Effective aerosol delivery during high‐frequency ventilation in neonatal pigs

ABSTRACTBackground and objective: Pulmonary delivery of aerosols during high‐frequency oscillatory ventilation (HFOV) has not been studied in vivo. This study investigated the pulmonary delivery of aerosolized gadopentetate dimeglumine (Gd‐DTPA) in a HFOV circuit in piglets using MRI to visualize contrast excretion in the kidneys.Methods: Four ventilated piglets (3–7 days old, 1.7–2.4 kg at birth) received aerosolized Gd‐DTPA in a HFOV circuit for different durations of time (60, 30, 20 and 10 min). Aerosols were generated using the MiniHeart jet nebulizer. As MR‐compatible HFOV was not available, aerosolized Gd‐DTPA was administered in the HFOV circuit outside the MR suite followed by MRI 10–20 min later. T1‐weighted spin echo sequences were obtained using the Bruker/Siemens 4T MR scanner.Results: Enhancement of the kidneys was observed 10 min after aerosol initiation in piglets who received Gd‐DTPA aerosol for 60, 30 and 20 min in the HFOV circuit but not in the piglet who received aerosol for 10 min. Renal concentration of Gd‐DTPA, determined from the signal intensity, increased linearly with time until 40 min post Gd‐DTPA delivery.Conclusions: Effective pulmonary aerosol delivery during HFOV was confirmed by contrast visualization in the kidneys within 30 min of aerosol initiation reflecting, alveolar absorption, glomerular filtration and renal concentration.

Effective aerosol delivery during high‐frequency ventilation in neonatal pigs Journal Articles