Jet versus vibrating mesh nebulizer for tobramycin aerosol in spontaneously breathing children with tracheostomies: A simulation study

Tracheostomy tubes act as foreign bodies, predisposing the surrounding airway to respiratory infections. Initial treatment for infections is topical - nebulized tobramycin - although guidelines for standardized treatment are lacking. To quantify tobramycin delivery to simulated, tracheostomized children to inform future administration guidelines. A breathing simulator was programmed for volume-controlled ventilation at 6 mL.kg^-1, for a 3 kg and a 16 kg child representing under or over 6-yrs, respectively. Nebulized tobramycin doses based on current guidelines for non-tracheostomized children (80 mg, or 300 mg, under and over 6-yrs, respectively) were delivered using standard hospital protocol, collected on filters, and assayed with chromatography to quantify average tobramycin delivered dose from six replicate measurements. The jet nebulizer delivered more tobramycin than the vibrating mesh nebulizer from an 80 mg (ages <6-yrs) dose for both a 3 kg child: 2.1 vs. 0.7 mg (3 mm, p = 0.047) and a 16 kg child: 8.7 vs. 3.5 mg (5 mm size, p = 0.022), 11.4 vs. 8.3 mg (4 mm size, p = 0.2). The jet nebulizer delivered more tobramycin than the vibrating mesh nebulizer from a 300 mg dose for both a 3 kg child: 8.4 vs. 3.7 mg (3 mm, p = 0.00076) and a 16 kg child: 33.2 vs. 25 mg (5 mm, p = 0.2) but not for a 16 kg child: 39.4 vs. 46.5 mg (4 mm, p = 0.18) The low amount and poor distribution of drug delivered warrants consideration and review of dosing regimens for treatment. Future research should investigate improving the efficiency of drug delivery to tracheostomized children and the safety and efficacy of higher-dosage regimens.