Abstract: PUB154
Salicylate Intoxication: When Bicarbonate Is Not Enough
Session Information
Category: Dialysis
- 801 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Mena, Alexis Fernando, Universidad UTE Facultad de Ciencias de la Salud Eugenio Espejo, Quito, Pichincha, Ecuador
- Mena, Jose D., Nephrology Associates of the Carolinas, PA, Shelby, North Carolina, United States
Introduction
Accidental or intentional overdose of salicylates is a medical emergency that can precipitate severe metabolic derangements and in some cases death. In 2014 more than 24,700 salicylate intoxication cases were documented in the US. We present a case of acute aspirin overdose with emphasis in the indications of renal replacement therapy.
Case Description
A 47-year-old male with a past medical history of polysubstance abuse, depression and CKD presented to the emergency department after being found unresponsive.
On arrival, vital signs showed a heart rate of 120 bpm, respiratory rate of 35, SpO2 97% on room air and blood pressure of 130/80.
On physical exam he was tachypneic, lethargic and non responsive to voice commands. Breath sounds were clear bilaterally.
Labs showed a creatinine 1.46 mg/dl (baseline), sodium 138 mmol/L, potassium 4.1 mmol/L, CO2 13 mmol/L. Blood gas: pH 7.42, pO2 63 mmHg, pCO2 20.1 mmHg. Urine toxicology was positive for cocaine. Salicylate level was 96.8 mg/dL.
He was started on sodium bicarbonate infusion and poison control was contacted. Despite initial management, salicylate levels didn't improve. He was started on intermittent hemodialysis (iHD) and was continued for 6 hours with improvement in salicylate levels from 89.6 mg/dL pre iHD to 14.7 mg/dL post iHD.
Discussion
The history of substance abuse in a patient with encephalopathy and anion gap metabolic acidosis should raise the concern for salicylate toxicity. Initial treatment includes discussion with poison control, fluid resuscitation and bicarbonate administration. The goal of bicarbonate is to generate alkalemia to minimize the passage of salicylate to the central nervous system and to increase the excretion of salicylate alkalinizing the urine.
The low volume of distribution, absence of tissue binding and the small size of salicylate, make iHD the best way to remove this drug. Dialysis is recommended when salicylate levels are above >100 mg/dl or >90 mg/dl with impaired kidney function. It is also recommended in the presence of encephalopathy or new hypoxemia and if standard therapy fails.
In this case, iHD was continued for 6 hours with improvement in salicylate levels and improvement in his symptoms. Guidelines recommend to stop dialysis when clinical improvement is apparent and when salicylate levels are below 19 mg/dL. If salicylate levels are not available, iHD should be performed for at least 4 to 6 hours.