The Science Journal of the American Association for Respiratory Care

2011 OPEN FORUM Abstracts


Joel M. Brown, John S. Emberger, Brett Booker, Gerald O'Brien; Christiana Care Health System, Newark, DE

Background: The method of ventilation during interventional rigid bronchoscopy is a variable that can dictate the success of the procedure. Traditionally, the manual jet ventilator is used during this procedure. Manual jet ventilation requires ongoing arbitrary manipulation of the device which can be time consuming and may result in inconsistent ventilation. Considering the problems of the jet, we have explored the use of the Pulmonetics LTV 1200 (LTV), a turbine driven mechanical ventilator during this procedure. This study compared the variability in tidal volume (Vt) delivery when using the jet ventilator and the LTV during rigid bronchoscopy. Method: The Laerdal AirMan was attached to a Michigan Test Lung TTL (Michigan Instruments Inc.) to act simulated patient with realistic trachea. The compliance of the test lung was set to 40 cm H2O/L with a fixed airway resistance of 5 cm/H20/L/sec. The Storz 14-33 Rigid Bronchoscope was advanced into the manikin's upper airway and stabilized 7cm past the vocal chords. The NICO Management System (Novametrix Medical System Inc.) was used to obtain the exhaled tidal volume. The Vt observed during jet ventilation was obtained during "Burst" breaths (full depression of the flow lever that last less than one second) and "Max" breaths (depression of the flow lever until chest pressure stabilized) at 3 different working pressures (40, 50, and 60 PSI). The Vt observed during ventilation with the LTV was obtained using pressure control ventilation with 3 different set peak inspiratory pressures (20, 25, and 30 cm H20), 2 different inspiratory times (0.6 and 1.0 seconds), and PEEP of 0. Results: The average Vt difference from Burst to the Max breaths when employing the jet ventilator was 615mL with a standard deviation +/- 622mL. The average Vt difference from 0.6 second inspiratory time to a 1.0 second inspiratory time when employing the LTV was 681ml with a standard deviation +/- 194mL. See Graph for additional data. Conclusion: Inspiratory time has a greater effect on the Vt delivery than the pressure setting for both the LTV and jet ventilation. The jet ventilator demonstrated a greater variation in Vt than the LTV which could result in underventilation or volutrauma over the range of inspiratory times tested.
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