Characteristics of analytically confirmed gamma-hydroxybutyrate (GHB) positive patients in the emergency department: presentation, poly-drug use, disposition and impact on intensive care resource utilisation

Abstract

Background

Gamma-hydroxybutyrate is a potent central nervous system depressant with a narrow recreational dose window and analytical detection time. We describe data relating to intoxicated patients presenting to emergency departments across metropolitan Adelaide who tested positive for gamma-hydroxybutyrate. This work was part of the Emergency Department Admission Blood Psychoactive Testing study.

Methods

Over a 15-month period, patients presenting to four metropolitan emergency departments with symptoms of drug intoxication were enrolled in the study. The methodology involved the collection of demographic and clinical data and a de-identified blood sample which underwent comprehensive toxicological analysis. Gamma-hydroxybutyrate was determined using an acid-catalysed cyclisation followed by liquid-liquid extraction and gas chromatography-mass spectrometry. Data relating to samples positive for gamma-hydroxybutyrate were examined.

Results and discussion

A total of 1120 patients were enrolled between March 2019 and May 2020, 309 of whom were positive for gamma-hydroxybutyrate (27.6%). Of these, 256 (83%) were also positive for metamfetamine (methamphetamine). The most common clinical observation in gamma-hydroxybutyrate-positive patients was central nervous system depression (89%). There was a significant relationship between gamma-hydroxybutyrate status and sex; although males outnumbered females in absolute terms, a higher proportion of females (32%) tested positive for gamma-hydroxybutyrate than males (25%, P = 0.0155). Blood gamma-hydroxybutyrate concentrations ranged from 10 to 651 mg/L (0.096–6.2 mmol/L) and increasing gamma-hydroxybutyrate concentration correlated with severe toxicity. The presence of gamma-hydroxybutyrate had a significant impact on the patient discharge destination: the majority (69.2%) of gamma-hydroxybutyrate-positive patients were managed and discharged from the emergency department or their attached short stay wards. A significantly higher proportion of gamma-hydroxybutyrate-positive patients were admitted to the intensive care unit (28.2%) compared with gamma-hydroxybutyrate-negative patients (12.7%, chi-squared = 36.85, P <0 .001). Gamma-hydroxybutyrate positive cases accounted for 45.8% of all study-related intensive care unit admissions.

Conclusions

Gamma-hydroxybutyrate is commonly detected in illicit drug-related emergency department presentations and is detected disproportionately in the patient cohort who require intensive care unit level care.

Keywords:

• Metamfetamine
• methamphetamine
• gamma-hydroxybutyrate (GHB)
• emergency medicine
• emergency toxicology
• intensive care

Acknowledgements

This project is supported in part by a grant from the National Centre for Clinical Research on Emerging Drugs (NCCRED), funded by the Australian Government Department of Health. The continued in-kind support provided by staff at SA Health hospital EDs, Forensic Science SA and SA Pathology courier service is essential to the project and is greatly appreciated by the authors. Andrew Luong (Forensic Science SA) and Arthur Vignon (Sigma Clermont Engineering School, France) are acknowledged for their contribution to the development and validation of the analytical methodology for GHB.

Ethical approval

Ethics approval was provided by the Central Adelaide Local Health Network Human Research Ethics Committee (HREC/17/RAH/439 R20171015).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by National Centre for Clinical Research on Emerging Drugs [Seed Funding Grant, 2019].