2006 OPEN FORUM Abstracts
Performance of a Novel Humidification Device in Mechanical Ventilation
N.H. Tiffin, BSc RRT MSA1, L.A.
Weinstein, MS1, D.E. Sunstein, SB2,
T.Q. Tran, BS1 and J.B. Taylor, BFA3. 1Pari
Respiratory Equipment, Midlothian, VA, United States; 2Sunrise Labs,
Auburn, NH, United States and 3Farm Design, Hollis, NH, United
States.
Background: A novel active humidification system has been developed
which can heat and humidify dry therapeutic gases. This study measures the ability of this
in-line humidification device (PARI Hydrate
Pari Respiratory Equipment,
Midlothian
,
VA
) to heat and humidify gas during mechanical
ventilation. The new technology (C-Force
Pari Respiratory Equipment) produces water vapor in a
pressurized stream from an in-line, small device placed proximal to the
patient. A controller allows precise
water introduction into the bottom of a ceramic disk. A heating plate on the
top of the disk vaporizes the water inside the ceramic and the resultant vapor
stream is directed into the gas flow. Energy efficiency is over 90% and there
are no moving parts in the disk.
Method: We used a Puritan Bennett 7200
mechanical ventilator with a rate of 15 bpm, Vt=700 mL, PEEP=10 cm H2O
and descending waveform setting. Our test lung (Quick Lung, Ingmar Medical,
Pittsburg, PA, USA) was set to normal lung settings to simulate Cp=0.2
L/cm H2O and Ra=5 cm H2O/L/s. The device was inserted into the
ventilator circuit 6
wyewyeoC.
Results: Average RH after 5 minutes was 84.5 + 8.1% and after 20
minutes was 90.1 + 2.8%. (average + stand deviation). Average
temperature over the span of testing was 37.3 + 0.6 oC
with a maximum of 38.7oC. The inspiratory
line of the circuit remained dry from the ventilator to the distal outlet of
the device. No water was found in the 6wye
Conclusions: Minimum recommended absolute humidity for mechanical
ventilation is 30 mg H2O/L at 30°C and recommended levels of absolute humidity
between 36 mg/L to 40 mg/L. The Pari
Hydrate, at an average temperature of 37.3oC and 90.1% RH, is
capable of heating and humidifying dry oxygen flow up to 40 L/min to over 35oC
and over 90% relative humidity.
Application to mechanical ventilation is possible. The device
effectively heats the ventilator gas to within a narrow and clinically safe
range of temperature and can humidify dry oxygen during mechanical ventilation
to recommended levels at the patient wyeinspiratory
line of the circuit dry.