Comparison of CSF Lactate and Serum Procalcitonin in Diagnosing Pyogenic Meningitis

Background: Meningitis, a potentially life-threatening inflammation of the meninges, poses diagnostic challenges, particularly in differentiating bacterial meningitis (BM) from other forms. The identification of effective biomarkers is crucial for accurate diagnosis and treatment. Objective: This study aimed to evaluate the diagnostic utility of cerebrospinal fluid (CSF) lactate levels and serum procalcitonin (PCT) in distinguishing BM from tuberculous and viral meningitis. Methods: Conducted at the Neurology Department of Pak Emirates Military Hospital from February to May 2023, this observational study included 55 patients, with a mean age of 44.03 years. Patients were selected based on clinical signs and symptoms of meningitis, with those having received prior antibiotic treatment excluded. CSF and serum PCT levels were measured, and statistical analyses were performed to compare these biomarkers across different meningitis etiologies. Results: Of the 55 patients, 30 (54.50%) were diagnosed with BM, 15 (27.30%) with viral meningitis, and 10 (18.20%) with tuberculous meningitis. The mean CSF lactate level in BM patients was 9.36 ± 7.95 mmol/L, significantly higher than in non-bacterial cases. Similarly, serum PCT levels were markedly elevated in BM patients (24.05 ng/ml ± 39.82 ng/ml). The study found a strong correlation between elevated CSF lactate and serum PCT levels with the diagnosis of BM (P < 0.05). Conclusion: CSF lactate levels and serum PCT are reliable biomarkers for diagnosing BM. Their elevated levels in BM patients compared to those with tuberculous or viral meningitis can assist in accurate and timely diagnosis, contributing to improved patient outcomes and effective antibiotic stewardship.