Efficiency of Aerosol Therapy through Jet Nebulizer, Breath-Actuated Nebulizer, and Pressurized Metered Dose Inhaler in a Simulated Spontaneous Breathing Adult

BACKGROUND: Aerosol therapy using albuterol is one of the most prescribed asthma treatments. The most frequently used methods of aerosol delivery are pneumatic jet nebulizer (JN), pressurized metered-dose inhaler (pMDI), and breath-actuated nebulizer (BAN). Choosing among these devices is usually not based on thorough comparison of efficiency or cost. We compare the efficiency of these three devices using a spontaneously breathing adult model. METHODS: We connected each aerosol generator—JN, BAN, or pMDI with a valved holding chamber (VHC)—to the face of an adult teaching manikin. Below the bifurcation, an elbow adaptor was connected to a corrugated tube and was angled to be at a lower level than the collecting filter to prevent droplets from dripping directly into the collecting filter. From the collecting filter, another corrugated tube was connected to a prevention filter, which was then connected to an adult breathing simulator. Spontaneous breathing parameters were VT 450 ml, RR 20/min, and I: E ratio 1:2. First, we compared JN, BAN (2.5 mg/3 ml), and pMDI (4 puffs); second, we compared JN and BAN 2.5 mg/0.5 ml plus 0.5 ml normal saline. Data were analyzed using spectrophotometry (276 nm). One-way ANOVA and independent sample t-tests were used (p<0.05). RESULTS: There were no differences in inhaled mass percentage (p=0.172) JN, BAN, and pMDI in the first experiment. Treatment time with BAN was significantly longer (p=0.0001) than with JN or pMDI. In the second experiment, BAN delivered more medication (p=0.004) than jet nebulizer. Treatment time was significantly less with JN (p=0.010). There was no difference in residual volume among JN and BAN in both experiment (p=0.765, p=0.115). CONCLUSIONS: All the devices that were compared using a 3 ml or 4 pMDI puffs delivered comparable amount of medication with no significant difference. However, BAN using 1 ml fill volume delivers more drug compared to JN. Additionally, treatment time was longest with BAN. Even with reduction of its filling volume, BAN delivers a higher amount of medication to that of pMDI but was not statistically significant.