Is volume of injectate the appropriate end point for injection of blood in epidural blood patch?

We read with interest the recent Obstetric Anaesthetists Association (OAA) guidelines pertaining to the diagnosis and management of post-dural puncture headache (PDPH).1 The OAA guideline states “a volume of blood of 20 mL is recommended when performing an epidural blood patch (EBP) and injection should stop before 20 mL if not tolerated by the patient”. This statement gives the impression that 20 mL represents an optimum endpoint for injecting blood during EBP. Our local practice is to use patient symptoms (back discomfort) as the endpoint and hence we often exceed a volume of 20 mL.
Source: International Journal of Obstetric Anesthesia - Category: Anesthesiology Authors: Tags: Correspondence Source Type: research