What is the evidence for using bicarbonate (sodium bicarbonate) during status asthmaticus and subsequent cardiac arrest?

From the Guidelines

The use of sodium bicarbonate during status asthmaticus and subsequent cardiac arrest is not routinely recommended and lacks strong supporting evidence. In status asthmaticus, severe bronchospasm leads to carbon dioxide retention and respiratory acidosis, but this is best addressed by improving ventilation rather than administering bicarbonate 1. During cardiac arrest following status asthmaticus, sodium bicarbonate should only be considered in specific situations: when there is documented severe acidosis (pH < 7.1), hyperkalemia, or in prolonged cardiac arrest unresponsive to standard resuscitation measures.

Key Considerations

• The theoretical rationale for bicarbonate use is to correct severe acidosis that may impair myocardial function and response to catecholamines.
• However, bicarbonate administration can worsen intracellular acidosis, produce excess carbon dioxide (which requires ventilation for elimination), cause hypernatremia, and potentially worsen bronchospasm 1.
• If used, typical adult dosing is 1 mEq/kg IV initially, with subsequent doses guided by arterial blood gas results.

Management Approach

• The cornerstone of management remains addressing the underlying cause through aggressive bronchodilator therapy, appropriate ventilation strategies, and standard advanced cardiac life support protocols rather than relying on bicarbonate therapy.
• The 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care suggest that routine use of sodium bicarbonate is not recommended for patients in cardiac arrest (Class III, LOE B) 1.

Special Situations

• Bicarbonate can be beneficial in special resuscitation situations, such as preexisting metabolic acidosis, hyperkalemia, or tricyclic antidepressant overdose, as noted in the guidelines 1.
• In these situations, the use of bicarbonate should be guided by the bicarbonate concentration or calculated base deficit obtained from blood gas analysis or laboratory measurement, and providers should avoid attempting complete correction of the calculated base deficit to minimize the risk of iatrogenically induced alkalosis 1.

From the Research

Status Asthmaticus and Cardiac Arrest

• The use of bicarbonate (sodium bicarbonate) during status asthmaticus and subsequent cardiac arrest is a topic of ongoing debate, with some studies suggesting its potential benefits and others raising concerns about its effectiveness and safety 2, 3, 4.
• In the context of cardiac arrest, the administration of sodium bicarbonate is generally not recommended, except in specific situations such as hyperkalemic cardiac arrest, severe cardiotoxicity, or overdose due to tricyclic antidepressants 2, 4.
• However, a recent study found that sodium bicarbonate administration was associated with improved survival in asystolic and PEA out-of-hospital cardiac arrest, suggesting that it may have a role in certain types of cardiac arrest 5.

Bicarbonate Use in Status Asthmaticus

• One study from 1983 reported the use of a combined ventilator and bicarbonate strategy in the management of status asthmaticus, which reduced peak inflation pressure and maintained a physiologic pH while allowing pCO2 to remain elevated 6.
• This approach suggests that bicarbonate may have a potential role in the management of status asthmaticus, particularly in severe cases requiring intubation.

Key Findings

• The evidence for the use of bicarbonate during status asthmaticus and subsequent cardiac arrest is limited and inconclusive 2, 3, 4.
• Further studies are needed to determine the potential benefits and risks of bicarbonate administration in these scenarios 2, 5.
• The current guidelines and literature review suggest that bicarbonate should not be used routinely in cardiac arrest, except in specific situations 2, 4.