Is Unilateral Vocal Fold Paralysis a Rare Complication of Spinal Anesthesia? A Case Report

Abstract

A 47 year old woman underwent an open reduction and internal fixation of a left ankle fracture under spinal anesthesia. In the recovery room, she noticed a sudden onset of dysphonia. Fiberoptic examination revealed an immobile right vocal fold. Her symptoms gradually improved over the next few weeks with conservative treatment. By the eighth week, her voice had returned to normal. Anesthesiologists should be aware that dysphonia that develops immediately or shortly after spinal anesthesia may represent a unilateral vocal fold paralysis (VFP).Keywords: Vocal fold paralysis; Hoarseness; Dysphonia; Vagus nerve; Cranial neuropathy; Recurrent laryngeal nerve; Abducens nerve; Intracranial hypotension; Spinal anesthesia complications Case ReportA 47 year old woman underwent an open reduction and internal fixation of a left posterior pilon (tibia) and fibula fracture. The patient refused general anesthesia and intubation because she had undergone a partial cricotracheal resection for subglottic stenosis seven years earlier. Her only symptom at that time was dyspnea. She had never been previously intubated; she had not experienced any changes in her vocal quality or strength. The cause of her subglottic stenosis was considered to be idiopathic. Her cricotracheal resection had been performed successfully and she had normal vocal fold function postoperatively. The patient was 58 kg and 173 cm in height. She was ASA Class II, not a diabetic, and a nonsmoker. She had no history of neuritis, neuropathies, inflammatory conditions, recent vaccinations, or any recent upper respiratory infections. Past surgical history included a cesarean section under epidural anesthesia and a breast augmentation under local anesthesia. Medications included vitamins, calcium, fish oil, and magnesium.The patient was consented for a spinal anesthetic with peripheral nerve blocks for postoperative pain management. After intravenous sedation with three milligrams of midazolam, the patient was placed into a sitting position for the spinal anesthetic. A 25 gauge pencil-point needle was used to place the spinal block at the L3-4 interspace. On the first attempt, in an atraumatic fashion, the patient received twelve milligrams of hyperbaric bupivacaine. The patient was returned to a supine position and five milligrams of ephedrine was given when there was an initial decrease in mean arterial pressure from 85 to 70 mmHg. The spinal block produced a surgical level block to T4. An ultrasoundguided saphenous nerve block was performed utilizing 10 mL of 0.25% bupivacaine.The patient was placed into the prone position. All pressure points were well-padded, avoiding hyperextension and hyperflexion of the neck and shoulders. During positioning the patient spoke in a normal manner and stated that she was comfortable. Intravenous sedation consisted of propofol at a rate of 50-75 mcg/kg/minute and a total of three milligrams of midazolam and 500 mcg of fentanyl were administered incrementally.At the completion of the three hour surgery, the patient receive...