ROUTINE SCREENING FOR ASPIRIN IN DELIBERATE SELF

POISONING?Nic Ionmhain, U. ¹, Kavanagh, K. ¹, Griffin, E. ², Rokovac, A. ¹, Crowley, V. ¹, Shields, D ¹.

¹St James’s Hospital Dublin ²National Self-Harm Registry Ireland, National Suicide Research Foundation

INTRODUCTION

• Acute salicylate ingestion is a well-recognised overdose with significantpotential toxicity and fatality with aknown toxidrome

• Many Irish and UK hospitals stillperform routine salicylate assays indeliberate self-poisoning (DSP)screening (no longer standard practicein Australia) despite research evidenceover the past 20 years of its limitedutility

• Toxbase.org advises that clinical historyof ingestion, evidence of salicylism,coma or metabolic derangementshould guide its screening use

AIMS AND METHODS• Aims:

• To establish the relative national and local (SJH) frequency of DSPattendances to Emergency Departments (ED) and to investigate theproportion ingesting salicylate or paracetamol containing compounds

• To assess the cost-effectiveness of routine screening salicylate-assays

in DSP at a local level, by reviewing the number of assays from

June 2010 to April 2014

• Method: Retrospective observational cross sectional cohort study

• National statistics were obtained from the National Self-Harm RegistryIreland

• For local data, the SJH Biochemistry Department’s Telepath databaseidentified all salicylate levels performed by patient number and date of

assay.All cases with levels >5mg/dL underwent chart review for

• (1) Clinical and biochemical evidence of salicylate poisoning

• (2) Requirement for treatment of salicylate ingestion

• (3) Reported ingestion of salicylate-containing compounds

RESULTSFEATURES OF SALICYLATE

TOXICITY (n = 31)

(1 notes not available)

YES NO UNKNOWN /

NOT

DOCUMENTED

TINNITUS 31 (100%)

DEAFNESS 31 (100%)

VERTIGO 31 (100%)

VOMITING 6 (19.4%) 25 (80.6%)

AGITATION 31 (100%)

TACHYPNOEA 31 (100%)

FEVER 1(SEPTIC)

(3.2%)

27 (87.1%) 3 (9.7%)

CEREBRAL OEDEMA 31(100%)

METABOLIC ACIDOSIS 2 (SEIZURE)

(6.5%)

16 (51.5%) 13 (42%)

RESP ALKALOSIS 19 (61.3%) 12 (38.7%)

SEIZURE 2 (6.5%) 29 (93.5%)

DECEASED 31 (100%)

31658

9728 (30.7%)

975 (3.1%)2016 620 (30.8%) 52 (2.58%)

0

5000

10000

15000

20000

25000

30000

35000

All deliberate selfpoisoning attendances

All self poisoningsinvolving Paracetamol

ingestion

All self poisoningsinvolving Salicylate

ingestions

National (n=31658)

St James's Hospital(n=2016)

Total Valid Tests Total Cases

2998 2782

Positive Tests 46 (1.5%) 32 (1.2%)

Negative Tests 2959 (98.5)% 2750 (98.8%)

National Registry of Deliberate Self–Harm June 2010- April 2014

Total tests performed in SJH June 2010-April 2014

Clinical and Metabolic Features of Salicylate Toxicity

Reported Salicylate ingestion on history 23 (74%)

Peak Level 38mg /dL

Average / Median level across all cases 16.3mg/dL / 15.5mg/dL

Required treatment Nil

Admissions due to salicylate ingestion None

Additional Data

DISCUSSION AND LIMITATIONS• DISCUSSION

• DSP involving salicylates is rare on a national and local level. Routine screening ofall poisonings is unlikely to yield many positive results. Reasons for this areunclear, perhaps related to packaging restrictions ¹ or decreased use of aspirin as ahousehold analgesic

• 2782 attendances underwent routine biochemical screening for salicylate ingestionwith no evidence of toxidrome. No assays were in the toxic levels and no caserequired treatment or admission secondary to salicylate ingestion

• Our data and methods are in keeping with prior publications over the past 20 yearswhich describe salicylate ingestion as a rare overdose with limited costeffectiveness of routine screening in the awake asymptomatic patient and the highsensitivity of history and clinical symptoms for ingestion. (Wood et al 2005 ²,Graham et al 2006³, Sporer et al 1996 ⁴. )

• Routine salicylate assays cost €2.50 / test. This demonstrates a cost saving of€7,495 over the course of the study period excluding additional laboratory costs– staff, equipment etc.

• LIMITATIONS

• This study is limited by its retrospective nature involving chart review and relianceon accurate documentation and history

CONCLUSION• Salicylate ingestion nationally in Ireland and locally (St James’s Hospital) is rare

• Unlike paracetamol ingestion, it has a recognised clinical toxidrome

• Routine biochemical screening in all cases of deliberate self poisoning for salicylateingestion is unlikely to be cost-effective or clinically beneficial in the awake,asymptomatic patient

• Indications to consider performing a salicylate level should include – history ofingestion, evidence of a toxidrome, coma or metabolic derangement consistentwith a suspicion of salicylate poisoning (as per Toxbase guidelines)

• References– ¹ Hawton et al. 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):1203-7.– ² Wood et al. Measuring plasma salicylate concentrations in all patients with drug overdose or altered consciousness: is it necessary? Emerg Med J. 2005 Jun;22(6):401-3. – ³ Graham et al. Paracetamol and salicylate testing: routinely required for all overdose patients? Eur J Emerg Med 2006 Feb;13(1):26-8.– ⁴ Sporer et al. Acetaminophen and salicylate serum levels in patients with suicidal ingestion or altered mental status. Am J Emerg Med 1996 Sep;14(5):443-6

• Contact: Dr Una Nic Ionmhain nicionmu@tcd.ie