Pre-Arrest Acidemia and the Effect of Sodium Bicarbonate on ROSC


Sodium bicarbonate during a cardiac arrest is widely debated and used in many cases. In a 2018 PULMCrit post, Dr. Josh Farkas reviews much of the data and concludes that use of sodium bicarbonate is a “source of eternal disagreement.” A 2013 EMCrit article and podcast by Dr. Scott Weingart also details some of the controversy. The 2020 ACLS Guidelines state that routine use of sodium bicarbonate is not recommended in cardiac arrest [1]. Despite this recommendation, sodium bicarbonate is still often administered during resuscitations if a metabolic (or respiratory) acidosis is suspected or after a prolonged downtime. A recent study evaluated the effect of pre-arrest acid-base status on response to sodium bicarbonate and achievement of return of spontaneous circulation (ROSC) [2].


This was a retrospective review of in-hospital cardiac arrests (IHCA) in patients with pre-arrest serum bicarbonate levels ≤21 mmol/L compared to >21 mmol/L. Pre-arrest bicarbonate levels were obtained <24 hours prior to the arrest. Similarly, post-arrest bicarb levels were obtained <24 hours following the arrest. Bicarbonate levels were recorded from basic chemistry panels rather than blood gases. All patients received a median sodium bicarbonate dose of 100 mEq. The groups were relatively well-matched, with the only major difference being the time to first bicarb administration was faster in the ‘acidotic’ group (6.9 vs. 9.2 minutes). Initial ECG rhythms were similar between the groups.

  • 102 patients in ‘acidotic’ group with a median pre-arrest bicarb level of 17 mmol/L
  • 123 patients in ‘non-acidotic’ group with a median pre-arrest bicarb level of 27 mmol/L
  • There was no difference in ROSC (53.9% vs 48.8%, p=0.44) or survival to discharge (8.8% vs 5.7%, p=0.36) between the acidotic group versus the nonacidotic group

Thoughts and Limitations

  • A meta-analysis found no difference in sustained ROSC or survival to discharge with sodium bicarbonate (Alshahrani 2021).
  • In the current study, prearrest bicarb levels could have resulted up to 24 hours prior to the arrest and the authors don’t comment on when exactly they were drawn. The timing limits the ability to know true acid-base status just prior to the arrest. And, that really limits applying this to out-of-hospital cardiac arrest where patients may have more significant acidemia if resuscitation is delayed.
  • A median bicarbonate concentration of 17 mmol/L isn’t really that low, relatively speaking, to indicate a potential impact from administering sodium bicarbonate.
  • Retrospective cardiac arrest studies are challenging. Many interventions happen around the same, making it impossible to connect any one of them with a specific outcome.
  • The study that would be more helpful is taking patients with metabolic/respiratory acidosis and giving have bicarb and the other placebo.

Bottom Line

  • In this cohort of IHCA patients, sodium bicarbonate administration did not improve the chances of ROSC or survival to hospital discharge, irrespective of pre-arrest acid-base status. In other words, attempting to correct ‘acidosis’ does not seem to change rate of ROSC.
  • Sodium bicarbonate use in cardiac arrest should be targeted (e.g., hyperkalemia with metabolic acidosis, sodium channel blockade secondary to an overdose).

Want to learn more about EM Pharmacology?

Read other articles in the EM Pharm Pearls Series and find previous pearls on the PharmERToxguy site.


  1. Panchal AR, Bartos JA, Cabañas JG, et al. Part 3: adult basic and advanced life support: 2020 american heart association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2020;142(16_suppl_2):S366-S468. doi: 10.1161/CIR.0000000000000916. PMID: 33081529.
  2. Mclean H, Wells L, Marler J. The effect of prearrest acid-base status on response to sodium bicarbonate and achievement of return of spontaneous circulation. Ann Pharmacother. Published online August 5, 2021:10600280211038392. doi: 10.1177/10600280211038393. PMID: 34353142.

Beta-Blockers for Inhalant-Induced Ventricular Dysrhythmias


There are a few unique scenarios when beta-blockers may be indicated for patients in cardiac arrest. Use of esmolol for refractory ventricular fibrillation was summarized in a 2016 PharmERToxGuy post with an accompanying infographic. Another potential use for beta-blockers is in the rare case of a patient with inhalant-induced ventricular dysrhythmias. The term ‘sudden sniffing death’ refers to acute cardiotoxicity associated with inhaling hydrocarbons. Check out this ACMT Toxicology Visual Pearl for more information about the background and diagnosis of inhalant abuse.

It is thought that inhalants causes myocardial sensitization via changes in various cardiac channels (e.g., sodium channels, potassium channels, calcium channels, or gap junctions) leading to prolonged repolarization and conduction [1, 2]. Additionally, chronic inhalant use can lead to structural heart damage. When the above alterations are combined with a sudden increase in catecholamines (e.g., exercise, caught sniffing), a dysrhythmia can develop which is often fatal [2-4].


There are no case reports to support the use beta-blockers to treat inhalant-induced dysrhythmias. However, the case reports below include patients that ingested various hydrocarbons who developed ventricular dysrhythmias and improved following the initiation of beta-blockers. As the adverse cardiac effects should be similar between inhaled and ingested hydrocarbons, we can potentially extrapolate this data to patients with inhalant-induced dysrhythmias.

DemographicsAgent(s) Ingested Cardiac EffectsInterventionsResolution of dysrhythmia following BB?
39 yo M [5]TrichloroethylenepVT/VF arrestDefibrillation, Propranolol bolus and infusion


70 yo F [6]TrichloroethyleneBigeminy, Junctional rhythmEsmolol bolus and infusion


23 yo F [7]Chloral hydrateVF arrestEsmolol bolus and infusion


27 yo M [8]Chloral hydrate, Loxapine, FluoxetineStable VTPropranolol bolus and infusion


3 yo M [9]Chloral hydrateSinus tachycardia, Bigeminy, Trigeminy, NSVTEsmolol bolus and infusion


44 yo M [10]Chloral hydrateStable VTPropranolol bolus, Labetalol infusion


BB=beta-blocker; pVT=polymorphic ventricular tachycardia; VT=ventricular tachycardia; VF=ventricular fibrillation; NSVT=non-sustained ventricular tachycardia

Bottom Line

  • Patients presenting to the ED with cardiopulmonary manifestations of inhalant use should have routine electrolytes and an ECG to assess cardiac status
  • A quiet environment is important to decrease stimulation and minimize catecholamine surges
  • For both stable and non-perfusing dysrhythmias, propranolol or esmolol are reasonable choices to counteract the catecholamine effects, in addition to standard care [5-10]
    • Consider avoiding epinephrine and other catecholamines unless necessary, as they may worsen the dysrhythmia

Want to learn more about EM Pharmacology?

Read other articles in the EM Pharm Pearls Series and find previous pearls on the PharmERToxguy site.


  1. Nelson LS. Toxicologic myocardial sensitization. J Toxicol Clin Toxicol. 2002;40(7):867–79. doi: 10.1081/clt-120016958. PMID: 12507056.
  2. Tormoehlen LM, Tekulve KJ, Nañagas KA. Hydrocarbon toxicity: A review. Clin Toxicol (Phila). 2014 Jun;52(5):479–89. doi: 10.3109/15563650.2014.923904. PMID: 24911841.
  3. Bass M. Sudden sniffing death. JAMA. 1970 Jun 22;212(12):2075–9. PMID: 5467774.
  4. Baydala L. Inhalant abuse. Paediatr Child Health. 2010 Sep;15(7):443–54. doi: 10.1093/pch/15.7.443. PMID: 21886449.
  5. Gindre G, Le Gall S, Condat P, Bazin JE. [Late ventricular fibrillation after trichloroethylene poisoning]. Ann Fr Anesth Reanim. 1997;16(2):202–3. doi: 10.1016/s0750-7658(97)87204-8. PMID: 9686084.
  6. Mortiz F, de La Chapelle A, Bauer F, Leroy JP, Goullé JP, Bonmarchand G. Esmolol in the treatment of severe arrhythmia after acute trichloroethylene poisoning. Intensive Care Med. 2000 Feb;26(2):256. doi: 10.1007/s001340050062. PMID: 10784325.
  7. Shakeer SK, Kalapati B, Al Abri SA, Al Busaidi M. Chloral hydrate overdose survived after cardiac arrest with excellent response to intravenous β-blocker. Oman Med J. 2019 May;34(3):244–8. doi: 10.5001/omj.2019.46. PMID: 31110633.
  8. Zahedi A, Grant MH, Wong DT. Successful treatment of chloral hydrate cardiac toxicity with propranolol. Am J Emerg Med. 1999 Sep;17(5):490–1. doi: 10.1016/s0735-6757(99)90256-5. PMID: 10496517.
  9. Nordt SP, Rangan C, Hardmaslani M, Clark RF, Wendler C, Valente M. Pediatric chloral hydrate poisonings and death following outpatient procedural sedation. J Med Toxicol. 2014 Jun;10(2):219–22. doi: 10.1007/s13181-013-0358-z. PMID: 24532346.
  10. Wong O, Lam T, Fung H. Two cases of chloral hydrate overdose. Hong Kong Journal of Emergency Medicine. 2009 Jul;16(3):161–7. doi: 10.1177/102490790901600307.

Trick of the Trade: Upsize the IV with the tourniquet infusion technique

peripheral iv catheterThere you are, middle of the night and EMS just brought you one of the sickest of the sick: a septic-looking, chronically ill-appearing, frail, and malnourished patient with low blood pressures. They need vascular access for fluids, antibiotics, and possibly even vasopressors. The patient arrives with only a 22-gauge peripheral IV in the hand. You ask for two large bore IVs. But unfortunately, your best nurses and techs can’t find a vein, and their initial attempts are unsuccessful. Do you move right towards ultrasound-guided placement, intraosseous needle, or a central line? What if the patient only needs a fluid bolus, antibiotics, and admission to the floor?

Trick of the Trade: Tourniquet infusion technique

The tourniquet-infusion technique provides a method to increase the chance of a successfully placed larger bore peripheral IV in the volume-depleted patient.


  1. Apply a tourniquet to the extremity, proximal to the existing smaller-gauge IV access site.
  2. Rapidly infuse 50-100 mL of IV fluids, causing distension of the venous system between the IV and the tourniquet. This distension creates a larger target for venous cannulation in volume-depleted patients.
trick tourniquet infusion technique dilate upsizing vein arm peripheral IV

Tourniquet Infusion Technique: After applying a tourniquet and instillation of an IV bolus of fluids through a small distal 22-gauge IV, large veins are more visible for a second larger-bore IV



This technique has been described in the literature for decades [1-3], and has been anecdotally successful in clinical practice. Its methodology capitalizes on pre-existing or easily-placed distal small gauge access (i.e., a 22g IV in the hand) as a stepping stone to larger venous cannulation.

Quinn and Sheikh investigated the employment of this technique for 22 adult patients with an acute abdomen who had been referred from the ED in hypovolemic shock. A peripheral IV had not been obtained in any of these patients using standard cannulation methods. By employing this tourniquet-infusion technique to upsize the IVs, they were able to successfully obtain adequate access for resuscitation in 15 of the 22 patients (68%). They noted no complications secondary to this technique. The authors noted that of the other 7 patients in this small study, 2 died and 5 required ultrasound-guided IJ venous line placement. In total, 15 patients were potentially spared unnecessary central venous catheterization. This technique is a simple, quick, and effective way of establishing a more appropriate line for resuscitation of sicker patients [1].


  • For large-bore antecubital IV placement, consider placing a tourniquet in close proximity and just proximal to the elbow joint.
  • Consider the patient’s cardiac and pulmonary history to ensure that an additional fluid bolus is clinically appropriate.


  1. Stein JI. A new technique for obtaining large-bore peripheral intravenous access. Anesthesiology. 2005 Sep;103(3):670. doi: 10.1097/00000542-200509000-00041. PMID: 16130004.
  2. Quinn LM, Sheikh A. Establishing intravenous access in an emergency situation. Emerg Med J. 2014 Jul;31(7):593. doi: 10.1136/emermed-2012-202106. Epub 2013 Jun 15. PMID: 23771897.
  3. Williams DJ, Bayliss R, Hinchliffe R. Surgical technique. Intravenous access: obtaining large-bore access in the shocked patient. Ann R Coll Surg Engl. 1997 Nov;79(6):466. PMID: 9422881; PMCID: PMC2502954.
By |2021-05-30T23:44:23-07:00May 31, 2021|Critical Care/ Resus, Tricks of the Trade|

2020 ACLS Guidelines on Medications for Toxicology-Related Conditions

ACLS 2020 toxicology

The 2020 ACLS guidelines provide recommendations on the medication-specific management recommendations for toxicology [1]. Although the name of the guidelines emphasize they are ‘Advanced,’ these are still relatively basic toxicology recommendations and largely apply to patients in cardiac arrest or refractory shock. There are also our 2020 ACLS guideline summaries on vasopressor and non-vasopressor medications used during cardiac arrest and arrhythmia management.


  • Flumazenil if NOT recommended in undifferentiated coma (COR3, LOE B-R)


  • Benzodiazepines, alpha blockers, calcium channel blockers, nitroglycerin, and/or morphine can be beneficial for hypertension, tachycardia, agitation, or chest discomfort (COR 2a, LOE B-NR)
  • Pure beta-adrenergic blockers may be reasonable to avoid, although “contradictory evidence exists (COR 2b, LOE C-LD)

Local Anesthetics

  • IV lipid emulsion may be reasonable (COR 2b, LOE C-LD)

Sodium Channel Blockers (e.g. tricyclic antidepressants)

  • Sodium bicarbonate can be beneficial for cardiac arrest or life-threatening conduction delays, such as QRS >120 msec (COR 2a, LOE C-LD)
  • Extracorporeal membrane oxygenation (ECMO) may be considered for cardiac arrest or refractory shock (COR 2b, LOE C-LD)


  • Antidigoxin Fab should be administered in severe toxicity (COR 2b, LOE B-R)

Carbon Monoxide

  • Hyperbaric oxygen may be helpful in severe toxicity (COR 2b, LOE B-R)


  • Hydroxocobalamin can be beneficial, along with oxygen +/- sodium thiosulfate (COR 2a, LOE C-LD)

Atrioventricular Nodal Blockers

InterventionBeta-adrenergic blockerCalcium channel blockerEvidence (COR/LOE)
High-dose insulinReasonableReasonable2a/C-LD
Glucagon IVReasonableMay be considered2a/C-LD and 2b/C-LD
CalciumMay be consideredReasonable2b/C-LD and 2a/C-LD
ECMOMight be consideredMight be considered2b/C-LD

Table: Medications and interventions in the management of beta-adrenergic and calcium channel blocker toxicity (COR: class of recommendation, LOE: level of evidence, ECMO: extracorporeal membrane oxygenation)


Panchal AR, Bartos JA, Cabañas JG, et al; Adult Basic and Advanced Life Support Writing Group. Part 3: Adult Basic and Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2020 Oct 20;142(16_suppl_2):S366-S468. doi: 10.1161/CIR.0000000000000916. Epub 2020 Oct 21. PMID: 33081529.

2020 ACLS Guidelines on Medications for Management of Specific Arrhythmias

ACLS 2020 arrhythmias

The 2020 ACLS guidelines provide recommendations on the medication-specific management for arrhythmias including wide-complex tachycardia, regular narrow-complex tachycardia, atrial fibrillation/flutter, and bradycardia [1]. There are also our 2020 ACLS guideline summaries on vasopressor and non-vasopressor medications used during cardiac arrest and toxicology-related conditions.

Wide-complex tachycardia (WCT)

Wide-complex tachycardiaMedication(s)Evidence
Hemodynamically stableAdenosineCOR 2b, LOE B-NR
Amiodarone, procainamide, or sotalolCOR 2b, LOE B-R
NOTE: Verapamil is harmfulCOR 3, LOE B-NR
Polymorphic VT with long QT (torsades de points)MagnesiumCOR 2b, LOE C-LD
Polymorphic VT without long QTLidocaine or amiodaroneCOR 2b, LOE C-LD

Regular narrow-complex tachycardia

  1. Vagal maneuvers (COR 1, LOE B-R)
  2. Adenosine (COR 1, LOE B-R)
  3. Diltiazem or verapamil (COR 2a, LOE B-R)
  4. Beta-blockers (COR 2a, LOE C-LD)

Atrial fibrillation/flutter with rapid ventricular rate

  1. Beta-blocker or diltiazem or verapamil (COR 1, LOE B-NR)
  2. Amiodarone (COR 2a, LOE B-NR)


  1. Treat reversible causes (COE 1, LOE C-EO)
  2. Atropine if hemodynamic compromise (COR 2a, LOE B-NR)
  3. Epinephrine or transcutaneous pacing if unresponsive to atropine (COR 2b, LOE C-LD)


Panchal AR, Bartos JA, Cabañas JG, et al; Adult Basic and Advanced Life Support Writing Group. Part 3: Adult Basic and Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2020 Oct 20;142(16_suppl_2):S366-S468. doi: 10.1161/CIR.0000000000000916. Epub 2020 Oct 21. PMID: 33081529.

2020 ACLS Guidelines on Vasopressors and Non-Vasopressors During Cardiac Arrest

The 2020 ACLS Guidelines were published in October 2020 [1]. This first of 3 blog posts will focus on vasopressor and non-vasopressor medications during cardiac arrest. Part 2 will focus on specific arrhythmia management and Part 3 will focus on toxicologic interventions.


There were no major updates for vasopressors and non-vasopressors used during cardiac arrest. The American Heart Association (AHA) published Highlights of the 2020 Guidelines [PDF] as a clear and concise summary. Now that the AHA is releasing focused updates in the 5-year period between guidelines (like this one on lidocaine), fewer major changes likely will be needed when the full guidelines are published.




  • Recommended for patients in cardiac arrest (COR 1, LOE B-R)
  • Reasonable to administer 1 mg every 3-5 minute (COR 2a, LOE B-R)
  • Reasonable to administer as soon as feasible in non-shockable rhythm (COR 2a, LOE C-LD)
  • May be reasonable to administer after initial defibrillation attempts have failed in shockable rhythm (COR 2b, LOE C-LD)

Amiodarone or lidocaine

  • May be considered for VF/pVT unresponsive to defibrillation (COR 2b, LOE B-R)





  • Offers no advantage over epinephrine (COR 2b, LOE C-LD)


  • During CPR, are of uncertain benefit in OHCA (COR 2b, LOE C-LD)


  • Routine use NOT recommended (COR 3, LOE B-NR)

Sodium bicarbonate

  • Routine use NOT recommended (COR 3)


  • Routine use NOT recommended (LOE B-R)

Table: Vasopressors and non-vasopressors used during cardiac arrest (VF: ventricular fibrillation, pVT: pulseless ventricular tachycardia)



Panchal AR, Bartos JA, Cabañas JG, et al; Adult Basic and Advanced Life Support Writing Group. Part 3: Adult Basic and Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2020 Oct 20;142(16_suppl_2):S366-S468. doi: 10.1161/CIR.0000000000000916. Epub 2020 Oct 21. PMID: 33081529.

ACEP E-QUAL: The Electronic ICU



Building on already increasing interest in telehealth, the COVID-19 pandemic accelerated the development and implementation of telemedicine services in a variety of clinical settings. In 2018, Dr. Jason Woods hosted an episode of the ACEP E-QUAL Network podcast highlighting the creation of an electronic intensive care unit (eICU) through Emory Healthcare. In this episode, Dr. Tim Buchman and Critical Care Nurse Cheryl Hiddelson share their innovative approach to delivering critical care services via telehealth. We present highlights from this discussion below.



What is an eICU?

The eICU allows for critical care oversight, without having to be on site. It provides comprehensive monitoring and data analysis and online audio or video support for patients and families. Utilizing advanced information technology (IT) platforms and approaching with a business strategy, telehealth allows for innovative ways to provide critical care services remotely.

Why is there a need for an eICU?

The US population is aging, with the number of Americans age 65 or older increasing steadily. Demand for critical care services increases with age. The availability of critical care physicians is limited in large areas of the US. Similarly, as more nurses are reaching retirement than those entering the workforce, critical care providers are becoming hard to come by. Recruiting and maintaining critical care providers is only one part of the issue, with staffing on nights, weekends, and holidays creating a constant challenge. Telehealth poses a contemporary solution to the scarcity of healthcare providers.

What does the eICU setup look like?

The eICU is akin to airline control towers. There is 24/7 coverage by nursing and physician staff, overseeing more than a hundred beds. Various screens facilitate a “sentry” role in which surveillance monitoring algorithms allow staff to detect problems possibly even before the bedside staff. The eICU integrates bedside monitor data with additional system-wide data to create different views of what is occurring in the unit being monitored. Staff can track discharge readiness and filter lists by system or condition.

Camera sessions allow for bi-directional communication with patients and families, but also for just-in-time-training with staff as well as consultation with specialists.

What unique challenges has the eICU been able to address?

  • On-site advanced practice providers (APPs) such as physician assistants, nurse-practitioners, can be supervised by critical care nurses and physicians to provide in-person care.
  • Alternative staffing from geographic areas that are in a different time zone can help fill night shifts. The Emory group used travel nurses and physicians who were stationed in Australia.
  • Distance and delay to care become irrelevant when an intensivist can be available 24/7.

What benefits have been observed with the eICU?

The Emory eICU was able to realize decreased mortality, decreased transfer rates, decreased length of stay, and an increase in patient experience metrics for the hospitals it covered compared to other local facilities. Analysis of costs suggested savings of thousands of dollars per patient and increased revenue for small community hospitals that could retain and increase their daily census of critical care patients.

Can this concept be applied to Emergency Medicine?

There may be a role in applying telehealth data monitoring to emergency department waiting rooms in an attempt to identify patients at high risk for sudden deterioration or decompensation.

Interested in more ACEP-EQUAL podcasts?

Listen to the other ACEP E-QUAL podcasts on our Soundcloud account.

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