2006 OPEN FORUM Abstracts
PORTABLE VENTILATORS : A COMPARISON OF DURATION OF OPERATION FROM AN E-CYLINDER
Ellen Lyons RRT,
Jay Johannigman
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 |
Duration of
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.