Accidental subdural anesthesia after epidural puncture

case report

Abstract

Epidural anesthesia is a widely performed procedure worldwide, for its safety and benefits offered. The subdural space is located between the arachnoid and dura mater membranes, as a virtual space. The accidentaly puncture from subdural space is rare. The purpose of this report is to demonstrate a case of subdural block during a surgical procedure for correction of incisional hernia, whose anesthetic technique was epidural anesthesia. The lumbar puncture was performed without intercurrences. A test dose of lidocaine with epinephrine was performed and then administered Bupivacaine, fentanyl and morphine. The patient evolved with desired anesthesia, presenting hemodynamic stability. During the surgical procedure, the patient presented a decrease in saturation, lowering of the level of consciousness, opting for orotracheal intubation. Ending the procedure, extubation was chosen. The patient remained in the recovery room post anesthetic hemodynamically stable, with preserved consciousness level and satisfactory oxygen saturation. Subdural block is a rare occurrence complication. The clinical findings of this entity were classified into major and minor criteria. The major criteria are: negative aspiration test for cerebrospinal fluid; or unexpectedly extensive sensory block following epidural injection. Minor criteria are: late onset for a sensory or motor nerve block; variable motor block despite the use of low doses of Bupivacaine; or sympathetic block disproportionate to the dose of local anesthetic administered. If both major criteria and one of the minor criteria are present, consider subdural block. The possibility of subdural block was raised because there was extensive sensory / motor blockade, with negative aspiration of cerebrospinal fluid and late onset of blockade. Supporting treatment was instituted, with hemodynamic monitoring, ventilatory support and follow-up to evaluate any possible complications. Although it is a rare complication of epidural blockade, subdural anesthesia may occur and its recognition and proper management is necessary.