Salicylate levels as a predictor of outcome
Serum salicylate levels >80 mg/dL (>5.8 mmol/L) in adults and >70 mg/dL (>5.1 mmol/L) in children or older people indicate severe poisoning and increased likelihood of fatal ingestion.[18]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.
https://emj.bmj.com/content/19/3/206.full
http://www.ncbi.nlm.nih.gov/pubmed/11971828?tool=bestpractice.com
Patients with chronic salicylism and levels 40 to 60 mg/dL (2.9 to 4.3 mmol/L) can be severely ill and at risk of death. Nonfatal salicylate poisoning is associated with a full recovery.[18]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.
https://emj.bmj.com/content/19/3/206.full
http://www.ncbi.nlm.nih.gov/pubmed/11971828?tool=bestpractice.com
It is important to note that substantial clinical signs and symptoms, particularly neurologic signs and noncardiogenic pulmonary edema, can be present with lower levels of salicylate, particularly in cases of chronic ingestions. Therefore, salicylate level alone is not a reliable predictor of outcome.[32]Shively RM, Hoffman RS, Manini AF. Acute salicylate poisoning: risk factors for severe outcome. Clin Toxicol (Phila). 2017 Mar;55(3):175-80.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5376291
http://www.ncbi.nlm.nih.gov/pubmed/28064509?tool=bestpractice.com
Time from ingestion to treatment
Risk of death and serious toxicity from acute ingestion increases with increasing interval between ingestion and treatment. One study showed that substantial morbidity and mortality increased if the estimated interval between ingestion of large amounts of salicylate and treatment exceeded 12 hours.[33]Done AK. Salicylate intoxication: significance of measurements of salicylate in blood in cases of acute ingestion. Pediatrics. 1960 Nov;26:800-7.
http://www.ncbi.nlm.nih.gov/pubmed/13723722?tool=bestpractice.com
Unfortunately, accurate reporting of timing of poisoning and estimation of dose is highly variable in the literature.[2]Chyka PA, Erdman AR, Christianson G, et al. Salicylate poisoning: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2007;45(2):95-131.
https://www.tandfonline.com/doi/full/10.1080/15563650600907140
http://www.ncbi.nlm.nih.gov/pubmed/17364628?tool=bestpractice.com