Efficacy of neutrophil-lymphocyte ratio and clinical predicting indexes on differentiating subarachnoid hemorrhage from acute headache patients at emergency department

ABSTRACT

OBJECTIVE: This study evaluated the clinical usefulness of the neutrophil-lymphocyte ratio (NLR), Ottawa subarachnoid hemorrhage (SAH) rule and EMERALD (Emergency Medicine, Registry Analysis, Learning and Diagnosis) SAH rule for predicting SAH in patients with acute headache. METHODS: This clinical retrospective study was conducted at an urban emergency department between January 2008 and December 2017. Alert, neurologically intact adult patients with acute headache were included. All data were drawn from electrical medical charts. The Ottawa SAH rule (positive if any of age ≥40, neck pain, loss of consciousness, onset during exertion, thunderclap headache, and neck stiffness), EMERALD SAH rule (positive if any of systolic blood pressure >150 mmHg, diastolic blood pressure >90 mmHg, serum glucose >115 mg/dL, or serum potassium 2.1) was added to the last step to have achieve 99.0% sensitivity and 56.7% specificity. CONCLUSION: The stepwise application of the Ottawa, EMERALD SAH rule, and NLR increased the specificity compared to each application. On the other hand, further studies will be needed to increase the sensitivity.