VOLUME 37, ISSUE 2
Christian Horazeck, M.D.
Assistant Professor of Anesthesiology
Baylor College of Medicine-Temple
Senior Staff Anesthesiologist-Baylor Scott & White Medical Center-Temple
Temple, TX
An Update for the Nomenclature of Fascial Plane Blocks
The field of regional anesthesia has seen a rapid expansion in recent years due to the addition of numerous fascial plane blocks. And with the blocks came many names and acronyms. Most experts can agree what an interscalene block is; with the PECS 2, it may not be so simple. Inconsistent nomenclature has long posed challenges for education, research, and clinical practice, as studies are difficult to compare and apply. The 2021 ASRA-ESRA Delphi consensus study by El-Boghdadly et al. addressed this issue by standardizing the nomenclature for abdominal wall, paraspinal, and chest wall blocks.1 We highlight the newly standardized names and anatomical descriptions for the most commonly employed blocks: superficial parasternal intercostal plane block, interpectoral plane block, pectoserratus plane block, and the three quadratus lumborum blocks. The goal is to equip anesthesiologists with clear, unified terminology to enhance communication and patient care.
Superficial Parasternal Intercostal Plane Block
History of Names: This new term unifies many previous terms that all described the same block, including “transversus thoracis plane block”, “pecto-intercostal fascial plane block”, “parasternal PECs block”, “subpectoral interfascial plane block”, and “parasternal block”, with up to six further variations noted in the literature.
Anatomy and Technique: The superficial parasternal intercostal plane (PIP) block involves injecting local anesthetic in the plane superficial to the internal intercostal muscles and ribs, deep to the pectoralis major muscle. This targets the anterior cutaneous branches of intercostal nerves, providing analgesia for sternal or anterior chest wall procedures.
New Name Rationale: The term “superficial parasternal intercostal plane block” (95% consensus) was adopted to reflect the precise anatomical location and distinguish it from the deep PIP block. “Superficial” clarifies the injection plane relative to the intercostal muscles, and “parasternal” specifies the medial chest wall target, harmonizing previously disparate terms.
Interpectoral Plane Block
History of Names: Historically known as the “PECS I block,” this technique was introduced by Blanco in 2011 for breast surgery analgesia. The name “PECS I” (pectoral nerves block) was misleading, as it suggested nerve-specific targeting, and its relation to PECS II caused confusion.
Anatomy and Technique: The interpectoral plane block involves injecting local anesthetic in the plane between the pectoralis major and pectoralis minor muscles. This targets the medial and lateral pectoral nerves, providing analgesia for procedures that involve the pectoral muscles, such as tissue expander placement and pacemaker insertion.
New Name Rationale: The name “interpectoral plane block” (73% consensus, weak) replaces PECS I to emphasize the anatomical injection site between the pectoral muscles. This descriptive term clarifies the technique’s focus on the fascial plane, reducing confusion with PECS II and aligning with the study’s goal of anatomically precise nomenclature.
Pectoserratus Plane Block
History of Names: Previously part of the “PECS II block,” which combined a PECS I injection with a second injection deep to pectoralis minor, the PECS II name led to misconceptions that it was a single deep injection. Variants like “deep pectoralis block” added further ambiguity.
Anatomy and Technique: The pectoserratus plane block involves injecting local anesthetic in the plane between the pectoralis minor and serratus anterior muscles. This targets the lateral cutaneous branches of intercostal nerves, providing analgesia for broader chest wall or axillary procedures.
New Name Rationale: The term “pectoserratus plane block” (53% consensus, weak) was adopted to describe the second injection of the original PECS II, emphasizing the fascial plane between pectoralis minor and serratus anterior. This name enhances clarity by specifying the anatomical target, and the original PECS II is now described as a combination of interpectoral and pectoserratus plane blocks. This also allows a description of just the second component of the former PECS II.
Quadratus Lumborum Blocks (Anterior, Lateral, Posterior)
History of Names: Quadratus lumborum blocks (QLBs) have been described under multiple names, including QLB types 1, 2, 3, transmuscular, and subcostal approaches. These variations, often based on injection site or approach, led to significant nomenclature heterogeneity.
Anatomy and Techniques:
- Anterior QLB (93% consensus): Injection in the plane between the quadratus lumborum and psoas major muscles, targeting the lumbar plexus branches and providing visceral and somatic analgesia for abdominal procedures.
- Lateral QLB (80% consensus): Injection in the plane between the aponeuroses of the internal oblique and transversus abdominis muscles at the lateral border of the quadratus lumborum muscle. This targets the iliohypogastric and ilioinguinal nerves, suitable for lower abdominal analgesia.
- Posterior QLB (96% consensus): Injection in the plane between the quadratus lumborum and erector spinae muscles, on the posterior surface of the quadratus lumborum muscle, providing analgesia for hip or lower abdominal surgeries.
New Name Rationale: The terms “anterior,” “lateral,” and “posterior” QLB replace numbered or descriptive variants to reflect the anatomical injection sites relative to the quadratus lumborum muscle. The lateral QLB unified the posterior transversus abdominis plane and lateral QLB approaches, achieving clarity and consistency. These names align with the study’s emphasis on anatomically descriptive terminology, facilitating precise communication.
Implications for Practice
The standardized nomenclature addresses long-standing confusion in regional anesthesia, offering clear, anatomically descriptive terms that enhance teaching, research, and clinical application. For instance, replacing PECS I/II with interpectoral and pectoserratus plane blocks clarifies the distinct injection sites, while the QLB triad (anterior, lateral, posterior) streamlines a previously fragmented lexicon. We encourage anesthesiologists to adopt these terms in clinical documentation, academic discussions, and training programs. The consensus, supported by 60 international experts, marks a significant step toward universal language in regional anesthesia, though weak consensus on some names (e.g., pectoserratus, interpectoral) suggests areas for ongoing dialogue. The study recommends revisiting the nomenclature
every 5–10 years to incorporate new evidence.
El-Boghdadly K, Wolmarans M, et al. Standardizing nomenclature in regional anesthesia: an ASRA-ESRA Delphi consensus study of abdominal wall, paraspinal, and chest wall blocks. Reg Anesth Pain Med. 2021 Jul;46(7):571-580. doi: 10.1136/rapm-2020-102451. PMID: 34145070.
