Comparison 1 Plane-2 Injection and 2 Plane-2 Injection Ultrasound-guided Supraclavicular Brachial Plexus Block

A Randomized Comparison Between 1 Plane-2 Injection and 2 Plane-2 Injection Ultrasound-guided Supraclavicular Brachial Plexus Block (US-SCBPB) in Upper Extremity Surgery

The supraclavicular block can provide effective surgical anesthesia of the forearm and hand. There have been many different approaches to ultrasound-guided supraclavicular brachial plexus block (US-SCBPB) according to the needle injection site (e.g. corner pocket approach, cluster approach) or number of needling (single or double injection). Numerous studies demonstrates good results (e.g. faster onset time) when using double injections rather than single injection. But double injection does not guarantee complete sensory block because ulnar nerve tends to be spared by its anatomical location.

The investigators hypothesized that double injection in different plane (we call this new approach as a 2 plane-2 injection approach;2P2I) would overcome the weakness of the existing double injection in same plane (we call this approach as a 1 plane-2 injection approach;1P2I) like "ulnar nerve sparing effect", and could have a good results (e.g. shortening the onset time or increasing rate of all four nerves block). Because 2P2I can achieve an effect of a "tridimensionally administered LA", rather 1P2I only achieve an effect of a " two-dimensionally administered LA".

Inclusion Criteria:

• all patients anticipating surgery of the wrist or hand
• age: 18 to 80 years
• American Society of Anesthesiologists physical status (ASA): I or II

Exclusion Criteria:

• neuropathy in the operated limb
• ASA greater than III
• coagulation disorders
• known allergy to local anesthetics
• local infection at the puncture site
• chronic obstructive pulmonary disease or respiratory failure
• pregnancy or breast-feeding
• prior surgery in the supraclavicular region
• BMI ≥ 35 kg/㎡
• uncooperative patients
• patients' refusal