What is the treatment for Salicylate poisoning with intravenous (IV) sodium bicarbonate (bicarb)?

From the Guidelines

Intravenous sodium bicarbonate is recommended for treating salicylate poisoning, particularly in moderate to severe cases, with a typical regimen involving administering 1-2 mEq/kg IV bolus of sodium bicarbonate, followed by a continuous infusion of 150 mEq sodium bicarbonate in 1L D5W to maintain alkalosis, as suggested by the 2010 American Heart Association guidelines 1.

Treatment Approach

The goal of treatment is to achieve and maintain a urine pH of 7.5-8.0, which enhances salicylate elimination through a process called ion trapping. This alkalinization of the urine increases the ionized form of salicylate, preventing its reabsorption in the renal tubules and accelerating excretion. Additionally, IV bicarbonate helps correct metabolic acidosis commonly seen in salicylate toxicity and prevents salicylate entry into the central nervous system, reducing neurotoxicity.

Key Considerations

• Close monitoring of serum electrolytes, pH, and fluid status is essential, as overaggressive alkalinization can lead to metabolic alkalosis, hypokalemia, and fluid overload.
• In severe cases with altered mental status, seizures, or renal failure, hemodialysis may be necessary alongside bicarbonate therapy, as recommended by the EXTRIP workgroup 1.
• The decision to implement extracorporeal treatment should be based on the severity of poisoning, with consideration of factors such as salicylate concentration, acidemia, and end-organ toxicity.

Recommendations

• Administer 1-2 mEq/kg IV bolus of sodium bicarbonate, followed by a continuous infusion of 150 mEq sodium bicarbonate in 1L D5W to maintain alkalosis.
• Monitor serum electrolytes, pH, and fluid status closely.
• Consider hemodialysis in severe cases with altered mental status, seizures, or renal failure.
• Implement extracorporeal treatment based on the severity of poisoning, with consideration of factors such as salicylate concentration, acidemia, and end-organ toxicity.

From the FDA Drug Label

Sodium bicarbonate is further indicated in the treatment of certain drug intoxications, including ... in poisoning by salicylates

• Sodium bicarbonate IV is indicated for the treatment of salicylate poisoning.
• The use of IV bicarbonate in salicylate poisoning is supported by the drug label. 2

From the Research

Treatment of Salicylate Poisoning

• The treatment of salicylate poisoning is based on the prevention of further absorption and enhancement of excretion of already absorbed drug 3.
• Methods used to treat salicylate poisoning include forced alkaline diuresis, alkalinisation alone, and the use of activated charcoal 3, 4.
• Alkalinisation alone has been shown to be safer and equally successful as forced alkaline diuresis 3, 4.
• The use of activated charcoal as an acute absorbing agent for drug still in the upper gastrointestinal tract is beneficial in minimising further absorption 3.
• Multiple-dose activated charcoal and alkalinisation are currently the most popular methods of treatment 3.

Use of IV Bicarbonate

• IV bicarbonate can be used to alkalinise the urine and enhance the excretion of salicylate 5, 4.
• A study found that alkali alone was at least as effective and possibly more effective than forced alkaline diuresis in enhancing salicylate removal 4.
• The renal excretion of salicylate depends much more on urine pH than flow rate, and forced diuresis alone had little useful effect 4.
• IV bicarbonate can help to increase the urine pH and enhance the excretion of salicylate, but the optimal duration and mode of therapy are still unclear 5.

Clinical Approach

• A systematic approach to diagnosing and treating salicylate poisoning is essential, including the use of evidence-based interventions to mitigate negative outcomes 6.
• Clinicians should be aware of the difficulty associated with appropriately distinguishing between toxic ingestions and the hallmark indicators that can assist in appropriate diagnoses 6.
• Key interventions, such as the use of IV bicarbonate and activated charcoal, should be initiated in a timely manner to increase the chance of recovery for patients with salicylate poisoning 5, 3, 6.