Regional Anesthesia Management in a Fontan Patient Presenting for Ambulatory Shoulder Surgery: A Case Report.

Interscalene blocks, commonly used for shoulder surgery analgesia, often cause transient phrenic nerve palsy, leading to hemi-diaphragmatic paresis. This complication is particularly problematic in patients with pulmonary comorbidities and has been extensively investigated. However, its impact on patients with Fontan physiology remains less understood with limited representation in the literature. Hemi-diaphragmatic paresis can significantly reduce negative pressure spontaneous ventilation, leading to decreased venous return and increased pulmonary vascular resistance, which critically affects cardiac output. This case report explores regional anesthesia management in a Fontan patient undergoing shoulder surgery, emphasizing the suprascapular nerve block as an effective alternative for ambulatory patients.