Tehran University Medical Journal

Background: Total spinal anesthesia is a complication of lumbar epidural anesthesia following undiagnosed subarachnoid or subdural injection of local anesthetic. Although many achondroplastic dwarfs have a normal spine, catheter insertion may be more problematic with a narrow epidural space making a subarachnoid tap more probable.  Other malformations associated with achondroplasia, such as prolapsed intervertebral discs, reduced interpedicular distance, shortened pedicles, and osteophyte formation, combined with a narrow epidural space may make identification of the space difficult and increases the risk of dural puncture. Furthermore, subarachnoid tap or dural puncture may be hard to recognize if a free flow of CSF is difficult to achieve due spinal stenosis. Yet, for those who meet the criteria, epidural regional anesthesia is frequently preferred over other forms, which often have more or more dangerous side effects in this type of patient.

Case report: A 22-year-old achondroplastic male dwarf patient was scheduled for pelvic mass resection and was considered a candidate for continuous epidural anesthesia. The anesthesia became complicated by total spinal anesthesia, which was reversed following supportive management for about two hours.

Conclusion: There is significant debate over the composition and volume of the test dose, especially for patients with achondroplasia. We nevertheless recommend repeated test-doses during the accomplishment of epidural anesthesia to exclude unintended intravascular, intrathecal or subdural injection, keeping in mind that a test dose of local anesthetic does not completely prevent complications.