The Pulmonetics LTV800 Ventilator Supports an Open Breathing Circuit for Portable Mouthpiece Ventilation in Neuromuscular Patients

Volume driven mouthpiece ventilation has been shown to provide both adequate ventilatory support and an improved quality of life when compared to ventilation by tracheostomy in neuromuscular patients with chronic respiratory failure. To date, mouthpiece ventilation has been supported by piston actuated volume ventilator systems. These ventilators are heavy and require significant space, making their instillation on power wheelchairs for portable ventilatory support both costly and time consuming. Patients using these systems are often limited in their ability to move within their home environment because of the increased length of the wheelchair ventilator system. We tested a new model 800 of the LTV series ventilators by Pulmonetics Inc., Colton, CA. The compact, portable LTV 800 ventilator was re-engineered to support assist breath triggering in the assist/control mode by negative pressure whereas the previous models have been flow triggered. The LTV 800 was tested using an open breathing circuit system consisting of an Airlife volume ventilator circuit, (Allegance Healthcare Corp.), combined with a 15mm angled mouthpiece, (Respironics Inc.). The ventilator was tested in the assist/control mode at variable tidal volumes, breath rates and inspiratory flow rates. The low pressure alarm was set at 0 centimeters of water pressure. The ventilator produced accurate breath volumes on a test lung from 500 to 1500 cc?s. Low inspiratory flow rates did not trigger the low pressure alarm and the control breath rate could be set as low as one breath per minute without ventilator alarming by adjusting the apnea duration to 60 seconds. Negative pressure triggering was set as low as ?1 centimeter of water pressure without causing autocycling machine breaths. The LTV 800 model ventilator supported an open breathing circuit for mouthpiece ventilation under a variable range of breath volumes and inspiratory flow rates without low pressure alarming. The LTV 800 ventilator can provide a significant gain in the support of portable open circuit mouthpiece ventilation for neuromuscular patients with respiratory failure. The LTV 800 ventilator is significantly more compact and lighter weight than currently used portable volume ventilators. It may provide a lower cost and faster instillation for power wheelchairs as well as the potential for significantly greater chair maneuverability with a more compact wheelchair ventilator system.