ASA levels and toxicity

Q: Serum salicylate (ASA) concentration tends to ____________ clinical signs? - select one

A) lags

B) precedes

Answer: A

Although it is recommended to repeat serum salicylate concentration every 2-4 hours to avoid missing prolonged or delayed absorption, the serum ASA level usually lags behind the clinical status by many hours, particularly in the early phase. That's why ASA toxicity is a clinical diagnosis, because of history, physical exam, and other lab findings. This is due to a change in the tissue concentration. It takes time for tissue concentration to equilibrate the clinical status.

The clinical implication of the above discordance is enormous. Clinicians may get baffled by the life-threatening effects of salicylate toxicity but a decreasing or near-therapeutic serum ASA levels. A decreasing ASA concentration in a patient with progressively worsening clinical manifestations of ѕаlicуlism, i.e., worsening acidosis or lеthargу indicates altered tissue distribution and more severe disease rather than increased elimination. 

#toxicity

References:

1. Peketi SH, Upadrista PK, Cadet B, Cadet J, Cadet N. Salicylate Poisoning and Rebound Toxicity. Cureus. 2024 May 13;16(5):e60241. doi: 10.7759/cureus.60241. PMID: 38746490; PMCID: PMC11093619.

2. American College of Medical Toxicology. Guidance document: management priorities in salicylate toxicity. J Med Toxicol. 2015 Mar;11(1):149-52. doi: 10.1007/s13181-013-0362-3. PMID: 25715929; PMCID: PMC4371029.

3. Akshintala D, Mendez A, Ikladios OI, Emani VK. Severe salicylate poisoning resistant to conventional management. J Community Hosp Intern Med Perspect. 2018 Dec 11;8(6):373-375. doi: 10.1080/20009666.2018.1551027. PMID: 30559949; PMCID: PMC6292349.