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Background: This cadaveric study investigated the innervations of the clavicle and clavicular joints (ie, sternoclavicular and acromioclavicular joints)., Methods: Twenty cadavers (40 clavicles) were dissected. A skin incision was made to permit exposure of the posterior cervical triangle and infraclavicular fossa. The platysma, sternocleidomastoid, and trapezius muscles were cleaned in order to identify the supraclavicular nerves. Subsequently, the suprascapular and subclavian nerves were localized after removal of the prevertebral layer of the deep cervical fascia. In the infraclavicular region, the pectoralis major and minor muscles were retracted laterally in order to visualize the lateral pectoral nerve. The contribution of all these nerves to the clavicular bone and joints were recorded., Results: Along their entire length, all clavicular specimens received contributions from the supraclavicular nerves. The latter innervated the cephalad and ventral aspects of the clavicular bone. The caudal and dorsal aspects of the clavicle were innervated by the subclavian nerve (middle and medial thirds). The lateral pectoral nerve supplied the caudad aspect of the clavicle (middle and lateral thirds). The sternoclavicular joint derived its innervation solely from the supraclavicular nerves whereas the acromioclavicular joint was supplied by the supraclavicular and lateral pectoral nerves., Conclusion: The clavicle and clavicular joints are innervated by the subclavian, lateral pectoral, and supraclavicular nerves. Clinical trials are required to determine the relative importance and functional contribution of each nerve., Competing Interests: Competing interests: None declared., (© American Society of Regional Anesthesia & Pain Medicine 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Objectives: The primary objective of this study was to compare the analgesic efficacy of combined suprascapular and axillary nerve block (SSAX) with interscalene block (ISB) after arthroscopic shoulder surgery. Our hypothesis was that ultrasound-guided SSAX would provide postoperative analgesia equivalent to ISB., Methods: Sixty adult patients undergoing arthroscopic shoulder surgery received either SSAX or ISB prior to general anesthesia, in a randomized fashion. Pain scores, satisfaction, and adverse effects were recorded in the recovery room, 6 hours, 24 hours, and 7 days after surgery., Results: Combined suprascapular and axillary nerve block provided nonequivalent analgesia when compared with ISB at different time points postoperatively, except on postoperative day 7. Interscalene block had better mean static pain score in the recovery room (ISB 1.80 [95% confidence interval [CI], 1.10-2.50] vs SSAX 5.45 [95% CI, 4.40-6.49; P < 0.001]). At 24 hours, SSAX had better mean static pain score (ISB 6.35 [95% CI, 5.16-7.54] vs SSAX 3.92 [95% CI, 2.52-5.31]; P = 0.01) with similar satisfaction between the groups., Conclusions: Combined suprascapular and axillary nerve block provides nonequivalent analgesia compared with ISB after arthroscopic shoulder surgery. While SSAX provides better quality pain relief at rest and fewer adverse effects at 24 hours, ISB provides better analgesia in the immediate postoperative period. For arthroscopic shoulder surgery, SSAX can be a clinically acceptable analgesic option with different analgesic profile compared with ISB.

Background and Objectives: Postoperative neurologic symptoms after interscalene block and shoulder surgery have been reported to be relatively frequent. Reports of such symptoms after ultrasound-guided block have been variable. We evaluated 300 patients for neurologic symptoms after low-volume, ultrasound-guided interscalene block and arthroscopic shoulder surgery., Methods: Patients underwent ultrasound-guided interscalene block with 16 to 20 mL of 0.5% bupivacaine or a mix of 0.2% bupivacaine/1.2% mepivacaine solution, followed by propofol/ketamine sedation for ambulatory arthroscopic shoulder surgery. Patients were called at 10 days for evaluation of neurologic symptoms, and those with persistent symptoms were called again at 30 days, at which point neurologic evaluation was initiated. Details of patient demographics and block characteristics were collected to assess any association with persistent neurologic symptoms., Results: Six of 300 patients reported symptoms at 10 days (2%), with one of these patients having persistent symptoms at 30 days (0.3%). This was significantly lower than rates of neurologic symptoms reported in preultrasound investigations with focused neurologic follow-up and similar to other studies performed in the ultrasound era. There was a modest correlation between the number of needle redirections during the block procedure and the presence of postoperative neurologic symptoms., Conclusions: Ultrasound guidance of interscalene block with 16- to 20-mL volumes of local anesthetic solution results in a lower frequency of postoperative neurologic symptoms at 10 and 30 days as compared with investigations in the preultrasound period.

Background and Objectives: In this randomized double-blind prospective study in patients undergoing shoulder arthroscopy, we compared the effects of ultrasound-guided interscalene nerve block using 20 mL (intervention group) and 40 mL (control group) of a mepivacaine 1.5% and bupivacaine 0.5% mixture (1:1 volume) on ipsilateral handgrip strength and other postoperative end points., Methods: One hundred fifty-four patients scheduled for ambulatory shoulder arthroscopy were randomly assigned to receive a single-injection interscalene block under ultrasound guidance with either 40 mL (control) or 20 mL (intervention) and intravenous sedation. The primary outcome was the change in ipsilateral handgrip strength in the postanesthesia care unit (PACU) measured with a dynamometer. Secondary end points were recorded, including negative inspiratory force, incidences of hoarseness and Horner syndrome, time to readiness for discharge from PACU, time to discharge from PACU, patient satisfaction, time to block resolution, and pain scores., Results: Postoperative handgrip strength was greater in the 20-mL group compared with the 40-mL group (difference in means, 2.3 kg [95% confidence interval, 0.6-4.0 kg]; P = 0.009). A smaller proportion of patients in the intervention group experienced hoarseness postoperatively compared with the control group (odds ratio, 0.26 [95% confidence interval, 0.08-0.82]; P = 0.015). Patient satisfaction and duration of analgesia were similar in both groups., Conclusions: When used for surgical anesthesia for shoulder arthroscopies in the ambulatory setting, a 20-mL volume in an ultrasound-guided interscalene block preserves greater handgrip strength on the ipsilateral side in the PACU compared with 40 mL without significant decrease in block success, duration of analgesia, and patient satisfaction.

Background and Objectives: The suprascapular nerve (SSN) block is frequently performed for different shoulder pain conditions and for perioperative and postoperative pain control after shoulder surgery. Blind and image-guided techniques have been described, all of which target the nerve within the supraspinous fossa or at the suprascapular notch. This classic target point is not always ideal when ultrasound (US) is used because it is located deep under the muscles, and hence the nerve is not always visible. Blocking the nerve in the supraclavicular region, where it passes underneath the omohyoid muscle, could be an attractive alternative., Methods: In the first step, 60 volunteers were scanned with US, both in the supraclavicular and the classic target area. The visibility of the SSN in both regions was compared. In the second step, 20 needles were placed into or immediately next to the SSN in the supraclavicular region of 10 cadavers. The accuracy of needle placement was determined by injection of dye and following dissection., Results: In the supraclavicular region of volunteers, the nerve was identified in 81% of examinations (95% confidence interval [CI], 74%-88%) and located at a median depth of 8 mm (interquartile range, 6-9 mm). Near the suprascapular notch (supraspinous fossa), the nerve was unambiguously identified in 36% of examinations (95% CI, 28%-44%) (P < 0.001) and located at a median depth of 35 mm (interquartile range, 31-38 mm; P < 0.001). In the cadaver investigation, the rate of correct needle placement of the supraclavicular approach was 95% (95% CI, 86%-100%)., Conclusions: Visualization of the SSN with US is better in the supraclavicular region as compared with the supraspinous fossa. The anatomic dissections confirmed that our novel supraclavicular SSN block technique is accurate.

Background and Objectives: This study was performed to determine the minimum effective volume of ropivacaine 0.75% required to produce effective shoulder analgesia for an ultrasound (US)-guided block at the C7 root level with assessment of pulmonary function., Methods: Using the Dixon and Massey up-and-down method study design, 20 patients scheduled for elective open shoulder surgery under combined general anesthesia and continuous interscalene brachial plexus block were included. Initial volume of ropivacaine 0.75% was 6 mL; block success or failure determined a 1-mL decrease or increase for the subsequent patient, respectively. General anesthesia was standardized. A continuous infusion of ropivacaine 0.2% was started at a rate of 6 mL/hr at 2 hrs after completion of surgery. Ventilatory function was assessed using spirometry, and movement of the hemidiaphragm was assessed by US., Results: The minimum effective volume of local anesthetic in 50% and 95% of the patients was 2.9 mL (95% confidence interval, 2.4-3.5 mL) and 3.6 mL (95% confidence interval, 3.3-6.2 mL), respectively. Ventilatory function and hemidiaphragmatic movement was not reduced up to and including 2 hrs after completion of surgery, but 22 hrs after start of the continuous infusion of ropivacaine 0.2%, ventilatory function and hemidiaphragmatic movement were significantly reduced (P < 0.001)., Conclusions: The minimum effective volume of local anesthetic for shoulder analgesia for a US-guided block at the C7 root level in 50% and 95% of the patients was 2.9 and 3.6 mL, respectively. Pulmonary function was unchanged until 2 hrs after completion surgery, but reduced 22 hrs after start of a continuous infusion of ropivacaine 0.2%.

Objective: We present an occurrence of a severe but transient neurologic complication after intraneural injection during an ultrasound-guided interscalene block., Case Report: A 36-year-old man underwent ultrasound-guided interscalene nerve blockade before shoulder incision and drainage. On postoperative day 1, he exhibited new-onset arm weakness with dysesthesias. Intraneural injection was recognized based on a retrospective review of the recorded ultrasound imaging. The symptoms persisted for more than 2 weeks and completely resolved by 6 weeks., Conclusions: Our report suggests that intraneural injection during ultrasound-guided interscalene block carries a risk of neurologic complications.

Objective: We describe a case of persistent hiccups after attempted interscalene brachial plexus block., Case Report: A 38-year-old man was admitted for arthroscopic repair of a right shoulder injury. An interscalene block was attempted in the preoperative area and combined with general anesthesia for surgery. The procedure lasted 5(1/4) hours. After transfer to the recovery room, the patient complained of severe right shoulder pain and had no discernible sensory or motor block. He was noted to be hiccuping. The patient was discharged home the following morning but returned 2 days later complaining of persistent hiccups since surgery, with associated insomnia and nausea. He was readmitted and given chlorpromazine 50 mg intravenously every 8 hours and metoclopramide 10 mg intravenously every 6 hours. The patient was discharged 4 days later on chlorpromazine 25 mg by mouth every 8 hours and baclofen 5 mg by mouth every 12 hours, with hiccups greatly reduced in both intensity and frequency. Hiccups ceased 1 day after discharge. Eighteen days after surgery, he was off all medication with no return of his hiccups; 1 month later he remains hiccup free., Conclusions: Persistent hiccups have many postulated causes, including several that are common in the perioperative period, but this is the first time to our knowledge that persistent hiccups have been described in association with attempted interscalene brachial plexus block.

Background and Objectives: The aim of this study was to compare the same volume and concentration of bupivacaine and ropivacaine for interscalene brachial plexus block anesthesia and postoperative analgesia in shoulder surgery., Methods: Forty-four patients scheduled for elective shoulder surgery were prospectively randomized to receive in a double-blind fashion 30 mL of either 0.5% bupivacaine or ropivacaine for interscalene block. The block was prolonged after surgery by using a patient-controlled interscalene analgesia with 0.15% of either bupivacaine or ropivacaine. The mean onset times of surgical blocks were determined after interscalene block. Pain relief was regularly assessed by using a visual analog scale, side effects were noted, and the patients were asked to rate their satisfaction at the end of the study., Results: Two patients with bupivacaine and 1 with ropivacaine failed to achieve surgical block and were excluded. The mean onset times of surgical blocks were 18 +/- 12 minutes with ropivacaine and 21 +/- 13 minutes with bupivacaine. The pain scores, total volume infused of local anesthetics, incremental dose requested and received, total rescue analgesic, and side effects were similar between the groups. Postoperative pain control was similarly effective and patient satisfaction was high in both groups., Conclusions: This study shows that the same volume and concentration of bupivacaine and ropivacaine (30 mL of 0.5%) for interscalene brachial plexus block anesthesia produce similar surgical block. When prolonging the block with a patient-controlled interscalene analgesia infusion, 0.15% bupivacaine or ropivacaine provide adequate pain relief, similar side effects, and high patient satisfaction after shoulder surgery.