Effect of Humidification System Choice on Aerosol Delivery during Mechanical Ventilation
Gavin Bennett1, Sorcha Murphy1, Ian McDonnacha1, Mary Joyce1, Louise Sweeney1 & Ronan MacLoughlin1
1Aerogen, IDA Business Park, Dangan, Galway, Ireland.
Summary
Humidification is essential for proper function of the mucociliary escalator in mechanically ventilated patients. Several manufacturers systems are available, each generating active humidification by means of a hot pot and a column of water, producing water vapour. The design of these systems can differ greatly in both geometry and means of vapour production. Consequently, the ability of aerosolised medication may be affected and differ between systems. This study evaluates aerosol delivery across two market leading humidification systems during simulated adult and paediatric mechanical ventilation.
The comparison of two humidification systems (Teleflex Hudson RCI Neptune and Fisher & Paykel MR850) was completed by measuring the aerosol dose of Albuterol sulphate (2 mg/ml) delivered to the end of an endotracheal tube. Simulated adult and paediatric mechanical ventilation were assessed in combination with four nebuliser placement positions within the circuit; at the ventilator, at the wye, at the dry side of the humidifier and at the wet side of the humidifier.
Under simulated adult breathing settings, the range in lung dose recorded was 17.08 – 24.83% of the dose placed in the nebuliser’s medication cup. Under simulated paediatric breathing settings, the range in lung dose recorded was 2.99 – 4.40%. Under adult breathing settings, statistically significant results were observed between systems at the wye and at the wet side of the humidifier. Under paediatric breathing settings, statistically significant results were noted between systems at the dry side of the humidifier. Although there were some statistically significant results observed, this study recorded similar levels of aerosol delivery across the two humidification systems under test.
