The yield of head CT in syncope: a pilot study

Although head CT is often routinely performed in emergency department (ED) patients with syncope, few studies have assessed its value. Objectives: To determine the yield of routine head CT in ED patients with syncope and analyse the factors associated with a positive CT. Methods: Prospective, observational, cohort study of consecutive patients presenting with syncope to an urban tertiary-care ED (48 000 annual visits). Inclusion criteria: age >= 18 and loss of consciousness (LOC). Exclusion criteria included persistent altered mental status, drug-related or post-39%trauma LOC, seizure or hypoglycaemia. Primary outcome was abnormal head CT including subarachnoid, subdural or parenchymal haemorrhage, infarction, signs of acute stroke and newly diagnosed brain mass. Results: Of 293 eligible patients, 113 (39%) underwent head CT and comprise the study cohort. Ninety-five patients (84%) were admitted to the hospital. Five patients, 5% (95% CI=0.8%-8%), had an abnormal head CT: 2 subarachnoid haemorrhage, 2 cerebral haemorrhage and 1 stroke. Post hoc examination of patients with an abnormal head CT revealed focal neurologic findings in 2 and a new headache in 1. The remaining 2 patients had no new neurologic findings but physical findings of trauma (head lacerations with periorbital ecchymoses suggestive of orbital fractures). All patients with positive findings on CT were >65 years of age. Of the 108 remaining patients who had head CT, 45 (32%-51%) had signs or symptoms of neurologic disease including headache, trauma above the clavicles or took coumadin. Limiting head CT to this population would potentially reduce scans by 56% (47%-65%). If age >60 were an additional criteria, scans would be reduced by 24% (16%-32%). Of the patients who did not have head CT, none were found to have new neurologic disease during hospitalisation or 30-day follow-up. Conclusions: Our data suggest that the derivation of a prospectively derived decision rule has the potential to decrease the routine use of head CT in patients presenting to the ED with syncope.