Respiratory Failure After Unilateral Shoulder Arthroplasty: A Telltale of Interscalene Block Complication

Phrenic nerve palsy is a common complication of interscalene block (ISB), which is usually found incidentally and is typically asymptomatic when affecting only the unilateral side. However, underlying lung diseases like sleep apnea can manifest as respiratory failure. We present a case of a 73-year-old woman with a history of sleep apnea who was found to have acute hypoxic hypercarbia respiratory failure and was found to have right-sided diaphragm paralysis due to ipsilateral phrenic nerve injury.