2004 OPEN FORUM Abstracts
IN VITRO DELIVERY OF ALBUTEROL THROUGH A PEDIATRIC VENTILATOR CIRCUIT USING A JET NEBULIZER AND AN AERONEB PRO NEBULIZER.
David Thelander
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.