A Pediatric Bench Model of Continuous Albuterol Delivery Using Heliox.

Background: The optimal setup for continuously administering albuterol with heliox remains unclear, especially for pediatric patients. This study aimed to evaluate the efficiency of continuous albuterol delivery with heliox using different nebulizer setups in a pediatric model.

Methods: A pediatric manikin with simulated spontaneous breathing was used to receive continuous albuterol (20 mg/h) with heliox (80/20) in 3 setups: (1) The MiniHEART nebulizer, driven by oxygen at 3 L/min, was attached to a Y-piece, linking to a non-rebreather mask and a valved reservoir with 11 L/min heliox; (2) a vibrating mesh nebulizer (VMN) placed at the humidifier inlet of high-flow nasal cannula (HFNC) with 11 L/min heliox and the manikin's mouth sealed; and (3) a VMN placed between a valved reservoir with 11 L/min heliox and a non-rebreather mask. Both tight-fitting and loose-fitting mask configurations were tested in the setup with vibrating mesh nebulizer and mask. Heliox of 70/30 was tested with a VMN and a loose-fitting mask. Albuterol was delivered continuously to the nebulizer via an infusion pump at 8 mL (20 mg)/h for each 20-min run and each experiment was repeated five times. A collecting filter placed between the manikin's trachea and lung model was removed after each run, and the drug was eluted and assayed via ultraviolet spectrophotometry (276 nm).

Results: During continuous albuterol nebulization using heliox, the VMN either in line with HFNC or with a tight-fitting mask achieved the highest and similar inhaled dose (8.5 ± 0.4 vs 8.8 ± 0.7%, P = .35), while the MiniHEART nebulizer yielded the lowest aerosol deposition (1.5 ± 0.2%). The inhaled dose was lower with the loose-fitting mask than with the tight-fitting mask (5.9 ± 0.9 vs 8.8 ± 0.7%, P =.009), and heliox of 80/20 delivered a higher inhaled dose than heliox of 70/30 (5.9 ± 0.9 vs 3.9 ± 0.4%, P = .009).

Conclusions: When administering continuous albuterol with heliox in a pediatric model, utilizing a VMN in line with HFNC during closed-mouth breathing yielded a higher inhaled dose compared to both the MiniHEART nebulizer and VMN with a loose-fitting mask.