How to slay a vampire: When some ideas just won’t die
Myron Yaster MD, Jayant K Deshpande MD MPH, and Justin L. Lockman MD, MSEd
We love science fiction! And who doesn’t like werewolf and vampire stories, especially at this time of year? Although stories have described multiple ways to kill a vampire, the classics (drive a stake through the heart and exposure to sunlight) remain the most popular and effective.
“Vampires?” you ask. “In the PAAD?” Well, YES! In pediatric anesthesia there are several vampire ideas that simply cannot be killed even with exposure to sunlight (evidence). Two that we’ve discussed in the past are prolonged preoperative fasting and the use of sodium bicarbonate to treat acidosis during pediatric in hospital cardiac arrests.
Mythology, dogma, and ingrained habits have a way of persisting despite evidence to the contrary. Indeed, implementation science tells us that it can take up to 20 years for evidence-based findings to make their way into widespread clinical practice.1, 2 When Jay and Myron were in training almost 50 years ago, dinosaurs ruled the earth and resuscitation science was still in its infancy. The “cocktail” for CPR included the ABC’s (airway-breathing-circulation) and D’s (drugs – epinephrine-bicarb-calcium). Over the past 30 years, rigorous outcomes studies have demonstrated the clear importance of early recognition or low-flow or no-flow states, early defibrillation (when appropriate), and timely initiation of high quality chest compressions.3 All of these have been incorporated in the regularly updated resuscitation guidelines published by the American Heart Association (AHA) and are reflected in SPA’s PediCrisis app.3 On the other hand, the routine use of calcium in resuscitation was removed from recommendations more than 15 years ago. And, with the exception of its use in certain circumstances like in the treatment of hyperkalemia or sodium channel blocker ingestions, the routine use of sodium bicarbonate in CPR is also no longer recommended. And yet, the use of bicarb during pediatric in-hospital resuscitations continues despite evidence that it may negatively affect outcomes. Since sunlight/evidence isn’t working, the authors for today’s PAAD and the accompanying editorial attempt to drive a stake into the heart of bicarb – to once and for all slay this vampire idea!
Original article
Cashen K, et al. Sodium Bicarbonate Use During Pediatric Cardiopulmonary Resuscitation: A Secondary Analysis of the ICU-RESUScitation Project Trial. Pediatr Crit Care Med. 2022 Oct 1;23(10):784-792. doi: 10.1097/PCC.0000000000003045. Epub 2022 Jul 26. PMID: 35880872; PMCID: PMC9529841.
Editorial
DelSignore L. Sodium Bicarbonate and Poor Outcomes in Cardiopulmonary Resuscitation: Coincidence or Culprit? Pediatr Crit Care Med. 2022 Oct 1;23(10):848-851. doi: 10.1097/PCC.0000000000003059. Epub 2022 Oct 3. PMID: 36190362.
Here’s the problem, in a nutshell: “Historically, acidosis has prompted the use of sodium bicarbonate as a theoretical buffer with the intent of improving hemodynamics during pediatric in-hospital arrests. Yet, sodium bicarbonate is not a benign therapy. With repeated use, it can lead to hyperosmolarity, electrolyte derangements (hypokalemia, hypocalcemia, and hypernatremia) and paradoxically, intracellular acidosis. Sodium bicarbonate rapidly combines with hydrogen ion (H+) to produce carbonic acid (H2CO3) which metabolizes into byproducts of water (H2O) and carbon dioxide (CO2). If effective ventilation is not present, then intracellular acidosis will result from rapid intracellular diffusion of CO2. This can decrease myocardial contractility and make myocytes less responsive to vasoactive agents, thereby working against the goal of improving hemodynamics. CO2 can also rapidly diffuse into the cerebrospinal fluid and worsen CNS acidosis, which may be problematic in patients undergoing cardiopulmonary resuscitation (CPR) who are at risk for poor neurologic outcomes.”1
Cashen et al.4 in a multi-center data registry, analyzed the association between sodium bicarbonate administration during pediatric in-hospital arrests and patient outcomes. Cutting to the chase, they found that bicarbonate administration during pediatric in-hospital arrests decreased survival to hospital discharge and decreased survival to hospital discharge with favorable neurologic outcomes. As you probably suspected, bicarbonate use was more common in specific contexts: sicker patients, longer resuscitations, patients with pre-existing cardiac diagnoses, pulseless rhythms at the time of arrest, and hypotension as the immediate cause. Thus, were these results a chicken and egg phenomenon? Did bicarbonate administration worsen outcomes, or were the patients who received bicarbonate sicker and in worse condition to begin with? Based on their analysis of the data, the authors make the case (once again!) that bicarbonate causes harm.
Additionally, Cashen et al.4 found that despite limited AHA indications for sodium bicarbonate during pediatric in-hospital cardiac arrests, it was administered in almost half of these events. Why? Our good friend and colleague, Dr. Peter Davis at the Children's Hospital of Pittsburgh, always likes to point out that context matters. Personal habits and anecdotal experiences and memories of your last disastrous experience are powerful influences that affect your responses to the next crisis. Thus, if you are faced with an in-hospital arrest, your decision to use or not use bicarb will be very much influenced by how you treated your last cardiac arrest patient and how that arrest turned out rather than from evidence-based studies. Further, if an on-going cardiac arrest is not going well and there is no return of spontaneous circulation, it’s almost impossible to not say to yourself, “What’s the harm in trying it?” But over the past two decades the data has been accumulating that there may be harm in trying sodium bicarbonate during arrests when there is not an indication for sodium bicarbonate. In anesthesia and critical care, we often feel a “duty to do something.” Sometimes, the best thing you can do for the patient’s survival and outcome may be to NOT do something. We fear that this vampire will never die, but we applaud the authors for continuing to try to slay it. And we encourage you to think twice the next time you consider sodium bicarbonate (without an indication) during CPR. What do you think?
References
1. DelSignore L. Sodium Bicarbonate and Poor Outcomes in Cardiopulmonary Resuscitation: Coincidence or Culprit? Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies. Oct 1 2022;23(10):848-851. doi:10.1097/pcc.0000000000003059
2. Bauer MS, Kirchner J. Implementation science: What is it and why should I care? Psychiatry Res. Jan 2020;283:112376. doi:10.1016/j.psychres.2019.04.025
3. Topjian AA, Raymond TT, Atkins D, et al. Part 4: Pediatric Basic and Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. Oct 20 2020;142(16_suppl_2):S469-s523. doi:10.1161/cir.0000000000000901
4. Cashen K, Reeder RW, Ahmed T, et al. Sodium Bicarbonate Use During Pediatric Cardiopulmonary Resuscitation: A Secondary Analysis of the ICU-RESUScitation Project Trial. Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies. Oct 1 2022;23(10):784-792. doi:10.1097/pcc.0000000000003045