Study Status: Completed
Recruit Status: Completed
Study Type: Interventional
Official Title: Investigation Into the Effect of 0.25% Bupivacaine for Interscalene Peripheral Nerve Block vs 0.125% Bupivacaine on Pulmonary Function
Brief Summary: Peripheral nerve blocks are used to provide post-operative pain relief. Nerve blocks in the neck, in the interscalene area, provide pain relief after shoulder surgery but can cause temporary weakness or paralysis of the diaphragm. The investigators hypothesized that a lower concentration of bupivacaine would cause less weakness of the diaphragm but still provide good pain relief. Lung function and pain control was studied after interscalene peripheral nerve block with 20 milliliters of 0.25% bupivacaine or 0.125% bupivacaine.