Shadowboxing
First brought to my attention by Gary Klein in EMCrit 179, shadowboxing is considered one of the best ways to relay tacit knowledge. Shadowboxing has a situation presented to an expert with a pause before they answer at critical junctions. During the pause, the learner should mentally commit to what they are thinking and what they would do.
Today's Participants
One of our regulars is one of my former fellows, Ryan (Barney) Barnicle.
Ryan Barnicle
Ryan Barnicle is one of the newest faculty in the Education Section at Yale University School of Medicine’s Department of Emergency Medicine. He completed his emergency medicine residency at Stony Brook University Hospital followed by fellowship in Advanced Resuscitation. A former high school teacher, he has maintained his passion for teaching with residents and medical students. His interests include resuscitation education and critical care echocardiography.
each month, we will have a resident presenting their case; today's resident is:
Shayan Ali
Shayan is a senior emergency medicine resident at Yale-New Haven Hospital with interest in international emergency medicine, prehospital care and medication-assisted treatment for substance addiction.
Now on to the Case…
Disclaimer: Patient information has be obscured for HIPPA compliance. The case unfolds below as the primary emergency medicine team encountered it. Place yourselves in the situation and ask yourself how you would respond. Commentary and pertinent updates are provided.
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Time -0:45
Initial Presentation at Freestanding ED:
A 71-year-old male presents to a nearby freestanding emergency department with a chief complaint of dyspnea. He is mentating appropriately and states that he has felt progressively short of breath for about one week. The team finds him to be hypoxemic on initial vital signs with SpO2 80% and he has obvious tachypnea. The patient is immediately given supplemental oxygen via a non-rebreather mask and SpO2 increases to high 90s.
Vital Signs: BP (!) 109/90 | Pulse (!) 145 | Temp (!) 95.8 °F (35.4 °C) (Temporal) | Resp (!) 50 | Ht 5′ 7″ (1.702 m) | Wt 78.5 kg | SpO2 95% | BMI 27.10 kg/m²
His heart rate is anywhere from 120s-140s bpm and is irregularly irregular. His ECG taken a few minutes later is shown below.
The decision is made to transfer the patient immediately to the tertiary-care hospital which is approximately 20 minutes away via ambulance. He was going to need admission, almost certainly to an intensive care unit. While waiting for EMS, blood was drawn.
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Time 0:00
Initial Presentation at Main ED:
The patient presented to the resuscitation room as a medical alert after a transfer from the freestanding ED for further evaluation and management. However, in transport, vital signs had changed. He was arriving of hypoxia again (SpO2 81%) despite non-rebreather at 15 lpm with 100 FiO2, hypotension (SBP 80s), tachypnea (RR 40s-60s) and tachycardia (HR, irregular, 120s-140s).
On arrival, the patient was hypoxic at 81% on the EMS pulse oximeter. He was in atrial fibrillation with a rapid ventricular response but he was able to inform the team that normally his rate is well-controlled and he only occasionally feels it when the HR is elevated.
Decision Point 1: The patient has respiratory failure and circulatory failure.
- Does this patient need to be intubated? If so, what is the best strategy?
- The patient is now hypotensive and has undifferentiated shock at this point with a narrow complex tachyarrhythmia. How is this best addressed upon arrival? Do you start vasopressors?
- There are many people in the resuscitation room, how does the team leader best utilize each of them?
- The patient’s end-tidal capnography is reading 11 (low). What is the significance of this?
Dr. Barnicle (attending) Commentary: It was an extremely busy shift and although we normally get a signout about transfer patients, this patient arrived with no warning because of multiple other resuscitations going on at the same time. My immediate impression was that the patient was very ill and that things were going to have to happen quickly. Every vital sign was abnormal. He was clearly in shock and hypoxemic, which told me the tachyarrhythmia was almost certainly secondary to these issues and I decided to defer cardioversion at this time.
The senior resident leading the resuscitation appropriately called for non-invasive positive pressure ventilation to be started. I was anticipating the patient would need to be intubated but we had other issues to address first, including preoxygenation which my gut told me would require PEEP.
I asked for our amazing nurses to start a norepinephrine infusion as soon as possible through a good peripheral intravenous catheter. Fortunately, our hospital has a very progressive policy regarding peripheral vasopressors. (Read More: PMID: 25669592)
We had push-dose phenylephrine (PMID: 26104846) available if needed, although I admittedly more comfortable with mixing and using push-dose epinephrine. Fortunately, we had an emergency pharmacist with us and there was not going to be a significant delay to pressors.
My immediate differential of the shock and hypoxemia included cardiogenic shock due to the atrial fibrillation, septic shock (likely due to respiratory infection), massive pulmonary embolism, tension pneumothorax, cardiac tamponade. Less likely was anaphylaxis, acute valvopathy, poisoning, hypovolemia. First, I needed the ultrasound!
Dr. Weingart (expert) Commentary: Timing of intubation here? ETCO2. Shocking afib? Your Ddx?
EMS Handovers
Should use DeMIST PAD (PAD was added by the folks at BADEM)
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Time: 0:05
Updated VS: HR 147, RR 50, BP 88/45, MAP 59, SpO2 unable to obtain
Exam: alert, able to speak, accessory muscles, dusky / purple hands, cool lower extremities
Dr. Barnicle (attending) Commentary: The physical exam was consistent with cardiogenic shock, but I felt that the ultrasound would rule out some very important etiologies of his low blood pressure as mentioned above. I was most worried about a tension pneumothorax and massive pulmonary embolism being immediate threats. Aortic catastrophe was in the back of my mind because EMS had mentioned he had a known abdominal aortic aneurysm but this seemed inconsistent.
The point-of-care partial RUSH exam revealed the following pertinent findings:
– Heart: tachycardia irregular, moderately reduced ejection fraction, dilated left atrium, significant mitral regurgitation, no pericardial effusion, aortic root 3.5cm, unremarkable right heart without dilation or hypokinesis.
– Lungs: Bilateral lung sliding with obvious B lines in all lung fields. No significant pleural effusion.
– Abdominal: No free fluid. Known AAA was hard to visualize though.
Overall impression: Pulmonary edema, heart failure with reduced ejection fraction, mitral regurgitation, no pneumothorax, no indirect signs of pulmonary embolism, no peritoneal free fluid.
Labs: These had been drawn at the other ED and were now available on review.
– CBC: WBC 18, Hgb 14, Hct 42, Plt 396
– BMP: Na 134, Cl 97, CO2 16, AG 21, K 5, Glu 236, BUN 34, Cr 1.77, Ca 9,, Mg 2.2
– Lactate: 5.5
– VBG: 7.34 / 33 / <30 / 17.4 / -8
– Troponin I: 0.10
– BNP: 1300
Interventions:
– Norepinpehrine gtt started
Time 0:11
Updated VS: HR 119, RR 55, BP 96/69, MAP 77, SpO2 73%
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Time 0:18
Interventions:
– NIPPV (CPAP 8) started
Diagnostics:
– CXR: IMPRESSION: Findings consistent with fluid overload, cardiac enlargement, central pulmonary vascular congestion and pulmonary edema. Given these findings, infiltrates are not radiographically excluded and should be correlated for clinically.
More history is now available that the blood pressure and hypoxemia is temporarily addressed:
The patient saw his cardiologist a week prior and was feeling well at that time. A few days later, he went to an urgent care clinic because of a productive cough and was started on azithromycin for likely bronchitis. He denied fevers but had a few nights with chills lasting approximately 30 minutes at a time. He continued to be short of breath over the week and became progressively more so both at rest and on exertion. This was associated with some increase in dizziness that became so bad that he decided to present to the emergency department. He endorsed sinus pain, rhinorrhea, snoring, and occasional daytime sleepiness. He denied having chest or abdominal pain, swelling of his extremities, nausea, vomiting, diarrhea.He reported compliance w/ his medications.
Past Medical History: hypertension, hyperlipidemia, peripheral artery disease, chronic kidney disease, coronary artery disease (no stends)
Medications: He takes aspirin, eliquis, amlodipine, carvedilol, and atorvastatin
His last formal echocardiogram was less than two months prior to arrival with a documented LVEF of 51%, RVSP of 39. There was moderate-severe MR, with a severely dilated LA in the setting of permanent atrial fibrillation.
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Time 0:45
Updated VS: HR 145, Resp: 48, BP 122/83, SpO2 96%, MAP 86
Decision Point 2: The patient is semi-stabilized now on vasopressors and non-invasive positive pressure ventilation.
- Does this patient need an arterial line?
- The differential is narrowing. He remains afebrile but should sepsis be treated?
Dr. Barnicle (attending) Commentary: By now I was convinced this was cardiogenic shock. The exam, story, echo, and labs all added up for me. I figured something had tipped his chronic rapid atrial fibrillation and mitral regurgitation over and it did not allow for an adequate cardiac output. However, a very wise doctor once told me any sick patient with unexplained hypotension in the emergency department deserves a dose of empiric broad-spectrum antibiotics.
Intervention:
– arterial line placed in right radial artery
– Sepsis Bundle Finished: lactate repeated, blood cultures drawn, empiric antibiotics (vancomycin and piperacillin/tazobactam), respiratory viral panel swab collected, crystalloids held given obvious heart failure
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Decision Point 3: There is persistent atrial fibrillation with rapid ventricular response to the 160s.
- Could the rapid rate and mitral regurgitation be leading to acute cardiogenic shock and respiratory failure? Is there an ideal rate to target?
Dr. Barnicle (attending) Commentary: “Stabilizing” the patient did not seem to slow his heart rate significantly. I began to question whether this was primary unstable rapid atrial fibrillation after all. Although the patient was convincingly anticoagulated and arguably critically ill, he was always in atrial fibrillation and I did not think cardioversion would readily work. That would also require sedation of a patient who was beginning to look much better than when he arrived. I opted to slow down the patient’s heart rate in an attempt to optimize diastolic filling time, coronary perfusion, and cardiac output to get the patient off of the norepinephrine while waiting for cardiology consultation and recommendations. I started with giving magnesium, because why not? I specifically avoided metoprolol and diltiazem IV pushes because I did not want to do anything permanent or drastic. I considered digoxin but knew it would take too long. I was not admittedly unsure how to titrate amiodarone to a HR<110 (PMID: 20231232). So we settled on esmolol. I debated the bolus for a few minutes with the pharmacist and we agreed to skip the bolus and see what happened. I figured if it all went bad, I would just shut it off. (PMID: 30711368 supports my rationale, though it focuses more on acute rapid atrial fibrillation)
Intervention:
- 2g Magnesium (IV) over 10 minutes
- 0.05 mg/kg/min infusion without loading dose
========================================================================
Time: 1:20
Updated VS: HR 107, BP 134/89, RR 34, SpO2 96%
Cardiology recommendation: C/f acute decompensated heart failure likely due to a combination of worsening mitral regurgitation, LV dysfunction, and suboptimal rate control of atrial fibrillation. Recommended discontinuing esmolol and replacing with amiodarone given the former's negative inotropy, as pt was demonstrating pressor requirement; furthermore, EF is reduced.
Diagnostics:
– NT-proBNP 17,000
Intervention:
– Amiodarone 150mg IVP, followed by gtt at 1mg/kg
– Lasix 80mg IVP
Dr. Ali (resident) Commentary: Intravenous amiodarone is efficacious and hemodynamically well tolerated in the acute control of heart rate in critically ill patients who develop atrial tachyarrhythmias with rapid ventricular response. In a study conducted by Clemo HF et al (PMID: 9514456) intravenous diltiazem, esmolol and digoxin were shown to have no effect on lowering the heart rate but were found to cause a reduction in systolic blood pressure by 6 +/- 4 mm Hg (p <0.05) whereas the infusion of amiodarone was associated with a decrease in heart rate by 37 +/- 8 beats/min and an increase in systolic blood pressure of 24 +/- 6 mm Hg. Amiodarone, when given intravenously, has various properties that contribute to slowing of conduction through the atrioventricular node through its ability to block calcium and sodium channels, and complex antiadrenergic characteristics. It blocks potassium channels further contributing to overall atrioventricular nodal conduction slowing. Amiodarone increases peripheral and coronary blood flow and may also have cardioprotective properties.
Dr. Barnicle (attending) Commentary: Esmolol had worked to achieve a more reasonable heart rate. Ultimately, the cardiology fellow did not agree with esmolol because of its negative inotropy and the patient’s obvious newly decreased ejection fraction. They recommended an amiodarone infusion be started. This was reasonable. The patient was transitioned from esmolol to amiodarone and was admitted to the CCU.
Dr. Weingart (expert) Commentary: amiodarone vs esmolol?
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Time: 1:30
Patient admitted to ICU.
Time 2:15
Diagnostics:
– Covid 19 negative
– Lactate cleared
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Early Hospital Course:
The patient boarded for about 17 hours in the emergency department but was stable with CPAP, amiodarone, and ongoing diuresis. He was titrated off of norepinephrine within 4 hours.
The patient was admitted to CCU for presumed acute HFrEF as a cause of symptoms. His formal echo the next day showed that his filling pressures were normal, with a collapsible IVC on formal echo and an LVEF 32%. Moreover, only modest pulm edema was seen on CTA PE which is out of proportion to respiratory status. It was deemed that a primary pulmonary/infectious process was in play because the CT showed bilateral ground glass opacities and the viral panel tested positive for parainfluenza overnight.
Dr. Barnicle (attending) Commentary: Ultimately, the patient had viral sepsis. He did well in the ED because the team that took over for us kept a close eye on him. We do not have a dedicated ED ICU or RCU but we take boarding of critically ill patients (PMID: 33000066) very seriously. In the end…it is always sepsis. However, he also had concurrent severe heart failure. His formal echo was expected to have reduced filling pressures because he had been significantly diuresed overnight.
While in the unit, the patient again had increasing work of breathing and altered mental status with need for intubation and mechanical ventilation. Lung protective ventilation was started for severe ARDS with P/F ratio of 8, focusing on TV of 6 ml/kg predicted body weight. Broad spectrum antibiotic coverage was continued and patient was diuresed as needed to keep urine output net even to slightly negative. The patient was subsequently extubated and continues to be followed for further optimization from cardiopulmonary perspective. His hospital course was been further complicated by multiple lacunar strokes presumed to be in watershed areas affected by his prolonged shock in the ICU. He also had liver toxicity secondary to amiodarone infusion several weeks later.
References
- Loubani OM, Green RS. A systematic review of extravasation and local tissue injury from administration of vasopressors through peripheral intravenous catheters and central venous catheters. J Crit Care. 2015 Jun;30(3):653.e9-17.
- Panchal AR, Satyanarayan A, Bahadir JD, Hays D, Mosier J. Efficacy of Bolus-dose Phenylephrine for Peri-intubation Hypotension. J Emerg Med. 2015 Oct;49(4):488-94.
- Milojevic K, Beltramini A, Nagash M, Muret A, Richard O, Lambert Y. Esmolol Compared with Amiodarone in the Treatment of Recent-Onset Atrial Fibrillation (RAF): An Emergency Medicine External Validity Study. J Emerg Med. 2019 Mar;56(3):308-318.
- Clemo HF, Wood MA, Gilligan DM, Ellenbogen KA. Intravenous amiodarone for acute heart rate control in the critically ill patient with atrial tachyarrhythmias. Am J Cardiol 1998; 81:594.
- Mohr NM, Wessman BT, Bassin B, Elie-Turenne MC, Ellender T, Emlet LL, Ginsberg Z, Gunnerson K, Jones KM, Kram B, Marcolini E, Rudy S. Boarding of critically Ill patients in the emergency department. J Am Coll Emerg Physicians Open. 2020 Jul 17;1(4):423-431.
- Van Gelder IC, Groenveld HF, Crijns HJ, Tuininga YS, Tijssen JG, Alings AM, Hillege HL, Bergsma-Kadijk JA, Cornel JH, Kamp O, Tukkie R, Bosker HA, Van Veldhuisen DJ, Van den Berg MP; RACE II Investigators. Lenient versus strict rate control in patients with atrial fibrillation. N Engl J Med. 2010 Apr 15;362(15):1363-73.
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Great case and great format. Thanks Being a bit of a Pocus geek, my first response in reading over the case even after the first question was placed was… Well what were his Pocus findings? That is, I wouldn’t have intervened in any way shape or form at that point in time of the first question, without a Resus Pocus exam. That is, a respiratory distress lung, Cardiac, and IVC Pocus. Shouldn’t take more than 3 mins. Next comment is again on Pocus. When the lung pocus is carried diffuse B lines with an absence of pleural effusions are found.… Read more »
fantastic stuff! Did you listen to the podcast or were these comments predicated on the case write-up?
Agree on dig having no negatives. I have been thoroughly unimpressed with its positives when I have used it acutely.
You are right. Did not listen to podcast. Sorry didn’t see the link initially. Sorry bout that.
Listened to it today. Podcast answers points re pleural effusions (they were in fact present). Point re pleural characteristics remains.
Agree with Dig being slow in onset. Still in longitudinal care, post ED, will be +’ve inotropy which he needs. Of course as per your comments need something quicker for rate control prn in interim
Thx for great teaching.
Great shadowboxing exercise. Curious about vaccination status, recent booster? Thanks!
all up to date
This real life undifferentiated patient presentation helps me immensely, I have a better frame of reference for my next hypotensive shock patient. Thank you!
Also, if RR is that high always remember to check bipap machine. What are the tidal volumes for the patients setting? May need a higher IPAP
Great case! Happy to see more of this. Scott, you said you would just bolus amio and not start an infusion, why is that? If no effect after 300 mg bolus would you more as bolus and if so, how much?
*give more
150 mg q 10 min x 6 doses is CTICU standard
Excellent podcast. I really enjoyed the format of the shadow boxing. I’m a CRNA and love listening to ways to better care for critical care patients.
Definitely felt this format (and case) were really useful and I hope you keep doing it regularly! I’ve enjoyed the Bouncebacks series and this reminds me of the critical care text from them. I wish I had sat down with the emcrit website up and in front of me, so that I could view the media (US, CXR, ECG, etc) along with the case. I only listened and still felt it was really useful but I think I would have gotten more from it if I was viewing the case at the same time I was listening. Thanks!
Just wanted to say – great idea! Very interesting discussion. Keep ’em coming.
This was great! I learned a ton and would love more similar episodes
I love the Shadow Boxing format! Keep these going for sure. Working pre-hospital, it’s great to hear the mindset and interventions taken in the hospital. Helps me with my patient care and better preparation for turnover to the ED.
There are lots of different medical measurements/values in the States [to New Zealand] but that is less useful to a field Paramedic anyway. We don’t get lab results to help guide us! Really useful hearing the thought processes going on in Doctors minds. Unless the case is an exceptional one, we are largely on our own in the field so knowledge of the Emergency Doctors wants, needs, and approach is very helpful to what we can do pre-hospitally. Thanks. P.S. Like everything except the prompt sound! 🙂
Love the format , love the case. I always find it interesting how different regions of North America approach stabilization in these settings . This format really brings that to light . Always best to have 3 ways to treat anything in EM (mantra ) but often style and where we trained comes into play. I typically delay Lasix in the setting of CHF cardiogenic / mixed shock / pressors. Amal Mattu has a nice discussion / lecture on this topic . Just curious how others approach and use lasix in this clinical context . I always find cardio likes… Read more »
Quality stuff and very much in line with what we try to do at on the podcast (Critical Care Scenarios). It is a LOT of work to keep generating cases with this much detail (even, or especially, if they’re based on real patients), but if you can do it, all the better. Two lessons we’ve learned: do what you can to optimize audio quality (usually toughest for the guests), and when selecting cases there is a sweet spot of novelty/uniqueness. Total zebras aren’t that helpful except for teaching that one rare situation, but 100% routine cases are a waste of… Read more »
thanks, Brandon!!
Love this format!
Great format, thanks much.
I have been working as Tele ICU Intensivist lately with many very different health care systems, so encountered a wide range of different approaches to similar patient scenarios.
Could you please comment on simultaneous use of Esmolol and Levophed in this case? Is there any particular circumstances which would make you prefer this combination over Amio and Levophed?
Would you consider changing a vasopressor to phenylephrine after HR increased on Levophed instead of adding esmolol?
Thanks
Love this! Keep them coming
Love this layout. Going to be doing a version of this at an up coming conference. I’ll mention your name and website if that’s all right?