Abstract
Background: Salicylate self poisoning is potentially fatal. Plasma salicylate concentrations can be used to guide management when taken in the context of clinical features of toxicity and acid base status. Previous studies in the USA and Hong Kong have shown that routine measurement of plasma salicylate concentrations in all overdose patients is inappropriate, but there have been no previous studies in the UK.
Methods: A retrospective case note study from 1 February 2001 to 31 January 2002 was undertaken at the emergency department of St. Thomas' Hospital, London. Records were reviewed and information on demographic data, history, details of salicylate overdose, and documentation of clinical features of salicylate toxicity recorded.
Results: In total, 722 patient episodes were identified, of which 596 case notes were available and appropriate for inclusion in this study. Plasma salicylate concentrations (range 15–428 mg/l) were detectable in 50 patients (three notes not available), of whom 38 had given a positive history. The history of salicylate poisoning had a sensitivity of 81% (95% confidence interval (CI) 67 to 91%) and the predictive value of a negative history of salicylate ingestion in not detecting salicylate concentrations was 98% (95% CI 97 to 99%). Insufficient information on clinical features of salicylate toxicity was recorded in 569 patients (including 35 patients who had a history of salicylate ingestion).
Conclusion: History of salicylate ingestion has a high sensitivity and negative predictive value with respect to the detection of plasma salicylate concentrations. However, current practice indicates that insufficient information is obtained from patients about the clinical features of toxicity. Routine measurement of plasma salicylate concentrations is not required unless there is (a) a positive history of ingestion of salicylates or (b) a reduced level of consciousness or other reason limiting the validity of the history obtained, together with clinical features consistent with salicylate poisoning.
Full Text
The Full Text of this article is available as a PDF (52.5 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Baskin L. B., Morgan D. L. Drugs detected in patients suspected of acute intoxication. Tex Med. 1997 Sep;93(9):50–58. [PubMed] [Google Scholar]
- Brett A. S. Implications of discordance between clinical impression and toxicology analysis in drug overdose. Arch Intern Med. 1988 Feb;148(2):437–441. [PubMed] [Google Scholar]
- Buckley N. A., Whyte I. M., Dawson A. H., Reith D. A. Preformatted admission charts for poisoning admissions facilitate clinical assessment and research. Ann Emerg Med. 1999 Oct;34(4 Pt 1):476–482. [PubMed] [Google Scholar]
- Chan T. Y., Chan A. Y., Ho C. S., Critchley J. A. The clinical value of screening for salicylates in acute poisoning. Vet Hum Toxicol. 1995 Feb;37(1):37–38. [PubMed] [Google Scholar]
- Chan T. Y., Chan A. Y. Use of a plasma salicylate assay service in a medical unit in Hong Kong: a follow-up study. Vet Hum Toxicol. 1996 Aug;38(4):278–279. [PubMed] [Google Scholar]
- Dargan P. I., Wallace C. I., Jones A. L. An evidence based flowchart to guide the management of acute salicylate (aspirin) overdose. Emerg Med J. 2002 May;19(3):206–209. doi: 10.1136/emj.19.3.206. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dawson A. H., Whyte I. M. Therapeutic drug monitoring in drug overdose. Br J Clin Pharmacol. 1999 Sep;48(3):278–283. doi: 10.1046/j.1365-2125.1999.00033.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hawton K., Townsend E., Deeks J., Appleby L., Gunnell D., Bennewith O., Cooper J. Effects of legislation restricting pack sizes of paracetamol and salicylate on self poisoning in the United Kingdom: before and after study. BMJ. 2001 May 19;322(7296):1203–1207. doi: 10.1136/bmj.322.7296.1203. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Krause D. S., Wolf B. A., Shaw L. M. Acute aspirin overdose: mechanisms of toxicity. Ther Drug Monit. 1992 Dec;14(6):441–451. doi: 10.1097/00007691-199212000-00001. [DOI] [PubMed] [Google Scholar]
- Mahoney J. D., Gross P. L., Stern T. A., Browne B. J., Pollack M. H., Reder V., Mulley A. G. Quantitative serum toxic screening in the management of suspected drug overdose. Am J Emerg Med. 1990 Jan;8(1):16–22. doi: 10.1016/0735-6757(90)90287-a. [DOI] [PubMed] [Google Scholar]
- Sporer K. A., Khayam-Bashi H. Acetaminophen and salicylate serum levels in patients with suicidal ingestion or altered mental status. Am J Emerg Med. 1996 Sep;14(5):443–446. doi: 10.1016/S0735-6757(96)90146-1. [DOI] [PubMed] [Google Scholar]
- Teitelbaum D. T., Morgan J., Gray G. Nonconcordance between clinical impression and laboratory findings in clinical toxicology. Clin Toxicol. 1977;10(4):417–422. doi: 10.3109/15563657709046277. [DOI] [PubMed] [Google Scholar]
- Temple A. R. Acute and chronic effects of aspirin toxicity and their treatment. Arch Intern Med. 1981 Feb 23;141(3 Spec No):364–369. doi: 10.1001/archinte.141.3.364. [DOI] [PubMed] [Google Scholar]
- Wright N. An assessment of the unreliability of the history given by self-poisoned patients. Clin Toxicol. 1980 May;16(3):381–384. doi: 10.3109/15563658008989963. [DOI] [PubMed] [Google Scholar]