Comparison of vibrating mesh, jet, and breath-enhanced nebulizers during mechanical ventilation

Abstract

BACKGROUND: This study compared 3 nebulizer technologies for inter-and intradevice reproducibility, humidification, and fill volume sensitivity during mechanical ventilation: a breathenhanced jet nebulizer, a vibrating mesh nebulizer, and a jet nebulizer. The breath-enhanced jet nebulizer featured a new design located on the wet side of the humidifier to reduce aerosol loss and potential humidifier contamination. The vibrating mesh nebulizer and the jet nebulizer were placed on the dry side. METHODS: Aerosol delivery was measured using multiple ventilator settings (inspiratory time 5 0.45–1.01 s). Using radiolabeled saline and a gamma camera, bench studies were performed using a ventilator to test 4 breathing patterns. Four scenarios were assessed during testing: 3 mL and 6 mL fill volumes with and without heated wire humidification. Measurements included inhaled mass (as a percentage of the nebulizer charge), nebulizer residual, mass balance, and aerosol particle size distribution. Statistics were determined using MannWhitney and linear regression. RESULTS: The inhaled mass for the breath-enhanced jet nebulizer was 10.5–29.2% and was affected by fill volume (P 5.004) but not by humidity. The inhaled mass for the vibrating mesh nebulizer was 0.9–33% and was unaffected by fill volume and humidity. The inhaled mass for the jet nebulizer was 2.5–25.9% and was affected by both fill volume (P 5.009) andhumidity(3mL,P 5.002). The inhaled mass for the vibrating mesh nebulizer was more variable due to random failures to achieve complete nebulization, and inhaled mass correlated closely with residual mass: IM% 5 –0.233(Residual%) + 24.3, r2 5 0.67, P