Cranial Computed Tomography, Lumbar Puncture, and Clinical Deterioration in Bacterial Meningitis: A Nationwide Cohort Study

Background. It is unclear how often lumbar puncture (LP) is complicated by cerebral herniation in patients with bacterial meningitis and whether cranial computed tomography (CT) can be used to identify patients at risk for herniation. Methods. We performed a nationwide prospective cohort study of patients with community-acquired bacterial meningitis from 2006 to 2014 and identified patients with clinical deterioration possibly caused by LP. For systematic evaluation of contraindications for LP on cranial CT, these patients were matched to patients in the cohort without deterioration. Four experts, blinded for outcome, scored cranial CT results for contraindications for LP. A Fleiss' generalized kappa for this assessment was determined. Results. Of 1533 episodes, 47 (3.1%) had deterioration possibly caused by LP. Two patients deteriorated within 1 hour after LP (0.1%). In 43 of 47 patients with deterioration, cranial CT was performed prior to LP, so CT results were matched with 43 patients without deterioration. The interrater reliability of assessment of contraindications for LP on cranial CT was moderate (Fleiss' generalized kappa = 0.47). A contraindication for LP was reported by all 4 raters in 6 patients with deterioration (14%) and in 5 without deterioration (11%). Conclusions. LP can be performed safely in the large majority of patients with bacterial meningitis, as it is only very rarely complicated by cerebral herniation. Cranial CT can be considered a screening method for contraindications for LP, but the interrater reliability of this assessment is moderate.