Maximal drug delivery was measured using constant flow through each device. Breathing pattern effects were assessed for sealed devices (no leaks) and with facemasks (possible leaks at the facemask). Inhaled mass from both nebulizers and pMDI VHCs was affected by breathing pattern, but compared to nebulizers the pMDI VHCs were significantly more variable and sensitive to several factors. The influence of VHC conditioning combined with effects of breathing pattern resulted in the inhaled mass ranging from 0.7 +/- 0.5 to 53.3 +/- 6.2%. Nebulizers were less variable (9.6 +/- 0.7 to 24.3 +/- 3.1%). Detergent coating of VHC markedly increased the inhaled mass and reproducibility of drug delivery (27.2 +/- 1.4 to 53.3 +/- 6.2%) for pMDI VHC combinations, but these effects were lost in the presence of facemasks. Using pediatric patterns of breathing, nebulizer/facemask combinations delivered 4.1 +/- 0.8 to 19.3 +/- 2.3% of the label dose while pMDI and detergent-coated VHC delivered 4.0 +/- 1.6 to 28.6 +/- 2.5%. Facemask seal is a key factor in drug delivery. Leaks around the facemask reduce drug delivery and for pMDI VHCs can negate effects of detergent coating.

Clinical Controversies in Aerosol Therapy for Infants and Children

“…[35][36][37][38] One study 39 showed the opposite effect in a pediatric lung model, wherein a standard bottom-loaded aerosol mask resulted in greater drug delivery than a frontloaded design. It is important to note that a common nebulizer was not used with each of the different face masks during the testing, so it is unclear if these results were based solely on the mask or the nebulizer being used.…”

The Science Guiding Selection of an Aerosol Delivery Device

“…Even small leaks of 0.5 cm around the face mask decrease drug inhaled by children and infants by more than 50%. [30][31][32][33][34] Delivery of aerosolized medications in a blow-by fashion is commonly used for crying babies or uncooperative children, where the nebulization port of a nebulizer is directed toward the patient's face. Studies have documented blow-by medication administration is less efficient, compared with a face mask, as aerosol drug deposition decreases significantly with distance, and this use should be discouraged.…”

“…Studies have documented blow-by medication administration is less efficient, compared with a face mask, as aerosol drug deposition decreases significantly with distance, and this use should be discouraged. 30,[34][35][36] In summary, while the domain of SVNs can be highly variable, based on the nuances and characteristics described previously, the entire category has some common advantages and disadvantages, which are listed in Table 6.…”

Inhaled corticosteroid therapy with nebulized beclometasone dipropionate

“…The use of a facemask requires a tight seal between the face and the mask to reduce drug waste, avoid deposition in the eyes, and to ensure delivery of an appropriate dose to the airways [53]. Another common issue in aerosol delivery is crying, which occurs in 38% of children, M A N U S C R I P T…”