The Science Journal of the American Association for Respiratory Care

2006 OPEN FORUM Abstracts

THE EFFECT OF RESISTANCE ON TIDAL VOLUME DELIVERED FROM THE PNEUPAC ventiPAC MODEL V200D MRI-COMPATIBLE PORTABLE VENTILATOR

Lance Lothert, RRT, CPFT, Immanuel St. Joseph's Hospital Mayo Health System, Mankato MN, USA.

Background: Portable ventilators are used in multiple settings such as transport, emergency departments and MRI. Most portable ventilators do not measure tidal volume (VT). This study was performed to assess the effects of increased resistance on tidal volume delivered from a pneumatic, time-cycled portable ventilator.

Method: The ventiPAC ventilator was connected to a mechanical lung (Michigan Instruments, Grand Rapids, MI) with a compliance of .10 L/cm H2O. An inspiratory flow of 30 L/min and an FIO2 of .45 were held constant during each measurement. 

The delivered VT was measured by a pneumotachometer (direct connect, Medical Graphics, St.Paul, MN). Two fixed resistors were placed in-line and multiple measurements were made at multiple inspiratory and expiratory times.

Results: 

TI TE 5 cmH2O/L/sec 20 cmH2O/L/sec
   
.5 1.5 -0.6% -1.8%
.5 2 -1.2% -1.2%
.5 4 -1.2% -1.2%
.75 1 .09% -1.7%
.75 1.5 -1.7% -4.4%
.75 2 -3.9% -6.3%
.75 4 -10.1% -12.6%
1 1 -0.3% -2.9%
1 1.5 -2.6% -5.3%
1 2 -2.8% -5.3%
1 4 -8.8% -11.1%
1.5 1.5 0.3% -2.6%
1.5 2 -1.1% -3.6%
1.5 4 -4.1% -6.9%
2 2 2.2% -0.6%
2 4 -0.4% -3.9%

Conclusion:

1.      T was affected less than 13% at an increased resistance of 20 cmH2O/L/sec.

2.      T would not be significantly affected in the event of a physiologic increase in inspiratory resistance, which would make a pneumatic, time-cycled portable ventilator, safe for clinical work.


You are here: RCJournal.com » Past OPEN FORUM Abstracts » 2006 Abstracts » THE EFFECT OF RESISTANCE ON TIDAL VOLUME DELIVERED FROM THE PNEUPAC ventiPAC MODEL V200D MRI-COMPATIBLE PORTABLE VENTILATOR