2006 OPEN FORUM Abstracts
COMPARISON OF TIDAL VOLUME USING ADULT VS PEDIATRIC CIRCUITS DURING VOLUME-TARGETED, ASSIST-CONTROL WITH THE LTV 1000: IS IT REASONABLE TO STOCK ONLY ONE CIRCUIT?
Eric Peart, Phillip Elle BS, Lonny Ashworth MEd RRT, Boise State
University, Boise, ID.
Background: Due to the limited available space on a helicopter or ambulance, the space must be used as efficiently as possible. Having two sets of ventilator circuits, adult and pediatric, may not be necessary. Displayed and measured tidal volumes, with adult and pediatric circuits, were evaluated.
Method: The Pulmonetics LTV 1000 was connected to the Hans Rudolph Electronic Breathing Simulator (HR1101). HR1101 settings: resistance (RAW) 5, 15 and 25 cm H2O/L/sec; compliance (CST) 20, 40 and 60 mL/cm H2O; Rate 2 BPM; Amplitude 1.0 cm H2O; Effort slope 50.0; % inhale 20.0; Target volume 3000 mL. LTV 1000 settings: Volume A/C; I-time 0.5 seconds with 100 and 300 mL breaths; I-time 1.0 second with 500, 700 and 900 mL breaths; Rate 6 BPM; PEEP 5 cm H2O. Tidal volume was the average of a minimum of 5 breaths, while CST and RAW were changed. Displayed exhaled volume was recorded with the LTV 1000 adult circuit (LTV-A) and the pediatric circuit (LTV-P). Measured delivered volume was recorded with the HR1101 adult circuit (HR-A), and the pediatric circuit (HR-P).
Results: At a CST of 40 mL/cm H2O and RAW of 5, 15 and 25 cm H2O/L/sec: at a set volume of 100 mL, volume on the LTV-A was 79, 56, 47 mL; on the LTV-P was 75, 52, 48 mL; on the HR-A was 106, 103, 101 mL; on the HR-P was 107, 105, 102 mL. At a set volume of 500 mL, volume on the LTV-A was 458, 442, 421 mL; on the LTV-P was 442, 410, 387 mL; on the HR-A was 484, 480, 477 mL; on the HR-P was 488, 489, 488 mL. At a set volume of 900 mL, volume on the LTV-A was 857, 843, 834 mL; on the LTV-P was 815, 795, 794 mL; on the HR-A was 887, 887, 887 mL; on the HR-P was 903, 905, 905 mL. Similar trends were found with a CST of 20 and 60 mL/cm H2O.
Conclusion: The adult and pediatric circuits deliver similar volumes while using the LTV 1000. However, peak inspiratory pressure must be monitored closely because the pediatric circuit has an increased resistance due to the reduced diameter of the circuit. Although both circuits delivered similar volumes to the electronic lung simulator, additional evaluation on patients should be performed before stocking a single circuit on a transport vehicle.