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Can emergency department clinicians diagnose gamma-hydroxybutyrate (GHB) intoxication based on clinical observations alone?
  1. Thomas Smits1,
  2. Femke Gresnigt2,
  3. Milly Attema-de Jonge3,
  4. Eric Franssen1
  1. 1Hospital Pharmacy, OLVG, Amsterdam, The Netherlands
  2. 2Emergency Department, OLVG, Amsterdam, Noord-Holland, The Netherlands
  3. 3Hospital Pharmacy, Meander Medisch Centrum, Amersfoort, The Netherlands
  1. Correspondence to Dr Femke Gresnigt, Emergency Department, OLVG, Amsterdam, The Netherlands; F.M.J.Gresnigt{at}


Objectives Gamma-hydroxybutyrate (GHB) is a drug of abuse with central depressing effects, which may cause coma with a GCS score as low as 3. A rapid diagnosis ‘GHB intoxication’ may prevent unnecessary diagnostic work-up and may lead to guided, less invasive, treatment. The aim of this study was to evaluate if ED physicians’ clinical evaluation were sufficient for diagnosis in patients with suspected GHB-intoxication.

Methods Patients presenting at the ED with a GCS<15 and a potential intoxication with drugs of abuse for whom urine toxicology screen was performed were included consecutively. After a first assessment, the ED physician registered the most likely initial diagnosis in the hospital information system. Urine of these patients was tested with a validated gas chromatography analytical method for GHB (confirmation test). The initial diagnoses were compared for agreement with the results of the confirmation test.

Results A total of 506 patients were included, 100 patients tested positive for GHB and 406 patients tested negative for GHB. Sensitivity and specificity of the ED physicians compared with the confirmation test to diagnose GHB intoxications were 63% (95% CI 52 to 73) and 93% (95% CI 90 to 95), respectively. The positive predictive value was 67% (95% CI 60 to 77) and the negative predictive value was 92% (95% CI 88 to 94).

Conclusion Physicians underestimate the presence of GHB intoxication and can fail to diagnose GHB intoxication based on clinical observations alone. In the future, a rapid reliable initial analytical GHB test in addition to clinical judgement could be valuable to reduce false negative diagnosis.

  • toxicology
  • drug abuse
  • clinical assessment
  • diagnosis
  • poisoning

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  • Handling editor Gene Yong-Kwang Ong

  • TS and FG contributed equally.

  • Contributors TS, FG, MA-dJ and EF conceived the study. TS and FG performed the background searches. Data linkage and statistical analysis of results was done by TS. Interpretation of data was performed by TS, FG, MA-dJ and EF. TS and FG drafted the initial manuscript and all authors contributed to its revision.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Ethics approval Ethical approval was obtained from the Institutional Review Board on 4 April 2016. The need for formal ethics approval was waived on 23 March 2016 by the Medical Research Ethics Committees United (MEC-U) according to the Dutch Law on Medical Research in Humans.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available upon reasonable request. Individual participant data that underlie the results reported in this article will be available, after deidentification (text and tables). The data will be available for individual participant data meta-analysis beginning 9 months and ending 36 months following article publication. Data will be shared with investigators whose proposed use of the data has been approved by an independent review committee identified for this purpose. Proposals should be directed to To gain access, data requestors will need to sign a data access agreement.

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