Fatal Air Embolism from Misuse of Closed-Wound Suction Units
Hazard [Health Devices May-Jun 1990;19(5-6):200-2]
A member hospital reported a patient death from an air
embolism associated with the use of a closed-wound suction unit. In several
departments throughout the reporting hospital, users had difficulty draining thick
secretions through the unit's inlet port antireflux valve, which prevents back flow of
serosanguineous fluid and air. For this reason, in the reported case the user bypassed the
antireflux valve by inserting a length of tubing connected to a stopcock through the
valve. The drain plug in the outlet port, which allows air to be released while
compressing the unit to create suction, inadvertently closed. Consequently, air was forced
into the patient's chest, resulting in a fatal air embolism.
The closed-wound suction unit is used to drain
surgical wounds of serosanguineous fluid to prevent infections, hematomas, or
other materials from accumulating and interfering with wound healing. Perforated tubing is inserted into the wound and connected to the evacuator
container up to the indicator ring. The container maintains a near-constant medium-level
vacuum, which causes the serosanguineous fluid to drain from the
wound. Squeezing the pump bulb inflates a balloon and displaces air inside the
container; air then flows through the open outlet port (drain plug out). As the balloon
inflates, the antireflux valve prevents air from flowing into the patient. Following the evacuation
of air from the container, closing the outlet port with the drain plug and the
resultant slow release of air through the release valve in the pump
bulb creates a vacuum in the container and drainage tube.
Two conditions led directly or contributed to air embolism in the reported
case: 1) The antireflux valve was bypassed by the tubing, and 2) the drain plug was in
the outlet port, closing it off. These improper practices caused air to flow into the
patient when the clinician inflated the balloon.
The manufacturer was not aware that this type of wound-drainage
system was being used for chest drainage, and other units are available for this
application. Although the manufacturer does not specifically advise against this use, either
on the unit or in its operator's manual, it does recommend against modifying the unit's
setup. Also, the system's guidelines for selecting procedure-specific drain-and-closed-wound
suction evacuators do not include chest-drainage procedures.
We believe that similar occurrences to the reported case are possible with
any wound-drainage systems in which suction is created mechanically. However, the
antireflux valve is built into the unit for patient safety. Disabling or bypassing this
safety feature contravenes the manufacturer's instructions and not only defeats the
function of the valve by preventing reflux of infectious material into the wound, but
increases the risk of air embolism. If any modifications are necessary or the
manufacturer's instructions are unclear, users should always
manufacturer for advice.
- Alert users that under no conditions should they
bypass the antireflux valve on closed-wound suction units.
- Follow the manufacturer's directions carefully, and
do not use a modified setup.
- Do no use closed-wound suction units for
chest drainage unless they are specifically labeled for that use.
Wound Drainage Kits [16-521]
Cause of Device-Related Incident
Device factor: Design/labeling error
User errors: Abuse of device; Device misasssembly
Mechanism of Injury or Death