Two Cases of Respiratory Insufficiency Secondary to Pre-procedural Nerve Blocks for Upper Extremity Injuries.

Interscalene nerve blocks are common procedures performed before upper extremity surgeries in order to provide post-op pain relief and improve recovery time. Here we present two cases of patients who underwent a unilateral supraclavicular and bilateral interscalene nerve block, respectively. The first patient had no risk factors but the second presented with a body mass index of 45.5 and a history of symptoms consistent with obstructive sleep apnea but never diagnosed. Both patients experienced some form of respiratory distress diagnosed via changes in chest x-ray and clinical presentation. The mechanism of injury that occurs in these procedures is typically from inadvertent damage to the phrenic nerve. Mild adverse effects in interscalene nerve block are relatively common. However, there is minimal data in regards to performing bilateral interscalene nerve blocks. The purpose of this study is to highlight that severe complication in both high and low-risk patients can occur but may be reduced with a safer approach and more effective communication among multidisciplinary team members.