2006 OPEN FORUM Abstracts
Manually Ventilating & Suctioning In-line with a SensorMedics 3100B High Frequency Oscillatory Ventilator Bench Test
Joseph Hickey AS, RRT, Kathryn
L. Mattare BS, RRT, Anthony Bilenki MA, RRT, The Johns Hopkins Hospital,
Baltimore, Maryland
Background:
Manual
ventilation (bagging) and/or suctioning of adult patients on a SensorMedics
3100B High Frequency Oscillatory Ventilator (HFOV) frequently leads to episodes
of de-compensation. Decreases in oxygen saturation have been attributed to alveolar
collapse occurring when mean airway pressure (MAP) from the ventilator is
interrupted during manual ventilation and/or suctioning. Another potential risk
of manual ventilation is inadvertent excessive alveolar pressures and/or tidal
volumes.
Objective:
To
devise a method of safe manual ventilation and suctioning for patients while on
HFOV.
Methods:
A pediatric
ventilator "Y" adaptor from an Airlife Isothermal Breathing
Circuit was connected to an 8.0 mm endotracheal
tube (ETT). One side of the "Y" was connected directly to the end of the HFOV
circuit. The other side was connected to a 14 Fr Ballard Double Swivel Elbow In-Line Suction
Catheter with a one-way valve (Hudson RCI) attached to the opening via a
connector from the Viasys HFOV circuit. To minimize deadspace,
2 cm of extra length were trimmed from the ETT. The high airway pressure limit
on the HFOV was set 30cmH20 above the set MAP to prevent circuit decompression.
A Vital Signs Adult Manual Resuscitator
was attached to the one-way valve, and oscillation was stopped. A manual breath
was delivered above the MAP through this configuration to an Ingmar Quick Lung until the ΔP on
the HFOV measured 15-20cmH20. Exhaled volumes were measured using a Ferraris Wright Respirometer.
The in-line suction catheter was inserted and suction (-80 to -120 mmHg via an Ohmeda gauge
and Argyle suction tubing) was only
applied when a manual breath was delivered.
Results:
After
stopping oscillation and manually ventilating to a ΔP of 15-20cmH20, the
loss of MAP was prevented and acceptable tidal volumes of 200-500ml were
delivered. Tidal volumes greater than 700ml could not be generated due to the
constant bleed off at the control pressure mushroom valve.
The exhaled tidal volumes were measured while using lung compliances of 10 and
20ml/cmH20 and MAP's set at 20, 25 and 30cmH20,
simulating patients requiring HFOV.
Conclusion:
Using
the Manual Ventilation and Suction Adapter prevented loss of MAP while manually
ventilating at safe volumes and/or suctioning on an Ingmar quick lung. Clinical
data collection is ongoing.