2005 OPEN FORUM Abstracts
An EVALUATION OF Fifteen Transport Ventilators
Daniel W. Chipman, RRT, Maria P. Carames, MD, Eriko Miyoshi, MD, Joseph Kratohvil, RRT, Robert M. Kacmarek, PhD, RRT Massachusetts General Hospital, Boston Massachusetts
Numerous mechanical ventilators are currently designed and marketed for use in patient transport. The complexity of these ventilators varies considerably, however very little data exists comparing the operational capabilities of these units. Using bench and laboratory models, we compared the operation of the Univent Eagle 754, Pulmonetic LPT, Versamed I-vent, Bird Avian, Ocean Medical Products Magellan, Newport HT50, Pneupac Parapac Transport 200D, Pneupac Parapac Medic, Pneupac Compac 200, Biomed Devices IC2A, Biomed Devices Crossvent 3, Carevent ATV+, LifeSupport Products Autovent 2000, Percussionaire TXP, and Respirtec Pro ventilators.
Methods:We evaluated gas consumption, battery life, ease of use, need for compressed gas and ability to deliver set parameters using a Michigan Instruments test lung under three different test conditions (high resistance, normal compliance; normal resistance, normal compliance; and normal resistance, low compliance). For each condition the ventilators were set to deliver a tidal volume of 500 ml at rates of 15 and 30 breaths per minute, and a tidal volume of 1 liter at rates of 10 and 20 breaths per minute. In addition we evaluated each ventilator's ability to maintain ventilation and oxygenation in a normal and lung injured sheep model.
Results: Gas consumption ranged from 30 to 77 minutes and was measured as the duration of operation at 100% oxygen and a minute volume of 10 liters/minute using a full oxygen e-cylinder. Battery life was evaluated based on the ventilator's capability of providing ventilation without the use of external compressed gas. Five of the ventilators tested (Univent, Pulmonetic, Versamed, Newport, Compac) incorporated a battery. The rest were pneumatic. With a fully charged battery and the minute ventilation set at 10 liters/minute the operational range was 70 minutes to > 8 hours. All the ventilators were capable of providing variable FIO2 when connected to an oxygen source. Ten of the ventilators (Univent, Pulmonetic, Versamed, Newport, Compac, Bird, Crossvent, Parapac Transport, Parapac Medic, Carevent) incorporated alarms to alert the user to both a high pressure situation as well as patient disconnect. All except three ventilators (Compac, Autovent, Carevent) met the bench test criteria. Their upper range of respiratory rate limited these three. Most of the ventilators tested were relatively simple to operate with clearly marked controls. Two of the ventilators (Respirtec and Percussionaire) were difficult to set initially and required significant further adjustment to effect parameter changes. The controls on the Compac were simple to set, but difficult to access due to the physical design of the unit. All ventilators, with the exception of the Respirtec were capable of maintaining ventilation, oxygenation, and hemodynamics in both the normal and lung injured sheep model. The size of the animals (20 to 31kg) limited our ability to set the appropriate tidal volume with this ventilator.
Conclusions: All except three of the ventilators tested were capable of meeting the minute volume requirements under all evaluation conditions. Some of the settings were inaccurate. The physical characteristics and gas consumption of some of the ventilators may render them less desirable for patient transport.