J Korean Soc Emerg Med.  2018 Aug;29(4):371-379. 10.0000/jksem.2018.29.4.371.

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

• Kim K
• Park SO
• Kim JW
• Lee KR
• Hong DY
• Baek KJ
• Kim SY
• Kim JY

• KMID: 2435489
• DOI: http://doi.org/10.0000/jksem.2018.29.4.371

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 < 3.9 mEq/L) and NLR were assessed. The sensitivity and specificity of these tools for detecting or ruling out SAH was calculated.
RESULTS
Among the 1,230 patients enrolled in this study, 299 (24.3%) were diagnosed with SAH. To predict SAH, the Ottawa SAH rule offered 100% sensitivity but 31.6% specificity. Applying the EMERALD SAH rule to patients positive for the Ottawa SAH rule led to 92.6% sensitivity and 48.0% specificity. As the NLR alone showed less efficacy with the area under curve of 0.696 by receiver operating analysis, NLR (>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.

Keyword

Subarachnoid hemorrhage; Headache; Differential diagnosis

MeSH Terms

Adult
Area Under Curve
Blood Glucose
Blood Pressure
Diagnosis, Differential
Emergencies*
Emergency Service, Hospital*
Hand
Headache Disorders, Primary
Headache*
Humans
Learning
Neck
Neck Pain
Potassium
Retrospective Studies
Sensitivity and Specificity
Subarachnoid Hemorrhage*
Unconsciousness
Potassium