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Background and objectivesThe erector spinae plane (ESP) block is a relatively new interfascial block technique. Previous cadaveric studies have shown extensive cephalocaudal spread with a single ESP injection at the thoracic level. However, little data exist for lumbar ESP block. The objective of this study was to examine the anatomical spread of dye following an ultrasound-guided lumbar ESP block in a human cadaveric model.MethodsAn ultrasound-guided ESP block was performed in unembalmed human cadavers using an in-plane approach with a curvilinear transducer oriented longitudinally. 20 mL of 0.166% methylene blue was injected into the plane between the distal end of the L4 transverse process and erector spinae muscle bilaterally in four specimens and unilaterally in one specimen (nine ESP blocks in total). The superficial and deep back muscles were dissected, and the extent of dye spread was documented in both cephalocaudal and medial–lateral directions.ResultsThere was cephalocaudal spread from L3 to L5 in all specimens with extension to L2 in four specimens. Medial–lateral spread was documented from the multifidus muscle to the lateral edge of the thoracolumbar fascia. There was extensive dye in and around the erector spinae musculature and spread to the dorsal rami in all specimens. There was no dye spread anteriorly into the dorsal root ganglion, ventral rami, or paravertebral space.ConclusionsA lumbar ESP injection has limited craniocaudal spread compared with injection in the thoracic region. It has consistent spread to dorsal rami, but no anterior spread to ventral rami or paravertebral space.

Background and objectivesThe costoclavicular brachial plexus block is performed deep and posterior to the midpoint of the clavicle. There are limited data evaluating the spread of the costoclavicular brachial plexus block. We performed a cadaveric study to evaluate the spread of injectate after a costoclavicular brachial plexus block.MethodsFive ultrasound-guided costoclavicular block injections were performed with 20 mL of 0.1% methylene blue. The brachial plexus and its branches were dissected from the level of C4 to the lower axilla. The extent of dye spread was recorded including spread to the phrenic nerve, suprascapular nerve, roots, trunks, divisions, cords and terminal branches of the brachial plexus.ResultsThe dye extended cephalad to the level of the cricoid cartilage in two of the five injections; three injections had dye extending 0.75 cm, 1.5 cm and 2 cm caudad to the level of the cricoid cartilage, respectively. The C7, C8 and T1 nerve roots were stained in all injections. The dye did not extend cephalad to the C5 and C6 nerve roots. All trunks, cords and divisions of the brachial plexus were stained, as was the suprascapular nerve. There was no spread of dye to the phrenic nerve in any of the specimens.ConclusionsThis cadaveric study demonstrates that ultrasound-guided injection in the costoclavicular space spreads cephalad to the brachial plexus in the supraclavicular space, consistently reaching the suprascapular nerve and all trunks and cords of the brachial plexus, while sparing the phrenic nerve.

Background: Minimally invasive repair of pectus excavatum (MIRPE) is now performed in adults.Managing adult patients' pain postoperatively has been challenging due to increased chest wall rigidity and the pressure required for supporting the elevated sternum. The optimal pain management regimen has not been determined. We designed this prospective, randomized trial to compare postoperative pain management and outcomes between thoracic epidural analgesia (TEA) and bilateral subcutaneous infusion pump catheters (On-Q). Methods: Patients undergoing MIRPE (modified Nuss) underwent random assignment to TEA or On-Q group. Both groups received intravenous, patient-controlled opioid analgesia, with concomitant delivery of local anesthetic. Primary outcomes were length of stay (LOS), opioid use, and pain scores. Results: Of 85 randomly assigned patients, 68 completed the study [52 men, 76.5%; mean (range) age, 32.2 (20.0-58.0) years; Haller index, 5.9 (range, 3.0-26.7)]. The groups were equally matched for preoperative variables; however, the On-Q arm had more patients (60.3%). No significant differences were found between groups in mean daily pain scores (P=0.52), morphine-equivalent opioid usage (P=0.28), or hospital stay 3.5 vs. 3.3 days (TEA vs. On-Q; P=0.55). Thirteen patients randomized to TEA refused the epidural and withdrew from the study because they perceived greater benefit of the On-Q system.Conclusions: Postoperative pain management in adults after MIRPE can be difficult. Both continuous local anesthetic delivery by TEA and On-Q catheters with concomitant, intravenous, patient-controlled anesthesia maintained acceptable analgesia with a reasonable LOS. In our cohort, there was preference for the On-Q system for pain management.

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