Aerosol delivery to ventilated infant and pediatric patients

Area of Science:

• Pediatric Respiratory Medicine
• Pharmacokinetics
• Medical Device Engineering

Background:

• Infants possess distinct respiratory mechanics, including low tidal volumes and short respiratory cycles.
• These physiological characteristics limit aerosol particle residence time in the lungs, resulting in significantly lower pulmonary deposition rates (<1%) compared to adults (8-22%).
• In vitro models may overestimate deposition due to not accounting for exhaled aerosol, while animal and human studies corroborate low deposition rates.

Purpose of the Study:

• To analyze the challenges and efficacy of aerosol drug delivery in infants.
• To compare aerosol deposition in infants versus adults.
• To identify factors influencing aerosol delivery efficiency in pediatric patients.

Main Methods:

• Review of scintigraphy data from intubated and nonintubated infants.
• Comparison of in vitro testing, animal models, and human study data.
• Analysis of aerosol delivery systems and their impact on drug deposition.

Main Results:

• Pulmonary aerosol deposition in infants is consistently low (<1%), regardless of intubation status.
• Despite low deposition percentages, infants receive higher drug doses per kilogram of body weight than adults.
• Existing aerosol delivery systems, particularly those with low residual volume nebulizers, can achieve up to 13% deposition.

Conclusions:

• Efficient aerosol delivery to infants is hindered by low deposition and high patient variability.
• Understanding the variables affecting aerosol delivery is crucial for optimizing treatment.
• Mechanically ventilated infants can benefit from effective aerosolized drug administration with appropriate systems and awareness of delivery parameters.