The Science Journal of the American Association for Respiratory Care

2010 OPEN FORUM Abstracts

DOES THE LTV 1200 MAINTAIN A SAFE OPERATING TEMPERATURE WHEN INCREASED RESISTIVE LOADS, (PEEP LEVELS UP TO 30 CMH20), ARE PLACED ON THE TURBINE?

Richard P. Mitchell, Matt McNally; Respiratory Care, Dartmouth Hitchcock Medical Center, Lebanon, NH

BACKGROUND: During the 2009-2010 Influenza Pandemic, the Dartmouth Hitchcock Advanced Response Team (DHART) transported several patients with 2009 H1N1 related ARDS. Several of these patients required PEEP greater than 20cmH2O, the maximum setting on the LTV 1200 ventilator. We tested the LTV 1200 to determine if it could be used safely with the addition of an external PEEP valve for patients requiring greater than 20 cmH2O of PEEP. A bench test was performed to see if PEEP could be increased by adding an adjustable PEEP exhalation valve, (CareFusion PN# 10824), and applying external PEEP to the internal PEEP of the LTV 1200. Using a Michigan Instruments TTL Test Lung, we found that PEEP settings up to 30 cmH2O could be achieved by adding internal PEEP (15 cmH2O) to the external PEEP valve, (15 cmH2O), while maintaining reasonable accuracy of delivered parameters, as measured by the TTL and LTV 1200 with low Cstat/high Raw test lung settings and ARDSNet patient settings. We noted increased heat radiating from the ventilator case during our test runs. The maximum operating External Surface Temperature, (measured on the ventilator case), is 50∞ C., according to the LTV 1200 Operator’s Manual, (P/N 19802-001, Rev A, page A-7). METHOD: We set up the LTV 1200 in the above described manner and secured a temperature sensor centered on the ventilator case. We simultaneously measured the internal temperature. Normal ventilator operating parameters and lung mechanics were used as a baseline. ARDSNet compatible settings were tested with severely reduced compliance and increased Raw under increasing PEEP conditions. Temperature measurements were taken with a Fluke 52II Dual Channel Thermometer and readings taken after each condition was run for two hours and readings were stable. RESULTS: The maximum External Surface Temperature, as shown in Table 1, of the LTV 1200 was not exceeded during our test runs. CONCLUSIONS: We conclude that modifying the PEEP delivery system to be able to deliver up to 30 cmH2O of PEEP does not create an unsafe increase in operating temperature of the LTV 1200. Sponsored Research - None