Episode #17 Strong Work On Residual Neuromuscular Blockade

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.

The Special 35^th Anniversary Jade Edition APSF Newsletter is live and there is so much to talk about!!  In creating this special Newsletter, the APSF Editorial Board put on their reading glasses and read through 35 years of APSF Newsletter articles (and this was done prior to the onset of the Covid-19 pandemic) before voting on the top 10 most impactful articles to include in this newsletter and review through the lens of What then and What now with the help of our current editorial team and past editors.

Today, we are going to head into the operating room and talk about something that improves anesthesia safety and continues to be a patient safety issue.

Before we dive into today’s episode, we’d like to recognize Preferred Physicians Medical Risk Retention Group, a major corporate supporter of APSF. Preferred Physicians Medical Risk Retention Group has generously provided unrestricted support as well as research and educational grants to further our vision that “no one shall be harmed by anesthesia care”. Thank you, Preferred Physicians Medical Risk Retention Group – we wouldn’t be able to do all that we do without you!”

So, what is the topic for today that both improves safety and threatens safety?  If you said, Neuromuscular Blockade, you would be correct.  Today, we are going to look at the #7 most impactful article from the 35^th Anniversary APSF Newsletter.  The article hails from February 2016 and it is “Monitoring of Neuromuscular Blockade: What Would you Expect If You Were the Patient,” by Robert Stoelting.  To get to this article, you can click on the Newsletter heading on APSF.org. 4^th one down is Newsletter Archives. Then, scroll down to 2016 and click on February 2016. If you are listening in front of a computer or on your cell phone, I hope that you will follow along.

The article opens with an Editor’s Note about the articles contained in the February 2016 Newsletter and states that this issue contains articles related to the safe use of nondepolarizing neuromuscular blocking drugs. All anesthesia professionals need to be aware of the safe use of these medications with regard to monitoring and reversing neuromuscular blockade and this Newsletter series was dedicated to increase awareness and education and improve patient safety. With that, let’s get into the article.

The APSF believes that residual neuromuscular blockade is a threat to patient safety postop.  The good news is that there is something we can do about it…improved and consistent use of a qualitative standard train of four nerve stimulator or better yet by using a quantitative monitor in addition to traditional subjective observations. The APSF as well as other anesthesia professionals advocate for monitoring of the intensity of the neuromuscular blockade any time nondepolarizing neuromuscular blocking drugs are used and monitoring for effective reversal and intact neuromuscular function before extubation. There is a lot of literature that has reported on the incidence of residual neuromuscular blockade post op…back in 2016, as many as 40% of patients arrival to the PACU had evidence of this. The article includes a table of the complications that may be seen in patients with residual neuromuscular blockade and I will include this table in the show notes. Here are the potential adverse effects:

• Re-intubation
• Impaired oxygenation and ventilation
• Impaired pulmonary function including decreased forced vital capacity & peak expiratory flow rate
• Increased risk for aspiration and pneumonia
• Pharyngeal dysfunction
• Delayed discharge from the PACU

Stoelting wrote that even though there was plenty of evidence to support the routine use of quantitative twitch monitoring, the actual use of quantitative monitoring…especially to assess for adequate reversal was just not done everywhere and every time. There is a likely reason for this. Most of the time, anesthesia professionals will safely drop off patients in the PACU and hand-off care well before there are any problems from residual neuromuscular blockade so they may not be seeing 1^st hand that this is a problem.  Another contributing factor is the lack of easy to use, reliable twitch monitors. Without these monitors, anesthesia professionals may turn to clinical signs including head lift, grip strength, negative inspiratory force, and tidal volume, but these are only applicable in awake patients and do not guarantee adequate reversal. In addition, many anesthesia professionals rely on visual or tactile train of four monitoring and are unable to detect clinically relevant fade. Even double-burst stimulation and fade with 100Hz tetanic stimulation which are better at detecting residual blockade are inferior to quantitative monitoring such as acceleromyography.

At the time of this article, there was no recommendation for the routine use of qualitative or quantitative peripheral nerve stimulators to monitor neuromuscular blockade in the “Standards for Basic Anesthetic Monitoring” by any of the North American professional anesthesia association. These anesthesia professional associations either don’t say anything or state monitor neuromuscular response or peripheral nerve stimulator should be available when patients receive neuromuscular blockers.  But if you keep looking in the literature, you will find the 2015 Recommendations for standards of monitoring during anesthesia and recovery published by the Association of Anesthetists of Great Britain and Ireland that requires that “a peripheral nerve stimulator must be used whenever neuromuscular blocking drugs are given.” In addition, these recommendations require that a peripheral nerve stimulator  be used as part of the “minimum monitoring for anesthesia” with a pulse ox and capnography whenever neuromuscular blocking drugs are used.

The author points out that we should not ignore this evidence-based patient safety issue and an updated change in practice is needed at this point and going forward to include routine and mandated use of quantitative/objective monitoring with peripheral nerve stimulators to  assess for adequate reversal and help to decrease the risk of residual neuromuscular blockade and the early postoperative complications that we talked about earlier in the show.

The author leaves us a major call to action which is fitting for the APSF President, which Stoelting was in February 2016. He writes “What will it take for “North American” anesthesia professionals to accept the reality of this patient safety risk? Why are “we” so “hesitant” to routinely use qualitative or quantitative assessments of neuromuscular function with peripheral nerve stimulators to guide both the administration and reversal of nondepolarizing NMBDs?

Would “we,” knowing what we know, or should know, regarding the facts relevant to residual weakness due to nondepolarizing NMBDs, expect, at a minimum, qualitative monitoring with peripheral nerve stimulators if we were the patient?

My guess is “we” would expect qualitative, and more likely, quantitative monitoring of neuromuscular blockade as part of our care!

It is time to “Do as I would expect, not as I do!”

Time to leave the past and the What Then and take a look at What Now?

[Music Clip]

Let’s check out the article by Glenn Murphy in the 35^th Anniversary APSF Newsletter, Residual Neuromuscular Blockade: A Continuing Patient Safety Issue.”

Murphy starts off with a call to action for intraoperative monitoring and appropriate management of neuromuscular blockade in order to improve patient recovery and postoperative outcomes. From the 2016 article, remember that the APSF recommended that every patient who is given a muscle relaxant should have at least qualitative monitoring with a peripheral nerve stimulator, but preferably quantitative monitoring with a device that objectively measures muscular function and use this monitoring to evaluate for the need for pharmacological reversal and for intact neuromuscular function prior to extubation. Residual neuromuscular blockade was a big problem that went largely unrecognized and untreated since it occurred in up to 40% of patients.  Patients with train of four ratios less than 0.9 may develop hypoxemia, airway obstruction, impaired pharyngeal function and are at increased risk for aspiration, delayed PACU discharge, pulmonary complications, and re-intubation.

If only there was something that could reduce the risk of these adverse outcomes? The good news is that there is…quantitative monitoring. Unfortunately, these were not used frequently in clinical practice, likely due to thinking that residual neuromuscular blockade was not a significant problem, not having a simple and easy to use quantitative monitor, and persistent use of poor indicators for intact neuromuscular function such as 5-sec head-life and no fade on train of four stimulation.

Murphy takes us briefly through 3 other articles related to this problem from the 2016 Newsletter publication. The 2^nd article looks at an evidence-based initiative used at Mass General Hospital to tackle this problem. The initiative included an education program, a cognitive aid, feedback about departmental progress, and required of train of four documentation for the quarterly QI incentive bonus. This provided a framework for improved patient safety with the implementation and continued use of best practices related to neuromuscular management in order to decrease residual neuromuscular blockade.

The 3^rd article included information about Sugammadex, a modified cyclodextrin that can bind steroidal muscle relaxants, which was approved in the European Union in 2008 and in the United States by the FDA in 2015. The delay was due to concerns related to anaphylaxis, coagulation, and the QT interval.

The 4^th article provided a literature review on neuromuscular management strategies and postoperative outcomes. Some of the reported findings included increased postoperative mortality in patients who received muscle relaxants compared to those who did not. Another study evaluated patients who received a single intubating dose without reversal after 2 or more hours and the findings were that 37% of these patients had train of four ratios less than 0.9. The article highlighted the variable practices of anesthesia professionals with regards to monitoring and reversal of neuromuscular blockade leading to increased incidence of residual neuromuscular blockade.

Next up, Murphy asks a great question, “What do we now know about neuromuscular management and postoperative outcomes?”  Unfortunately, in the past 4 years, studies have continued to demonstrate a high incidence of residual neuromuscular blockade around the world. If we look at the RECITE-US study, the investigators reported that 64.7% of the 255 patients had train of four ratios less than 0.9 at tracheal extubation even though these patients were reversed from the rocuronium administration with neostigmine and a qualitative peripheral nerve stimulator was used. Trials in Canada and China revealed similar findings. It looked like this was going to continue to be a problem whenever quantitative monitoring and Sugammadex were not used. In addition, the most important predictor for adverse respiratory events in the early postoperative phase was found to be residual neuromuscular blockade and another study found that patients with a train of four ratio less than 0.9 were 3 times more likely to be admitted to the ICU than those who had a train of four ratio greater than or equal to 0.9.

Now let’s look at the effect of reversal strategies on postoperative outcomes. One strategy is to not reverse patients who receive a neuromuscular blocking agent. But this may lead to a higher risk for postoperative pulmonary complications, need for reintubation, and unplanned ICU admission. A better strategy may be to reverse with Sugammadex. Sugammadex may significantly decrease the risk for postop residual neuromuscular blockade and improve patient outcomes with lower rates of postoperative complications in patients who receive Sugammadex for reversal compared to those reversed with neostigmine or not reversed. Let’s look at the literature. A retrospective study by Oh and colleagues looked at 1,479 patients undergoing abdominal surgery who were reversed with either neostigmine or Sugammadex and patients who received Sugammadex had a 34% lower 30-day unplanned readmission rate, a 20% shorter hospital stay, and a 24% reduction in hospital charges. Other studies showed decreased respiratory complications in patients who were reversed with Sugammadex including a study of over 22,000 patients in each group. Patients who received Sugammadex were matched with patients who were given Neostigmine and in the group that received Sugammadex, there was a decreased risk of pulmonary complications, pneumonia, and respiratory failure. Now, there was a study that failed to show decreased postop pulmonary complications in patients who were reversed from neuromuscular blockade and there were no improved pulmonary outcomes in patients who received Sugammadex compared to patients who received neostigmine. After publication of this study though there were several Letters to the Editor that were published which revealed limitations of this observational study.

Let’s turn out attention from reversal with Sugammadex to monitoring neuromuscular function with new quantitative monitors. The What Now update includes the recent Consensus Statement on the Use of Perioperative Monitoring which recommends quantitative monitoring for patients who receive nondepolarizing muscle relaxants. Ideally, these monitors need be reliable, self-calibrating, work independent of patient hand positioning, and have minimal set-up time. Three dimensional acceleromyographic technology is now part of newer quantitative monitors with good agreement with the clinical gold standard at all phases of neuromuscular recovery. In addition, portable EMG devices have been approved for clinical care with rapid acquisition of train of four ratios without needing to immobilize the studied muscle, preload application, or free movement of the thumb. This sounds like a good quantitative monitor option for patients who need to have their arms tucked, but more studies are needed to evaluate the accuracy and reliability of these quantitative devices.

Murphy concludes by reminding us that despite making progress with our reversal agent, Sugammadex, and new quantitative monitoring devices, postop residual neuromuscular blockade is still a problem and a threat to patient safety under anesthesia care. The articles from 2016 helped to increase the knowledge and awareness of residual neuromuscular blockade and the complications that may arise from this in clinical practice. As we move from 2020 into the future, it is likely that less patients will have residual neuromuscular blockade and the associated complications with increased use of Sugammadex that is dosed in conjunction with neuromuscular monitoring and increased and routine use of quantitative monitoring by all anesthesia care teams who administer neuromuscular blocking agents.

Thank you so much for joining us today on this journey towards improved patient safety. We can’t wait to crack open the Jade Edition Newsletter again in a future show!!

If you have any questions or comments from today’s show, please email us at [email protected].

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Until next time, stay vigilant so that no one shall be harmed by anesthesia care.

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