Several years ago, my brother had a minor surgical procedure to remove a small, benign lesion from his back. The nurse practitioner who performed the procedure used an electrosurgical device called a hyfrecator to help control bleeding while removing the lesion. Lying on a hospital stretcher with his arms dangling along the sides, my brother happened to touch the metal frame of the gurney when the nurse practitioner was activating the hyfrecator, and he felt something that nearly caused him to jump off the stretcher. He'd been shocked technically, he received a burn from the hyfrecator by essentially grounding his arm on the stretcher frame. Luckily he wasn't seriously hurt, but his reaction could have caused a major problem with a more serious or delicate procedure.
The scariest part of this story? The nurse practitioner wasn't able to explain to my brother what had happened or why. She clearly hadn't been instructed adequately on how electrosurgery works or, more importantly, how this dangerous technology can cause debilitating injuries if not used properly. Here's a review of how electrosurgical devices work and the precautions your staff and clinicians should take to ensure patients are protected from thermal injury.
All about current flow
Look at Fig. 1 for an illustration of how monopolar electrosurgery works. Radiofrequency electrosurgical current is conducted through a complete circuit, including the electrosurgical generator, insulated active electrode cables, active electrode, patient and return electrode and insulated return electrode cables. Secondary and unintended pathways, such as an arm touching a stretcher frame, can easily become part of the electrosurgery circuit, putting the patient in harm's way.
Consider an example I encountered as part of my job at ECRI Institute. I was asked to help identify the cause of an injury to the spermatic cord of a 1-year-old baby treated for repair of a bilateral hernia. The surgeon successfully completed the hernia repair on one side but found that one of the baby's testicles, which was ascended, was atrophied and not viable, and therefore had to be removed. During the second hernia repair, the remaining testicle was also ascended but in good condition. However, it had a small amount of bleeding that the surgeon used electrosurgery to control. The testicle was held outside of the hernia repair incision with forceps while a monopolar electrosurgical electrode was applied to the area of bleeding.
Electrosurgery is all about current flow. In this case, radiofrequency current from the electrosurgical unit traveled from the tip of the monopolar electrode onto the surface of the bleeding testicle. It then dispersed over the body of the testicle seeking a path to the return electrode underneath the patient to complete the electrosurgery circuit (see Fig. 2). Because the testicle was being held outside of the incision, the only return path for the current was through the very narrow spermatic cord. When electrosurgical current is delivered to a very small area like the spermatic cord, tissue heating will occur. In this case, it was sufficient to heat, and seal, the entire length of the spermatic cord. This left the patient completely sterile because of the removal of the atrophied testicle during the first part of the hernia repair.
I was asked to investigate this incident because it was believed that the electrosurgical unit somehow malfunctioned and caused the injury to the spermatic cord. It turned out that the device actually worked exactly as designed. The injury happened because there was a lack of understanding of how the electrosurgical unit worked and, more specifically, how the electrosurgical current flows in the patient. In this case, there are two things the surgical team could have done differently to prevent the injury or at least minimize the risk: use bipolar rather than monopolar electrosurgery, or keep the testicle and the spermatic cord inside the incision so that the thermal energy could have dispersed more effectively through the patient instead of traveling through one narrow channel, increasing the risk of tissue damage.
Getting to know your ESU
Your surgeons and OR nurses must thoroughly understand how the electrosurgery circuit works and how secondary or unintended pathways, such as the baby's spermatic cord, can occur and cause injury. Clinical staff are constantly being introduced to new devices and technologies, so it's essential to reinforce their training regularly at least once a year to keep their knowledge fresh. Focus your reviews of electrosurgical unit safety on four points.
1. The principles of electrosurgery. Any staff member who's going to be involved with the use of your electrosurgical equipment should understand how it works. This seems simple, but many staff members will be involved in procedures using electrosurgery, particularly in hospitals, and it can be difficult to track the competency of all users. Hold training sessions regularly so everyone can attend. Use visual aids, such as Fig. 1, to demonstrate how currents travel from the electrosurgical unit through the instruments and the patient.
2. Electrosurgery-related risks. Your perioperative staff should be aware of the specific risks to patient safety this technology poses, including:
- internal burns, a particular concern in laparoscopic surgery, which may go undetected until after the patient is discharged;
- external burns, which can occur when active electrodes accidentally contact the patient's skin or when a return electrode is misapplied; and
- OR fires.
Focus on the causes of adverse events, including such operator errors as poor patient positioning, careless instrument placement and failure to adhere to pre-operative protocols (for example, removal of metal bracelets), as well as such device problems as insulation failure and capacitive coupling.
3. Safety features. Electrosurgical generators and instruments have built-in safety features. Here, the distinction between bipolar and monopolar electrosurgery is important. In the bipolar mode, two prongs of a set of forceps act as the active and return electrode, and the only tissue the current has to travel through is that which is grasped between the forceps. This technique greatly reduces the risk of stray current causing damage to tissue as it seeks a pathway back to the generator.
In the more common monopolar mode, which requires the use of both an active and return electrode, the threat of electrosurgical injuries is greater. Two types of monitoring technologies can help reduce the risk:
- Active electrode monitoring. Detects alternate current pathway problems from active electrode insulation failures or capacitive coupling during laparoscopic surgery.
- Return electrode contact monitoring. Detects problems related to the return electrode, such as a detached electrode pad or placement of the electrode over a hairy section of skin.
4. Device inspection protocols. Before each procedure, a member of the surgical team should activate all the switches on the electrosurgical device to make sure all the tones sound at an adequate level and the controls are working as expected. Someone should also visually inspect the insulation on all electrosurgical instruments to look for any obvious signs of damage.
Keep track of how old your reusable electrodes are and, based on your use volume, set a time period for replacing them before the insulation begins to break down. Visually inspect all instruments before and after reprocessing as well. One way to help preserve the integrity of your electrosurgical instruments is to separate them from other instruments during reprocessing.
Practice makes perfect
My 16-year-old son must spend 50 hours practicing driving before he can get his driver's license. How much practice time is a clinician required to have before he can use a new technology on his own? Typically not much, or sometimes not at all. With equipment as potentially dangerous as an electrosurgical unit, a hands-off approach to training simply won't do.