Single-Injection Adductor Canal Block With Multiple Adjuvants Provides Equivalent Analgesia When Compared With Continuous Adductor Canal Blockade for Primary Total Knee Arthroplasty: A Double-Blinded, Randomized, Controlled, Equivalency Trial.

BACKGROUND: Peripheral nerve blockade is used to provide analgesia for patients undergoing total knee arthroplasty. This study compared a single-injection adductor canal block (SACB) with adjuvants to continuous adductor canal blockade (CACB). The hypothesis was that the 2 groups would have equivalent analgesia at 30 hours after neural blockade. METHODS: This was a double-blinded, randomized, controlled, equivalency trial. Sixty patients were randomized to either the SACB group (20 mL of 0.25% bupivacaine, 1.67 mcg/mL of clonidine, 2 mg of dexamethasone, 150 mcg of buprenorphine, and 2.5 mcg/mL of epinephrine) or the CACB group (20 mL 0.25% of bupivacaine injection with 2.5 mcg/mL of epinephrine followed by an 8 mL/h infusion of 0.125% bupivacaine continued through postoperative day 2). The primary outcome was movement pain scores at 30 hours using the numeric rating scale (NRS). The secondary outcomes included serial postoperative NRS pain scores (rest and movement every 6 hours), opioid consumption, time to first opioid administration, ability to straight leg raise, patient satisfaction, length of stay, and the incidence of nausea/vomiting. RESULTS: An intention-to-treat analysis included 59 patients. The NRS pain scores with movement were equivalent at 30 hours (SACB 5.5 ± 2.8 vs CACB 5.7 ± 2.9 [mean NRS ± standard deviation]; mean difference 0.2 [-1.5 to 1.0 {90% confidence interval}]). All NRS pain scores were equivalent until 42 hours (rest) and 48 hours (rest and movement) with the CACB group having lower pain scores. Other secondary outcomes were not statistically different. CONCLUSION: An SACB provides equivalent analgesia for up to 36 hours after block placement when compared with a CACB for patients undergoing total knee arthroplasty, though a CACB was favored at 42 hours and beyond.

Neuromuscular ultrasound of the brachial plexus: A standardized approach.

Reliable assessment of brachial plexus disorders can be challenging due to the complexity of the anatomy and variation of potential pathology. Electrodiagnostic testing can be both uncomfortable for the patient and inconclusive. Ultrasound can serve as a complement to clinical assessment, electrodiagnostic testing, and other imaging modalities. This study describes a systematic approach for performing neuromuscular ultrasound for suspected pathology in the brachial plexus. The literature regarding techniques for brachial plexus ultrasound was reviewed. A team composed of specialists in neurology, physiatry, anesthesiology, orthopedic surgery, and vascular surgery used this as the basis for describing standardized techniques for performing brachial plexus ultrasound. Four standard views, along with other supplemental views, are described for the evaluation of the brachial plexus. An illustrative case is presented. Ultrasound is a high-resolution point of care diagnostic tool that allows assessment of structural pathology affecting the brachial plexus. Muscle Nerve 58: 618-624, 2018.