Therapeutic epidural blood patch in obstetric patients over ten years

Background In previous studies, the efficacy of epidural blood patch (EBP) ranged between 33% [6] and 93% [4]. We did an observational prospective study to evaluate the efficacy and morbidity of EBP in an inpatient population. Materials and Methods: This study included all the obstetric patients who underwent EBP from 1997 to 2006. Results and Discussion: Over ten years, 15,384 analgesic/anaesthetic epidurals were performed (80% of all deliveries). One hundred wet taps (0,6%) were detected, 72 of which developed PDPH. Twenty-six patients (36%) needed EBP. Mean interval±SD from wet tap to EBP was 6.1±3.1 days. We performed EBP mostly between day 4 and 5. EBP performed over day 5 were due to the refusal of the patient or when moderate/mild PDPH presented a torpid evolution. Mean injected volume±SD was 19.0±1.5 ml. EBP was totally effective in 22 patients (85%), partially effective in 3 (11%) and ineffective in 1 patient, who needed a second EBP. No recurrences were registered. At 24 hours, 10 patients (28%) had lumbar pain, which in 2 (8%) persisted after one week. No other complications were registered. Conclusion(s): We speculate that the high efficacy of the EBP and the non recurrence of PDPH in our population might be attributable to the conjunction of three factors: the EBP performed always >72 hours after the wet tap, the volume of blood injected (aprox. 20 mL), and the 2-4 hours mandatory rest.