Hazard [Health Devices Jun 1994;23(6):257-9]

Problem

ECRI investigated an incident in which a patient died from complications of a gas embolism caused by intra-abdominal overpressurization during a laparoscopic cholecystectomy. An argon beam coagulator was used to coagulate bleeding on the liver bed during the incident. Shortly after application of argon enhanced coagulation (AEC), the patient's intra-abdominal pressure increased above the insufflator's alarm limit, activating an audible alarm. When the alarm was noticed, the intra-abdominal pressure displayed on the insufflator was 33 mm Hg. Concurrently, the patient began experiencing difficulties consistent with gas embolism; the embolism was later confirmed by autopsy.

Since our initial investigation, we have also become aware of two other incidents during laparoscopic use of an AEC system (FDA 1993 [MDR File No. 67284]; Mastragelopulos et al. 1992) that resulted in gas embolism and mechanical lung damage.

ECRI believes that the use of AEC during laparoscopic procedures presents patients with a significant risk of gas embolism from abdominal overpressurization and displacement of CO₂ by argon gas. Therefore, AEC should be used only during laparoscopic procedures when no equal or superior modality of coagulation is available and when the associated patient risks and benefits have been fully examined. If clinicians decide to use AEC, they must exercise extreme caution during the procedure.

Surgeons use AEC systems to deliver electrosurgical energy to coagulate bleeding tissue during surgical procedures. Using an argon gas stream to form an ionized arc has been shown to enhance electrosurgical coagulation. However, since our 1990 Evaluation "Argon Beam Coagulation Systems" (Health Devices 19[9], September 1990), we have been concerned about the presence of argon gas flowing at open surgical sites and possible argon gas pressurization of closed surgical sites. Although, at the time of our study, we were not aware of any incidents of gas embolism (involving humans) associated with the use of AEC systems, we had investigated and reviewed many serious incidents with other technologies that deliver gas (e.g., air, CO₂) into the body or at the surgical site. Also, the risk of embolism during AEC has been addressed in the literature (Palmer et al. 1993).

Our evaluation testing in 1990 revealed that, under some conditions, it may be possible for argon gas to enter open blood vessels, contributing to a serious or fatal gas embolism. In our 1990 article, we also emphasized that AEC should not be used through endoscopes or in closed cavities (i.e., laparoscopically) because AEC systems act as a secondary source of pressurized gas that can cause intra-abdominal pressure to rise rapidly and exceed venous pressure, possibly creating argon-enriched gas emboli. Because argon is less soluble in blood than the CO₂ gas normally used for insufflation, argon-enriched emboli are not as readily absorbed and may exist long enough to travel to the heart. Excessively high intra-abdominal pressures can also create cardiorespiratory complications because of diaphragm elevation and vena caval compression.

Many laparoscopic insufflators (the primary pressure source for the pneumoperitoneum) do not regulate intra-abdominal pressure by actively venting excessive gas from the abdomen and therefore cannot relieve increased pressure resulting from the use of AEC systems. Furthermore, some laparoscopic insufflators currently in use do not have an audible overpressurization alarm, which would signal the surgeon to vent excess gas. In our 1992 Evaluation "Laparoscopic Insufflators," we reported that none of the evaluated units satisfied all of our overpressurization protection criteria, and we provided guidance for the safe use of these devices (see Health Devices 21[5]:176-7, May 1992).

At the time of this writing, only two manufacturers market AEC systems in the United States. Both manufacturers are aware of the risk of gas embolism during laparoscopic application of AEC and provide specific instructions to minimize the associated risks, as noted in the following recommendations:

1. Limit the argon flow settings to the lowest levels that will provide the desired clinical effect (i.e., 4 L/min or less).
2. Purge the electrode and argon gas tank line of air according to the manufacturer's instructions.
3. Never place the electrode tip less than several millimeters from the surgical site.
4. Flush the intra-abdominal cavity with several liters of CO₂ between extended activation periods of AEC.
5. Always leave one instrument cannula vent open to the atmosphere during AEC, and remove the electrode from the body cavity when AEC is not being performed.
6. Use only laparoscopic insufflators with nondefeatable audible and visual overpressurization alarms.
7. Use patient monitoring (e.g., end-tidal CO₂, Doppler flow) that is considered effective for early detection of venous or pulmonary gas embolism.
8. Follow the manufacturer's specific recommendations, and continue to follow established procedures to prevent gas embolism during laparoscopic surgery; ensure that staff is properly trained to detect and manage gas embolism in laparoscopic procedures.

Daniell J, Fisher B, Alexander W. Laparoscopic evaluation of the argon beam coagulator—Initial report. J Reprod Med 1993 Feb;38(2):121-5.

Daniell JF, Kurtz BR, Nair S. Laparoscopic treatment of endometriosis with the argon beam coagulator: Initial report. Gynecol Endosc 1993;2:13-9.

ECRI.

Argon beam coagulation systems [evaluation]. Health Devices 1990 Sep;19[9]:299-320.

Laparoscopic insufflators [evaluation]. Health Devices 1992 May;21[5]:143-79.

FDA. Medical Device Report (MDR) File No. 67284, Accession No. 396287, 1993 Jun 18.

Leach MO, Bell CMJ, Harvey TC. The release rate of ³⁷Ar from human subjects following intravenous injection. Phys Med Biol 1984 Jul;29(7):779-88.

Mastragelopulos N, Sarkar MR, Kaissling G, et al. Argon gas embolism in laparoscopic cholecystectomy with the Argon Beam One Coagulator. Chirurg 1992 Dec;63(12):1053-4.

Palmer M, Miller CW, Van Way CW 3d, et al. Venous gas embolism associated with argon-enhanced coagulation of the liver. J Investig Surg 1993;6:391-9.

UMDNS Terms

• Electrosurgical Units, Monopolar, Argon-Enhanced  Coagulation [17-739]
• Electrosurgical Units, Monopolar/Bipolar, Argon-Enhanced  Coagulation [18-232]
• Gas Delivery Units, Argon Beam Coagulation [17-738]

Device factor: Design/labeling error

User error: Incorrect clinical use

External factor: Medical gas and vacuum supplies

Support system failure: Failure to train and/or credential

Embolism (gaseous)