The beef with Bicarb Part 3. The Use of Sodium Bicarbonate in Cardiac Arrest by Jimmy Pruitt

Show Timestamps

1:14 Review of previous episodes of the series
2:40 Pharmacy Friday Pearls
3:24 EMPoweRx Conference
5:28 Cardiac Arrest Patho of Acidosis
6:04 Why have we been using sodium bicarbonate
7:08 Adverse Effects of sodium bicarbonate
9:29 History of sodium bicarbonate for ACLS
10:17 Bishop et al study
11:45 Wang et al study
12:26 Ahn et al
13:18 Kwano et al
14:37 Wu et al
16:31 Alshahrani et al
17:45 Summary

1. Why this topic
   1. Something we commonly do without much evidence to support its use
2. Pathophysiology of acidosis in Cardiac Arrest
   1. One of the critical pathophysiologic components of cardiac arrest is the generation of both metabolic and respiratory acidosis. Obviously, if you are not breathing to oxygenate your blood and remove CO2, you will generate respiratory acidosis. Also, if your heart is not delivering oxygen-rich blood to the tissues and CO2 is unable to be removed, then metabolic acidosis will ensue. 
   2. The hypothesis of using alkalizing agents in cardiac arrest is to scavenge hydrogen ions, thus improving the body’s systemic acidosis to improve cardiovascular function.

Adverse Effects

1. Transient aggravation of the intracellular acidosis with further reduced contractility of the myocardium as a consequence [11,43,86,87]
   1. Am J Physiol 1982;242:F586–91
   1. Am J Physiol 1958;195:412–6
   1. Am J Physiol 1967;212:917–23.
   1. Science 1985;227:754–6
2. Administration of only 1 mequiv./kg of sodium bicarbonate has been demonstrated to increase arterial PCO2 by more than 20 mmHg during CPR.
   1. J Am Med Assoc 1976;235:506–9.
3. Thus, treatment with sodium bicarbonate may add substantial quantities of the potent negative inotrope carbon dioxide to the burdens of an arrested or recently resuscitated heart.
   1. Crit Care Med 1993;21:901–6.
4. Clowes et al suggested that both metabolic (pH < 7.25) and respiratory (Pco2 > 65 mm Hg) acidosis were associated with decreased survival in postoperative patients
   1.  
5. Hypotension
   1. It has been suggested that the observed effect may be explained by a reduction in diastolic pressure due to arterial vasodilation in combination with a modest increase in right atrial pressure due to increased preload produced by the hypertonic buffer.
   1. The hypotensive effect of hypertonic solutions has been postulated to be mediated by a vagal reflex [96], or to result from a direct action of hypertonic solutions on arterial resistance vessels [97].
      1. J Appl Physiol 1969;27:251–5
      1. Chest 1981;79:552–4.
   1. Sodium bicarbonate combined with epinephrine tended to produce lower systemic blood pressure than other combinations.
6. Cerebral Effects
   1. Sodium bicarbonate therapy has been demonstrated to reduce cerebral O2 availability, and cerebral hypoxia contributes to the brain dysfunction encountered after the initiation of such therapy in acidaemia.
      1. J Pediatr 1980;96:968–73
   1. Hyperosmolar states due to sodium excess may cause congestion of cerebral white matter and intracranial hemorrhage [104–106]
      1. Am J Med 1974;56:162–8
      1. New Engl J Med 1974;291:6–10
      1. Acta Paediatr Scand 1976;65:429– 32.

Properties	Sodium Bicarbonate
Dose	0.5-1 mEq/kg/dose repeat doses should be guided by arterial blood gases
Administration	IV injection during cardiac arrest
PK/PD	Onset IV: Rapid Duration IV: 8 to 10 minutes Excretion: Urine (<1%)
Adverse Effect	Hypocalemia Intracellular acidosis (without adequate ventilation) Hypernatremia Hyperosmosis Shift O2 release by hemoglobin
Compatibility	sodium bicarbonate solution may inactivate catecholamine’s such as epinephrine*

1. History of Bicarb
   1. Correction of metabolic acidosis with SB was recommended by early advanced cardiac life support (ACLS) guidelines published in 1976, and SB was the medication most frequently used during cardiac arrest until the mid-1980s.
   1. The 2010 ACLS guidelines for adults published by the American Heart Association (AHA) state that “Routine use of sodium bicarbonate is not recommended for patients in cardiac arrest” (class III recommendation, based on level of evidence (LOE) B)

How did we get here to using bicarb in the manner that we do now?

References

1. Sodium bicarbonate. Micromedex [Electronic version].Greenwood Village, CO: Truven Health Analytics. Retrieved October 11, 2018, from http://www.micromedexsolutions.com/
2. Bishop RL, et al. Sodium bicarbonate administration during cardiac arrest. Effect on arterial pH PCO2, and osmolality. JAMA. 1976 Feb 2;235(5):506-9.
3. Vukmir RB, et al. Sodium bicarbonate in cardiac arrest: a reappraisal. Am J Emerg Med. 1996 Mar;14(2):192-206.
4. Vukmir RB, et al. Sodium bicarbonate improves outcome in prolonged prehospital cardiac arrest. Am J Emerg Med. 2006 Mar;24(2):156-61.
5. Wang CH,et al. The effects of calcium and sodium bicarbonate on severe hyperkalaemia during cardiopulmonary resuscitation: A retrospective cohort study of adult in-hospital cardiac arrest. Resuscitation. 2016 Jan;98:105-11.
6. Ahn S, et al. Sodium bicarbonate on severe metabolic acidosis during prolonged cardiopulmonary resuscitation: a double-blind, randomized, placebo-controlled pilot study. J Thorac Dis. 2018 Apr;10(4):2295-2302
7. Kawano T, et al. Prehospital sodium bicarbonate use could worsen long term survival with favorable neurological recovery among patients with out-of-hospital cardiac arrest. Resuscitation. 2017 Oct;119:63-69.
8. Chen YC, et al. The association of emergency department administration of sodium bicarbonate after out of hospital cardiac arrest with outcomes.  Am J Emerg Med. 2018 Mar 5. pii: S0735-6757(18)30187-6.
9. Wu KH, Chang CY, Chen YC, Chang CP, Hsiao CT, Weng HH. Effectiveness of Sodium Bicarbonate Administration on Mortality in Cardiac Arrest Patients: A Systematic Review and Meta-analysis. J Emerg Med. 2020 Dec;59(6):856-864. doi: 10.1016/j.jemermed.2020.08.012. Epub 2020 Sep 22. PMID: 32978028.
10. Alshahrani MS, Aldandan HW. Use of sodium bicarbonate in out-of-hospital cardiac arrest: a systematic review and meta-analysis. Int J Emerg Med. 2021 Apr 13;14(1):21. doi: 10.1186/s12245-021-00344-x. PMID: 33849429; PMCID: PMC8042972.

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