To the Editor:—
We read with interest the article by Safa-Tisseront et al. 1reporting their experience on epidural blood patch (EBP), and would like to comment with regard to obstetric anesthetic practice. These authors reported that large diameter needles (less than 20 gauge) and a short time interval between dural puncture and blood patching (fewer than 4 days) independently predicted failure of EBP. Therefore, considering needle diameter, one must note that only 68 patients (13%) were really at risk of failure, as they underwent dural punctures with Tuohy needles (17–18 gauge). This fact likely contributed to the high success rate of a single EBP reported in the study. It can also explain why only 3.7% of the patients required a second EBP. As spontaneous relief is the natural outcome of postdural puncture headache (PDPH) when small diameter needles are involved, 2we can consider that the CSF leak may decrease over time, therefore supporting a lapse of time before performing EBP. This is also probably a strong factor of efficacy if EBP is performed at least 4 days after the dural puncture, assuming that 87% of patients in the study had undergone diagnostic or therapeutic lumbar punctures with small gauge needles.
However, despite the threshold lapse of 4 days, as shown in the study, Safa-Tisseront et al. 1did not recommend to delay EBP. This message is very important for obstetric anesthesiologists, although a higher failure rate must be expected after a single EBP. In our experience of 21 consecutive cases of PDPH complicating epidural procedures with 17 gauge needles, all but one patient had an EBP within 4 days, including 15 women who had their EBP within the first 2 days. Ten patients required a second EBP for headache relief on the day after the first EBP, because although they had experienced complete relief, the effect was transient. Several points are in favor of early EBP. Indeed, given that PDPH are usually severe and incapacitating in obstetric patients and prevent women from taking care of their newborns, given that the delay of an effective treatment makes the patient depressive andtheir family aggressive, and finally, given the low morbidity of EBP, confirmed by the authors, we believe that, at least in the obstetric setting, EBP should be performed as soon as possible and should not be delayed. We therefore strongly support Quaynor and Corbey's assertion:3“Epidural blood patch: why delay?”. Furthermore, obstetric patients undergoing EBP and their families should be informed of the fact that PDPH relief is sometimes transient, and that a second EBP might be required.
