Ultrasound-Guided Epidural Blood Patch

Editor, Ultrasound-guided epidural blood patch Epidural blood patch (EBP) is the gold standard for treatment of postdural puncture headache (PDPH).1 Physicians, even those who are experienced, may nevertheless worry when performing an epidural patch about the depth and the difficulty of identifying the epidural space. In addition, the blood patch has to be repeated in some patients because of persisting PDPH for unknown reasons. Ultrasound imaging now makes it possible to precisely localize the epidural space2 and could be a valuable support when performing an EBP. We, therefore, report a case of ultrasound-guided blood patch for PDPH. Case report A 38-year-old, American Society of Anesthesiologists I (ASA I) woman, height 174 cm, weight 72 kg, was scheduled for right knee arthroscopy. Her medical history included two epidural anaesthetics without any problems, for pain relief during labour. The patient agreed to undergo spinal anaesthesia for the arthroscopy. In the operating theatre, the lumbar puncture was performed in the sitting position, at the L5–S1 interspace with a 25-gauge, short bevel spinal needle and a free cerebrospinal fluid (CSF) flow was obtained at the first attempt. Hyperbaric bupivacaine 10 mg was injected and the patient was placed in the right lateral decubitus position. The morning after surgery, she complained of postural, bilateral, frontoparietal headache that worsened over the next 2 days, leading to the decision to perform an EBP. The patient was placed in the sitting position and an M-Turbo (Sonosite Inc., Bothell, Washington, USA) ultrasound system equipped with a 2–5 MHz linear array probe was used for the first scout scan in the transverse plane at the L5–S1 interspace. Neuroaxial structures were identified, and the depth of the epidural space was measured at 5.69 cm from the skin. No dural hole was documented when checking the posterior dura mater at the lumbar level. The puncture point was marked with a dermographic pen. After disinfection, and local infiltration with 1% lidocaine, an epidural needle (Tuohy G 17, Braun) was inserted in the sagittal plane using the standard ‘loss-of-resistance’ technique. Simultaneously, sterile sleeves and ultrasound gel were used for the transducer that was operated by another practitioner, and real time monitoring of the Tuohy needle advancing into the epidural space was performed in the longitudinal plane and median access. An autologous venous blood sample was withdrawn from an antecubital vein and slowly injected into the epidural space through the Tuohy needle at a rate of 0.5 ml s−1. The injection was stopped after 28 ml because the patient had back pain. A slight anterior displacement of the posterior dura and widening of the epidural space were effective (Fig. 1) and extension of the blood patch was documented from the middle of the L5 to the middle of the S1 vertebral bodies. The patient experienced complete pain relief, recovered daily activity, and was discharged on the following day.Fig. 1Discussion Paramedian and median approaches have been used to document epidural anatomy.2,3 Ultrasonography has enabled the safe application of a blood patch by precise localization of the epidural space depth and control of needle progression. A satisfactory preliminary experience has also been reported by Grau et al.4 in four patients. In addition, ultrasound guidance allowed not only the path of the needle to be followed, but also the injection of the blood sample to be controlled, checking for its distribution in the epidural space. We, thus, recommend that ultrasonography of the epidural space should be used more commonly when performing an EBP in order to control the procedure and ensure its safety.