Severe respiratory failure secondary to unilateral phrenic nerve injury: A case report

Patients with unilateral phrenic nerve paralysis are usually asymptomatic at rest. We present a 77-year-old woman with a chest wall osteoarthropathy associated with synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome that developed severe hypercapnic respiratory failure following cryoballoon ablation for the management of atrial fibrillation. Her right phrenic nerve injury (PNI) was confirmed by chest radiography, phrenic nerve conduction studies, and diaphragmatic ultrasonography. We conclude that unilateral PNI during ablation invalidated the diaphragmatic compensation for pre-existing reduced thoracic expansion, resulted in severe hypoventilation. Clinicians should be careful of the fact even unilateral PNI could cause catastrophic respiratory failure in patients with restricted thoracic expansion.