2004 OPEN FORUM Abstracts
IN VITRO DELIVERY OF ALBUTEROL THROUGH A PEDIATRIC VENTILATOR CIRCUIT USING A JET NEBULIZER AND AN AERONEB PRO NEBULIZER.
BS RRT NPS, Children’s Memorial Hospital, Chicago IL.
BACKGROUND: Our institution has historically used a jet nebulizer (Airlife Misty-Neb) attached to an "IMV " type set up which includes 2 t-pieces, an elbow , a one way valve and a reservoir bag attached to the wet side of the humidifier, operated with the humidifier off. We wanted to determine efficiency of an aerosol system that would not reduce trigger sensitivity or affect ventilator parameters.
METHODS: A Servo 300 ventilator was set up with a pediatric heated wire circuit(Allegiance) attached to a 4.0 mm ID ETT and a filter between the ETT and a test lung (Siemens 190). Ventilator parameters were: SIMV (Pressure Control and Pressure Support), RR 20/min, Pressure Control 15 cmH2O, PEEP 5 cmH2O, I time 0.6 s, Bias Flow 2 L/min. A unit dose of albuterol (2.5 mg in 3 ml) was nebulized with a jet neb placed on the wet side of the humidifier (humidifier off). The Aeroneb Pro (Aerogen, Inc.) was operated on both the wet and dry side of the humidifier and 6 inches back from the circuit wye with humidifier on or off. Aerosol was collected on an absolute filter and sent as blinded samples to an independent laboratory(Nemours, FL)for drug to be eluted and assayed using spectrophotometry. All experiments were repeated in triplicate.
RESULTS: The amount of albuterol(mean ± SD) deposited on the filter distal to the ETT was 15.2 ±3.7 mcg with the jet neb and 82.0 ±60.5 mcg with Aeroneb Pro under similar condition. With humidifier on, the Aeroneb Pro deposited 79.1 ±6.8 mcg (dry side of humidifier); 83.1 ±35.3 mcg (wet side of humidifier), 141.3 ±33.2 mcg (6 inches back from wye). The Aeroneb Pro delivered 5 – 9 fold more drug than the jet neb. The Aeroneb Pro delivered similar amounts of albuterol independent of placement before or after humidifier, with and without the humidifier on.
CONCLUSIONS: The Aeroneb Pro delivered more albuterol than our jet neb set up regardless of where it was placed in the circuit with or without humidity.