Correlation of Adverse Neurological Outcomes with Increasing Volumes and Delayed Administration of Autologous Epidural Blood Patches for Postdural Puncture Headaches

Introduction: Epidural blood patches (EBPs) usually afford rapid and successful treatment outcomes for postdural puncture headaches (PDPH) with few adverse sequelae. Patients and Methods: In order to identify potential risk factors for any adverse outcomes of EBP, a Medline search, 1966 to the present, of case reports and series of any adverse outcomes following EBP for PDPH was conducted. The literature search identified 26 patient cases with 21 cases defined as adverse neurological outcomes, and further stratified as compression or noncompression syndromes, and five cases defined as persistent cranial nerve (CN) palsies. Cases were also stratified by age, sex, and blood volumes of EBP or delays in administration, and compared for statistically significant differences in continuous variables by unpaired, two‐tailed t‐tests and for significant correlations between predictor variables, including EBP volumes and delays in administration, and adverse neurological outcomes, by simple linear regression analysis. Results: There were no statistically significant sex differences in the mean ages or weights of the study population, or in the total volumes of autologous blood injected in EBPs. When the study population was compared for adverse neurological outcomes by compression or noncompression syndromes, patients experiencing compression syndromes received significantly more EBP volumes (35.36 mL) than patients experiencing noncompression (17.46 mL) syndromes (P = 0.025). Regression analysis confirmed a significant direct linear relationship between increasing EBP volumes and worsening adverse neurological outcomes (P = 0.008). In patients with CN palsies associated with PDPH and unrelieved by EBP, regression analysis again confirmed significant direct linear relationships between increasing days waited to perform EBP and increasing duration of CN palsies in months (P = 0.001). Conclusions: Epidural blood patches for the management of PDPH, especially PDPH associated with CN palsies, should be administered as soon as the diagnosis of PDPH is made with lower volumes of autologous blood (≤20 mL) to assure the best treatment outcomes.