International consensus on anatomical structures to identify on ultrasound for the performance of basic blocks in ultrasound-guided regional anesthesia

Abstract

There is no universally agreed set of anatomical structures that must be identified on ultrasound for the performance of ultrasound-guided regional anesthesia (UGRA) techniques. This study aimed to produce standardized recommendations for core (minimum) structures to identify during seven basic blocks. An international consensus was sought through a modified Delphi process. A long-list of anatomical structures was refined through serial review by key opinion leaders in UGRA. All rounds were conducted remotely and anonymously to facilitate equal contribution of each participant. Blocks were considered twice in each round: for “orientation scanning” (the dynamic process of acquiring the final view) and for the “block view” (which visualizes the block site and is maintained for needle insertion/injection). Strong recommendations for inclusion were made if ≥75% of participants rated a structure as “definitely include” in any round. Weak recommendations were made if >50% of participants rated a structure as “definitely include” or “probably include” for all rounds (but the criterion for “strong recommendation” was never met). Thirty-six participants (94.7%) completed all rounds. 128 structures were reviewed; a “strong recommendation” is made for 35 structures on orientation scanning and 28 for the block view. A “weak recommendation” is made for 36 and 20 structures, respectively. This study provides recommendations on the core (minimum) set of anatomical structures to identify during ultrasound scanning for seven basic blocks in UGRA. They are intended to support consistent practice, empower non-experts using basic UGRA techniques, and standardize teaching and research.

Evaluation of the impact of assistive artificial intelligence on ultrasound scanning for regional anaesthesia

“…Although the view is not binary (correct/incorrect) in clinical practice, the correct view in this study was based on expert interpretation of ultrasound images containing structures defined by consensus work endorsed by Regional Anaesthesia UK, the American Society of Regional Anesthesia and Pain Medicine, and the European Society of Regional Anaesthesia & Pain Therapy. 16 The acquisition and interpretation of ultrasound images, despite being an essential skill in UGRA, 1 is known to be variable, even amongst experts. 18 This exploratory study shows the potential for assistive AI technology to aid non-experts in one of the fundamental components of UGRA.…”

Assistive artificial intelligence for ultrasound image interpretation in regional anaesthesia: an external validation study

“…The structures highlighted by the AI models closely match those that an international consensus of expert opinion recommends that non-experts identify when performing these procedures. 13 Subjective expert opinion was that highlighting would reduce the risk of recognised complications in 62.9e86.2% of scans. The potential for unintentional needle trauma of a safety critical structure is another limiting factor in the practice of UGRA.…”

Core outcome set for peripheral regional anesthesia research: a systematic review and Delphi study

“…To our knowledge, this is the first COS in this area. Delphi-based methodology has been used elsewhere in recent regional anesthesia publications examining the nomenclature of regional anesthesia techniques22 and sonographic structures to be identified for basic blocks (the ‘Plan A blocks’) 23…”