Can emergency department clinicians diagnose gamma-hydroxybutyrate (GHB) intoxication based on clinical observations alone?

Abstract

ObjectivesGamma-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.MethodsPatients 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.ResultsA 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).ConclusionPhysicians 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.

Characteristics and dose‐effect relationship of clinical gamma‐hydroxybutyrate intoxication: A case series

“…These results from our data suggest that GHB overdose does not necessarily influence the pulse rate and, when there was an abnormal pulse rate, it tended to be an increase in heart rate, as described by several authors [24,[50][51][52], rather than a decrease, which was conjectured by others [18,19,22,27,28]. Further symptoms, observed after GHB overdose, were nausea and vomiting [17], which may have occurred due to coconsumption of alcohol [18,53].…”

“…Although the GC‐MS is considered to be the most reliable method, the enzymatic test provided results in good agreement with the “gold standard.” Therefore, this test can be recommended for rapid detection of GHB overdoses, which might be useful in cases of acute GHB intoxication presenting in urban EDs. Recently, Smits et al suggested that, in addition to clinical judgment, the use of a rapid reliable initial analytical GHB test—especially in serum—would be valuable in reducing false negative diagnosis [22]…”

“…Similar results were previously reported by others, who determined a mean of 28 years, ranging from 18 to 51 [19] or a mean of 28 years, ranging from 15 to 53 [40] among GHB users, respectively. A younger average age was determined by Van Sassenbroek et al [32] with a median of 21 years (range [17][18][19][20][21][22][23][24][25][26].…”

“…Typical symptoms related to GHB-intoxications were explored in order to determine a possible dose-effect relationship ranging from the standard signs and symptoms common in therapeutically used dosage through to those present in toxic overdoses. As physicians may underestimate the presence of GHB-intoxication, and can fail to diagnose GHB-intoxication based on clinical observations alone [22], a rapid enzymatic assay for the detection of GHB in serum and urine was also evaluated.…”

“…F I G U R E 1 Number of GHB intoxicated patients per year from 2006 to 2016 of acute GHB intoxication presenting in urban EDs. Recently, Smits et al suggested that, in addition to clinical judgment, the use of arapid reliable initial analytical GHB test-especially in serum-would be valuable in reducing false negative diagnosis[22]…”