Simulation for Practicing the ASRA Guidelines for the Management of Local Anesthetic Systemic Toxicity (LAST)
By Harshad Gurnaney, MD, MPH, and Devika Singh, MD
Children’s Hospital of Philadelphia
Perelman School of Medicine at University of Pennsylvania
A rare but catastrophic complication that can occur while performing a regional anesthetic technique is local anesthetic systemic toxicity (LAST). This occurs as a result of inadvertent intravascular injection of local anesthetic, which leads to elevated plasma concentrations of local anesthetics. The presentation of local anesthetic toxicity can vary from early and mild signs such as ringing in the ears and metallic taste in the mouth to more ominous signs namely seizures and cardiac arrhythmias. Barrington et al. report that the incidence of LAST for both ultrasound-guided and the nerve stimulator guided blocks is approximately 1:1000(1). As this complication been well documented in the literature American Society of Regional Anesthesia (ASRA) in 2010 published a practice advisory guidelines for practitioners to manage LAST(2). In this practice advisory they stated that “The extensive use of local anesthetics, the frequent use of doses sufficient to cause significant morbidity or mortality for these peripheral nerve blocks, and the imperfect nature of our ability to prevent, detect, and treat these complications, it remains the responsibility of all clinicians using local anesthetics to understand their potential for severe systemic toxicity and to be prepared to respond immediately to these events when they occur”(2). A recent report from the Pediatric Regional anesthesia network (PRAN) found use of higher doses encroaching the upper limit of recommended safe doses (in 24% of cases) for the caudal blocks without any major complications at institutions that were a part of PRAN (3).
As educators we are constantly striving to develop active learning sessions that enable pediatric anesthesia practitioners to acquire comfort in managing critical events. Simulation based training has become an important and established tool for education of practitioners of pediatric anesthesia. Simulation is being utilized to practice crisis management of critical events that can be life threatening but are, fortunately, only rarely encountered by a practitioner in the clinical arena(4, 5). Such training provides the participants an opportunity to identify the crisis, gather appropriate resources in a timely fashion, use cognitive aids as appropriate and implement and execute a plan to manage the crisis(6).
In this article, we discuss the implementation of a simulation scenario to practice the management of LAST into our simulation program, its implementation in a non-hospital setting and its impact on enhancing the educational experience of trainees and clinicians engaged in regional anesthesia practice.
Methods and Objectives
We developed a simulation scenario for perioperative practitioners for managing a patient with LAST in the preoperative period. The objectives outlined for the session included:
a. Elicit the signs and symptoms of local anesthetic toxicity;
b. Implement the treatment of LAST related neurologic and cardiovascular symptoms;
c. Understand the rationale for lowering the dose of epinephrine during a LAST resuscitation;
d. Execute the treatment of local anesthetic induced cardiac arrhythmias and
e. Administer the appropriate dose of lipid emulsion therapy.
Briefly, the simulation case scenario entails a 15-year old male presenting for ACL repair who has just received a femoral nerve block catheter and sciatic nerve single shot block in the holding/preoperative area under mild sedation with midazolam (2 mg) and fentanyl (50 mcg). He is recovering from his sedation for placement of the peripheral nerve blocks. His parents are at the bedside in the preoperative area when he begins to complain about ringing in his ears and a funny taste in his mouth. The nurse in the preoperative area calls the participants to come to the bedside because of these symptoms and to talk to the patient and his parents who are concerned about these signs.
After a brief introduction to the environment, explanation of the location, resources available and a brief overview of ground rules of simulation one of the participants enters the simulated preoperative room and gets a brief hand-off of the block and the patients complaints from the nurse. The simulation progresses with the patient exhibiting occasional ectopy as he is placed on additional cardiovascular monitors by the participant, followed within 3-4 minutes by, a cardiac arrest. The team of participants have to declare an emergency and call for help to obtain additional resources, accomplish good quality CPR (adequate rate, depth, with a backboard and rotation of compressors every 2 minutes) along with appropriate assisted ventilation ratio, administer appropriate cardiac resuscitation medications as per the PALS protocol, administer appropriate defibrillation using the defibrillator as per the PALS protocol and identify the cause of the cardiovascular collapse (LAST) and administer the appropriate dose of 20% intralipid based on the ASRA guidelines.
We attempted to create realism to aid a more immersive learning environment for the participants. Setting up this scenario outside of the perioperative setting certainly had some limitations including recreating a preoperative room in the space provided, providing the participants with appropriate equipment to manage the scenario, and clarifying the limitations of equipment availability (lack of wall oxygen and suction source in a non-hospital setting). When possible we would run this scenario in the Perioperative complex (PACU room, operating room or preoperative room) to place the practitioner’s in their work environment. This helped the participants use resources they are familiar with and also helped them realize any concerns they may have regarding the resources available to them and or additional resources they may need in case of a rare emergency(7). It also provides the participants an opportunity to use emergency supplies (code cart, defibrillator, intralipid) and get familiar with accessing these supplies.
The equipment we used included a patient transport stretcher with linen and an attached iv pole, Laerdal SimMan mannequin with a vital signs monitor, portable suction, 2 code boxes and or carts with simulated emergency drugs and airway equipment and a defibrillator. We setup the equipment in the conference room with the simulated emergency medications, airway equipment and defibrillator readily available upon participant’s request. A 250 ml bag of 20% intralipid (simulated) was also available upon request by the participants. The participants are asked to act as they would in a real crisis and administer all medications, CPR, and defibrillation as they would in a real crisis. As the person running the simulation has to program the responses based on the actions of the participants we ask the participants to speak up and announce all the tasks they complete (e.g. administered 0.5 mg of epinephrine) during the simulation.
We have used this scenario in various educational sessions. The scenario runs for approximately 20 minutes and was followed by a debriefing by the team with the facilitator and simulation personnel for about 20-30 minutes. The participants range from trainees at our institution (residents or fellows), CRNAs and anesthesia faculty. We have also used this at our ambulatory surgery centers to practice management of LAST with the entire perioperative team (anesthesiologists, OR nurses and surgeons). The learners can be at varied levels of training and we try to modify the scenario presentation and debriefing to their scope of practice which may differ for example anesthesia providers (resident, fellows, CRNAs, attending physicians, CRNAs) may have more clinical knowledge about LAST compared to perioperative nurses and surgeons.
We discovered that the simulation ran effectively despite the perceived barriers to realism. The differences in backgrounds and training did not prevent the simulated teams from navigating the scenario and appropriately managing the perioperative crisis. The debriefings revealed that the participants were familiar with ASRA guidelines but they found that implementation of their knowledge in the simulation uncovered some areas for improvement, such as some participants were unaware of where the intralipid was located or how to access it in an emergency in the perioperative complex. When we did in-situ simulation in our perioperative complex or at the surgery centers we would have the participants access the intralipid from the location it is stored in, to see if there were any concerns with the process for obtaining intralipid in case of an emergency. Other topics that were discussed during the debriefing included the correct dose of intralipid, dose of epinephrine during resuscitation from a LAST and rationale for reducing the dose of epinephrine from the ASRA guidelines(8), the rationale for early administration of intralipid during a LAST scenario and strategies participants have used to avoid accidental intravascular administration of local anesthetic. The debriefings also revealed that many practitioners were aware of the cognitive aids available at our institution and would access them to help guide the care of the patient during a crisis.
Based on the feedback from the simulation sessions, it is evident that the scenario was useful for a team of practitioners from varied backgrounds in practicing the management of a LAST scenario. This led to the practitioners having increased familiarity and understanding of the management of LAST, thus proving to be a useful educational tool. Our simulation program highlights the importance of some critical issues in maximizing the chances of successful resuscitation from LAST, where a practitioner must:
- Ensure familiarity with the appropriate dose and location for intra-lipid in all practice locations.
- Develop strategies to improve CRM (Crisis Resource Management) skills during a crisis such as establishing leadership, closed-loop communication, assign roles, resource allocation etc. which will help the team during treatment of a crisis.
- Adherence to PALS and ASRA guidelines for management of LAST and modifying dose of epinephrine for resuscitation during LAST
- Timely access for cognitive aids in all practice locations.
- Barrington MJ, Kluger R. Ultrasound guidance reduces the risk of local anesthetic systemic toxicity following peripheral nerve blockade. Regional Anesthesia and Pain Medicine. 2013;38(4):289-99.
- Neal JM, Bernards CM, Butterworth JFt, Di Gregorio G, Drasner K, Hejtmanek MR, et al. ASRA practice advisory on local anesthetic systemic toxicity. Regional Anesthesia and Pain Medicine. 2010;35(2):152-61.
- Suresh S, Long J, Birmingham PK, Oliveira GS, Jr. Are Caudal Blocks for Pain Control Safe in Children? An Analysis of 18,650 Caudal Blocks from the Pediatric Regional Anesthesia Network (PRAN) Database. Anesthesia and Analgesia. 2014.
- Murray DJ. Current trends in simulation training in anesthesia: a review. Minerva Anestesiologica. 2011;77(5):528-33.
- Scavone BM, Toledo P, Higgins N, Wojciechowski K, McCarthy RJ. A randomized controlled trial of the impact of simulation-based training on resident performance during a simulated obstetric anesthesia emergency. Simulation in healthcare: Journal of the Society for Simulation in Healthcare. 2010;5(6):320-4.
- Watkins SC, Anders S, Clebone A, Hughes E, Zeigler L, Patel V, et al. Paper or plastic? Simulation based evaluation of two versions of a cognitive aid for managing pediatric peri-operative critical events by anesthesia trainees: evaluation of the society for pediatric anesthesia emergency checklist. Journal of Clinical Monitoring and Computing. 2016;30(3):275-83.
- Sorensen JL, van der Vleuten C, Rosthoj S, Ostergaard D, LeBlanc V, Johansen M, et al. Simulation-based multiprofessional obstetric anaesthesia training conducted in situ versus off-site leads to similar individual and team outcomes: a randomised educational trial. BMJ open. 2015;5(10):e008344.
- Hiller DB, Gregorio GD, Ripper R, Kelly K, Massad M, Edelman L, et al. Epinephrine impairs lipid resuscitation from bupivacaine overdose: a threshold effect. Anesthesiology. 2009;111(3):498-505.