Risk of Spinal Haematoma after Lumbar Puncture: A Population-Based Cohort Study

Abstract

Background: Risk of spinal haematoma following lumbar puncture in patients with abnormal coagulation status remains unclear and may deter physicians from performing the procedure. Methods: We accessed nationwide, population-based medical registries to examine the risk of spinal haematoma in patients with coagulopathy (thrombocytopenia 1·4, or activated partial thromboplastin time [APTT] >39 seconds) at time of lumbar puncture in Denmark from 2008 to 2019. Next, we reviewed the medical records of all such patients in North Denmark Region from 1998 through 2018. Risks are provided as counts and percentages with 95% confidence intervals (CI). Adjusted hazard rate ratios (HRRs) were computed using Cox regression models. Findings: Using medical registries, we identified 83,711 lumbar punctures in 64,730 individuals. At time of the procedure, thrombocytopenia was present in 7,875 patients, high INR in 1,393 patients, and prolonged APTT in 2,604 patients. Spinal haematoma occurred within 30 days in 143/83,711 lumbar punctures yielding an overall risk of 0·17% (95% 0·14-0·20) compared with 0-0·33% among patients with coagulopathy. Independent risk factors for spinal haematoma were male sex (HRR 1·75 [95% 1·18-2·61]) and age group 61-80 years (HRR 2·41 [95% 1·20-4·84]). Results remained unchanged in subgroup analyses by paediatric specialty, medical indication, and cumulative number of procedures. Overall risk of traumatic lumbar puncture (>300 x 106 erythrocytes /L) was 27·8% and was increased in some subgroups of patients with coagulopathy (range 22·6-44·0%). Medical record review of 1,694 lumbar punctures in patients with coagulopathy uncovered one case (0·06%) of spinal haematoma in a thrombocytopenic patient. Interpretation: Risk of spinal haematoma after lumbar puncture is small and without substantial increases among patients with coagulopathy. These results offer clinicians a firm basis to proceed with a lumbar puncture, if needed, regardless of coagulopathy in patients with serious medical conditions. Funding Statement: None. Declaration of Interests: All authors declare no conflicts of interests. Ethics Approval Statement: The study was approved by the legal representatives of North Denmark Region (2018-45) and the Danish Board of Health (3-3013-2477/1).