What factors determine the need for lumbar puncture in patients with fever and headache?

We performed this study to find clinical features and laboratory parameters that could facilitate the process of selecting patients who should receive lumbar punctures from among those who present with headache and fever.

We selected patients aged ≥ 16 years who presented to and received lumbar puncture in the emergency department of Kangwon National University Hospital, South Korea, between 2011 and 2013. Patients who received lumbar punctures were divided into two groups - those who were diagnosed with viral meningitis and those who were not. We compared the clinical features and laboratory data between the two groups. Key indices were then used to develop a scoring system to diagnose viral meningitis in patients and identify those who should receive lumbar punctures.

Among the patients who were included in the study, 42 had viral meningitis and 96 did not. The variables of C-reactive protein level ≤ 1.291 mg/dL, neck stiffness and vomiting were assigned 3 points, 2 points and 1 point, respectively, in the scoring system. Overall scores ≥ 4 yielded a positive likelihood ratio of 7.79 (sensitivity 0.600, specificity 0.923), while negative likelihood ratio decreased to less than 0.1 (0.072) for overall scores < 3.

Using the proposed scoring system, we were able to determine the likelihood of viral meningitis in patients presenting with fever and headache, and to successfully identify those who should receive lumbar punctures.