Table 1.

Key anatomical structures for ultrasonography-guided regional anaesthesia safety and block success.

Peripheral nerve block region	Nerve	Artery	Serosal plane	Bone	Fascia
Interscalene-level brachial plexus block	C5 and C6 nerve roots
Upper-trunk block	Upper trunk of brachial plexus
Supraclavicular-level brachial plexus block	Trunks/divisions of brachial plexus	Subclavian artery	Pleura
Axillary-level brachial plexus block	Musculocutaneous, median, ulnar, and radial nerves	Axillary artery
Erector spinae plane block			Pleura	Transverse process
Rectus sheath block			Peritoneum		Rectus sheath
Suprainguinal fascia iliaca block		Deep circumflex iliac artery			Fascia iliaca
Adductor canal block	Saphenous nerve	Femoral artery
Popliteal-level sciatic nerve block	Sciatic nerve	Popliteal artery