2006 OPEN FORUM Abstracts
COMPARISON OF PEAK INSPIRATORY PRESSURES USING ADULT VS PEDIATRIC CIRCUITS DURING PRESSURE-TARGETED, ASSIST-CONTROL WITH THE LTV 1000: IS IT ACCEPTABLE TO STOCK ONLY ONE CIRCUIT?
Phillip Elle BS, Eric Peart, Lonny Ashworth
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 Peak Inspiratory Pressures (PIP), 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; Pressure A/C; I-time 1.0; Rate 6 BPM; PEEP 5 cm H2O. PIP was the average of a minimum of 5 breaths, while CST and RAW were changed. Displayed PIP was recorded with the LTV 1000 adult circuit (LTV-A) and the pediatric circuit (LTV-P). Measured PIP was recorded with the HR1101 adult circuit (HR-A), and the pediatric circuit (HR-P).
Results: At CST 40 mL/cm H2O and RAW 15 cm H2O/L/sec: at set pressures of 15, 20, 25 and 30 cm H2O, average PIP on the LTV-A was 15, 21, 26.4 and 31.2 cm H2O; on the LTV-P 15.4, 21, 27 and 32.8 cm H2O; on the HR-A 15.1, 21.6, 25.9 and 30.9 cm H2O; on the HR-P 15.1, 21.3, 27.1 and 32.4 cm H2O. Similar trends were found in PIP at each compliance and resistance setting. It is notable that the LTV 1000 displayed volumes with the pediatric circuit were approximately 6-20% lower than with the adult circuit, however, the measured percentage difference on the HR1101 was considerably smaller.
Conclusion: The adult and pediatric circuits deliver similar PIP while using the LTV 1000. Because the pediatric circuit has increased resistance due to the smaller diameter of the circuit, volume may be reduced and must be monitored closely. Although both circuits delivered similar pressures to the lung simulator, additional evaluation on patients should be performed prior to stocking a single circuit on a transport vehicle.