ALBUTEROL DELIVERY USING THE DHD CIRCUVENT AND THE AIRLIFE
VALVED TEE ADAPTER.
Terrence O. Brady, RRT; Dean R. Hess, PhD, RRT, FAARC.
Massachusetts General Hospital and Harvard Medical School, Boston MA.
Background: Inhaled albuterol is commonly administered to mechanically ventilated
patients. The Airlife Valved Tee Adapter (Allegiance Healthcare Corp) can be used to attach
a nebulizer into the ventilator circuit in a manner that does not open the circuit. The
CircuVent (DHD Healthcare) allows for delivery of aerosolized medications without
removing the heat-and-moisture exchanger from the circuit.
Hypothesis: Albuterol delivery
through an endotracheal tube is affected by the use of the Valved Tee Adapter and the
CircuVent.
Methods: A Draeger Evita 4 ventilator was set to deliver a tidal volume of 0.5 L,
respiratory rate 12/min, and a flow of 30 L/min. The circuit was attached to an endotracheal
tube (Mallinckrodt, 8 mm inner diameter), the distal end of which was attached to a Puritan-
Bennett D/Flex filter. The filter was attached to a test lung with a compliance of 50 mL/cm
H2O. A Hudson Micro Mist nebulizer was filled with 4 mL containing 2.5 mg of albuterol
and operated from the nebulizer control on the ventilator. The Valved Tee Adapter and the
standard nebulizer T-piece were each used with a dry circuit, a humidified circuit (35 C,
100% RH) and the CircuVent with a dry circuit. Albuterol washed from the filter was
measured by UV spectrophometry. Each set of conditions was repeated in triplicate.
Results: Albuterol delivery was significantly less for the Valved Tee
Adaptor compared to the
standard T-adapter (P<0.001). Albuterol delivery was significantly reduced with
a wet circuit
(P<0.001) and the CircuVent (P<0.001). The most efficient delivery was with a
dry circuit and a standard T-adapter. Use of the Valved Tee Adapter with the
CircuVent resulted in a
reduction in delivered albuterol of > 50% compared to the standard T-adapter.
Conclusions: Albuterol delivery by nebulizer during mechanical ventilation was affected by how the
nebulizer was introducted into the circuit, whether the gas was humidified or dry, and the use
of the CircuVent. If a Valved Tee Adapter or the CircuVent is used, it may be necessary to
increase the nebulizer dose to achieve an equivalent therapeutic dose. These data should be
subjected to clinical study.
albuterol amount (mg)
0.2
0.16
0.12
0.08
0.04
0
Standard T-adapter Valved T-adapter
Cidry wet rcuVent
