Regional anaesthesia truncal blocks for acute postoperative pain and recovery: a narrative review

Significant acute postoperative pain remains prevalent among patients who undergo truncal surgery and is associated with increased morbidity, prolonged patient recovery, and increased healthcare costs. The provision of high-quality postoperative analgesia is an important component of postoperative care, particularly within enhanced recovery programmes. Regional anaesthetic techniques have become increasingly prevalent within multimodal analgesic regimens and the widespread adoption of ultrasonography has facilitated the development of novel fascial plane blocks. The number of described fascial plane blocks has increased significantly over the past decade, leading to a burgeoning area of clinical investigation. Their applications are increasing, and truncal fascial plane blocks are increasingly recommended as part of procedure-specific guidelines. Some fascial plane blocks have been shown to be more efficacious than others, with favourable side-effect profiles compared with neuraxial analgesia, and are increasingly utilised in breast, thoracic, and other truncal surgery. However, use of these blocks is debated in regional anaesthesia circles because of limitations in our understanding of their mechanisms of action. This narrative review evaluates available evidence for the analgesic efficacy of the most commonly practised fascial plane blocks in breast, thoracic, and abdominal truncal surgery, in particular their efficacy compared with systemic analgesia, alternative blocks, and neuraxial techniques. We also highlight areas where investigations are ongoing and suggest priorities for original investigations.

Craniocaudal spread and clinical translation for combined erector spinae plane block and retrolaminar block in soft embalmed cadavers: a randomised controlled equivalence study

BACKGROUND

Erector spinae plane (ESP) block spread can be unpredictable. We previously improved the spread of ESP injection by addition of retrolaminar (RL) injection. However, it is not clear whether spread at high thoracic levels is similar to spread at midthoracic levels. Our primary objective was to demonstrate that craniocaudal dye spread was equivalent after combined ESP and RL injection using a 19 G Tuohy needle at the third (T3) and sixth (T6) vertebrae in soft embalmed Thiel cadavers.

METHODS

We randomised 20 combined ESP and RL injections to the T3 and T6 vertebral levels on both sides of 10 prone Thiel cadavers. A 3-8 MHz transducer was placed in the paramedian sagittal plane and a single anaesthetist injected 10 ml dye onto the transverse process, then 10 ml dye onto the laminae of T3 or T6. Cadavers were dissected 24 h later.

RESULTS

Mean (sd) craniocaudal spread of dye after combined ESP + RL injection at T3 and T6 vertebral levels was equivalent: 8.6 (1.8) vs 8.7 (2.3) levels, respectively; difference (90% confidence interval): -0.1 (-1.4 to 1.6), P=0.904. Dye extended uniformly, cranially and caudally, from the point of injection. A 3D prosection created from a Thiel cadaver confirmed that the dorsal ramus emerges from the costotransverse foramen deep to the intertransverse ligament within the retro-superior costotransverse ligament space. Combined ESP and RL block in six patients before mastectomy achieved extensive anterior, lateral, and posterior chest wall paraesthesia over four to six dermatomes.

CONCLUSIONS

Combined ESP and RL injections showed equivalent and consistent spread at T3 and T6 injection sites. A pilot study confirmed translation to patients.

Comparison of Ultrasound-Guided Versus Anatomical Landmark-Guided Thoracolumbar Retrolaminar Techniques in Canine Cadavers

The retrolaminar block was developed in humans as an easier and safer alternative to the thoracic paravertebral block. This study aims to describe an ultrasound-guided thoracolumbar retrolaminar injection in canine cadavers and compare the injectate distribution between a landmark-guided and an ultrasound-guided thoracolumbar retrolaminar technique using computed tomography. Ten canine cadavers were randomised to receive two injections each of 0.6 mL/kg of iodinated contrast at the level of the twelfth thoracic vertebra (T12): a landmark-guided retrolaminar injection was performed on one hemithorax (group B, n = 10) and an ultrasound-guided on the other hemithorax (group U, n = 10). Groups were compared using the Mann-Whitney U test. The median (range) spread of the contrast in the paravertebral space was 0 (0-3) and 1 (0-5) vertebrae in groups B and U, respectively (p = 0.038). The median (range) extent of the spread surrounding the interverbal foramina was 4 (0-5) in group B and 4 (3-5) in group U. The median (range) spread along the retrolaminar space cranial and caudal to T12 was 3 (0-6) retrolaminar segments in group B and 3 (3-4) in group U. The potential of the ultrasound-guided retrolaminar injection to provide analgesia for dogs suffering from thoracolumbar pain should be further investigated.

Awake Single-Stage Bilateral Clavicle Surgeries Under Bilateral Clavipectoral Fascial Plane Blocks: A Case Report and Review of Literature

The clavicle is a frequently fractured bone with an infrequent bilateral occurrence. Regional anesthesia (RA) for clavicle surgeries is always challenging due to its complex innervation arising from the two plexuses (cervical and brachial). Various RA techniques described for clavicle surgeries include plexus blocks, fascial plane blocks, and truncal blocks. Plexus blocks are associated with undesirable effects, such as phrenic nerve blockade and paralysis of the entire upper limb, limiting their application for bilateral regional clavicle surgeries. The clavipectoral fascial plane block (CPB) is a novel, procedure-specific, phrenic-sparing, and motor-sparing RA technique that can provide anesthesia or analgesia for clavicle surgeries. The decision to use the CPB and/or other RA techniques may depend on the site of clavicle injury or variations in clavicular innervation. We report a case of single-stage bilateral clavicle surgery successfully managed with a bilateral CPB alone using ultrasound guidance and landmark guidance separately. The patient was kept awake and comfortable throughout the surgery. In conclusion, CPB can be an effective alternate RA technique in avoiding undesired side effects of more proximal techniques such as phrenic nerve involvement and motor blockade of upper limbs. Landmark-guided CPB can be an alternative with equianalgesic efficacy as of ultrasound-guided CPB in resource-poor or emergency settings.

Ultrasound-Guided Continuous Bilateral Erector Spinae Plane Blocks Are Associated with Reduced Opioid Consumption and Length of Stay for Open Cardiac Surgery: A Retrospective Cohort Study

This study tested the hypothesis that continuous bilateral erector spinae plane blocks placed preoperatively would reduce opioid consumption and improve outcomes compared with standard practice in open cardiac surgery patients. Patients who received bilateral continuous erector spinae plane blocks for primary open coronary bypass, aortic valve, or ascending aortic surgery were compared to a historical control group. Patients in the block group received a 0.5% ropivacaine bolus preoperatively followed by a 0.2% ropivacaine infusion begun postoperatively. No other changes were made to the perioperative care protocol. The primary outcome was opioid consumption. Secondary outcomes were time to extubation and length of stay. Twenty-eight patients received continuous erector spinae plane blocks and fifty patients served as historic controls. Patients who received blocks consumed less opioids, expressed as oral morphine equivalents, both intraoperatively (34 ± 17 vs. 224 ± 125 mg) and during their hospitalization (224 ± 108 vs. 461 ± 185 mg). Patients who received blocks had shorter times to extubation (126 ± 87 vs. 257 ± 188 min) and lengths of stay in the intensive care unit (35 ± 17 vs. 58 ± 42 h) and hospital (5.6 ± 1.6 vs. 7.7 ± 4.6 days). Continuous erector spinae plane blocks placed prior to open cardiac surgical procedures reduced opioid consumption, time to extubation, and length of stay compared to a standard perioperative pathway.

Regional Analgesia for Cardiac Surgery. Part 2: Peripheral Regional Analgesia for Cardiac Surgery

The introduction of regional analgesia in the past decades have revolutionized postoperative pain management for various types of surgery, particularly orthopedic surgery. Nowadays, they are being constantly introduced into other types of surgeries including cardiac surgeries. Neuraxial and paravertebral plexus blocks for cardiac surgery are considered as deep blocks and have the risk of hematoma formation in the setting of anticoagulation associated with cardiac surgeries. Moreover, hemodynamic compromise resulting from sympathectomy in patients with limited cardiac reserve further limits the use of neuraxial techniques. A multitude of fascial plane blocks involving chest wall have been developed, which have been shown the potential to be included in the regional analgesia armamentarium for cardiac surgery. In myofascial plane blocks, the local anesthetic spreads passively and targets the intermediate and terminal branches of intercostal nerves. They are useful as important adjuncts for providing analgesia and are likely to be included in "Enhanced Recovery after Cardiac Surgery (ERACS)" protocols. There are several small studies and case reports that have shown efficacy of the regional blocks in reducing opioid requirements and improving patient satisfaction. This review article discusses the anatomy of various fascial plane blocks, mechanism of their efficacy, and available evidence on outcomes after cardiac surgery.

Fundamentals and innovations in regional anaesthesia for infants and children

Regional anaesthesia in children has evolved rapidly in the last decade. Although it previously consisted of primarily neuraxial techniques, the practice now incorporates advanced peripheral nerve blocks, which were only recently described in adults. These novel blocks provide new avenues for providing opioid-sparing analgesia while minimising invasiveness, and perhaps risk, associated with older techniques. At the same time, established methods, such as infant spinal anaesthesia, under-utilised in the last 20 years, are experiencing a revival. The impetus has been the concern regarding the potential long-term neurocognitive effects of general anaesthesia in the young child. These techniques have expanded from single shot spinal anaesthesia to combined spinal/epidural techniques, which can now effectively provide surgical anaesthesia for procedures below the umbilicus for a prolonged period of time, thereby avoiding the need for general anaesthesia. Continuous 2-chloroprocaine infusions, previously only described for intra-operative regional anaesthesia, have gained popularity as a means of providing prolonged postoperative analgesia in epidural and continuous nerve block techniques. The rapid, liver-independent metabolism of 2-chloroprocaine makes it ideal for prolonged local anaesthetic infusions in neonates and small infants, obviating the increased risk of local anaesthetic systemic toxicity that occurs with amide local anaesthetics. Debate continues over certain practices in paediatric regional anaesthesia. While the rarity of complications makes comparative analyses difficult, data from large prospective registries indicate that providing regional anaesthesia to children while under general anaesthesia appears to be at least as safe as in the sedated or awake patient. In addition, the estimated frequency of serious adverse events demonstrates that regional blocks in children under general anaesthesia are no less safe than in awake adults. In infants, the techniques of direct thoracic epidural placement or caudal placement with cephalad threading each have distinct advantages and disadvantages. As the data cannot support the safety of one technique over the other, the site of epidural insertion remains largely a matter of anaesthetist discretion.

Ultrasound-guided fascial plane blocks of the chest wall: a state-of-the-art review

Ultrasound-guided fascial plane blocks of the chest wall are increasingly popular alternatives to established techniques such as thoracic epidural or paravertebral blockade, as they are simple to perform and have an appealing safety profile. Many different techniques have been described, which can be broadly categorised into anteromedial, anterolateral and posterior chest wall blocks. Understanding the relevant clinical anatomy is critical not only for block performance, but also to match block techniques appropriately with surgical procedures. The sensory innervation of tissues deep to the skin (e.g. muscles, ligaments and bone) can be overlooked, but is often a significant source of pain. The primary mechanism of action for these blocks is a conduction blockade of sensory afferents travelling in the targeted fascial planes, as well as of peripheral nociceptors in the surrounding tissues. A systemic action of absorbed local anaesthetic is plausible but unlikely to be a major contributor. The current evidence for their clinical applications indicates that certain chest wall techniques provide significant benefit in breast and thoracic surgery, similar to that provided by thoracic paravertebral blockade. Their role in trauma and cardiac surgery is evolving and holds great potential. Further avenues of research into these versatile techniques include: optimal local anaesthetic dosing strategies; high-quality randomised controlled trials focusing on patient-centred outcomes beyond acute pain; and comparative studies to determine which of the myriad blocks currently on offer should be core competencies in anaesthetic practice.