Background: Lumbar epidural blood patch (EBP) is a common treatment of post-dural puncture headache, but its effectiveness and mode of action remain a matter of debate. The aim of this study was to assess both the effectiveness and the predictive factors of failure of EBP on severe post-dural puncture headache.
Methods: This prospective observational study includes all patients treated in the authors' hospital with EBP for incapacitating post-dural puncture headache, from 1988 to 2000. The EBP effect was classified into complete relief (disappearance of all symptoms), incomplete relief of symptoms (clinically improved patients who recovered sufficiently to perform normal daily activity), and failure (persistence of severe symptoms). The following data were analyzed using a logistic regression to identify predictive factors of failure of EBP: (1) patient characteristics; (2) circumstances of dural puncture; (3) delay between dural puncture and EBP; and (4) the volume of blood injected for EBP.
Results: A total of 504 patients were analyzed. The frequency rates of complete relief, incomplete relief of symptoms, and failure after EBP were 75% (n = 377), 18% (n = 93), and 7% (n = 34), respectively. In a multivariate analysis, only the diameter of the needle used to perform dura mater puncture (odds ratio = 5.96; 95% confidence interval, 2.63-13.47; P < 0.001) and a delay in EBP less than 4 days (odds ratio = 2.63; 95% confidence interval, 1.06-6.51; P = 0.037) were independent significant risk factors for a failure of EBP.
Conclusions: Epidural blood patch is an effective treatment of severe post-dural puncture headache. Its effectiveness is decreased if dura mater puncture is caused by a large bore needle.