Cause of Device-Related Incident
Device factors; Support system failures; User errors

Clinical Specialty or Hospital Department
Clinical/Biomedical Engineering; Obstetrics and Gynecology; OR / Surgery

Device Factors
Design / labeling error; Device interaction

Document Type
Hazard Reports

External Factors
*Not stated

Mechanism of Injury or Death
Burn (electrical, thermal, chemical)

Support System Failures
Failure to train and / or credential

Tampering and/or Sabotage
*Not stated

User Errors
Failure to perform pre-use inspection; Failure to read label; Improper connection; Inappropriate reliance on an automated feature

UMDNS
Electrodes, Electrosurgical, Active [16-860]; Electrodes, Electrosurgical, Active, Foot-Controlled [16-206]; Electrodes, Electrosurgical, Active, Hand-Controlled [11-499]; Electrosurgical Units [11-490]; Electrosurgical Units, Bipolar [18-230]; Electrosurgical Units, Monopolar/Bipolar [18-231]; Forceps, Electrosurgical [11-502]

Misconnection of Bipolar Electrosurgical Electrodes



Hazard [Health Devices Jan 1995;24(1):34-5]

Problem

We have received more than a dozen reports of serious patient injury due to inappropriate connection of bipolar electrosurgical electrodes to the handswitched monopolar electrode jacks on electrosurgical units (ESUs). We previously warned of this problem in Health Devices Alerts, FDA Data Edition, No. 1989-F5:1-2, May 26, 1989; but these incidents continue to occur. Such misconnection will almost always result in inadvertent activation of the ESU's monopolar mode, which can produce a much higher output than the bipolar mode. The problem has most often been reported following laparoscopic fallopian tube sterilization procedures with subsequent bowel perforation. (Also see our Guidance Article "Monopolar Electrosurgical Safety during Laparoscopy" for further discussion of bowel perforation and other patient injuries that can occur when monopolar electrosurgery is applied laparoscopically.)

Discussion

Most handswitched monopolar active electrode pencils have a rigid connector block with three banana-type plugs for connecting to the ESU. The ESU's monopolar receptacle has three jacks; one jack is for the active electrosurgical current, and the other two are for the switching leads, which control selection of the monopolar cut (CUT) and coagulation (COAG) operating modes. The ESU is activated in either mode by pressing the appropriate handswitch button, which shorts the active lead with one of the two switching leads.

Unfortunately, many bipolar electrodes also use banana-type plugs (see figure); unlike monopolar electrodes, the two bipolar plugs are typically mounted on flexible cables. Although this flexibility enhances the versatility of bipolar electrodes by allowing them to be connected to the bipolar output jacks of almost any ESU, regardless of how its connector jacks are spaced, the cables are also typically long enough to be misconnected to the monopolar receptacle (see figure). If the bipolar electrode leads are plugged into the active monopolar jack and either one of the monopolar switching jacks, the ESU will be inadvertently activated when the tips of the bipolar electrode or forceps either 1) touch and short the leads together or 2) span tissue with low enough impedance to permit activation.

Several factors contributed to the severity of the injuries in the cases reported to us: 1) failing to check ESU electrode cable connections before activation; 2) connecting a return electrode to the patient, which provides a direct path for the monopolar current from the bipolar electrode, through the patient, and back to the ESU; 3) adjusting the ESU to a nonzero setting in the monopolar output mode; and 4) failing to set the activation tone of the ESU to a clearly audible level.

The American National Standards Institute (ANSI) and the Association for the Advancement of Medical Instrumentation (AAMI) have addressed this problem in their recently revised American National Standard for Electrosurgical Devices (ANSI/AAMI HF18-1993). Section 4.2.6.3 requires that connectors on electrosurgical accessories not intended for connection to switched monopolar outputs be constructed to prevent connection to these outputs. We encourage all electrosurgical device manufacturers to comply with this criterion, as some have done by offering 1) bipolar electrodes with rigid connector blocks and electrode plugs that are spaced to prevent misconnection or 2) unique connectors on the ESUs.

Recommendations

  1. Alert operating room staff to the risk of misconnection of bipolar electrodes to monopolar jacks. Before each use or after reconnection of electrodes (e.g., after accidental disconnection), verify that the electrodes are connected to the proper receptacle. 
  2. Wherever possible, replace flexible bipolar electrode cables with cables designed to prevent misconnection to the monopolar receptacle, such as plugs mounted in rigid connector blocks. (Note, however, that the spacing between the two bipolar receptacle jacks on some ESUs is similar enough to the spacing between the monopolar jacks to still allow misconnection.)
  3. Do not place return electrodes on patients during bipolar electrosurgical procedures. Return electrodes can be applied to patients when monopolar electrosurgery may be required or desired by the surgeon in addition to bipolar electrosurgery; however, do not plug the return electrode cable into the ESU until the surgeon is ready to use the monopolar output. (Note that if the surgeon attempts to activate the monopolar mode before the return electrode is plugged in, the ESU's cable-continuity monitor will alarm and inhibit ESU activation.) During procedures in which bipolar and monopolar electrosurgery are used interchangeably, it is acceptable to keep the monopolar return electrode plugged in as long as proper electrode connection is confirmed.
  4. Set all unused ESU outputs/operating modes (e.g., all monopolar modes if only BIPOLAR COAG will be used) to their minimum setting. If an output mode is required during the middle of the procedure, do not adjust its output to the required level until the surgeon is ready to proceed in that mode.
  5. Always set the ESU audible activation indicator to a clearly audible level so that staff can be immediately warned of an inadvertent activation and take action to minimize patient injury. ESUs that lack audible activation tones should be removed from service. Units with adjustable tones that can be set to inaudible levels should be replaced or modified so that the minimum setting is at a clearly audible level.

UMDNS Terms

  • Electrodes, Electrosurgical, Active [16-860]
  • Electrodes, Electrosurgical, Active, Foot-Controlled [16-206]
  • Electrodes, Electrosurgical, Active, Hand-Controlled [11-499]
  • Electrosurgical Units [11-490]
  • Electrosurgical Units, Bipolar [18-230]
  • Electrosurgical Units, Monopolar/Bipolar [18-231] 
  • Forceps, Electrosurgical [11-502]

Cause of Device-Related Incident

Device factors: Design/labeling error; Device interaction

User errors: Failure to perform pre-use inspection; Failure to read label; Improper connection; Inappropriate reliance on an automated feature

Support system failure: Failure to train and/or credential

Mechanism of Injury or Death

Burn (electrical)


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