2006 OPEN FORUM Abstracts
PORTABLE VENTILATORS : A COMPARISON OF DURATION OF OPERATION FROM AN E-CYLINDER
Ellen Lyons RRT,
MD, Kenneth Davis MD, Betty Tsuei MD & Richard
Branson RRT. University of Cincinnati,
Department of Surgery, Cincinnati, OH 45267-0558.
Background: Portable ventilators (PV) used for transport have variable gas consumption characteristics based on control system and operation.
Methods: Five PV were studied : BioMed Devices IC-2A, Impact Eagle 754, Newport HT-50, Pulmonetics LTV-1000 and VersaMed iVent. Only 1 of each device was studied. All PV were set up according to manufacturers recommendations. Appropriate ventilator circuits were connected to each PV and to a test lung (TTL, Michigan Instruments). Lung compliance was 50 ml/cm H2O and resistance was 5 cm H2O/L/s. PV were operated at three conditions: 1) Rate of 10 breaths/min, VT of 1.0L, PEEP of 0 cm H2O, 2) Rate of 10 breaths/min, VT of 1.0L, PEEP of 20 cm H2O, and 3) Rate of 20 breaths/min, VT of 0.5L, PEEP of 0 cm H2O. Minute ventilation (10 L/min) and FIO2 (100%) were kept constant. Inspiratory time was 1.0 seconds and flow was 60 L/min. Runs were made in triplicate.. A pneumotachograph was placed between the ventilator circuit and test lung to record the minute ventilation and duration of operation.
Results: Duration of operation from an E-cylinder was significantly different between PV. PEEP of 20 cm H2O resulted in a slight decrease in duration of operation in all ventilators. Table 1 demonstrates results of the study. Data is minutes of operation (mean ± SD).
|Ventilator||10 x 1000 0 PEEP||10 x 1000 20 PEEP||20 x 500 0 PEEP||p- value|
|1 vs 2||1 vs 3||2 vs 3|
|IC-2A||37 ± 1||35 ± 2.3||32 ± 1.6||0.19||0.06||0.05|
|754||73 ± 2.3||69 ± 1.7||75 ± 6.1||0.03||0.38||0.21|
|HT-50||72 ± 5.6||66 ± 8.4||69 ± 4.9||0.32||0.4||0.2|
|LTV-1000||42 ± 1||39 ± 1||38 ± 2.3||0.24||0.28||0.51|
|iVent||69 ± 1||60 ± 2.2||68 ± 4.2||0.03||0.4||0.17|
operation was significantly longer for the Impact 754 and HT-50 vs iVent (p < 0.05), and LTV
1000 and IC-2A (p <0.001) at each condition.
Conclusions: Gas consumption of PV varies with driving mechanism, use of continuous flow, and elevated PEEP. Understanding duration of operation from an E-cylinder and gas consumption is important in utilization of ventilators. This study looks at only one facet of PV operation, ventilator comparisons should include evaluation of many performance characteristics.