In cardiac arrest, when can bicarbonate be used empirically, especially in patients with impaired renal (kidney) function, and at what dose?

From the Guidelines

Sodium bicarbonate should only be used empirically in cardiac arrest when there is a known or suspected severe metabolic acidosis, hyperkalemia, or in cases of tricyclic antidepressant overdose, and its use in renal failure should be approached with caution due to the risk of volume overload and hypernatremia. The recommended initial dose is 1 mEq/kg IV bolus, which may be followed by additional doses of 0.5 mEq/kg every 10 minutes based on arterial blood gas results and clinical response 1. In patients with renal impairment, careful monitoring is essential as they have reduced ability to excrete the sodium load and may develop volume overload or hypernatremia.

Some key points to consider when using bicarbonate in cardiac arrest include:

• The routine use of sodium bicarbonate is not recommended for patients in cardiac arrest (Class III, LOE B) 1
• Bicarbonate may compromise coronary perfusion pressure, create extracellular alkalosis, produce hypernatremia, and exacerbate central venous acidosis 1
• Blood gas analysis should guide subsequent dosing whenever possible, and providers should not attempt complete correction of the calculated base deficit to minimize the risk of iatrogenically induced alkalosis 1
• Other non–CO2-generating buffers such as THAM or tribonate have shown potential for minimizing some adverse effects of sodium bicarbonate, but clinical experience is limited and outcome studies are lacking 1

In clinical practice, the use of bicarbonate in cardiac arrest is generally reserved for specific situations, such as severe metabolic acidosis or hyperkalemia, and is not recommended for routine use due to the potential risks and lack of evidence supporting its benefit 1. The dose and frequency of bicarbonate administration should be guided by arterial blood gas results and clinical response, with careful monitoring of patients with renal impairment to minimize the risk of adverse effects.

From the FDA Drug Label

In cardiac arrest, a rapid intravenous dose of one to two 50 mL vials (44.6 to 100 mEq) may be given initially and continued at a rate of 50 mL (44. 6 to 50 mEq) every 5 to 10 minutes if necessary (as indicated by arterial pH and blood gas monitoring) to reverse the acidosis. Bicarbonate therapy should always be planned in a stepwise fashion since the degree of response from a given dose is not precisely predictable In metabolic acidosis associated with shock, therapy should be monitored by measuring blood gases, plasma osmolarity, arterial blood lactate, hemodynamics and cardiac rhythm.

Empirical Use in Cardiac Arrest: Bicarbonate can be used empirically in cardiac arrest when there is a need to reverse acidosis, as indicated by arterial pH and blood gas monitoring.

• The initial dose is one to two 50 mL vials (44.6 to 100 mEq).
• It can be repeated every 5 to 10 minutes if necessary. Use in Renal Failure: The label does not provide specific guidance on the use of bicarbonate in renal failure.
• However, in general, caution should be observed in emergencies where very rapid infusion of large quantities of bicarbonate is indicated, as bicarbonate solutions are hypertonic and may produce an undesirable rise in plasma sodium concentration. Clinical Practice: In clinical practice, bicarbonate therapy should be planned in a stepwise fashion, with the degree of response from a given dose not precisely predictable.
• The next step of therapy is dependent upon the clinical response of the patient.
• It is generally unwise to attempt full correction of a low total CO2 content during the first 24 hours of therapy 2.

From the Research

Empirical Use of Bicarbonate in Cardiac Arrest

• Bicarbonate can be used empirically in cardiac arrest patients with specific conditions, such as those with concomitant acute kidney injury and lactic acidosis, or those with cardiac arrest secondary to sodium channel blockade or hyperkalemia 3.
• However, the routine use of sodium bicarbonate in cardiac arrest is not recommended, as it may not improve patient-centered outcomes 3, 4.

Use of Bicarbonate in Renal Failure

• In patients with renal failure, the use of bicarbonate is not recommended empirically, as it may cause harm and does not improve patient outcomes 3, 5.
• The treatment of choice in cases of severe metabolic alkalosis, such as those caused by sodium bicarbonate abuse, should consist of vigorous chloride-containing fluid resuscitation, ammonium chloride, and hemodialysis 5.

Clinical Practice and Dosage

• The dose and frequency of bicarbonate administration can vary depending on the specific clinical scenario and the patient's condition 3, 6.
• In general, sodium bicarbonate can be administered as a hypertonic push, as a resuscitation fluid, or as an infusion, with a typical dose ranging from 50 to 100 mEq 3, 6.
• However, the use of bicarbonate should be individualized and guided by the patient's acid-base status, renal function, and other clinical factors 3, 4, 6.

Specific Scenarios

• In diabetic ketoacidosis, the use of intravenous bicarbonate therapy is not recommended, as it does not improve outcomes and may cause harm 7, 6.
• In cases of cardiac arrest due to diabetic ketoacidosis, insulin and fluid resuscitation are the mainstay of treatment, and extracorporeal life support should be considered when prolonged cardiac arrest is expected 7.