Disposable T-Tube Oxygenators: Do Not Use before Inspecting or Testing
Hazard [Health Devices Mar-Apr 1992;21(3-4):137]
A member hospital reported that a
pediatric patient in the Postanesthesia Care Unit (PACU) suffered barotrauma and
died after being connected to a T-tube oxygenator. She had been breathing
spontaneously through her tracheal tube when the defective, preassembled
oxygenator was removed from its wrapper and connected to provide supplemental
oxygen. No one inspected the oxygenator or noticed that the reservoir tube,
through which the excess oxygen and exhaled breaths normally exit, was occluded
by a tightly fitting disk near its end (see figure).
The disk was
apparently left in the tube inadvertently during the manufacturing process; the
manufacturer subsequently recalled the lot and found no other defective units.
The oxygenator had been connected to a wall oxygen outlet, with the flow
control set to deliver 10 L/min. When connected to the tracheal tube adapter, oxygen was
able to flow only into, and not out of, the patient's airway and lungs. The pressure rose
to a dangerous level within a few seconds (up to 50 psi).
As with all disposable anesthesia and respiratory care equipment, even a
device as simple as an oxygenator warrants inspection or testing before use with a
patient. ECRI databases have numerous reports of defects in disposable breathing devices
and components that were undetected by the quality control sampling and testing methods
typically performed by the manufacturers; many of these defects subsequently caused injury
or death. Most of the reports describe occluded fittings, split hoses and connectors, and
foreign bodies; some of the defects, such as splits, occurred during connection of a
Unlike anesthesia and ventilator breathing circuits that are fully tested
as components of a complete system, T-tube oxygenators are stand-alone devices that can be
used by nurses and others who typically do not inspect or test medical equipment.
Manufacturers should perform appropriate quality control procedures to ensure that
products received by the hospital are safe. In addition, the hospital should have its
respiratory therapy or anesthesia department staff inspect or test disposable products in
batches before use. Device packaging and individual wrappers should provide warning labels
and simple inspection and test methods (for devices that are used alone and not tested as
part of a larger system).
One simple method of pre-use inspection for complete or partial occlusion
in T-tube oxygenators, such as the one in the reported incident, is to look through the
open reservoir tube. Oxygenators that cannot be inspected by sighting (e.g., because of
the presence of a valve) should be tested before use with 10 L/min oxygen flow and a
pressure gauge connected to the patient port; the pressure should not exceed 5 cm H2O
or (if appropriate) the pressure setting of an integral PEEP valve.
- If no pre-use inspection or test procedure is
specified for the T-tube oxygenators used in your hospital, contact the
manufacturer for recommendations. If the manufacturer does not have an
inspection or test method available yet, use the procedures described above.
- Inform all users of these disposable devices to anticipate occasional
defective units and to always inspect or test them before use with a
For further information, see our Hazard Report "Pre-Use Inspection of
Oxygenators, T-Tube [17-925]
Cause of Device-Related Incident
Device factors: Improper maintenance, testing,
repair, or lack or failure of incoming inspection; Manufacturing error
User error: Failure to perform pre-use inspection
Support system failure: Lack or failure of
incoming and pre-use inspections
Mechanism of Injury or Death