Date: March 29th, 2019

On the last day of the last SMACC conference, Dr. Salim Razaie (REBEL EM) and I had a cage match debating four critical care controversies. It was all done in good fun and we both respect each other very much.

If you were not able to attend SMACC you can watch the debate on the SGEM Facebook page.

While we took a pro vs. con approach to the presentation, our positions are much closer than the debate demonstrates. We would be wise to remember what Dr. Andrew Worster (BEEM) taught me; the EBM answer is…it all depends.

The literature is far from perfect and should be used to inform our care but not dictate our care. We should be skeptical of the literature and develop critical appraisals skills. EBM should our clinical judgement when applying the literature. Importantly, we should also ask the patient what they value and prefer (Sackett et al BMJ 1996).

Dr. Justin Morgenstern from First10EM was the referee for this SMACC down. He also provided the introduction and the rules of this epic battle. It was great to have such an impartial Canadian referee.

Ladies and gentlemen. Today, we are going to witness the most anticipated evidence-based medicine battle (of the day). Are you ready?

For the thousands in attendance, and the millions on twitter around the world. Live from Sydney Australia’s Convention Centre. Let’s get ready to to rumble!

In this corner, from the great white north. He will hit you HARD, with EBM knowledge. But follow it up with nice Canadian apology. Aka BatDoc. It’s Ken “The Skeptic” Milne.

In the opposite corner. Coming to us from deep in the heart of Texas Officially the center of the FOAMed universe. Unofficially known as the sexiest man in FOAM. Salim “The REBEL” Rezaie.

Now this is an EBM match. Ken – there will be no hockey brawls tonight. Please keep it above the belt. No hits to your P-values

There will be four rounds of four minutes. Each round will address one critical care controversy. When you hear the bell ring…come out EBMing.

REBEL:

  • Mechanical CPR devices are not superior to manual CPR, but they may be equivalent in some settings
  • High quality CPR, with limited interruptions and early defibrillation are the keys to survival with good neuro outcomes in OHCA
  • Mechanical CPR provides standard depth and frequency of compressions for prolonged periods of time allowing for other aspects of patient care
    1. LINC Trial [3]: Higher CCF (0.84 vs 0.79), Shorter pauses (0sec vs 10sec) (Able to defibrillate through compressions without pauses)
    2. Application of device needs to be streamlined to avoid delays in CPR (compressions paused for 36sec to apply device) [3]
  • Location of compressions needs to be confirmed to ensure optimal point of compression is being compressed (Some studies without CPR feedback devices)
  • No difference in ROSC, survival, or survival with good neurologic outcomes [1]
  • Deployment of mechanical devices without appropriate training might cause patient harm through an increase in no-flow time during the early part of the cardiac arrest and delay defibrillation in patients with a shockable rhythm.
  • Injuries from mechanical CPR devices are possible, but most studies don’t have a comparator group.One study by Koster et al showed no difference in serious or life-threatening resuscitation-related visceral organ damage compared to manual CPR with LUCAS devices [4]
  • Consider mechanical CPR in limited man/woman power settings, pre-hospital (i.e. moving vehicle), prolonged CPR, cognitive offload

Skeptic:

  • mCPR may get you ROSC but not increase of survival to good neurologic outcome
  • ROSC with a non-shockable rhythm is low (<10%)
  • 30-day survival is even lower (1.2%) and good neuro almost zero
  • People rarely survive more than 30 minutes of CPR neurologically intact
  • Rare cases you may need prolonged CPR, but it needs to be a bridge to somewhere
  • It is crazy that we apply the same tool to every single patient with OHCA
  • Ensuring high-quality CPR with the right depth and rate is going to make very little difference to a 90yo with dementia from a nursing home with multiple co-morbidities
  • Safety?  How about some seatbelt/restraining device in the back of the EMS that allows for CPR
  • You might have the same outcomes but cost way less money than mCPR
  • We need to raise the bar before adopting new technology
  • Look at how many things in medicine are reversed when high quality studies are done

References:

  1. Gates S et al. Mechanical Chest Compression for out of hospital cardiac arrest: Systematic review and meta-analysis. Resus 2015. PMID: 26190673
  2. Perkins GD et al. Mechanical Versus Manual Chest Compression for Out-of-Hospital Cardiac Arrest (PARAMEDIC): A Pragmatic, cluster Randomised Controlled Trial. Lancet 2015. PMID: 28979419
  3. Rubertsson S et al. Mechanical Chest Compressions and Simultaneous Defibrillation vs Conventional Cardiopulmonary Resuscitation in Out-of-Hospital Cardiac Arrest: The LINC Randomized Trial. JAMA 2014. PMID: 24240611
  4. Koster RW et al. Safety of Mechanical Chest Compression Devices AutoPulse and LUCAS in Cardiac Arrest: A Randomized clinical Trial for Non-Inferiority. Eur Heart J 2017. PMID: 29088439
  5. Matsuyama et al. Impact of cardiopulmonary resuscitation duration on neurologically favourable outcome after out-of-hospital cardiac arrest: A population-based study in Japan. Resuscitation 2017
  6. Rajan et al. Incidence and survival outcome according to heart rhythm during resuscitation attempt in out-of-hospital cardiac arrest patients with presumed cardiac etiology. Resuscitation 2017
  7. Prasad and Cifu. Medical Reversal: Why We Must Raise the Bar Before Adopting New Technologies. Yale J Biol Med. 2011

REBEL:

  • Save the heart and the brain
    • Epinephrine increases peripheral vasoconstriction to increase coronary perfusion pressure (Alpha Effect)
    • Epinephrine also has adverse effects including myocardial oxygen consumption, post-ROSC myocardial dysfunction, ventricular arrhythmias, and decreased microcirculation to superficial areas of the brain (Beta Effect)
    • Jacob et al [1]: 1st RCT on topic, but now powered appropriately showed increased ROSC, but no difference in survival
    • PARAMEDIC-2 [2]: Largest RCT to date on topic, increased ROSC & Survival to Hospital, but more mRs of 4 & 5 in survivors (31% vs 18%)
    • Pooling all the evidence: 9 trials, 5 increased ROSC, 6 no survival difference, 2 increased mortality
    • We don’t know the optimal dosing of epinephrine in cardiac arrest…so until then, we have to fill in the gaps with clinical judgment
    • Is there a better way? HD-Guided Epi Drip
      • 4 Swine studies [3][4][5][6] showed improved, ROSC, Survival, & Cerebral Perfusion Pressure
      • Found one human trial from 1990 [7] that showed as CPP increased so did ROSC
      • The key difference with the drip vs bolus is linear titration, and much smaller doses, therefore potentially less beta effects on the brain

Skeptic:

  • There has never been any evidence that epinephrine improves survival with good neurologic outcome
  • The burden of proof is on those making the positive claim
  • We have given biological plausibility as the reason for many things over the years only to have them reversed once high-quality research is done
  • How does squeezing the vascular bed (brain/heart/kidney) be a good thing?
  • You presented a logical fallacy (false dichotomy) bolus vs. drip.
  • How about a placebo group…certainly there is equipoise because nothing has ever worked
  • Have you seen the new JAMA paper on AHA guidelines?
  • Less than 10% (8.5%) are based Level A based on multiple RCTs and 50% are level C (expert opinion)
  • Legend of Emergency Medicine, Dr. Ian Stiell’s classic OPALS paper in NEJM showed no superiority to ACLS
  • Randomized control triasl done in Australia and Norway demonstrated no patient-oriented benefit with epinephrine in OCHA.

References:

  1. Jacobs IG et al. Effect of Adrenaline on Survival in Out-of-Hospital Cardiac Arrest: A Randomised Double-Blind Placebo-Controlled Trial. Resus 2011. PMID: 21745533
  2. Perkins GD et al. A Randomized Trial of Epinephrine in Out-of-Hospital Cardiac Arrest. NEJM 2018. PMID: 30021076
  3. Friess SH et al. Hemodynamic Directed Cardiopulmonary Resuscitation Improves Short-Term Survival from Ventricular Fibrillation Cardiac Arrest. Crit Care Med 2013. PMID: 23887237
  4. Sutton RM et al. Hemodynamic directed CPR Improves Short-Term Survival From Asphyxia-Associated Cardiac Arrest. Resus 2013. PMID: 23142199
  5. Sutton RM et al. Patient-Centric Blood Pressure-Targeted Cardiopulmonary Resuscitation Improves Survival from Cardiac Arrest. Am J Respir Crit Care Med 2014. PMID: 25321490
  6. Friess SH et al. Hemodynamic Directed CPR Improves Cerebral Perfusion Pressure and Brain Tissue Oxygenation. Resus 2014. PMID: 24945902
  7. Paradis NA et al. Coronary Perfusion Pressure and the Return of Spontaneous Circulation in Human Cardiopulmonary Resuscitation. JAMA 1990. PMID: 2386557
  8. Fanaroff et al. Levels of Evidence Supporting American College of Cardiology/American Heart Association and European Society of Cardiology Guidelines, 2008-2018. JAMA 2019
  9. Olasveengen et al. Intravenous drug administration during out-of-hospital cardiac arrest: a randomized trial. JAMA
  10. Jacobs et al. Effect of adrenaline on survival in out-of-hospital cardiac arrest: A randomised double-blind placebo-controlled trial. Resuscitation 2011

REBEL: 

  • Time to tPA is Decreased
    • Majority of patients show up in the >90 minute range.<25% show up in the 0 – 90-minute window [1]
    • Stroke ambulances increase the percentage of patients in the 0 – 90-minute window (57.5% with STEMO vs 37.4% without STEMO)
    • Stroke ambulance decreased alarm to tPA time by 25 minutes
    • Patients in the STEMO arm had higher percentage of patients with NIHSS scores ≥20 (12% vs 6%)
    • No difference in in-hospital mortality, 7d mortality, days in hospital or ICH rates
    • Overall rate of ICH with STEMO was 2.2% despite more patients getting tPA (33% vs 21% of ischemic strokes)
    • mRs of 0 – 2 at 3 months: STEMO 40.7% vs No STEMO 50.6% but population too small to make absolute conclusions (Study not powered to assess this outcome)
    • Second study [4] evaluating over 50,000 patients with acute ischemic stroke trying to cut down door to tPA time
      1. Door to tPA time decreased from 77min to 67minIn hospital all-cause mortality decreased from 9.93 to 8.25% and symptomatic ICH decreased from 5.68% to 4.68%
    • Third study pooling ECASS, NINDS, and ATLANTIS showed time to tPA does improve patient-oriented outcomes (mRS 0 – 1) but still showed a 3% ICH rate which was less than the 6% ICH rate in the 271 – 360 min window [3]

Skeptic:

  • Show me the Patient-Oriented Outcome (POO)
  • It costs about $1 million to buy and $1 million/year to operate
  • Regular ambulance cost about $200,000 to buy and per year to operate
  • Why add something to our healthcare system without proven benefit?
  • Faster is not always better, look at what happened with STEMI and the false negatives taken to the cath lab
  • We know 1/3 of strokes are stroke mimics with a large portion being TIAs
  • Just because stroke mimics do better with only a 1-2% intracranial hemorrhage rate does not mean we should give a therapy to patients without the disease. There is no potential for benefit and only potential harm.
  • They changed the definition of TIAs in 2009 and that made both TIAs and CVAs look better (Lake Wobegon effect)
  • Would that money be better spent on the social determinants of health?

References:

  1. Ebinger M et al. Effect of the Use of Ambulance-Based Thrombolysis on Time to Thrombolysis in Acute Ischemic Stroke: A Randomized Clinical Trial. JAMA 2014. PMID: 24756512
  2. Lin E et al. World’s First 24/7 Mobile Stroke Unit: Initial 6-Month Experience at Mercy Health in Toledo, Ohio. Front Neurol 2018. PMID: 29867711
  3. Lees KR et al. Time to Treatment with Intravenous Alteplase and Outcome in Stroke: An Updated Pooled Analysis of ECASS, ATLANTIS, NINDS, and EPITHET Trials. Lancet 2010. PMID: 20472172
  4. Fonarow GC et al. Door-to-Needle Times for Tissue Plasminogen Activator Administration and Clinical Outcomes in Acute Ischemic Stroke Before and After a Quality Improvement Initiative. JAMA 2014. PMID: 24756513
  5. Calderon VJ et al. Review of the Mobile Stroke Unit Experience Worldwide. Intervent Neurol 2018. PMID: 30410512
  6. Zaher et al. Aggressive Measures to Decrease “Door to Balloon” Time and Incidence of Unnecessary Cardiac Catheterization: Potential Risks and Role of Quality Improvement. Mayo Clinic proceedings. Nov 2015 
  7. Hand et al. Distinguishing Between Stroke and Mimic at the Bedside: The Brain Attack Study. Stroke 2006
  8. Zinkstok et al. Safety of thrombolysis in stroke mimics: results from a multicenter cohort study. Stroke 2013
  9. Easton et al. Definition and evaluation of transient ischemic attack. Stroke. 2009;40:2276-2293.
  10. Lake Wobegon
  11. Social Determinants of Health. Government of Canada.

REBEL:

  • Higher first pass success rate
    • Prior to these studies 1st pass success rate ~85%
    • Increasing attempts worsens morbidity and mortality
  • Retrospective Study [1] of >500 pts: FPS was 95% with bougie 1st vs. 86% without bougie 1st, but duration of intubation was 40sec vs. 27sec respectively
  • Prospective RCT (BEAM trial) [2] of >700pts: FPS in pts with one difficult airway characteristic was 96% with bougie 1stvs 82% without bougie
    • Difficult airway characteristics: body fluids obscuring laryngeal view, airway obstruction or edema, obesity, short neck, small mandible, large tongue, facial trauma, or need for cervical immobilization
    • 1stpass success in all comers: 98% bougie 1stvs 87% no bougie, and in this study no difference in median duration of 1stintubation attempt 38sec vs 36sec respectively
  • Standard geometry blade (usually VL for me) with non-malleable bougie
  • Hyperangulated blade can be used if have a malleable bougie (more expensive)
  • Pre-loading or not pre-loading bougie makes no difference, just pick a technique and go with it

Skeptic:

  • It’s called ABC and we in EM/Critical care own the airway
  • Study by Brown et al in Annals EM showed we had an esophageal intubation rate of only 3%
  • Successful intubation rate was over 99%
  • The one study you cite was a retrospective single centre study where 80% were done boogie first already
  • In the RCT cited, only 1% of intubations were done by Attending (EM staff physicians) the other 99% were done by junior residents, senior residents or fellows.

References:

  1. Driver B et al. The Bougie and First-Pass Success in the Emergency Department. Ann Emerg Med 2017. PMID: 28601269
  2. Driver B et al. Effect of Use of Bougie vs Endotracheal Tube and Stylet on First-Attempt Intubation Success Among Patients with Difficult Airways Undergoing Emergency Intubation: A Randomized Clinical Trial. JAMA 2018. PMID: 29800096
  3. Brown et al. Techniques, Success, and Adverse Events of Emergency Department Adult Intubations. Ann Emerg Med 2015

Evidence based medicine includes the best literature, our clinical judgement and patients’ values and preferences. The literature should not dictate our care but rather guide our care.

Remember to be skeptical about anything you learn, even if you heard it on the Skeptics’ Guide to Emergency Medicine.