Effect of Face Mask Static Dead Volume, Respiratory Rate and Tidal Volume on Inhaled Albuterol Delivery.

BACKGROUND: Some pediatric tracheostomized patients who receive inhaled drugs undergo decannulation, and it is unknown whether the dose has to be adjusted. Pressurized metereddose inhalers (pMDIs) and soft mist inhalers (SMIs) used with valved holding chambers (VHCs) made of non-electrostatic material are available. We hypothesized that using an SMI and changing the delivery route from tracheostomy to oronasal would increase lung dose. METHODS: Four units of a metallic VHC were studied with albuterol hydrofluoroalkane (pMDI) and albuterol/ipratropium bromide with an SMI using an anatomically correct in vitro model of a 5-y-old spontaneously breathing tracheostomized child. The drug was captured in a filter and was termed lung dose. We tested breathing patterns with tidal volumes of 50, 155, and 300 mL. A mask and a special adapter were used as interfaces for oronasal and tracheostomy delivery, respectively. Spectrophotometry (276 nm) was used to determine albuterol concentration. RESULTS: The use of SMI resulted in a higher lung dose than the pMDI for all tested conditions except delivery through tracheostomy with tidal volume of 155 mL (P ‫؍‬ .69). Switching from oronasal to tracheostomy delivery increased the lung dose for all tested conditions except for the pMDI with the 300-mL tidal volume (P ‫؍‬ .83). The use of SMI resulted in higher deposition in the tracheostomy tube than the pMDI. CONCLUSIONS: In general, an SMI delivers a higher lung dose than a pMDI when using a metallic spacer during oronasal and tracheostomy route with the latter providing a higher lung dose.

Section: Discussionsupporting

confidence: 71%

Oronasal and Tracheostomy Delivery of Soft Mist and Pressurized Metered-Dose Inhalers With Valved Holding Chamber

Berlinski

Cooper

2016

“…Delivered volumes were calibrated and verified at the beginning of each experiment using a mass flow meter (TSI 4043, TSI, Shoreview, Minnesota) and its associated software. 14 Three different breathing patterns corresponding to a newborn, infant, and child were tested. The use of these breathing patterns has been recommended for evaluation of nebulized products intended for pediatric use (Table 1).…”

Section: Breathing Modelmentioning

confidence: 99%

“…9 Aerosol-related factors include type of aerosol generator, patient interface, particle size, treatment time, mask dead volume, type of power gas, and type of solution. [10][11][12][13][14] Patient-related factors include differences in anatomy, breathing patterns, and behavioral challenges. [15][16][17][18] Higher tidal volumes (V T ) are associated with higher intrapulmonary deposition.…”

Section: Introductionmentioning

confidence: 99%

In Vitro Evaluation of Aerosols Delivered via the Nasal Route

Taoum

Kim

et al. 2015

BACKGROUND: Infants and young children are obligate nose breathers; therefore, a transnasal route seems the logical delivery method of inhaled aerosols. The efficiency of aerosol delivery depends on several factors, such as interface, type of nebulizer, and patient age and breathing pattern. We hypothesized that the use of a vibrating mesh nebulizer, a tight-fitting face mask, and a head model and breathing pattern of an older child would result in a higher lung dose. We also hypothesized that the use of an anatomically correct model would more accurately reflect lung dose than models that do not include airways. METHODS: A model comprising a breathing simulator and an anatomically correct model of a 7-month-old infant and a 5-y-old child with an interposed collection filter (lung dose) were used. Breathing patterns of a newborn, infant, and child were used with 7 interfaces. A continuous output and a vibrating mesh nebulizer were loaded with albuterol sulfate solution (5 mg/3.5 mL) and operated for 5 min. Albuterol mass was determined via spectrophotometer (276 nm). RESULTS: Lung dose varied between 0 and 3%. The jet nebulizer was more efficient than the vibrating mesh nebulizer. The front-loaded mask was the most efficient interface. We also found that higher tidal volumes were associated with higher lung doses and that the use of a larger airway model resulted in a lower lung dose. Finally, the model showed a good correlation with in vivo data and rendered lung doses severalfold lower than previous data obtained with oral models. CONCLUSIONS: Careful pairing of the aerosol generator and interface is very important during transnasal aerosol delivery.

“…The breathing pattern was then selected in the breathing simulator, and the accuracy of the tidal volume was verified using a mass flow meter (TSI, Shoreview, Minnesota). 12 The model was used in a vertical position. 6 The face mask was sealed to the head/airway model with putty, and the VHC was then connected to it.…”

Section: Protocolmentioning

confidence: 99%

Albuterol Delivery via Facial and Tracheostomy Route in a Model of a Spontaneously Breathing Child

Cooper

Berlinski

2015

BACKGROUND: Some pediatric patients receiving therapeutic aerosols undergo tracheostomy, and others who are tracheostomized continue requiring inhaled therapies upon decannulation. It is unknown whether a dose adjustment is required. Different devices are available for facial and tracheostomy delivery, and in some instances, the assisted technique is used. We hypothesized that the change from face mask to tracheostomy would result in a decrease in the lung dose. METHODS: A breathing simulator connected in series to a filter holder and an anatomically correct head model of a child was used. The drug captured in the filter was termed the lung dose. Breathing patterns with tidal volumes of 50, 155, and 300 mL were tested. Albuterol hydrofluoroalkane (pressurized metered-dose inhaler [pMDI]) with an AeroChamber Mini (face and 4.5-mm tracheostomy), AeroTrach (4.5-mm tracheostomy), and AeroChamber (face) and albuterol (2.5 mg/3 mL) with a continuous output nebulizer (face and 4.5-mm tracheostomy) were tested. Masks were used for facial delivery. Four units of each device were tested. Particle size of the pMDI was measured by cascade impaction. Albuterol concentration was determined via spectrophotometry (276 nm). RESULTS: Switching from facial to tracheostomy delivery increased lung dose with nebulizer (all breathing patterns). When a pMDI was used, lung dose was unchanged or increased for the 50-and 155-mL and decreased for the 300-mL breathing pattern. The use of the assisted technique increased lung dose only during nebulization with the 300-mL breathing pattern. The particle size of the pMDI decreased by 19 -23% when traveling through the tracheostomy tube, which retained < 4% and < 26% of the nominal dose of a nebulizer and pMDI, respectively. CONCLUSIONS: The effect of changing the delivery route from face to tracheostomy was variable and depended on the delivery device and the breathing pattern. There is no advantage of using the assisted technique to enhance aerosol delivery.