Acute respiratory distress following ultrasound-guided supraclavicular block.

BACKGROUND: Brachial plexus blocks have become very common for patients undergoing upper extremity surgery. We report a case in which the patient developed ipsilateral phrenic nerve paralysis and acute respiratory failure following supraclavicular nerve block. CASE REPORT: A 61-year-old female diabetic, morbidly obese patient presented for a repeat debridement of necrotizing fasciitis on her left arm. She received a left-sided supraclavicular brachial plexus block. Within a few minutes, the patient began to experience acute dyspnea, anxiety, and oxygen saturation of 90%. Breath sounds were diminished in the left hemithorax. Arterial blood gases revealed evidence of acute respiratory acidosis. The chest x-ray was normal. After induction, we intubated the patient. Subsequent arterial blood gases showed marked improvement in respiratory acidosis. We believed left phrenic nerve paralysis to be the cause of the distress. The patient was extubated in the surgical intensive care unit the following day, and infusion of ropivacaine 0.2% was started. The catheter was removed afterward secondary to its occlusion.
CONCLUSION: Phrenic nerve injury leading to respiratory distress is a rare complication of supraclavicular brachial plexus block. Anesthesiologists should be ready for emergency intubation when performing this kind of block.