Bilateral hypoglossal nerve palsy and unilateral recurrent laryngeal nerve palsy following lumbar discectomy: A case report.
Having started with depositing 5 ml of bupivacaine 0.5% around each nerve, the 1 ml per nerve volume was reached by the fifth recruited patient. Successful surgical anaesthesia was accomplished in the next eight consecutive patients with the same volume. No immediate adverse event related to the nerve blocks, that is vascular injury or signs of local anaesthetic toxicity, was noted. Sensory block onset times (median value and interquartile range) for musculocutaneous, median, ulnar and radial nerves were 10 (5 10) 10 (5 20) 10 (5 15) and 10 (5 20) min, whereas motor block onset times were 10 (5 10) 15 (10 15) 10 (10 15) and 10 (5 15) min, respectively. All but one nerve of the entire study group were fully anaesthetised within 45 min of completion of the ABPB block. The outlier was the motor block in the median innervation territory of one patient (who got 1 ml of bupivacaine 0.5% with an onset time of 55 min. At that point, however, the patient had surgical anaesthesia of the entire forearm and the operation was uneventful under regional anaesthesia alone. The prolonged onset time could have been the consequence of an anatomical variation as branches have been described far away from the most visible main tract. Uneven local anaesthetic distribution could also delay the development of the block. All patients had adequate surgical anaesthesia without any discomfort in the surgical field. No patient requested intraoperative sedation. One patient (1 ml per nerve bupivacaine 0.5% used) experienced slight tourniquet pain 60 min after cuff inflation, which was successfully treated with 100 mcg of intravenous fentanyl. Tourniquet pain is not uncommon with higher doses of local anaesthetic; therefore it is unlikely to be a direct consequence of the low dose of local anaesthetic used.
European journal of anaesthesiology