The Science Journal of the American Association for Respiratory Care

2010 OPEN FORUM Abstracts

OXYGEN PLANNING FOR FIXED WING TRANSPORT WITH THE LTV 1200.

Ashley Thompson, Edward Schneider, Grant D. Wilson; Respiratory Care, Mayo Clinic, Rochester, MN

Background: Oxygen planning for fixed wing transport includes 3 parts: preflight estimate of patient needs, patient contact actual oxygen needs, and in-flight monitoring of oxygen usage. The LTV 1200 ventilator has an internal Oxygen Cylinder Duration Calculator that is useful for predicting available oxygen time when a patient is connected to the device; however, medical transport teams must predict oxygen usage prior to patient contact before departing toward the referral center. Goal: Develop a formula for preflight oxygen planning for the LTV 1200 ventilator. Methods: We tested the Viasys LTV 1200 ventilator in a number of patient scenarios, pediatric to adult, to confirm the oxygen consumption of the device is as indicated in the manufacturer’s specifications. For each scenario, the ventilator was attached to a test lung with a fixed inspired minute volume and 100% O2; the cylinder size and pressure were entered into the ventilator’s Oxygen Cylinder Duration Calculator and the resulting calculated tank duration recorded. The ventilator was then attached to an oxygen E cylinder and monitored for time until the ventilator failed to cycle. Results: The LTV 1200 ventilator’s specifications list a bias flow of 10 L/min that is active during the expiratory phase only. For the invasive ventilation scenarios, we found the ventilator consumed 7 to 8 L/min. of oxygen (dependent on I:E ratio) in addition to the inspired minute volume. When attached to a full E cylinder (707 Liters) the ventilator calculated cylinder duration at 71 minutes and had a measured duration of 78 minutes. The non-invasive simulations varied considerably with oxygen usage calculated as high as 30 L/min. with a modest mask leak. Conclusions: The LTV 1200 ventilator consumes oxygen at a predictable rate consistent with its specifications when used invasively and in a controlled mode; the LTV 1200’s internal Oxygen Cylinder Duration Calculator is fairly accurate, underestimating available oxygen slightly in the scenarios tested. Oxygen usage during Non-invasive ventilation with the LTV 1200 is not predictable, with consumption rates as high as 30 L/min. in the scenarios tested. For preflight oxygen planning when the internal calculator is not available, the formula: Inspired Minute Volume + 10L/min., for intubated patients, should provide a margin of safety that can be confirmed after the patient is attached. Sponsored Research - None