Ultrasound-guided interscalene brachial plexus block performed at the level of root C7 using 10 mL of ropivacaine 0.75% reduces the incidence of hemidiaphragmatic paresis.

Ultrasound-guided supraclavicular brachial plexus block, using 20 mL of 0.75% ropivacaine with the described technique, is not associated with hemidiaphragmatic paresis.

The minimum effective volume of local anesthetic for shoulder analgesia for a US-guided block at the C7 root level in 50% and 95% of the patients was 2.9 and 3.6 mL, respectively. Pulmonary function was unchanged until 2 hrs after completion surgery, but reduced 22 hrs after start of a continuous infusion of ropivacaine 0.2%.

An US-guided in-plane PhNB with catheter is feasible and avoids repeated PhNB when hiccups reoccur. Ultrasound investigation of the bilateral diaphragm should be performed before performing the nerve block.

The vertical infraclavicular approach provides a more complete block than the axillary approach when using a single injection technique and equal volumes/doses of local anaesthetic.