Episode #253 When Electrocautery Meets Implanted Devices: What Every Anesthesia Professional Needs to Know

Hello and welcome back to the Anesthesia Patient Safety Podcast. My name is Alli Bechtel, and I am your host. Thank you for joining us for another show. We are still in a celebratory mood for a major birthday milestone for the Anesthesia Patient Safety Podcast. There are over 250 episodes and counting!! Thank you to all of our listeners and APSF author contributors who have helped us reach this point as we continue to work towards improved anesthesia patient safety. Now, quick go tell a friend or colleague about our show. We would love to reach even more people on our way to 500 episodes. We are continuing our conversation from last week all about non-cardiac implantable electrical devices and how to keep patients with these devices safe during anesthesia care.

Before we dive further into the episode today, we’d like to recognize Blink, a major corporate supporter of APSF. Blink has generously provided unrestricted support to further our vision that “no one shall be harmed by anesthesia care”. Thank you, Blink – we wouldn’t be able to do all that we do without you!”

We are returning to the February 2025 APSF Newsletter today. Our featured article is “Recommendations for Managing Non-Cardiac Implantable Electrical Devices (NCIEDs) During Non-Neurologic Surgery and Procedures” by Jacqueline Morano and Jamie Uejima. This is the exciting conclusion to our two-part series. To follow along with us, head over to APSF.org and click on the Newsletter heading. First one down is the Current Issue. Then, scroll down until you get to our featured article today. I will include the link in the show notes as well.

Last week, we reviewed the most common non-cardiac implantable electrical devices and the preoperative considerations. Remember, for patients with these devices, it is important to perform a preoperative evaluation in the anesthesia preoperative clinic to make sure that you have time to contact the clinician managing the device, contact the manufacturers representative if needed, obtain a device interrogation, and inform the anesthesia professionals who will be providing care on the day of the surgery.  You can use the resources in this article during your preoperative evaluation. Check out Figure 1 and Table 1.

And now its time to get back into the article. I can see that our patient with a non-cardiac implantable electrical device has arrived for their surgery. The first step is to make sure that everyone providing care throughout the perioperative time period is aware that the patient has a device.

During the intraoperative period, there are two tools that can interact with these devices, electrocautery and intraoperative neuromonitoring. We are going to take a closer look at both of these interactions now.

First up, electrocautery which creates an electrical current within the body. For patients with non-cardiac implantable electrical devices, there is a risk for harm ranging from potentially re-programming the device and changing the stimulator output to much more significant harm including thermal skin burns, damage to the electrode, failure of the generator, or thermal injury to the underlying neurological tissue. The device manufacturers recognize these significant risks and most recommend avoiding using electrocautery. But what about in situations where electrocautery is necessary? Then, most manufacturers recommend confirmation of the device’s lead impedance with a recent interrogation followed by turning the device off during the procedure. If the device has a current output setting, this should be set to the lowest possible setting or to zero prior to turning off the device. Some devices have a safe surgery mode setting that can be used as well. Many of these devices are controlled with a remote to adjust the settings. For spinal cord stimulators and deep brain stimulators, holding the remote over the generator can turn off the device. Patients with vagal nerve stimulators often have a wand or bracelet remote that functions in a different way. Holding the remote over the generator for 2-3 seconds causes an impulse to be generated instead of shutting off the device. You will need to check with the manufacturer of the vagal nerve stimulator to determine how to turn off the device. It is important to confirm that the device has been turned off by checking the controller screen. The big takeaway is that it is vital to turn off the device or reprogram the device to a safe mode prior to using electrocautery. If there are any questions about the device settings, make sure that you contact the device representative.

Bipolar cautery is recommended instead of unipolar or monopolar cautery for patients with these devices. When monopolar cautery is used, the electrical current travels between the device tip and the return plate or the grounding pad on the patient so there is a higher risk of the current traveling through the device. When bipolar is used, most of the current travels between the tips of the bipolar cautery which is less likely to impact the device. If monopolar needs to be used, there are some important modifications that can be made to decrease the risk for harm. Use the lowest power setting possible. Place the grounding pad so that the current is least likely to travel through the device and its generator. This may be the contralateral distal limb. Using a full table grounding pad should be avoided for these patients. It is also important to inform patients about the use of electrocautery during the procedure and the associated potential risks of thermal injury to brain and nervous system tissue, reprogramming the device, and damage to leads.  There is some good news here. There are published reports of the safe use of monopolar and bipolar electrocautery. Check out the 2022 article that surveyed 167 paediatric spinal surgeons who reported no complications due to the use of intraoperative electrocautery including short-term use of monopolar cautery. After the surgery or procedure with the use of electrocautery, it is important to confirm that the device is turned back on and functioning properly.

Next up, let’s take a look at intraoperative neuromonitoring which involves transmission of an electrical current through the patient’s body which could in theory be conducted along the path of the device and cause damage to the device or tissue injury along the length of the leads. Transcortical motor-evoked potentials or MEPs use a higher energy system than somatosensory-evoked potentials or SSEPs. Thus, SSEPs are thought to be relatively safe and well tolerated for patients with these implantable devices. On the other hand, many functional neurosurgeons recommend that MEPs are not used for patients with these devices. There are case reports in the literature of intraoperative neuromonitoring for patients with spinal cord stimulators who did not have any postoperative complications. For patients with vagal nerve stimulators or deep brain stimulators the benefits from monitoring MEPs do not outweigh the potential risks. Keep in mind that if intraoperative neuromonitoring must be used for patients with any non-cardiac implantable electrical device, the lowest energy level possible to obtain signals should be used.

What about if a patient with a device requires emergent defibrillation or cardioversion? In this scenario, cardioversion or defibrillation in the setting of a cardiac emergency should be done according to the advanced cardiac life support guidelines. The pads should be placed as far as possible from the device and the lowest energy setting to treat the arrhythmia should be used. Make sure that the device is interrogated after the event to evaluate function.

Now, its time for our patient with a non-cardiac implantable device to head to the MRI scanner. There is a big threat to patient safety here, so we need to proceed with caution. The first step is to confirm the manufacturer and exact model of the device. In addition, the clinician managing the device should be contacted to discuss any safety concerns before the MRI. If there are still questions, then you can look at the device manual or call the manufacturer’s helpline to ask about specific scan requirements for the patient’s system. Many of the newer devices are MRI conditional which means that only part of the patient’s body can be scanned such as the limbs or they can only undergo scans for a specified time period followed by a rest period. There is variation between devices and models. Many older models are not MRI-conditional. You must confirm the specific MR-conditional components and location of the system to determine if the MRI can be safely completed.  Another crucial step is to check the lead impedance. If this is outside the acceptable range according to the manufacturer’s guidelines, then the MRI should not be completed. Devices may have an MRI safe mode that turns off stimulation and detection but allows other background processes to function. You need to turn on the MRI safe mode prior to entering the scanner and then return the device to the original settings once the patient is safely outside the scanner again. The device will also need to be interrogated again after the MRI after consultation with the managing clinician or device representative.

Keeping patients with these devices safe during regional and neuraxial anesthesia care may also be challenging. For patients with a deep brain stimulator or cranial nerve stimulator, any upper extremity block should be done with direct visualization using ultrasound or fluoroscopy to make sure that the needle does not come into contact or transect the device wires. Another important consideration is to avoid peripheral nerve stimulation to identify the brachial plexus. This prevents the stimulation needle from contacting the device which could conduct an electrical current to the implanted electrode or generator causing damage. There are case reports of peripheral nerve stimulation being used for an upper extremity block for patients with deep brain stimulators without complications. But the safest course of action is to use ultrasound guidance and to avoid blind peripheral nerve stimulation guided blocks in patients with non-cardiac implantable electrical devices. Check out table 2 in the article for a summary of the key points when performing acute pain procedures in a patient with a device. Did you know that patients with spinal cord stimulators can safely have a spinal or epidural if needed for their anesthetic? That’s right neuraxial anaesthesia is not contraindicated for patients with spinal cord stimulators, but it is important to perform a complete preoperative evaluation which includes the following:

Review of imaging to identify the location of the leads, level of insertion, extension wires, and internal pulse generator

Notify and discuss with the managing clinician for additional guidance.

Neuraxial placement must occur below the level of the spinal cord stimulator insertion to avoid transection of the device. Another important consideration is a special emphasis on sterility to avoid infection since there is a nearby implanted device. The feeling of loss of resistance may be different if the electrodes are near the entry level for the epidural. In addition, there may be fibrosis from the device leading to a patchy or failed block or a restricted epidural catheter movement either in a caudal direction or coiled in the epidural space. This places the patient at risk for compression of the cauda equina and lumbar roots.

We have one more special situation to discuss today. Can patients with these devices safely undergo ECT? ECT or electroconvulsive therapy is used to treat certain psychiatric conditions including refractory depression, bipolar depression, and catatonia. Patients are under general anesthesia and an electrical current is applied to the brain to induce a seizure. There is a concern for the electrical current to cause harm to the patient or the implanted device especially if a deep brain stimulator is present. There are no existing guidelines for the management of patients with a device undergoing ECT, but there are case reports that we can turn to where ECT was performed safely for these patients. Once again, the first step is to notify the managing clinician that the patient is being evaluated for ECT. The clinician managing the device can discuss safety concerns and their recommendations regarding the device before the procedure. It is likely the device would need to be reprogrammed to the lowest possible stimulation setting and then turned off prior to ECT. The device should be turned back on immediately after the ECT, especially for patients with deep brain stimulators. One of the considerations is to ensure only a brief interruption of the deep brain stimulator to minimize the symptoms being treated when the device is turned off. During the course of ECT treatment, the managing clinician will need to determine when the device should be interrogated and if any imaging is required. The placement of the ECT electrodes should take into consideration the electrode placement for the deep brain stimulator with a goal to direct the ECT stimulus current path away from the DBS electrodes. This is the time to remain vigilant to keep patients with these devices safe during anesthesia care for ECT.

Whew, we made it to the postoperative time period. For patients undergoing general anesthesia with the device turned off. It should be turned back on prior to emergence. This will help to avoid disease symptoms occurring during emergence and extubation. If a device representative is needed for reprogramming, then they will need to be present for emergence and recovery as well. It is important to examine the skin around the device and the generator to evaluate for any thermal injuries. Patients also should be evaluated for any neurologic changes as well.

The authors leave us with the call to action to maintain good communication with the managing clinician or manufacturing representative is vital especially as these devices are constantly being improved and updated. We hope that you can use this information to provide safe anesthesia care for patients with non-cardiac implantable electrical devices going forward.

[Bechtel] Before we wrap up for today, I also asked Morano what she envisions for the future when it comes to non-cardiac implantable electrical devices? Let’s take a listen to what she had to say.

[Morano] “For the future in regards to this topic, we hope that these devices will be viewed in the same light as implanted cardiac devices and pacemakers. We hope our anesthesia providers can have a better knowledge base on how to provide safe practices for our patients with non-cardiac implanted electrical devices, and that there are more resources to guide the care of these patients.”

[Bechtel] Thank you so much to Morano for contributing to the show today. This article is an important resource so that anesthesia professionals can provide safe anesthesia care for patients with these devices going forward.

If you have any questions or comments from today’s show, please email us at [email protected]. Please keep in mind that the information in this show is provided for informational purposes only and does not constitute medical or legal advice. We hope that you will visit APSF.org for detailed information and check out the show notes for links to all the topics we discussed today.

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