Module 8: Review and Further Study on Salicylate Toxicity

8.1 Provision of Selected Articles for Reading

– Dargan PI, Wallace CI, Jones AL. An evidence based flowchart to guide the management of acute salicylate (aspirin) overdose. Emerg Med J. 2002 May;19(3):206-9. doi: 10.1136/emj.19.3.206. PMID: 11971042; PMCID: PMC1725865.

This article provides a useful clinical decision tool for managing acute salicylate toxicity across various presentations.

– Kuzak N. Brubacher JR. Kennedy JR. Reversal of saliycate –induced euglycemic delirium with dextrose. Clinical Toxicology. 45:5; 526-529. PMID 17503260. 

This case report demonstrates the importance of glucose supplementation for neuroglycopenia in salicylism despite normal fingerstick glucose levels.

– McCabe, D et al. The association of hemodialysis and survival in intubated salicylate-poisoned patients. Am J Emerg Med 2017; 35: 899-903. PMID 284384469.

This study shows an association between hemodialysis and improved survival in mechanically ventilated patients with significant salicylate toxicity.

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8.2 Discussion Questions

Q1: What are some indications for starting hemodialysis in salicylate poisoning?

A1: Hemodialysis is indicated for salicylate levels above 100 mg/dL in acute ingestions, significant acidemia with pH < 7.2, altered mental status, seizures, respiratory failure, kidney failure, circulatory collapse, and failure of standard therapies.

Q2: How does hemodialysis impact outcomes in mechanically ventilated patients?

A2: A retrospective study found intubated patients with salicylate levels above 50 mg/dL had 83.9% survival with hemodialysis compared to 56% survival without it. Hemodialysis appears to improve outcomes in severely poisoned patients requiring intubation.

Q3: What neurologic effects may occur with normal glucose levels in salicylate toxicity?

A3: Salicylates can cause neuroglycopenia with delirium, seizures and coma despite normal serum glucose levels. This results from increased CNS glucose demand. Dextrose administration can reverse CNS toxicity even with normal fingerstick glucose.

Q4: What is an indication for using the salicylate toxicity clinical decision tool?

A4: The decision tool aids in determining the appropriate management steps based on the timing, clinical findings, and diagnostic results in acute salicylate ingestions when the exposure history is known.

Q5: What is the expected acid-base disturbance in chronic salicylate toxicity?

A5: Isolated metabolic acidosis is more common in chronic toxicity whereas acute ingestions classically begin with respiratory alkalosis progressing to a mixed disorder.

Q6: What risk factors for toxicity are important to consider in older adults?

A6: Reduced drug clearance, polypharmacy, drug interactions, reduced renal function, and comorbidities increase adverse reaction risk in older adults even at lower salicylate doses/levels.

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8.3 Advanced Topics for Further Study

– Pediatric considerations in salicylate toxicity

– Risk assessment tools for hepatotoxicity in repeat supratherapeutic acetaminophen ingestions

– Role of extracorporeal treatments beyond hemodialysis

– Pharmacogenomics impacting salicylate toxicity and treatment response