Page of

Arthroscopic Shoulder Surgery 

Arthroscopic Shoulder Surgery
Chapter:
Arthroscopic Shoulder Surgery
Source:
Acute Pain Medicine
Author(s):

M. Stephen Melton

, James Kyunghoon Kim

, and Karen C. Nielsen

DOI:
10.1093/med/9780190856649.003.0005

Case Scenario

A 62-year-old, obese man presents for outpatient arthroscopic rotator cuff repair (RCR) and biceps tenodesis. He has a medical history significant for smoking, nonobstructive coronary artery disease, and controlled hypertension on lisinopril.

1. Introduction

Shoulder arthroscopy is a common elective ambulatory surgery procedure performed for a multitude of surgical indications, including rotator cuff tears, instability, and stiffness. Patients may present for surgery after acute or chronic injury. The spectrum of patient comorbidities reflects a diverse patient population from teenagers to elderly adults, and from the athletic to the inactive. Significant postoperative pain associated with these procedures necessitates an adequate multimodal analgesic plan to optimize patient satisfaction, recovery, and rehabilitation. Peripheral nerve blockade (PNB) is commonly performed for intraoperative anesthesia and/or postoperative analgesia. This chapter will review pertinent patient- and surgery-specific considerations for outpatient shoulder arthroscopy anesthesia and postoperative analgesia.

Further Reading

Jain NB, Higgins LD, Losina E, Collins J, Blazar PE, Katz JN. Epidemiology of musculoskeletal upper extremity ambulatory surgery in the United States. BMC Musculoskelet Disord. 2014;15(1):4.Find this resource:

Robinson JC, Brown TT, Whaley C, Bozic KJ. Consumer choice between hospital-based and freestanding facilities for arthroscopy: impact on prices, spending, and surgical complications. J Bone Joint Surg Am. 2015;97(18):1473–1481.Find this resource:

Warrender WJ, Syed UAM, Hammoud S, et al. Pain management after outpatient shoulder arthroscopy. Am J Sports Med. 2016;20(1):036354651666790.Find this resource:

    2. Preoperative Evaluation: Patient-Related Considerations for Multimodal Perineural Analgesia

    2.1. What are considerations for patients with cardiac history undergoing shoulder arthroscopy?

    Patients with a history of cardiac disease should be evaluated and managed preoperatively in accordance with the American College of Cardiology/American Heart Association guidelines for noncardiac surgery. Decisions pertaining to anticoagulation and PNB should be managed according to these guidelines in addition to the American Society of Regional Anesthesia and Pain Medicine (ASRA) Evidence-Based Guidelines. Aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) do not have to be held prior to performing PNB. In some cardiac patients, aspirin should be continued perioperatively, if surgical bleeding risk allows. Consultation with the patient’s cardiologist and surgeon is appropriate to make this determination. Herbal medications, which may influence bleeding, such as ginseng and ginkgo biloba, should be held.

    Angiotensin converting enzyme inhibitors and angiotensin receptor blockers may be associated with a more profound degree of anesthesia-induced hypotension. Consideration should be given to holding these medications the morning of surgery. For shoulder surgery, the beach-chair position (BCP) with decreased venous return to the heart may exacerbate this hypotension. The physiology of the BCP presents a certain level of risk for cerebral hypotension. Avoidance of volatile anesthetics by utilizing ISB with propofol sedation and spontaneous respiration via a natural airway may reduce the risk of ischemic neurologic injury.

    Further Reading

    Horlocker TT, Wedel DJ, Rowlingson JC, et al. Regional anesthesia in the patient receiving antithrombotic or thrombolytic therapy: American Society of Regional Anesthesia and Pain Medicine Evidence-Based Guidelines (Third Edition). Reg Anesth Pain Med. 2010;35(1):64–101.Find this resource:

    Koh JL, Levin SD, Chehab EL, Murphy GS. Neer Award 2012: cerebral oxygenation in the beach chair position: a prospective study on the effect of general anesthesia compared with regional anesthesia and sedation. J Shoulder Elbow Surg. 2013;22(10):1325–1331.Find this resource:

    Fleisher LA, Fleischmann KE, Auerbach AD, et al. 2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery. J Am Coll Cardiol. 2014;64(22):1–107.Find this resource:

      Rohrbaugh M, Kentor ML, Orebaugh SL, Williams B. Outcomes of shoulder surgery in the sitting position with interscalene nerve block: a single-center series. Reg Anesth Pain Med. 2013;38(1):28–33.Find this resource:

      2.2. What are pulmonary-specific concerns associated with shoulder arthroscopy?

      If ISB is a part of the anesthesia plan, patients should be able to tolerate an approximate 25% decrease in pulmonary function secondary to phrenic nerve block and resultant hemidiaphragmatic paresis. In patients with moderate to severe pulmonary dysfunction, this risk may outweigh the benefit of ISB and continuous interscalene brachial plexus block (CISB).

      Further Reading

      Urmey WF, McDonald M. Hemidiaphragmatic paresis during interscalene brachial plexus block: effects on pulmonary function and chest wall mechanics. Anesth Analg. 1992;74(3):352–357.Find this resource:

      2.3. What is the mechanism for hemidiaphragmatic paresis after ISB?

      A potential disadvantage of ISB and CISB is a transient ipsilateral hemidiaphragmatic paresis from spread of LA to the phrenic nerve. Ipsilateral hemidiaphragmatic paresis inhibits normal lung expansion, as a result of the paralyzed hemidiaphragm moving in a paradoxical cephalad direction during inspiration. Previous studies have confirmed that concomitant paralysis of the ipsilateral hemidiaphragm is an unavoidable consequence of ISB when typical volumes of LA (10–45 mL) are used. Even ultra-low volumes of LA (5 mL) placed under ultrasound guidance are associated with a 45% incidence of hemidiaphragmatic paresis. Lower anesthetic concentrations may reduce the incidence of hemidiaphragmatic paresis. Five minutes after ISB and resultant hemidiaphragmatic paresis, Urmey and McDonald found that nonobese participants had a 27% decrease in forced vital capacity (FVC) and a 26% decrease in forced expiratory volume in 1 second (FEV1). Subsequent investigation in nonobese participants demonstrated that the magnitude of this reduction reached a plateau at 15 minutes with no significant change in FVC and FEV1 between 15 and 30 minutes. Further, ISB local anesthetic (LA) injection volume (20 mL versus 45 mL) produced no significant difference in onset or degree of pulmonary dysfunction over time. Extrafascial injection, as opposed to intrafascial injection between the fifth and sixth cervical roots, may be associated with reduced incidence of hemidiaphragmatic paresis and preservation of pulmonary function. Extrafascial CISB catheter tip location was associated with decreased incidence of hemidiaphragmatic paresis, but there was no difference in functional respiratory outcomes. Hemidiaphragmatic paresis is typically limited to LA duration of action. Fortunately, persistent phrenic nerve paresis is rare, with a reported incidence of 0.048% in one investigation. While symptomatic cervical spine disease was found to be a risk factor for the development of persistent phrenic nerve paresis, the etiology is multifactorial. Persistent phrenic nerve paresis remains a perplexing complication of ISB, and many questions remain unanswered.

      Further Reading

      Albrecht E, Bathory I, Fournier N, Jacot-Guillarmod A, Farron A, Brull R. Reduced hemidiaphragmatic paresis with extrafascial compared with conventional intrafascial tip placement for continuous interscalene brachial plexus block: a randomized, controlled, double-blind trial. Br J Anaesth. 2017;118(4):586–592.Find this resource:

      al-Kaisy AA, Chan VW, Perlas A. Respiratory effects of low-dose bupivacaine interscalene block. Br J Anaesth. 1999;82(2):217–220.Find this resource:

      Borgeat A, Perschak H, Bird P, Hodler J, Gerber C. Patient-controlled interscalene analgesia with ropivacaine 0.2% versus patient-controlled intravenous analgesia after major shoulder surgery: effects on diaphragmatic and respiratory function. Anesthesiology. 2000;92(1):102–108.Find this resource:

      Cuvillon P, Le Sache F, Demattei C, et al. Continuous interscalene brachial plexus nerve block prolongs unilateral diaphragmatic dysfunction. Anaesth Crit Care Pain Med. June 2016.Find this resource:

        Jules-Elysee K, Reid SC, Kahn RL, Edmonds CR, Urban MK. Prolonged diaphragm dysfunction after interscalene brachial plexus block and shoulder surgery: a prospective observational pilot study. Br J Anaesth. 2014;112(5):950–951.Find this resource:

        Pakala SR, Beckman JD, Lyman S, Zayas VM. Cervical spine disease is a risk factor for persistent phrenic nerve paresis following interscalene nerve block. Reg Anesth Pain Med. 2013;38(3):239–242.Find this resource:

        Palhais N, Brull R, Kern C, et al. Extrafascial injection for interscalene brachial plexus block reduces respiratory complications compared with a conventional intrafascial injection: a randomized, controlled, double-blind trial. Colvin L, ed. Br J Anaesth. 2016;116(4):531–537.Find this resource:

        Pere P, Pitkänen M, Rosenberg PH, Bjorkenheim JM, Linden H, Salorinne Y, Tuominen M: Effect of continuous interscalene brachial plexus block on diaphragm motion and on ventilatory function. Acta Anaesthesiol Scand. 1992;36:53–57.Find this resource:

        Riazi S, Carmichael N, Awad I, Holtby RM, McCartney CJL. Effect of local anaesthetic volume (20 vs 5 ml) on the efficacy and respiratory consequences of ultrasound-guided interscalene brachial plexus block. Br J Anaesth. 2008;101(4):549–556.Find this resource:

        Sala-Blanch X, Lázaro JR, Correa J, Gómez-Fernandez M. Phrenic nerve block caused by interscalene brachial plexus block: effects of digital pressure and a low volume of local anesthetic. Reg Anesth Pain Med. 1999;24(3):231–235.Find this resource:

        Sinha SK, Abrams JH, Barnett JT, et al. Decreasing the local anesthetic volume from 20 to 10 mL for ultrasound-guided interscalene block at the cricoid level does not reduce the incidence of hemidiaphragmatic paresis. Reg Anesth Pain Med. 2011;36(1):17–20.Find this resource:

        Urmey WF, Gloeggler PJ. Pulmonary function changes during interscalene brachial plexus block: effects of decreasing local anesthetic injection volume. Reg Anesth. 1993;18(4):244–249.Find this resource:

        Urmey WF, McDonald M. Hemidiaphragmatic paresis during interscalene brachial plexus block: effects on pulmonary function and chest wall mechanics. Anesth Analg. 1992;74(3):352–357.Find this resource:

        Urmey WF, Talts KH, Sharrock NE. One hundred percent incidence of hemidiaphragmatic paresis associated with interscalene brachial plexus anesthesia as diagnosed by ultrasonography. Anesth Analg. 1991;72(4):498–503.Find this resource:

        Wong AK, Keeney LG, Chen L, Williams R, Liu J, Elkassabany NM. Effect of local anesthetic concentration (0.2% vs 0.1% ropivacaine) on pulmonary function, and analgesia after ultrasound-guided interscalene brachial plexus block: a randomized controlled study. Pain Med. 2016;17(12):2397–2403.Find this resource:

        2.4. Will pulmonary dysfunction be more pronounced in obese subjects after ISB?

        In obese patients, due to restrictive pulmonary mechanics, the perception of reduced breathing associated with hemidiaphragmatic paresis may be more profound. This may be exacerbated in obese patients undergoing general anesthesia with a volatile anesthetic in conjunction with ISB. Specific benefits of ISB, including avoidance of volatile anesthetics, potential avoidance of airway manipulation, and reduced opioid consumption, must be weighed against the risks of ISB in obese patients.

        When compared with a nonobese group, obese subjects undergoing ISB and sedation for arthroscopic shoulder surgery demonstrated greater reductions in pulmonary function. Lung parameters decreased 28% to 40% in obese participants compared with 21% to 31% in the normal-weight participants. Neither time (30 minutes vs. postanesthesia care unit [PACU]) nor position (sitting vs. supine) affected this relationship. Changes in pulmonary function were not associated with increased breathlessness, and despite their persistence in the PACU, there were no delays in readiness for discharge or respiratory-related issues identified during overnight stays or follow-up phone calls.

        Further Reading

        Melton MS, Monroe HE, Qi W, Lewis SL, Nielsen KC, Klein SM: Effect of interscalene brachial plexus block on the pulmonary function of obese patients: a prospective, observational cohort study. Anesth Analg. 2017; 125:313–319.Find this resource:

        2.5. How will obstructive sleep apnea syndrome affect preoperative planning?

        In patients with moderate to severe obstructive sleep apnea (OSA), the appropriateness of shoulder arthroscopy and rotator cuff repair (RCR) in the outpatient setting may be questioned due to the potential increased risk of postoperative respiratory adverse events. While the effects of ISB/CISB and resultant hemidiaphragmatic paresis on OSA are unknown, the possible avoidance of general anesthesia (airway manipulation, volatile anesthetics, etc.) and reduced opioid consumption achieved with regional anesthesia as part of a multimodal postoperative analgesic regimen are beneficial in patients with OSA.

        Further Reading

        Borgeat A, Perschak H, Bird P, Hodler J, Gerber C. Patient-controlled interscalene analgesia with ropivacaine 0.2% versus patient-controlled intravenous analgesia after major shoulder surgery: effects on diaphragmatic and respiratory function. Anesthesiology. 2000;92(1):102–108.Find this resource:

        Joshi GP, Ankichetty SP, Gan TJ, Chung F. Society for Ambulatory Anesthesia consensus statement on preoperative selection of adult patients with obstructive sleep apnea scheduled for ambulatory surgery. Anesth Analg. 2012;115:1060–1068.Find this resource:

        2.6. What if a patient has preexisting numbness or tingling in the hand and/or cervical spine disease?

        A history and physical exam that document baseline neurologic assessment of the extremity are important. Cervical spine imaging, if available, should be reviewed. For some patients, the preoperative workup may include an electromyogram, while for others this will not be available or will not be necessary. The etiology of neurologic symptoms should be evaluated and discussed with the patient and surgeon. Decisions to incorporate or exclude PNB as part of the anesthesia plan should be made with the patient and surgeon, after the etiology or potential etiology is understood. Preexisting neuropathy may not be worsened by PNB, but outcomes tend to be worse when neurologic dysfunction occurs in the presence of preexisting neuropathy. It is important to review with the patient the possibility of postoperative neurologic symptoms (PONS) such as numbness, tingling, and/or weakness in the surgical extremity, which may occur after surgery, with or without ISB. The incidence of PONS after regional anesthesia in the literature is multifactorial, and reported numbers vary based on block type, procedure type, patient reported versus elicitation of symptoms, absence or presence of physical exam, follow-up, means of diagnosis, and so forth. In a study analyzing 1505 consecutive patients receiving continuous interscalene analgesia, 106 (7.3%, 95% CI 6.0%–8.7%) patients reported numbness or tingling in the arm or side of the neck, weakness in the hand, or pain in the forearm/hand persisting beyond 1 month. Forty-seven (3.2%, 95% CI 2.4%–4.3%) patients’ symptoms persisted beyond 3 months, 26 (1.8%, 95% CI 1.2%–2.6%) patients’ symptoms persisted beyond 6 months, and 11 (0.7%, 95% CI 0.4%–1.4%) patients’ symptoms persisted beyond 12 months. Of these 11 patients, 6 had a clear cause unrelated to the nerve block, and in the remaining 5 the etiology was undetermined. In a study by Borgeat et al., minor neurologic complications (paresthesias, dysesthesias, pain not related to surgery) after ISB for shoulder surgery were observed in 14.0%, 7.9%, 3.9%, 0.9%, and 0.2% of patients at 10 days, 1, 3, 6, and 9 months, respectively. Two patients (0.2%) had sensory-motor deficit, which necessitated 19 and 28 weeks to recover, with electromyography suggestive of partial axonotmesis. Persistent paresthesias, dysesthesia, or pain not related to surgery after ISB need to be evaluated as specific treatment may be required.

        Further Reading

        Borgeat A, Ekatodramis G, Kalberer F, Benz C. Acute and nonacute complications associated with interscalene block and shoulder surgery: a prospective study. Anesthesiology. 2001;95:875–880.Find this resource:

        Fredrickson MJ, Leightley P, Wong A, Chaddock M, Abeysekera A, Frampton C. An analysis of 1505 consecutive patients receiving continuous interscalene analgesia at home: a multicentre prospective safety study. Anaesthesia. 2016;71(4):373–379.Find this resource:

        Neal JM, Barrington MJ, Brull R, et al. The Second ASRA Practice Advisory on Neurologic Complications Associated With Regional Anesthesia and Pain Medicine: Executive Summary 2015. Reg Anesth Pain Med. 2015 Sep-Oct;40(5):401-30.Find this resource:

          2.7. What should be considered when evaluating patients for continuous perineural infusions?

          Preoperative decisions for perineural interscalene catheter placement include surgical, medical, and social considerations. Postoperative analgesia should anticipate postoperative pain demand and complement surgical- and patient-specific issues. After minor arthroscopic shoulder surgery, the addition of a continuous interscalene ropivacaine infusion to a single-injection ISB demonstrated a reduction in pain scores during the first 24 hours and opioid consumption during the first 2 days. In patients undergoing RCR, CISB has demonstrated improved analgesia, fewer sleep disturbances, increased patient satisfaction, and reduced opioid requirements and opioid related side effects as compared with single-injection ISB up to 7 days. After shoulder adhesive capsulitis manipulation, a pilot study found that CISB was associated with lower average/dynamic pain scores, decreased opioid requirements, fewer awakenings from pain, and improved shoulder range of motion during and up to 12 weeks.

          While surgery-specific factors might make CISB attractive, medical circumstances, including but not limited to anticoagulation, pulmonary function, obesity, and OSA, must be suitable and stable for continuous perineural analgesia in the home environment. Social elements, however, may not allow for the safety of LA infusion at home: patients with cognitive dysfunction, which may make assessment of pain and complications difficult; unreliability of patients (patients with drug dependency or psychiatric disorders may not follow instructions); patients without a home support system (patients living alone or without a continual caretaker, in a dorm, or patients caring for a dependent spouse); and patients in whom the continuous infusion may make ambulation difficult. Finally, does a current or heightened risk of postoperative neurologic symptoms exclude a potentially more invasive continuous catheter technique and render continuous sensory block unfavorable? Risks and benefits of continuous interscalene analgesia must be carefully evaluated, after discussion with the patient and surgical team.

          Further Reading

          Borgeat A, Schappi B, Biasca N, Gerber C. Patient-controlled analgesia after major shoulder surgery: patient-controlled interscalene analgesia versus patient-controlled analgesia. Anesthesiology. 1997;87(6):1343–1347.Find this resource:

          Fredrickson MJ, Ball CM, Dalgleish AJ. Analgesic effectiveness of a continuous versus single-injection interscalene block for minor arthroscopic shoulder surgery. Reg Anesth Pain Med. 2010;35(1):28–33.Find this resource:

          Greengrass RA, Nielsen KC: Management of peripheral nerve block catheters at home. Int Anesthesiol Clin. 2005;43:79–87.Find this resource:

          Ilfeld BM, Morey TE, Wright TW, Chidgey LK. Continuous interscalene brachial plexus block for postoperative pain control at home: a randomized, double-blinded, placebo-controlled study. Anesth Analg. 2003 Apr;96(4):1089-95.Find this resource:

            Malhotra N, Madison SJ, Ward SR, Mariano ER, Loland VJ, Ilfeld BM. Continuous interscalene nerve block following adhesive capsulitis manipulation. Reg Anesth Pain Med. 2013;38(2):171–172.Find this resource:

            Neal JM, Barrington MJ, Brull R, et al. The Second ASRA Practice Advisory on Neurologic Complications Associated With Regional Anesthesia and Pain Medicine: Executive Summary 2015. Reg Anesth Pain Med. 2015 Sep-Oct;40(5):401-30.Find this resource:

              Salviz EA, Xu D, Frulla A, et al. Continuous interscalene block in patients having outpatient rotator cuff repair surgery: a prospective randomized trial. Anesth Analg. 2013; 117(6):1485–1492.Find this resource:

              3. Intraoperative Management: Surgical/Regional Anesthetic Considerations for Multimodal Perineural Analgesia

              3.1. What are anesthetic options for patients undergoing shoulder arthroscopy and RCR?

              Comorbidities, airway, aspiration risk, anticoagulation status, preexisting neuropathies, patient position, and case duration are critical factors in evaluating anesthetic management for shoulder surgery. Most commonly, surgery for RCR is performed under a general anesthetic or sedation in combination with an ISB. ISB is typically performed at the C5-C6 root/superior trunk level of the brachial plexus. It provides both brachial (C5-C7) and cervical (C3-C4) plexus blockade. Incomplete blockade of the inferior trunk (C8, T1) is not uncommon. ISB is performed as a single injection or as a continuous catheter technique under ultrasound or nerve stimulation guidance, or a combination of the two. Benefits include potential avoidance of volatile anesthetics, reduced opioid consumption and opioid-related side effects, and improved postoperative analgesia and rehabilitation. Alternative PNB techniques available for postoperative analgesia are discussed later in the chapter.

              Further Reading

              Franco CD, Williams JM. Ultrasound-guided interscalene block: reevaluation of the “stoplight” sign and clinical implications. Reg Anesth Pain Med. 2016;41(4):452–459.Find this resource:

              Hadzic A, Williams BA, Karaca PE, et al. For outpatient rotator cuff surgery, nerve block anesthesia provides superior same-day recovery over general anesthesia. Anesthesiology. 2005;102(5):1001–1007.Find this resource:

              Malhotra N, Madison SJ, Ward SR, Mariano ER, Loland VJ, Ilfeld BM. Continuous interscalene nerve block following adhesive capsulitis manipulation. Reg Anesth Pain Med. 2013;38(2):171–172.Find this resource:

              3.2. What side effects and complications are associated with ISB?

              Common side effects associated with ISB/CISB result from LA spread to adjacent nerves, including (1) the phrenic nerve, resulting in diaphragmatic paresis; (2) the recurrent laryngeal nerve, resulting in hoarseness/difficulty swallowing; and (3) the superficial cervical plexus, resulting in Horner’s syndrome with nasal congestion, ipsilateral partial ptosis, miosis, and conjunctival hyperemia. These side effects, while most prevalent with the initial bolus for surgical anesthesia, may persist with continuous perineural infusions and should be discussed with patients preoperatively. Motor-sensory block of the hand has been described as unsatisfactory by patients with an ISB/CISB. Potential complications include transient/permanent nerve injury, persistent phrenic nerve paresis, pneumothorax, bleeding, infection, epidural/spinal/subdural injection, intravascular injection, and LA toxicity. Contralateral spread has also been described with CISB.

              Further Reading

              Dooley J, Fingerman M, Melton S, Klein SM. Contralateral local anesthetic spread from an outpatient interscalene catheter. Can J Anesth/J Can Anesth. 2010;57(10):936–939.Find this resource:

              Fredrickson MJ, Abeysekera A, Price DJ, Wong AC. Patient-initiated mandatory boluses for ambulatory continuous interscalene analgesia: an effective strategy for optimizing analgesia and minimizing side-effects. Br J Anaesth. 2011;106(2):239–245.Find this resource:

              Fredrickson MJ, Price DJ. Analgesic effectiveness of ropivacaine 0.2% vs 0.4% via an ultrasound-guided C5–6 root/superior trunk perineural ambulatory catheter. Br J Anaesth. 2009 Sep;103(3):434-9.Find this resource:

                Shin H-J, Na H-S, Oh A-Y, et al. A prospective, randomized and controlled study of interscalene brachial plexus block for arthroscopic shoulder surgery: a comparison of C5 and conventional approach, a CONSORT-compliant article. Medicine (Baltimore). 2016;95(37):e4921.Find this resource:

                3.3. What alternatives are there to classical ISB?

                In an effort to potentially reduce these side effects, alternative PNB techniques or approaches to the brachial plexus may be performed. The C5 approach for ISB provides effective postoperative pain after arthroscopic shoulder surgery for rotator cuff tears and minimizes lower brachial plexus (C7, C8, and T1) blockade, avoiding prolonged numbness and weakness of the arm/hand. Low-dose interscalene approaches at C7 or supraclavicular approaches may reduce the possibility of hemidiaphragmatic paresis, but they do not exclude this possibility. Low interscalene, supraclavicular approaches may sacrifice the analgesia in an effort to reduce potential phrenic nerve paresis. Alternatively, suprascapular nerve blocks, combined supraclavicular and suprascapular nerve blocks, or combined suprascapular and axillary nerve blocks (shoulder block) of varying approaches may be performed. In patients undergoing general anesthesia for arthroscopic shoulder surgery, combined ultrasound-guided supraclavicular and suprascapular (suprascapular groove) nerve blocks demonstrated equivalent postoperative pain scores at 6, 12, and 24 hours; similar time to first request for morphine; and similar total morphine consumption during the first 24 hours compared with ISB. Combined ultrasound-guided suprascapular and axillary nerve blocks provided nonequivalent analgesia compared with ISB with increased mean opioids intraoperatively and in the PACU, higher pain scores in the PACU and at the 6-hour time point, but lower pain scores at the next data collection time point at 24 hours. Mean opioid consumption was not reported at 6- and 24-hour time points. There were no differences at 7 days.

                Ultrasound-guided suprascapular nerve block alone, using an anterior approach, in patients undergoing arthroscopic shoulder surgery demonstrated noninferior pain control, superior unimpaired grip strength, and an absence of ISB-related side effects including hoarseness, Horner’s syndrome, and dyspnea, compared with ISB, and subjects reported greater satisfaction and were more likely to recommend this anesthetic technique. When compared with ISB placed with neurostimulation, suprascapular nerve block performed intraoperatively by the surgical team utilizing a landmark-based technique was associated with greater pain and opioid consumption in the PACU, but there was no difference in mean pain scores or opioid consumption at other time points (6 hours, postoperative days [] 1, 2, and 7 after surgery). Of note, successful continuous suprascapular nerve catheters, as an analgesic supplement to single-injection supraclavicular nerve blocks, were described in case reports of 2 patients after shoulder arthroscopy. An additional stated advantage of suprascapular and axillary nerve blocks is the demonstrated hand sparing, a source of patient dissatisfaction. However, if patients are given preoperative counseling regarding the presence of this side effect, a notable decrease in patient satisfaction does not occur. Furthermore, a continuous interscalene ropivacaine infusion has a low incidence of significant distal motor block, as patients can usually use the operative hand on POD 1. When questioned about dissatisfaction of an ambulatory CISB with ropivacaine 0.2%, only 2 of 100 patients reported arm weakness.

                Combined infraclavicular-suprascapular blocks have also been proposed as a potential diaphragm-sparing technique. The infraclavicular approach targets the posterior and lateral cords, which would anesthetize the axillary nerve (anterior/posterior shoulder joint innervation), as well as the subscapular and lateral pectoral nerves (anterior shoulder joint innervation), whereas the suprascapular nerve block anesthetizes the posterior shoulder. Future randomized trials are required to validate the efficacy of this combined approach for shoulder surgery analgesia. Finally, selective targeting of shoulder innervation using intermuscular plane injections such as the subscapularis and sub-omohyoid planes has been proposed. Dispersion of LA along the ventral surface of subscapularis muscle blocks both axillary and subscapular nerves; below the sub-omohyoid, the suprascapular nerve; and the addition of the pectoral nerve (PECS-1) block to anesthetize the lateral pectoral nerve, if the acromio-clavicular joint is being operated upon. Combined subscapularis plane and sub-omohyoid plane injections were proposed to serve as an alternative to peripheral nerve blocks for shoulder analgesia, with minimal impact on phrenic nerve function. However, further comparative trials will be needed to evaluate this method in relation to other analgesic modalities.

                Further Reading

                Desroches A, Klouche S, Schlur C, Bauer T, Waitzenegger T, Hardy P. Suprascapular nerve block versus interscalene block as analgesia after arthroscopic rotator cuff repair: a randomized controlled noninferiority trial. Arthroscopy. 2016;32(11):2203–2209.Find this resource:

                Elsharkawy HA, Abd-Elsayed AA, Cummings KC, Soliman LM. Analgesic efficacy and technique of ultrasound-guided suprascapular nerve catheters after shoulder arthroscopy. Ochsner J. 2014;14(2):259–263.Find this resource:

                  Fredrickson M, Borgeat A. Continuous interscalene block is preferable to the “shoulder block” for postoperative analgesia following shoulder surgery. Anaesth Intensive Care. 2008;36(1):119–120; author reply 120–121.Find this resource:

                  Koh WU, Kim HJ, Park HS, Choi WJ, Yang HS, Ro YJ. A randomised controlled trial comparing continuous supraclavicular and interscalene brachial plexus blockade for open rotator cuff surgery. Anaesthesia. 2016;71(6):692–699.Find this resource:

                  Marty P, Rontes O, Delbos A. A comparison of combined suprascapular and axillary nerve blocks to interscalene block: interpret with caution. Reg Anesth Pain Med. 2017;42(2):273–274. doi:10.1097/AAP.0000000000000551Find this resource:

                  Matsumoto D, Suenaga N, Oizumi N, Hisada Y, Minami A. A new nerve block procedure for the suprascapular nerve based on a cadaveric study. J Shoulder Elbow Surg. 2009;18(4):607–611. doi:10.1016/j.jse.2009.01.005Find this resource:

                  Pitombo PF, Barros RM, Matos MA, Módolo NSP. Selective suprascapular and axillary nerve block provides adequate analgesia and minimal motor block: comparison with interscalene block. Braz J Anesthesiol. 2013;63(1):45–51.Find this resource:

                  Price D. It’s not just about the diaphragm. Reg Anesth Pain Med. 2017;42(3):416–417. doi:10.1097/AAP.0000000000000597Find this resource:

                  Price D. Optimizing the combined suprascapular and axillary nerve (SSAX) block. Reg Anesth Pain Med. 2017;42(1):122. doi:10.1097/AAP.0000000000000518Find this resource:

                  Renes SH, van Geffen GJ, Rettig HC, Gielen MJ, Scheffer GJ. Minimum effective volume of local anesthetic for shoulder analgesia by ultrasound-guided block at root C7 with assessment of pulmonary function. Reg Anesth Pain Med. 2010;35(6):529–534.Find this resource:

                  Reply to Dr Price. Reg Anesth Pain Med. 2017;42(1):123. doi:10.1097/AAP.0000000000000530Find this resource:

                  Reply to Marty et al. Reg Anesth Pain Med. 2017;42(2):274–275. doi:10.1097/AAP.0000000000000557Find this resource:

                  Ryu T, Kil BT, Kim JH. Comparison between ultrasound-guided supraclavicular and interscalene brachial plexus blocks in patients undergoing arthroscopic shoulder surgery: a prospective, randomized, parallel study. Medicine (Baltimore). 2015;94(40):e1726.Find this resource:

                  Shin H-J, Na H-S, Oh A-Y, et al. A prospective, randomized and controlled study of interscalene brachial plexus block for arthroscopic shoulder surgery: a comparison of C5 and conventional approach, a CONSORT-compliant article. Medicine (Baltimore). 2016;95(37):e4921.Find this resource:

                  Siegenthaler A, Moriggl B, Mlekusch S, et al. Ultrasound-guided suprascapular nerve block, description of a novel supraclavicular approach. Reg Anesth Pain Med. 2012;37(3):325–328. doi:10.1097/AAP.0b013e3182409168Find this resource:

                  Sondekoppam RV, Lopera-Velasquez L-M, Naik L, Ganapathy S. Subscapularis and sub-omohyoid plane blocks: an alternative to peripheral nerve blocks for shoulder analgesia. Br J Anaesth. 2016;117(6):831–832. doi:10.1093/bja/aew370Find this resource:

                  Trabelsi W, Ben Gabsia A, Lebbi A, Sammoud W, Labbène I, Ferjani M. Suprascapular block associated with supraclavicular block: an alternative to isolated interscalene block for analgesia in shoulder instability surgery? Orthop Traumatol Surg Res. 2017;103(1):77–83.Find this resource:

                  Tran DQ, Aliste J, Elgueta MF, Finlayson RJ. Reply to Dr Price. Reg Anesth Pain Med. 2017;42(3):417–418. doi:10.1097/AAP.0000000000000582Find this resource:

                  Tran DQH, Elgueta MF, Aliste J, Finlayson RJ. Diaphragm-sparing nerve blocks for shoulder surgery.—PubMed—NCBI. Reg Anesth Pain Med. 2017;42(1):32–38.Find this resource:

                  Verelst P, van Zundert A. Respiratory impact of analgesic strategies for shoulder surgery. Reg Anesth Pain Med. 2013;38(1):50–53.Find this resource:

                  Wiegel M, Moriggl B, Schwarzkopf P, Petroff D, Reske AW. Anterior suprascapular nerve block versus interscalene brachial plexus block for shoulder surgery in the outpatient setting: a randomized controlled patient- and assessor-blinded trial. Reg Anesth Pain Med. 2017;42(3):310–318.Find this resource:

                  3.4. What are the disadvantages of alternative techniques?

                  As compared with an ISB, selective blockade of the suprascapular and axillary nerves will leave several nerves unblocked: upper subscapular (teres major), lower subscapular, thoracodorsal (latissimus dorsi), and lateral and medial pectoral nerves, which are involved in most shoulder surgeries. As a result, selective blockade of the suprascapular and axillary nerves does not provide dense motor blockade of the upper arm and shoulder girdle necessary for surgical anesthesia and, potentially, adequate postoperative analgesia and protection of the surgical repair. However, in patients undergoing total shoulder arthroplasty, mean pain scores and 24-hour opioid consumption for continuous interscalene, supraclavicular, and suprascapular blocks, respectively, were not significantly different. Fewer adverse effects (Horner’s syndrome, dyspnea, and hoarseness) were noted in the suprascapular group when compared with the interscalene group.

                  Further Reading

                  Auyong DB, Yuan SC, Choi DS, Pahang JA, Slee AE, Hanson NA. A double-blind randomized comparison of continuous interscalene, supraclavicular, and suprascapular blocks for total shoulder arthroplasty. Reg Anesth Pain Med. 2017;42(3):302–309.Find this resource:

                  Desroches A, Klouche S, Schlur C, Bauer T, Waitzenegger T, Hardy P. Suprascapular nerve block versus interscalene block as analgesia after arthroscopic rotator cuff repair: a randomized controlled noninferiority trial. Arthroscopy. 2016;32(11):2203–2209.Find this resource:

                  Elsharkawy HA, Abd-Elsayed AA, Cummings KC, Soliman LM. Analgesic efficacy and technique of ultrasound-guided suprascapular nerve catheters after shoulder arthroscopy. Ochsner J. 2014;14(2):259–263.Find this resource:

                    Fredrickson M, Borgeat A. Continuous interscalene block is preferable to the “shoulder block” for postoperative analgesia following shoulder surgery. Anaesth Intensive Care. 2008;36(1):119–120; author reply 120–121.Find this resource:

                    Wiegel M, Moriggl B, Schwarzkopf P, Petroff D, Reske AW. Anterior suprascapular nerve block versus interscalene brachial plexus block for shoulder surgery in the outpatient setting: a randomized controlled patient- and assessor-blinded trial. Reg Anesth Pain Med. 2017;42(3):310–318.Find this resource:

                    3.5. What volume and concentration should be utilized to maximize postoperative analgesia associated with single-injection and continuous catheter ISB techniques?

                    Single-injection block duration is influenced by both LA volume and concentration, a finding in opposition to the current trend to use lower volumes for ultrasound-guided regional anesthesia. Increasing the volume of ropivacaine 0.375% from 10 to 40 mL was estimated to increase median (quartiles) block duration from 10.0 (9.5–11.5) to 15.0 (10.75–21) hours. Similarly, increasing the concentration of 20 mL ropivacaine from 0.375% to 0.75% was estimated to increase median (quartiles) block duration from 10.75 (9.75–14.0) to 13.75 (10.5–21.0) hours. Nonetheless, 5 mL of 0.5% ropivacaine did not reduce block quality as assessed by pain scores, sleep quality, and total morphine consumption up to 24 hours after surgery in comparison with 20 mL of 0.5% ropivacaine. However, ISB was not utilized as a surgical block.

                    Successful surgical anesthesia with ultrasound-guided ISB for shoulder arthroscopy can be accomplished with 5 mL of 0.75% ropivacaine (100%, 95% CI 74.1%–100%) without clinically apparent deterioration in block onset or duration. However, because the lower limit of the CI may be associated with a 25% failure rate, no meaningful statement regarding any difference in block duration between 5 mL or >5 mL of LA can be made from this study. Additionally, a low volume of LA may not yield adequate motor relaxation in all patients whereas a higher volume of LA may result in a more expeditious onset and more consistent duration of blockade.

                    When used for surgical anesthesia for shoulder arthroscopies in the ambulatory setting, a 20-mL volume in an ultrasound-guided ISB preserved 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. While readiness for surgical anesthesia was achieved sooner with 20 mL 1% ropivacaine, postoperative analgesia mean duration (SD) was similar with 20 mL of 3 ropivacaine concentrations (11.5 [5] h, 10.7 [2] h, and 10 [2.4] h with 0.5%, 0.75%, and 1% concentrations, respectively). Similar efficacy for surgical anesthesia and postoperative analgesia has been demonstrated between 30-mL equal concentrations of ropivacaine and bupivacaine, and increasing the concentration of ropivacaine from 0.5% to 0.75% failed to improve the onset or duration (mean >12 hours) of ISB.

                    In an effort to determine the volume and concentration of ropivacaine that would prevent recovery room pain after shoulder surgery under general anesthesia and CISB, the ED(vol)50/ED(vol)95 of ropivacaine 0.5%, was determined to be 2.7/20.5 mL, and the ED(conc)50/ED(conc)95 of ropivacaine 20 mL was 0.15/0.34%. As such, 20 mL of 0.375% ropivacaine (ED[vol]95 and ED[conc]95) prevented recovery room pain in approximately 95% of patients. If sonographic images and/or needle-to-nerve or catheter-to-nerve proximity are less than ideal, such that LA deposition is less accurate, a larger volume of LA may be required. With the administration of a larger volume of LA, placement accuracy may be less critical.

                    Further Reading

                    Casati A, Fanelli G, Aldegheri G, et al. Interscalene brachial plexus anaesthesia with 0.5%, 0.75% or 1% ropivacaine: a double-blind comparison with 2% mepivacaine. Br J Anaesth. 1999;83(6):872–875. doi:10.1093/bja/83.6.872Find this resource:

                    Fredrickson MJ, Abeysekera A, White R. Randomized study of the effect of local anesthetic volume and concentration on the duration of peripheral nerve blockade. Reg Anesth Pain Med. 2012;37(5):495–501. doi:10.1097/AAP.0b013e3182580fd0Find this resource:

                    Fredrickson MJ, Smith KR, Wong AC. Importance of volume and concentration for ropivacaine interscalene block in preventing recovery room pain and minimizing motor block after shoulder surgery. Anesthesiology. 2010;112(6):1374–1381. doi:10.1097/ALN.0b013e3181d6929dFind this resource:

                    Gautier P, Vandepitte C, Ramquet C, DeCoopman M, Xu D, Hadzic A. The minimum effective anesthetic volume of 0.75% ropivacaine in ultrasound-guided interscalene brachial plexus block. Anesth Analg. 2011;113(4):951–955. doi:10.1213/ANE.0b013e31822b876fFind this resource:

                    Klein SM, Greengrass RA, Steele SM, D’Ercole FJ, Speer KP, Gleason DH, DeLong ER, Warner DS: A comparison of 0.5% bupivacaine, 0.5% ropivacaine, and 0.75% ropivacaine for interscalene brachial plexus block. Anesthe Analg. 1998;87:1316–1319.Find this resource:

                    Maalouf DB, Dorman SM, Sebeo J, et al. Prospective, randomized double-blind study: does decreasing interscalene nerve block volume for surgical anesthesia in ambulatory shoulder surgery offer same-day patient recovery advantages? Reg Anesth Pain Med. 2016;41(4):438–444. doi:10.1097/AAP.0000000000000418Find this resource:

                    Riazi S, Carmichael N, Awad I, Holtby RM, McCartney CJL. Effect of local anaesthetic volume (20 vs 5 ml) on the efficacy and respiratory consequences of ultrasound-guided interscalene brachial plexus block. Br J Anaesth. 2008;101(4):549–556. doi:10.1093/bja/aen229Find this resource:

                    3.6. Are there perineural LA additives that can be utilized to prolong postoperative analgesia associated with PNB?

                    In order to provide evidence for a perineural mechanism of action, studies involving perineural LA additives to prolong postoperative analgesia should ideally comprise perineural treatment groups, intravenous systemic control groups, and saline control groups. Further, such additives should be preservative-free. Many trials to date investigating perineural additives are conflicting in terms of these additives’ efficacy to prolong postoperative analgesia and their systemic or perineural mechanism of action. Certainly, the idea of achieving extended analgesia with a single-injection technique is attractive as compared with the disadvantages of continuous catheter techniques, including time for placement, management, follow-up, leakage, catheter disconnection, pump malfunction, and cost. Research is ongoing into the combined administration of midazolam-clonidine-buprenorphine-dexamethasone to ropivacaine for ISB in shoulder surgery. In terms of perineural dexamethasone administered in combination with LA, conflicting results on its site of action, potential neurotoxicity, and off-label use support the intravenous administration of dexamethasone as a suitable alternative to improve postoperative analgesia following arthroscopic shoulder surgery. Interestingly, a common preoperative antiemetic 4-mg intravenous dose of dexamethasone was shown to be comparable to a 10-mg dose in its systemic analgesic effect in patients undergoing shoulder arthroscopy with ISB.

                    Further Reading

                    Chalifoux F, Colin F, St-Pierre P, Godin N, Brulotte V. Low dose intravenous dexamethasone (4 mg and 10 mg) significantly prolongs the analgesic duration of single-shot interscalene block after arthroscopic shoulder surgery: a prospective randomized placebo-controlled study. Can J Anesth/J Can Anesth. 2017;64(3):280–289. doi:10.1007/s12630-016-0796-6Find this resource:

                    Desmet M, Vanneste B, Reynvoet M, et al. A randomised controlled trial of intravenous dexamethasone combined with interscalene brachial plexus blockade for shoulder surgery. Anaesthesia. 2015;70(10):1180–1185. doi:10.1111/anae.13156Find this resource:

                    Ilfeld BM. Continuous peripheral nerve blocks: an update of the published evidence and comparison with novel, alternative analgesic modalities. Anesth Analg. 2017;124(1):308–335. doi:10.1213/ANE.0000000000001581Find this resource:

                    Neal JM, Rathmell JP, Rowlingson JC. Publishing studies that involve “off-label” use of drugs: formalizing Regional Anesthesia and Pain Medicine’s policy. Reg Anesth Pain Med. 2009;34(5):391–392.Find this resource:

                    Williams BA, Ibinson JW, Mangione MP, Scanlan RL, Cohen PZ. Clinical benchmarks regarding multimodal peripheral nerve blocks for postoperative analgesia: observations regarding combined perineural midazolam-clonidine-buprenorphine-dexamethasone. Pain Med. 2015;16(1):1–6. doi:10.1111/pme.12599Find this resource:

                    YaDeau JT, Gordon MA, Goytizolo EA, et al. Buprenorphine, clonidine, dexamethasone, and ropivacaine for interscalene nerve blockade: a prospective, randomized, blinded, ropivacaine dose-response study. Pain Med. 2016;17(5):940–960. doi:10.1093/pm/pnv010Find this resource:

                    3.7. How do surgical position and anesthetic choice affect intraoperative blood pressure management?

                    Requests for blood pressure reduction in an effort to reduce bleeding and obscuring arthroscopic visualization are not uncommon. In the BCP, blood pressure readings at the arm may not reflect postural cerebral perfusion. The brachial mean arterial pressure and the estimated temporal mean arterial pressure ratio decrease as an anesthetized patient is placed into the BCP. Systolic blood pressure reduction no lower than 90 mmHg and/or systolic blood pressure and mean arterial pressure reduction no greater than 20% of baseline is typically recommended to maintain adequate cerebral perfusion and prevent catastrophic events such as cerebral ischemia. Studies suggest that patients may be able to safely tolerate a reduction in blood pressure greater than current recommendations. In patients undergoing shoulder surgery under general anesthesia with ISB, BCP was associated with diminished cerebral autoregulation as compared with the lateral decubitus position, but not with a difference in cognitive outcome. While studies have demonstrated the incidence of postoperative neurocognitive deficit is low (overall incidence 0.004%), case reports have described catastrophic neurocognitive complications after shoulder surgery in the BCP. Cerebral oximetry can provide noninvasive, real-time measurement of relative and absolute hemoglobin oxygen saturation in the cerebral cortex. Despite adequate mean arterial pressures, patients under general anesthesia with volatile anesthetics demonstrated substantial cerebral desaturation events, unlike sedated patients with ISB. Thus, the use of ISB along with sedation and spontaneous respiration via a natural airway may reduce the risk of ischemic neurologic injury.

                    Further Reading

                    Gillespie R, Shishani Y, Streit J, et al. The safety of controlled hypotension for shoulder arthroscopy in the beach-chair position. J Bone Joint Surg Am. 2012;94(14):1284–1290. doi:10.2106/JBJS.J.01550Find this resource:

                    Koh JL, Levin SD, Chehab EL, Murphy GS. Neer Award 2012: cerebral oxygenation in the beach chair position: a prospective study on the effect of general anesthesia compared with regional anesthesia and sedation. J Shoulder Elbow Surg. 2013;22(10):1325–1331. doi:10.1016/j.jse.2013.01.035Find this resource:

                    Lanier WL. Cerebral perfusion: err on the side of caution. APSF Newsletter. 2009. 24:1.Find this resource:

                      Laflam A, Joshi B, Brady K, et al. Shoulder surgery in the beach chair position is associated with diminished cerebral autoregulation but no differences in postoperative cognition or brain injury biomarker levels compared with supine positioning: the Anesthesia Patient Safety Foundation Beach Chair Study. Anesth Analg. 2015;120(1):176–185. doi:10.1213/ANE.0000000000000455Find this resource:

                      Rohrbaugh M, Kentor ML, Orebaugh SL, Williams B. Outcomes of shoulder surgery in the sitting position with interscalene nerve block: a single-center series. Reg Anesth Pain Med. 2013;38(1):28–33. doi:10.1097/AAP.0b013e318277a2ebFind this resource:

                      Salazar D, Hazel A, Tauchen AJ, Sears BW, Marra G. Neurocognitive deficits and cerebral desaturation during shoulder arthroscopy with patient in beach-chair position: a review of the current literature. Am J Orthop. 2016;45(3):E63–E68.Find this resource:

                        Triplet JJ, Lonetta CM, Everding NG, Moor MA, Levy JC. Association between temporal mean arterial pressure and brachial noninvasive blood pressure during shoulder surgery in the beach chair position during general anesthesia. J Shoulder Elbow Surg. 2015;24(1):127–132. doi:10.1016/j.jse.2014.05.011Find this resource:

                        YaDeau JT, Casciano M, Liu SS, et al. Stroke, regional anesthesia in the sitting position, and hypotension: a review of 4169 ambulatory surgery patients. Reg Anesth Pain Med. 2011;36(5):430–435. doi:10.1097/AAP.0b013e318228d54eFind this resource:

                        3.8. Are there additional cardiac implications of surgical position?

                        Sudden hypotensive bradycardic events (HBEs) have been reported during shoulder surgery in the sitting position under ISB. The Bezold-Jarish reflex has been one proposed mechanism for the occurrence of HBEs. The reflex originates in cardiac sensory receptors with vagal afferent pathways in the left ventricle. Stimulation of these inhibitory cardiac receptors by stretch, chemical substances, or drugs increases parasympathetic activity and inhibits sympathetic activity. These effects promote reflex bradycardia, vasodilation, and hypotension. Venous pooling in the sitting position with a resultant decreased preload stimulates endogenous catecholamine release and increased cardiac contractility, which may stimulate this reflex. Additionally, exogenous catecholamine sources in this setting include epinephrine added to LA for ISB and irrigation solution. Proposed prophylactic interventions include increasing preload by intravenous fluid administration, beta blockade, and adequate sedation, as a less sedated patient may have more endogenous catecholamines and heightened vagal tone. Additionally, norepinephrine as opposed to epinephrine in the irrigation fluid has been demonstrated to reduce the incidence of HBE while effectively controlling intraoperative bleeding and resultant surgical visualization.

                        Further Reading

                        Chierichini A, Frassanito L, Vergari A, et al. The effect of norepinephrine versus epinephrine in irrigation fluid on the incidence of hypotensive/bradycardic events during arthroscopic rotator cuff repair with interscalene block in the sitting position. Arthroscopy. 2015;31(5):800–806. doi:10.1016/j.arthro.2015.02.030Find this resource:

                        D’Alessio JG, Rosenblum M, Shea KP, Freitas DG. A retrospective comparison of interscalene block and general anesthesia for ambulatory surgery shoulder arthroscopy. Reg Anesth. 1995;20(1):62–68.Find this resource:

                        D’Alessio JG, Weller RS, Rosenblum M. Activation of the Bezold-Jarisch reflex in the sitting position for shoulder arthroscopy using interscalene block. Anesth Analg. 1995;80(6):1158–1162. doi:10.1016/j.jse.2014.05.011Find this resource:

                        Liguori GA, Kahn RL, Gordon J, Gordon MA. The use of metoprolol and glycopyrrolate to prevent hypotensive/bradycardic events during shoulder arthroscopy in the sitting position under interscalene block. Anesth Analg. 1998 Dec;87(6):1320-5.Find this resource:

                          4. Postoperative Management: Ambulatory Continuous Perineural Infusions

                          4.1. What is the ideal infusate for CISB?

                          Data suggest that ropivacaine, bupivacaine, and levobupivacaine provide similar analgesia. While ropivacaine is more expensive, it has a safer cardiac profile, and it may induce fewer finger paresthesias and less hand weakness than comparable concentrations of bupivacaine. Ropivacaine 0.2% provides more effective analgesia than ropivacaine 0.1% during the first 24 hours for CISB after shoulder surgery. There remains no medications other than LA approved for continuous perineural administration by the US Food and Drug Administration.

                          Further Reading

                          Choromanski DW, Patel PS, Frederick JM, Lemos SE, Chidiac EJ. The effect of continuous interscalene brachial plexus block with 0.125% bupivacaine vs 0.2% ropivacaine on pain relief, diaphragmatic motility, and ventilatory function. J Clin Anesth. 2015;27(8):619–626. doi:10.1016/j.jclinane.2015.03.006Find this resource:

                          Ilfeld BM. Continuous peripheral nerve blocks: an update of the published evidence and comparison with novel, alternative analgesic modalities. Anesth Analg. 2017;124(1):308–335. doi:10.1213/ANE.0000000000001581Find this resource:

                          Ilfeld BM. Continuous peripheral nerve blocks: a review of the published evidence. Anesth Analg. 2011;113(4):904–925. doi:10.1213/ANE.0b013e3182285e01Find this resource:

                          Yang CW, Jung SM, Kang PS, et al. A randomized comparison of ropivacaine 0.1% and 0.2% for continuous interscalene block after shoulder surgery.—PubMed—NCBI. Anesth Analg. 2013;116(3):730–733. doi:10.1213/ANE.0b013e318280e109Find this resource:

                            4.2. Are bolus doses better than basal infusions during CISB?

                            The addition of patient-controlled boluses to CISB may allow for (1) decreasing motor block by decreasing the required basal infusion rate; (2) decreasing the incidence of an insensate extremity; and (3) extending infusion/analgesia duration for outpatients discharged with a fixed LA reservoir volume. At the expense of increasing LA consumption, high basal rate (8 mL/h) ropivacaine 0.2% infusion combined with low-volume, patient-controlled bolus doses (2 mL/h) reduced baseline pain scores, sleep disturbances, and the incidence and severity of breakthrough pain in patients undergoing moderately painful outpatient shoulder surgery with a CISB. An alternative or additional bolus strategy is the addition of a mandatory/automatic bolus dose, in an effort to maximize perineural spread by distributing an equivalent slow basal infusion dose/volume as a bolus. However, in ultrasound-guided CISB after shoulder surgery, automated LA boluses combined with PRN boluses did not reduce LA consumption or rescue analgesia, compared with basal infusion combined with PRN boluses.

                            Further Reading

                            Byeon GJ, Shin SW, Yoon JU, Kim EJ, Baek SH, Ri HS. Infusion methods for continuous interscalene brachial plexus block for postoperative pain control after arthroscopic rotator cuff repair. Korean J Pain. 2015;28(3):210–216. doi:10.3344/kjp.2015.28.3.210Find this resource:

                              Fredrickson MJ, Abeysekera A, Price DJ, Wong AC. Patient-initiated mandatory boluses for ambulatory continuous interscalene analgesia: an effective strategy for optimizing analgesia and minimizing side-effects. Br J Anaesth. 2011;106(2):239–245. doi:10.1093/bja/aeq320Find this resource:

                              Hamdani M, Chassot O, Fournier R. Ultrasound-guided continuous interscalene block: the influence of local anesthetic background delivery method on postoperative analgesia after shoulder surgery: a randomized trial. Reg Anesth Pain Med. 2014;39(5):387–393. doi:10.1097/AAP.0000000000000112Find this resource:

                              Hashimoto A, Ito H, Sato Y, Fujiwara Y: Automated intermittent bolus infusion for continuous sciatic nerve block: a case report. Masui 2011;60:873–875.Find this resource:

                                Ilfeld BM, Morey TE, Wright TW, Chidgey LK, Enneking FK: Interscalene perineural ropivacaine infusion: a comparison of two dosing regimens for postoperative analgesia. Reg Anesth Pain Med. 2004;29:9–16.Find this resource:

                                4.3. What are the benefits of CISB?

                                Ambulatory perineural infusions are a critical component to efficacious multimodal postoperative analgesia following shoulder surgery in the outpatient setting. Implementation is indeed challenging, and there is often a perception that CISB and ambulatory perineural infusions are only feasible in an academic setting. However, following RCR in a multiprovider private practice setting, CISB was associated with reduced total opioid and antiemetic consumption, and occurred without a significant increase in the monetary cost.

                                Evidence suggests that poorly treated acute postoperative pain and acute postoperative opioid use can lead to nociception-induced central sensitization and opioid-induced secondary hyperalgesia, respectively. Both mechanisms may be involved in the pathogenesis of persistent postsurgical pain, an entity that can occur following rotator cuff surgery. CISB may play a part in efforts to reduce these mechanisms. In patients undergoing RCR, CISB has demonstrated improved analgesia and reduced opioid requirements compared with single-injection ISB up to 7 postoperative days. A pilot study found that CISB was associated with lower average/dynamic pain scores, decreased opioid requirements, fewer awakenings from pain, and improved shoulder range of motion up to 12 weeks after shoulder adhesive capsulitis manipulation.

                                Further Reading

                                Angst MS, Clark JD: Opioid-induced hyperalgesia: a qualitative systematic review. Anesthesiology 2006;104:570–587Find this resource:

                                Borgeat A, Schappi B, Biasca N, Gerber C. Patient-controlled analgesia after major shoulder surgery: patient-controlled interscalene analgesia versus patient-controlled analgesia. Anesthesiology. 1997;87(6):1343–1347.Find this resource:

                                Fredrickson MJ. Orthopedic anesthesia subspecialization: the way forward to increase utilization of perineural infusions? Reg Anesth Pain Med. 2012;37(3):359–360; author reply 360.Find this resource:

                                Fredrickson MJ, Stewart AW. Continuous interscalene analgesia for rotator cuff repair: a retrospective comparison of effectiveness and cost in 205 patients from a multi-provider private practice setting. Anaesth Intensive Care. 2008;36(6):786–791.Find this resource:

                                Ilfeld BM, Morey TE, Wright TW, Chidgey LK. Continuous interscalene brachial plexus block for postoperative pain control at home: a randomized, double-blinded, placebo-controlled study. Anesth Analg. 2003 Apr;96(4):1089-95.Find this resource:

                                  Kehlet H, Jensen TS, Woolf CJ. Persistent postsurgical pain: risk factors and prevention. Lancet. 2006;367(9522):1618–1625.Find this resource:

                                  Klein SM, Steele SM, Nielsen KC, et al. The difficulties of ambulatory interscalene and intra-articular infusions for rotator cuff surgery: a preliminary report. Can J Anaesth. 2003;50(3):265–269.Find this resource:

                                  Malhotra N, Madison SJ, Ward SR, Mariano ER, Loland VJ, Ilfeld BM. Continuous interscalene nerve block following adhesive capsulitis manipulation. Reg Anesth Pain Med. 2013;38(2):171–172. doi:10.1097/AAP.0b013e318283475bFind this resource:

                                  Salviz EA, Xu D, Frulla A, et al. Continuous interscalene block in patients having outpatient rotator cuff repair surgery: a prospective randomized trial. Anesth Analg. 2013;117(6):1485–1492. doi:10.1213/01.ane.0000436607.40643.0aFind this resource:

                                  4.4. What items should be discussed with patients, and accompanying caretakers, prior to discharge home with perineural infusions?

                                  It is essential to have specific written instructions discussed with both the patient and his or her accompanying caregiver prior to discharge. It is not recommended that ambulatory perineural infusions be used for any patient unless physician/nurse consultation is immediately available 24/7. Pain team contact numbers (daytime and after hours) should be printed on the instruction form. Instructions should include the following:

                                  1. 1. The expected transition time from surgical block with initial bolus to analgesic block with perineural infusion and signs of surgical block resolution;

                                  2. 2. Review of oral multimodal analgesic regimen;

                                  3. 3. The location of the catheter (interscalene);

                                  4. 4. The infusion system used;

                                  5. 5. The specific LA, including basal rate per hour (if applicable) and bolus dose with lockout interval (if applicable);

                                  6. 6. The expected duration of the infusion;

                                  7. 7. Caution as to protection of the insensate part of the body and care in ambulation;

                                  8. 8. Potential for leakage at catheter insertion site;

                                  9. 9. Instructions to discontinue the system and call the contact anesthesiologist immediately if patient develops skin rash, hives, other allergic responses, ringing in the ears, tingling of the mouth or tongue, or other signs/symptoms of LA toxicity;

                                  10. 10. Instructions for physician/nurse contact if patient develops fever, pain at the catheter insertion site, increased extremity numbness or weakness, inadequate pain control, or problems with the infusion system (malfunction, leakage, disconnection, etc.); and

                                  11. 11. Instructions for removal of catheter.

                                  Further Reading

                                  Greengrass RA, Nielsen KC. Management of peripheral nerve block catheters at home. Int Anesthesiol Clin. 2005;43(3):79–87.Find this resource:

                                  4.5. What are causes for PONS, and how can they be managed?

                                  Postoperative neurologic symptoms must be identified and addressed by the surgeon and anesthesiologist. New onset of PONS such as numbness, tingling, and/or weakness in the surgical extremity may occur after surgery, with or without ISB. Marecek describes complications in shoulder arthroscopy: nerve damage after shoulder arthroscopy is fortunately rare, with reported rates of ≤3%, with larger series reporting rates <0.2%; paresthesias have been reported in 10% to 30% of cases; injuries to the median, axillary, musculocutaneous, medial antebrachial cutaneous, radial, ulnar, medial pectoral, and anterior interosseous nerves, as well as cutaneous hypoesthesias, have all been reported. These injuries are generally transient, although permanent damage requiring tendon transfers has been described. Positioning, traction, joint distention and fluid extravasation, and direct injury from portal placement have all been implicated in postoperative nerve injuries. Sulcus ulnaris syndrome, carpal tunnel syndrome, and the development of complex regional pain syndrome are additional potential etiologies. By obtaining a detailed history and report of signs/symptoms, serious etiologies can often be excluded, and patient reassurance about the transient nature of such symptoms is the only necessary intervention. While transient numbness/tingling of the extremity is not uncommon, motor weakness after block resolution is more alarming and requires immediate evaluation. Early involvement of neurology for baseline electrophysiologic studies must be considered. Additionally, neurology and/or chronic pain specialists can be utilized to evaluate and manage neuropathic pain and/or symptoms that interfere with activities of daily living. In cases of persistent phrenic nerve paresis, pulmonology should be involved.

                                  Further Reading

                                  Borgeat A, Ekatodramis G, Kalberer F, Benz C. Acute and nonacute complications associated with interscalene block and shoulder surgery: a prospective study. Anesthesiology. 2001;95:875–880.Find this resource:

                                  Marecek GS, Saltzman MD. Complications in shoulder arthroscopy. Orthopedics. 2010;33(7):492–497.Find this resource:

                                  Neal JM, Barrington MJ, Brull R, et al. The Second ASRA Practice Advisory on Neurologic Complications Associated With Regional Anesthesia and Pain Medicine: Executive Summary 2015. Reg Anesth Pain Med. 2015 Sep-Oct;40(5):401-430.Find this resource:

                                  Painful arthroscopic shoulder surgery and RCR are almost exclusively performed on an outpatient basis. Patient-specific and surgery-specific considerations must be evaluated when making decisions for intraoperative anesthesia and postoperative analgesia. ISB is the most commonly performed PNB for shoulder surgery, although side effects associated with its use has spurred investigation into alternative techniques and combinations therein. The safety and efficacy of adjuvants to extend LA duration achieved with single-injection PNBs are still under investigation. As such, extended postoperative analgesia relies on continuous catheter techniques. Appropriate dosing regimens must be employed for both single-injection ISB and CISB to optimize intraoperative anesthesia and postoperative analgesia. A protocol must be in place for the safe and effective discharge and follow-up of patients going home with continuous perineural infusions.

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