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,
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.
To devise a method of safe manual ventilation and suctioning for patients while on HFOV.
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.
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.
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.