The Function of Computerized Tomography Head Scans in the Assessment of Patients Who Present with Drug Overdose and a Low Glasgow Coma Scale

Abstract

Background: Drug overdose is a common emergency medical presentation, with most patients presenting with reduced consciousness and a low Glasgow Coma Scale (GCS). Despite there are no guidelines, anecdotal evidence suggests that clinicians often perform computerized tomography (CT) head scans on these patients. While CT imaging is readily available and gives immediate information, we question the functionality of this test and aim to evaluate its place in the management of overdose patients presenting with a low GCS. Methods: We conducted a retrospective database search at the Northern General Hospital, of a 25-month period, to identify patients attending the emergency department with a reduced GCS due to a drug overdose. Data were subsequently collected and analyzed. Results: Our study cohort numbered 114 patients, 48 males and 66 females, with a mean age of 40 years (SD±15). The median GCS on admission was 3 (interquartile range [IQR] 3–10) and 63 (55%) received a CT head scan. However, only 4 (6%) scans were reported as abnormal. Previous overdose attempts were noted for 57 (50%) patients and 90 (79%) had a history of mental health disorder. The most frequently used drugs were amitriptyline in 21 (18%) cases, diazepam in 17 (15%), and paracetamol in 13 (11%). Further, 37 (32%) involved alcohol and 72 (63%) patients took a mixed overdose. Median inpatient length of stay was 2 days (IQR 1–5) and 5 (4%) patients died in hospital. Conclusion: Our data demonstrate a low diagnostic yield from CT head scans in this patient population, and therefore, we suggest that clinicians consider the risk versus benefit of conducting this scan. While management decisions are multifactorial, it appears that CT head scans are of limited value when performed routinely. These findings warrant further studies with the aim of providing definitive guidelines for the management of this patient’s population.