Phrenic Nerve Block on Severe Post‐hepatectomy Shoulder Pain: A Randomized, Double‐blind, Placebo‐controlled, Pilot Study

Severe shoulder pain occurs frequently after surgery close to the diaphragm, potentially caused by referred pain via the ipsilateral phrenic nerve. We aimed to assess the analgesic effect of an ultrasound‐guided phrenic nerve block on moderate to severe right‐sided shoulder pain after open partial hepatectomy.