A Near Total Spinal Anesthetic Following a Test Dose Prior to an Epidural Blood Patch

Abstract

To the Editor: We report a case of an unusually high neuraxial block following a test dose of local anesthetic prior to an epidural blood patch. A 36-yr-old woman Para 1 (weight 81 kg; height 162 cm) had an accidental dural puncture at L3–4 spinal interspace during initiation of epidural analgesia for labor pain. The epidural needle was reinserted at L2–3 interspace and the patient had an uneventful epidural analgesia for labor and delivery and was discharged home 2 days later. Three days after the dural puncture, the patient complained of severe postdural-puncture headache. She was offered and agreed to have a blood patch. With the patient in the lateral decubitus position, a Touhy needle was easily inserted into the epidural space at L3–4 interspace using loss-of-resistance to air technique, followed by a 3 mL 3% 2-chloroprocaine test dose. A bilateral sensory loss at T10–12 with no motor deficit was present 5 min after injection. Twenty milliliter of autologous blood was withdrawn in a sterile manner, injected into the epidural needle; the needle was removed and she was turned to the supine position. Two minutes later, the patient complained of shortness of breath, asked to sit up and started using accessory upper respiratory muscles. While sitting, her vital signs were: HR 66 BPM, BP 92/50 mm Hg, Spo2 96% with sensory loss from C5 to S5 bilaterally. She had bilateral weak hand grip and stated that she could breathe better sitting up. She was transferred to the postanesthesia care unit for observation. An hour later, she recovered completely, her headache had disappeared, and she was sent home 6 h later. We hypothesize that some of the local anesthetic entered the subarachnoid space via the dural puncture during the injection of the test dose, as well as via diffusion and was distributed to a wider area by the epidural blood patch that further reduced CSF volume.1 Total spinal anesthesia has been reported after a prophylactic blood patch was performed before resolution of epidural anesthesia in the presence of a large dural hole.2 We used the test dose because verifying the correct position of the epidural needle before injecting the blood significantly increased our success rate. However, after this incident, we now verify the correct position of the epidural needle prior to blood patching using the gravity technique.3 An IV extension tubing filled with saline is attached to the needle and observed for fluctuation of the fluid level with each heart beat. We suggest that blood patching should be delayed until a patient completely recovers from a neuraxial block, and that no local anesthetic should be administered immediately before the blood patch. Shaul Cohen, MD Maria Negron, MD UMDNJ-Robert Wood Johnson Medical School New Brunswick, New Jersey [email protected]