CLINICAL COURSE OF GAMMA-HYDROXYBUTYRATE OVERDOSE

Study objective: To describe the clinical characteristics and course o f gamma-hydroxybutyrate (GHB) overdose. Methods: We assembled a retros pective series of all cases of GHB ingestion seen in an urban public-h ospital emergency department and entered in a computerized database Ja nuary 1993 through December 1996. From these cases we extracted demogr aphic information, concurrent drug use, vital signs, Glasgow Coma Scal e (GCS) score, laboratory values, and clinical course. Results: Sixty- one (69%) of the 88 patients were male. The mean age was 28 years. Thi rty-four cases (39%) involved coingestion of ethanol, and 25 (28%) inv olved coingestion of another drug, most commonly amphetamines. Twenty- five cases (28%) had a GCS score of 3, and 28 (33%) had scores ranging from 4 through 8. The mean time to regained consciousness from initia l presentation among nonintubated patients with an initial GCS of 13 o r less was 146 minutes (range, 16-389). Twenty-two patients (31%) had an initial temperature of 35 degrees C or less. Thirty-two (36%) had a symptomatic bradycardia; in 29 of these cases, the initial GCS score w as 8 or less. Ten patients (11%) presented with hypotension (systolic blood pressure less than or equal to 90 mm Hg); 6 of these patients al so demonstrated concurrent bradycardia. Arterial blood gases were meas ured in 30 patients; 21 had a PCO2 of 45 or greater, with pH ranging f rom 7.24 to 7.34, consistent with mild acute respiratory acidosis. Twe nty-six patients (30%) had an episode of emesis; in 22 of these cases, the initial GCS was 8 or less. Conclusion: In our study population, p atients who overdosed on GHB presented with a markedly decreased level of consciousness. Coingestion of ethanol or other drugs is common, as are bradycardia, hypothermia, respiratory acidosis, and emesis. Hypot ension occurs occasionally. Patients typically regain consciousness sp ontaneously within 5 hours of the ingestion.