#200 Celebrating the 200th Episode - Safer Blocks and Enhancing Regional Anesthesia Safety

Welcome to the next installment of the Anesthesia Patient Safety podcast hosted by Alli Bechtel.  This podcast is an exciting journey towards improved anesthesia patient safety.

Can peripheral nerve blocks be the answer to improving patient satisfaction and joining the fight against the opioid crisis? Christina Ratto joins us for our milestone 200th episode to share her invaluable insights on this very question. We celebrate the world of regional anesthesia with important considerations for patient safety with peripheral nerve blocks. Together, we scrutinize the pros, like heightened patient contentment and a hopeful check on opioid usage, and consider the role of ultrasound guidance as a beacon for block success and minimizing complications. Our discussion navigates through the study by Sites and colleagues, offering a critical look at local anesthetic systemic toxicity and postoperative neurological symptoms, illuminating the imperative of safety in regional anesthesia.

Join us in this landmark celebration of knowledge and commitment to patient safety in the realm of regional anesthesia. As we celebrate 200 episodes, we extend an invitation to our listeners to interact, ask questions, and share insights, all in the service of a shared goal—no patient harm during anesthesia care. Your participation is the heartbeat of our podcast; your engagement online through likes, subscriptions, and shares propels our message further. Until we meet again in our next episode, we pledge to keep the conversation on patient safety alive, insightful, and at the heart of what we do.

Additional sound effects from: Zapsplat.

For show notes & transcript, visit our episode page at apsf.org: https://www.apsf.org/podcast/200-celebrating-the-200th-episode-safer-blocks-and-enhancing-regional-anesthesia-safety/

© 2024, The Anesthesia Patient Safety Foundation

Transcript

Marjorie Stiegler: 0:01

You're listening to the Anesthesia Patient Safety Podcast, the official podcast of the Anesthesia Patient Safety Foundation. We're bringing you the very best from the APSF newsletter and website, as well as the latest information in perioperative patient safety. Thanks for joining us.

Alli Bechtel: 0:29

Hello and welcome back to the Anesthesia Patient Safety Podcast. My name is Allie Bechtel and I'm your host. Thank you for joining us for another show, and this is a very special show. The Anesthesia Patient Safety Podcast has reached another huge milestone. This is our 200th episode. We couldn't have done it without all of our listeners, the amazing APSF family and the APSF newsletter authors, who continue to highlight threats to safe anesthesia care and important considerations to help keep our patients safe. So go ahead and share some high fives To celebrate our 200th episode.

Alli Bechtel: 1:21

We are turning on the ultrasound machine and drawing up some local anesthetic. That's right. Today's show is all about peripheral nerve blocks and safe anesthesia care. Before we dive into the episode today, we'd like to recognize Medtronic, a major corporate supporter of APSF. A major corporate supporter of APSF, medtronic has generously provided unrestricted support to further our vision that no one shall be harmed by anesthesia care. Thank you, medtronic. We wouldn't be able to do all that we do without you. Our featured article today is from the February 2024 APSF newsletter by Christina Rado, joseph Skokal and Paul Lee. It is Safety Considerations in Peripheral Nerve Blocks. To follow along with us, head over to APSForg 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 a link in the show notes as well, to help kick off our 200th episode. Today we have one of the authors from the article. Here she is now.

Christina Ratto: 2:44

Hi, my name is Christina Ratto and I'm an anesthesiologist at Keck Hospital of USC in Los Angeles.

Alli Bechtel: 2:51

I asked Ratto why she is so passionate about this topic. This is what she had to say.

Christina Ratto: 2:58

I'm very passionate about regional anesthesia for both personal and societal reasons. On a personal level, I get tons of satisfaction in alleviating patients' pain through these techniques, but I also value safety above all, and I believe it's important to prioritize safe practices in all aspects of healthcare, and this includes regional anesthesia. On a broader scale, I believe regional techniques can address important societal issues such as the opioid epidemic and substance abuse. I'm constantly advocating for regional anesthesia because the pain control is far superior and the consequences of decreased opioids has far-reaching effects. And since we're talking about patient safety, limiting opioids is another example of safer practices.

Alli Bechtel: 3:57

And now it's time to turn on the ultrasound machine and get into the article. Here's a brief overview of peripheral nerve blocks, which are safe and effective alternatives or supplements to general anesthesia. These are handy tools in the anesthesia professional's toolbox to provide pain control during and after surgery, while helping to avoid or decrease systemic opioids and the side effects. The benefits of peripheral nerve blocks include improved patient satisfaction, decreased resource utilization and perhaps a better environmental footprint, with decreased inhalational volatile gas administration. There has been a significant increase in the use of peripheral nerve blocks over time, according to a study using the National Anesthesia Clinical Outcomes Registry, data from almost 13 million outpatient surgeries between 2010 and 2015. Are peripheral nerve blocks part of your anesthesia practice? We are going to review safety concerns, including nerve injury, recognition and treatment of local anesthetic, systemic toxicity or LAST, and prevention of wrong-sided blocks with timeout protocols. It is a good thing that our ultrasound is warmed up, because we are going to start by talking about the role of the ultrasound during peripheral nerve blocks to improve patient safety.

Alli Bechtel: 5:33

During your training, did you learn peripheral nerve stimulation technique or ultrasound guided, or maybe a combination of the two? How do you practice now? Be a combination of the two, how do you practice now? Ultrasound guidance has several benefits, including improved block success, decreased need for rescue analgesia, decreased pain while performing the block and lower rates of vascular and pleural puncture. For perivertebral and supraclavicular blocks, the use of ultrasound has not been shown to reduce the risk of pneumothorax in the literature, but visualization of the pleura while performing the block may provide reassurance that the pleural space has not been punctured. We were optimistic that using ultrasound to directly visualize the needle and target nerve would further reduce the risk of nerve injury, but if we look at the literature, it does not reveal reduced postoperative neurologic symptoms with ultrasound-guided blocks compared to peripheral nerve stimulation. This post-block neurologic injury complication is likely due to mechanical injury to the fascicle and or injection of local anesthetic into a fascicle, causing myelin and axonal degeneration. The good news is that the neurologic symptoms are most often transient. Using data from the three largest registries, the incidence of long-term nerve injury following peripheral nerve block is 4 per 10,000 peripheral nerve blocks. This incidence is similar to the historic incidence before ultrasound was available and the blocks were performed with the peripheral nerve stimulation technique, the peripheral nerve stimulation technique. There may be factors related to the ultrasound equipment and the operator that can help to explain the current level of this devastating complication, including the following Quality of the ultrasound, skill of the proceduralist in identifying the intended nerve, inability to visualize the needle tip. Misinterpretation of surrounding artifacts. And keep in mind that needle movement and the use of hydrodissection does not prevent needle-to-nerve contact or vascular injection.

Alli Bechtel: 7:59

Let's look at the study by Sites and colleagues Incidents of local Anesthetic, systemic Toxicity and Postoperative Neurologic Symptoms Associated with 12,668 Ultrasound-Guided Nerve Blocks, an analysis from a prospective clinical registry published in 2012. I will include the citation in the show notes as well. I will include the citation in the show notes as well. The investigators set out to determine the incidence of local anesthetic, systemic toxicity and postoperative neurologic symptoms with ultrasound-guided peripheral nerve blocks. They used an 8-year time period and over 12,000 patients undergoing peripheral regional anesthesia to determine the incidence of post-op neurologic symptoms LAST pneumothorax and vascular trauma. Post-operative neurologic symptoms included any sensory or motor dysfunction that persisted for more than five days in a pattern consistent with the nerve block. The results are in for this study. The incidence of postoperative neurologic symptoms lasting for more than 5 days was 1.8 per 1,000 blocks, and this decreased to 0.9 per 1,000 blocks for symptoms lasting more than 6 months. Keep in mind that patients with pre-existing neuropathy may be at increased risk for postoperative neurologic symptoms. It is vital to avoid intraneural injection to keep patients safe while performing peripheral nerve blocks. The good news about ultrasound guidance for peripheral nerve blocks is that it does significantly reduce the risk for another major complication local anesthetic systemic toxicity. Check out the 2013 study by Barrington and Kluger.

Alli Bechtel: 9:57

Ultrasound guidance reduces the risk of local anesthetic systemic toxicity following peripheral nerve blockade. See the show notes for this citation as well. This study uses the Australian and New Zealand Registry of Regional Anesthesia, with 20 hospitals included, over a five-year time period from 2007 until 2012, to evaluate the occurrence of LAST following peripheral nerve block. Over 20,000 patients and over 25,000 blocks were included. The incidence of local anesthetic systemic toxicity was 0.87 per 1,000 blocks. Predictors of LAST included block site, local anesthetic used, dose per weight, total dose administered and patient weight. Ultrasound guidance helps to decrease the risk for LAST with real-time visualization of the needle and vessels to avoid vascular injury and intravascular injection of the local anesthetic. Another study determined that the incidence of LAST with ultrasound-guided blocks was incredibly low, at 2.7 per 10,000 cases. Even with this minimal risk, it is important for anesthesia professionals to remain vigilant.

Alli Bechtel: 11:22

And speaking of LAST, we are moving on for a review and discussion of LAST. If we travel back to 1998, that is when we first see the case report for potential treatment for LAST. Weinberg and colleagues used anesthetized rats and pre-treated them with saline or different intralipid solutions prior to administration of bupivacaine. In addition, saline or intralipid was administered for resuscitation after the bupivacaine bolus. The investigators found that the lipid emulsion could prevent or reverse cardiac arrest caused by the bupivacaine overdose in the intact anesthetized rat. The first successful use of 20% lipid infusion to resuscitate a patient following an interscalene block with bupivacaine and mepivacaine who developed cardiac arrest was reported in 2006. Check out the case report published in Anesthesiology by Rosenblatt and colleagues. It is riveting. I'm going to read some excerpts from it now and I will include the citation in the show notes as well.

Alli Bechtel: 12:36

"The patient was a 58-year-old, 82 kg, 170 cm male who presented for arthroscopic repair of a torn rotator cuff in the right shoulder. The patient arrived at the operating room holding area where standard monitors were applied. Blood pressure was 120, over 80 millimeters of mercury Room air oxygen saturation measured by pulse oximetry was 98% and heart rate was 60 beats per minute. Supplemental oxygen was delivered at 3 liters per minute via a nasal cannula. A 20-gauge intravenous catheter was placed in the dorsum of his left hand, through which 2 mg midazolam and 50 mg fentanyl were administered. A 50 mm 22-gauge stimuplex insulated needle was connected to a stimuPlex DIG nerve stimulator and the interscalene groove was identified at the level of C6. The brachial plexus was identified by eliciting bicep stimulation, following which 40 mLs local anesthetic solution, 20 mL bupivacaine 0.5% and 20 ml mepivacaine 1.5% were injected slowly over approximately 2.5 minutes in 5 ml increments, with gentle aspiration between doses.

Alli Bechtel: 14:04

The patient was awake and conversant during the performance of the block. At no time was any blood aspirated, nor did he report pain or paresthesias. Approximately 30 seconds after removal of the block needle, the patient became incoherent and then developed a tonic-clonic seizure. Oxygen was delivered by a face mask attached to a self-inflating resuscitation bag a face mask attached to a self-inflating resuscitation bag. While 50 mg propofol was injected intravenously, the seizure stopped and spontaneous respirations resumed.

Alli Bechtel: 14:38

Approximately 90 seconds later, the patient began to seize again. This time 100 mg intravenous propofol was administered. The electrocardiogram showed asystole and no pulse by carotid or femoral palpation or blood pressure was detectable. Advanced cardiac life support was immediately started. The trachea was intubated and end-tidal carbon dioxide was detected.

Alli Bechtel: 15:04

During the first 20 minutes of advanced cardiac life support, a total of 3 mg epinephrine, given in divided doses, 2 mg atropine, 300 mg amiodarone and 40 units vasopressin were administered. In addition, monophasic defibrillation was used at escalating energy levels 200, 300, 360, and 360 joules, according to the Advanced Cardiac Life Support Protocol. The arrhythmias observed during most of the resuscitation period were pulseless ventricular tachycardia and asystole. After 20 minutes, at which time plans were being made to institute cardiopulmonary bypass, the administration of a lipid emulsion was suggested and 100 mLs of 20% intralipid was given through the peripheral intravenous catheter.

Alli Bechtel: 15:58

Cardiac compressions continued and a defibrillation shock at 360 joules was given. Within seconds, a single sinus beat appeared on the electrocardiogram and 1 mg atropine and 1 mg epinephrine were administered Within 15 seconds. While external chest compressions were continued, the cardiac rhythm returned to sinus at a rate of 90 beats per minute. The blood pressure and pulse became detectable. An infusion of lipid emulsion was started and continued at 0.5 mL per kg per minute over the following two hours and then discontinued. The patient remained in sinus rhythm. He was weaned from mechanical ventilation and his trachea was extubated. Approximately 2.5 hours later he was awake and responsive and had right upper extremity weakness consistent with a brachial plexus block. No neurologic sequelae were sustained and he was subsequently transferred to a monitored setting for overnight observation. There was no evidence of complications secondary to the administration of intralipid, such as pancreatitis, during the following two weeks." Wow, what an incredible case report and life-saving treatment with interlipid.

Alli Bechtel: 17:16

The last checklist developed by the American Society of Regional Anesthesia and Pain Medicine was first published in 2010 and reviewed in 2012, 2017, and 2020. The most recent revision was in response to simulation and user feedback that earlier versions did not highlight the differences between last resuscitation and ACLS-guided resuscitation. This is critical and can be life-saving, since some of the standard medications used for ACLS, including codose, epinephrine and vasopressin, have been shown to worsen outcomes in LAST animal models During simulation. With the use of both LAST and ACLS checklists, there was confusion leading to delayed and wrong treatment during LAST resuscitation. The latest revision uses a standard triangular caution sign to highlight the differences between last and ACLS resuscitation.

Alli Bechtel: 18:19

The dose for lipid emulsion has been simplified for patients over 70 kgs to receive a single bolus of 100 mLs followed by an infusion, instead of needing to calculate an initial weight-based dose. Check out figure 1 in the article to see the updated last checklist, and we will review this in more detail again next week. Before we wrap up for today, we are going to hear from Rado again. I also asked her what she hopes to see going forward. Let's take a listen to what she had to say.

Christina Ratto: 18:56

I envision a future where regional anesthesia is not only widely accepted, but it's also the standard of care for a majority of surgical procedures. There is so much versatility in the kinds of regional blocks. We can offer everything from peripheral nerve blocks to truncal blocks, so there's really no limit to where we can provide pain control. We can do it anywhere in the body. Moving forward, we need to bring more attention to nerve blocks, their safe practices and their efficacy, so that there's widespread acceptance of them from everyone, including surgeons and patients. I think as long as we keep this discussion open and continue to educate ourselves and each other, we will see further advances in this field, making it more and more safe and also more and more common.

Alli Bechtel: 19:54

Thank you so much to Ratto for contributing to the show today. We are excited about further advances in the field of regional anesthesia and peripheral nerve blocks. We are also excited to continue to talk about this article next week for part two. Excited to continue to talk about this article next week for part two. You don't want to miss it when we continue the conversation about keeping patients safe during peripheral nerve blocks, with considerations for performing these blocks under sedation and preventing wrong-sided blocks.

Alli Bechtel: 20:25

If you have any questions or comments from today's show, please email us at podcast at apsforg. 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 apsforg for detailed information and check out the show notes for links to all the topics we discussed today. And check out the show notes for links to all the topics we discussed today. Thank you for following along on this journey towards improved anesthesia, patient safety for 200 episodes and counting. To celebrate, we hope that you will like, subscribe, share and continue to download this podcast from wherever you get your podcasts. Thanks for listening, from wherever you get your podcasts. Thanks for listening. Until next time, stay vigilant so that no one shall be harmed by anesthesia care.