Person:

Zimetbaum, Peter

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 >8 and loss of consciousness (LOC). Exclusion criteria included persistent altered mental status, drug-related or post-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.

Background: The emergency department diagnosis of sinus versus nonsinus tachycardia is an important clinical challenge. The objective of this study was to identify subjects with a high prevalence of nonsinus tachycardia. Methods: Heart rate and cardiac rhythm were prospective reviewed in 500 consecutive patients with heart rate ≥ 100 beats/min in a busy emergency department. A predictive model based on age and heart rate was then developed to identify the probability of nonsinus tachycardia. Results: As age and heart rate increased, nonsinus tachycardias became more frequent. The probability of nonsinus tachycardia in a subject ≥ 71 years with heart rate ≥ 141 beats/minute was 93%, compared to only three percent in a subject ≤ 50 years with heart rate 100–120 beats/minute. A simple point score system based on age and heart rate helps predict the probability of sinus tachycardia versus nonsinus tachycardia. Conclusion: Nonsinus tachycardia is significantly more common than sinus tachycardia in elderly patients in the emergency department. The diagnosis of sinus tachycardia becomes much less likely as age and heart rate increase.