012 - Effect of nebulizer device set on measurement of tidal volume and pressure ventilator during two mode of ventilation - 05/12/08

Rationale: Numerous factors affect aerosolized drug delivery during invasive ventilation. However, there is few data concerning measurement of tidal volume and pressures on the ventilator and similarly on the lung during a nebulization.

Aim: To evaluate the effect of aerosol devices in two modes of mechanical ventilation on the measurement of tidal volume and pressures on the adult and infant test lung.

Methods: A Servo 300 and a Galileo ventilator were set for Volume assisted Control (VAC) and Pressure Control (PC) and were connected to a Michigan test lung. Albuterol sulfate inhalation solution was nebulized with 5 aerosol devices: MistyNeb and Sidestream jet nebulizer, Aeroneb Pro vibrating aperture plate nebulizer, Ring nebulizer and AMGH ultrasonic nebulizer. Tidal volumes were set respectively at 450 ml and 180 ml for the adult and infant test lung. Frequency was 15/min in adult and 20/min in infant. Tidal volumes, peak pressure, PEEP were measured on the ventilator and on the test lung before and during nebulization.

Results: Graph 1 shows the pressure curves by test devices and ventilation modes.

Jet nebulizers: During VAC, there was no significant difference on the pressure measurement on the ventilator and the test lung before and during nebulization. The tidal volume measurement increased to 28% in adult and 45% in infant. In PC, tidal volume was not modified and pressure measurements were increased during nebulization.

Ultrasonic nebulizer: During VAC, measurements of pressure and tidal volume were similar with or without nebulizer. During VP, the tidal volume measurement was decreased at 32% in adult and 13% in infant.

Aeroneb Pro and Ring nebulizer: tidal volume and pressure measurements were comparable before and during nebulization.

Conclusion: Aerosol device influenced significantly pressure or volume measurement during mechanical ventilation. These variations of pressure or volume could be dangerous for the patients and incite to choice the optimal ventilation mode for an aerosol device.

Pressure and volumes measurement were not affected by use of Aeroneb Pro and Ring nebulizers during mechanical ventilation and allow a safe clinical practice.