Risk factors of post-dural puncture headache receiving a blood patch in obstetric patients.

Background: Post-dural puncture headache (PDPH) is one of the most frequent complications of neuraxial anesthesia and analgesia. The objective is to determine risk factors of PDPH receiving a blood patch in the obstetric population.
Methods: Between November 2009 and January 2013, 10914 women delivered in Port Royal maternity unit (Paris, France). The incidence of PDPH receiving a blood patch was calculated among those who received neuraxial analgesia or anesthesia for delivery. Then we performed a case-control study to identify risk factors for PDPH receiving a blood patch by comparing women who experienced PDPH receiving a blood patch with some women randomly selected by computer among those who delivered during the study period (4 controls for 1 case, univariate and multivariate analysis).
Results: Among the 10685 women who had neuraxial analgesia or anesthesia, 0.4% had a PDPH receiving a blood patch. In the univariate analysis, cervix dilatation ≥7 cm, lateral decubitus position during the neuraxial procedure and multiple punctures were significantly associated with PDPH receiving a blood patch, whereas maternal Body Mass Index, age, mode of delivery, performance at night and level of needle insertion were not. In the multivariate analysis, cervix dilatation ≥7 cm and multiple punctures significantly increased the risk of PDPH receiving a blood patch (odd ratios 6.5 [95% CI: 1.5-29.3] and 5.6 [95% CI: 2.2-14.0], respectively). Experience of the anesthesiologist was not associated with PDPH in both univariate and multivariate analysis.
Conclusions: In the obstetric population, a cervix dilation ≥7 cm during labor and multiple punctures are independent risk factors for PDPH receiving a blood patch.