Effect of functional principle, delivery technique, and connection used on aerosol delivery from different nebulizers: An in-vitro study.

Objective: Nebulizers can be divided according to their functional principle into jet, ultrasonic and vibrating mesh nebulizers with intermittent or continuous aerosol delivery and may be used with many different adapters and connections and all can influence their efficiency. The aim of the present work was to evaluate the effect functional principle, delivery technique, and connection used on aerosol delivered from four different nebulizers.

Methods: Four nebulizers were used in the study; three of them were jet nebulizers (JNs; AeroEclipse, NebuTech, En ful Kit) and one of them was Aerogen Solo vibrating mesh nebulizers (VMN). AeroEclipse and NebuTech are intermittent output nebulizers, while the rest are continuous output nebulizers. Aerogen Solo was used with either a standard T-piece or Aerogen Ultra holding chamber, and En ful Kit was used with a standard T-piece or Circulaire II holding chamber. 2 ml of salbutamol was nebulized to determine the total emitted dose (TED) and aerodynamic droplet characteristics of the emitted aerosol from the 6 different sets (4 nebulizers with T-piece and 2 holding chambers).

Results: The mean ± SD TED from VMN was significantly higher than all the JNs (p < 0.05). Aerogen Ultra with VMN did not show a significant effect on TED compare to T-piece, but it significantly increased (p < 0.05) fine particle dose (FPD; 3091.5 ± 189.4 μg) and fine particle fraction (FPF; 72.7 ± 3.6%). However, the Circulaire II with En ful Kit had significantly higher TED, FPD, and FPF compared to T-piece (p < 0.05). Intermittent JNs (AeroEclipse and NebuTech) had significantly higher TED (p < 0.05) compared to the continuous JNs (En ful Kit) with no significant effect on the other parameters studied. AeroEclipse had the highest MMAD and Aerogen Solo Ultra has the lowest in MMAD.

Conclusions: The functional principle, delivery technique, and connection used had a significant effect on aerosol delivered from nebulizers. VMNs are significantly better than JNs. Intermittent delivery has significantly better TED than continuous delivery. Holding chamber with both VMNs and JNs improved aerosol delivery compared to standard T-piece.