Current Approaches to Regional Anesthesia

Educational Objectives

The goals of this program are to improve the use of continuous peripheral nerve catheter infusions and to identify benefits of regional anesthesia (RA) over general anesthesia (GA). After hearing and assimilating this program, the clinician will be better able to:

1.   Discuss the efficiency of analgesia and rapid return of function associated with continuous peripheral nerve block infusions for major orthopedic procedures.

2.   Explain the adjunctive use of multimodal non-narcotic analgesia with peripheral nerve catheter infusions for improving efficacy and pain relief in the postoperative period.

3.   Apply continuous peripheral nerve infusions in the outpatient setting.

4.   List issues for the surgeon, patient, and anesthesia provider to consider when choosing RA.

5.   Appraise the benefits of RA over GA for particular surgical populations and specific procedures.

Faculty Disclosure

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and planning commit­tee members to disclose relevant financial relationships within the past 12 months that might create any personal con­flicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, the faculty and planning commit­tee reported nothing to disclose.

Acknowledgments

Dr. Mulroy spoke in New York, NY, at the 62nd Annual Postgraduate Assembly in Anesthesiology, held December 12-16, 2008, and sponsored by the New York State Society of Anesthesiologists. Dr. Liguori spoke in Seattle, WA, at Sleepless in Seattle: East Meets West 2, Regional Anesthesia 2008, held August 8-10, 2008, and sponsored by the Vir­ginia Mason Medical Center, Seattle, WA. The Audio-Digest Foundation thanks the speakers and the sponsors for their cooperation in the production of this program.

Catheters in House and at Home

Michael F. Mulroy, MD, Clinical Professor of Anesthesiology, University of Washington School of Medicine, and Faculty Anesthesiologist, Virginia Mason Medical Center, Seattle, WA

Overview: recent survey confirms earlier data showing postoperative pain relief inadequate; pain has detrimental ef­fects on physiologic response to surgical experience, mental health, and rehabilitation; ³23%  of patients experi­ence side effects from systemic opioids, including nausea, vomiting, and dysphoria; feedback from surgeons about “how miserable their patients are” and difficulties with rehabilitation due to inadequate pain control inspired start of peripheral nerve catheter service; in inpatient setting, epidural analgesia effective; many studies confirm superi­ority over systemic opioids for abdominal and thoracic surgery, and even for some major lower extremity orthope­dic procedures; challenges associated with epidural anesthesia  —  hematomas common in orthopedic patients started on anticoagulation in immediate postoperative period; risk for respiratory depression with use of opioids (absent with use of local anesthetics in peripheral catheters); difficult to send patient home if receiving epidural in­fusion; comparative studies of peripheral nerve catheter infusions of upper and lower extremities vs systemic opioids  —  in all cases, catheter infusions provided better pain relief at all measurement times and for all catheter lo­cations (ie, interscalene, femoral, sciatic); also less opioid use, reduced nausea, vomiting, sedation, and pruritus, and better sleep patterns

Inpatient procedures: for major orthopedic procedures (frequently involve postoperative anticoagulation therapy), use of continuous catheters shown to provide excellent analgesia and faster return of function for shoulder, knee, and hip replacements; particularly for total knee replacement, use of continuous peripheral nerve catheter infu­sion provides better analgesia; femoral nerve catheters shown to provide significant (but not complete) analgesia and reduction of opioid consumption; addition of sciatic or obturator block provides improved analgesia, but sec­ond block often precluded by time constraints of busy practice; speaker saves rescue block for recovery room

Multimodal oral analgesics (eg, celecoxib [Celebrex], gaba-pentin, acetaminophen): when given morning before surgery, dramatically reduce requests for rescue analgesia in recovery room; subarachnoid morphine effective for first 24 hr, but has significant side effects (eg, pruritus, respiratory depression); getting patient “up and moving” while integrating femoral nerve catheter service (ie, need to limit length of stay [LOS]) major issue in United States; studies from Virginia Mason Medical Center and Cleveland Clinic show average LOS 3 to 4 days for or­thopedic surgeries using peripheral nerve catheter; speaker has shifted to preoperative multimodal oral analgesics to overcome problem of femoral nerve block interfering with rehabilitation

Continuous catheter infusion procedure: catheter placed preoperatively on morning of surgery; spinal anesthetic ad­minstered for surgery; if patient continues to have significant posterior pain in recovery room, supplemental sci­atic block performed; requests for supplemental block have diminished significantly since speaker began implementing multimodal analgesia; in catheter, speaker uses infusion of ropivacaine, 0.2%; less potent than bu­pivacaine (shorter duration and less density of motor block, so more easily reversed); infusion discontinued on morning of first postoperative day, and patient able to begin rehabilitation exercises; catheter re-bolused in eve­ning to provide comfortable overnight stay, then removed on second morning (36 hr after surgery) to allow for more intensive rehabilitation; use of systemic opioids has decreased significantly (with corresponding reduction of side effects); patients, surgeons, and physical therapists satisfied

Challenges: need to label clearly to avoid erroneous injections through tubing; must secure catheter correctly; in­fection has not been issue due to short placement time (only 36 hr); choose drug “that’s a little less dense in its motor block” and coordinate with physical therapy

Effectiveness in hospital: Capdevila et al reported 96% of patients had effective analgesia at £56 hr

Outpatient procedures: patients with rotator cuff repair, anterior cruciate ligament (ACL) repair, and major foot sur­gery appropriate candidates for interscalene, femoral, and popliteal compartment blocks, respectively

Advantages: study by Ilfeld et al looked at interscalene catheters for shoulder surgery; found better analgesia (lower visual analogue scale [VAS] scores) at rest and at maximum pain; also found patients with continuous infusion slept better (not waking frequently to take pain medication); rebound occurs when infusion discontinued, but pa­tient satisfaction high in first 3 days; speaker finds patient fully alert and able to leave recovery room quickly; surgeon satisfaction high after rotator cuff repair; continuous catheter also found to provide effective analgesia for lower extremity procedures, particularly ACL repair (patellar tendon graft more painful than cadaver or ham­string graft); Williams et al similarly found excellent analgesia and patient satisfaction with continuous femoral nerve infusions; Ilfeld has shown continuous sciatic nerve infusions provide better analgesia, less opioid con­sumption, and better sleep patterns; conclusions  —  literature supports better analgesia, better rehabilitation, and better function with peripheral nerve infusions

Potential risks: Swenson et al demonstrated in large trial (>600 patients) that discharging to home with continuous catheters and infusion devices practical and safe; patients managed with minimal physician intervention; most patients comfortable with discharge from hospital and removal of catheter at home

Practical considerations: placement of peripheral nerve catheter requires more effort and time before procedure, but results in greater patient and surgeon satisfaction; placement of catheters billable (but follow-up telephone calls are not); reimbursement relatively generous and helps support service; requires extra effort or additional person­nel to prepare setup (ie, anesthesia tray, equipment) in advance; requires 24-hr coverage; thorough patient educa­tion also necessary (at speaker’s institution, provided in surgeon’s office, in anesthesia preoperative clinic, and in joint replacement class)

Technical issues: write down protocols for performing block and for patient management; establish routines to han­dle common scenarios (educate nurses about catheter management); provide written orders for inpatients and written instructions for outpatients (including, eg, expectations, dealing with numb extremity); speaker prefers bupivacaine for single-injection block, and ropivacaine for infusion; in outpatients, use ropivacaine for infusion (weaker drug; patients prefer some sensation); variety of catheters and infusion pumps available; speaker changes frequently, based on experience and desire to try new products

Regional Anesthesia: Is it Really Worth the Trouble?

Gregory A. Liguori, MD, Clinical Associate Professor of Anesthesiology, Weill Medical College of Cornell University, Director, Department of Anesthesiology, and Anesthesiologist-in-Chief, Hospital for Special Sur­gery, New York, NY

Introduction: speaker considers regional anesthesia (RA) preferable to general anesthesia (GA); however, RA pres­ents some concerns for surgeons, patients, and anesthesia providers

Concerns: surgeon  —  influences patients’ choice of operative anesthesia in obstetric (OB) and surgical populations; to perform RA, surgeon must agree with anesthesia provider; concerns include delays in operating room and unpre­dictable success; anesthesia providers must learn to perform RA more quickly, safely, and effectively on more reg­ular basis; patient  —  must be convinced to have RA; concerns include seeing surgery, having needle placed in back, and experiencing pain during surgery; change attitudes about RA by providing education (talk to patient one-on-one and explain advantages); media reports sometimes beneficial; websites also explain RA from patient’s perspec­tive; American Society of Regional Anesthesia (ASRA) and American Society of Anesthesiologists (ASA) have at­tempted to educate public about RA; anesthesia provider  —must learn to perform RA on regular basis; must determine whether RA training during residency sufficient for proficient practice; Accreditation Council for Grad­uate Medical Education (ACGME) states that residents required to perform 40 epidural anesthetics, 40 spinal anes­thetics, and 40 peripheral nerve blocks (eg, 40 axillary blocks); 40 combined spinal-epidural (CSE) anesthetics substitute for 40 spinals and 40 epidurals; studies show residents generally meet minimum procedure requirements; however, individually, many residents not learning enough RA; Swiss study which looked at training necessary to perform RA competently showed that 90 epidurals and 62 brachial plexus blocks required; study from Virginia Ma­son Medical Center showed  each resident needs to perform 45 spinal anesthetics and 60 epidural anesthetics to achieve competence (ie, procedure success rate 90%); most providers achieve required competence through exten­sive clinical experience and fellowship training; expertise in RA important because surgical morbidity and mortal­ity increases in cases in which conversion to GA becomes necessary; summary    —  convince surgeons of efficiency of RA by minimizing delays using effective techniques; once surgeons “on our side,” patients will follow easily; educate patient about true benefits of and dispel myths about RA; train qualified RA providers

Regional anesthesia vs general anesthesia: superiority of RA over GA depends on several criteria, including defini­tion of “better,” specific type of RA, surgical population, and, most importantly, specific procedure

Definitions: speaker defines major morbidities as cardiovascular (CV) complications (eg, coagulation issues, pul­monary embolism [PE], deep venous thrombosis [DVT]), other pulmonary complications, death); minor mor­bidities include pain, and postoperative nausea and vomiting (PONV); other outcomes (eg, satisfaction, efficiency) harder to measure

Major morbidities: CV complications  —  several studies show decreased cardiac sympathetic outflow, favorable impact on heart rate and blood pressure, and possibly improved coronary blood flow (BF) with thoracic epidu­ral anesthesia and analgesia; coagulation  —increased peripheral BF, preservation of fibrinolytic activity, and decreased blood viscosity seen with neuraxial anesthesia and analgesia; pulmonary morbidities  —  improved diaphragmatic activity seen with RA postoperatively; also preserves hypoxic pulmonary vasoconstriction and facilitates pulmonary rehabilitation; death  —relatively rare event; meta-analysis and large database analysis find epidural anesthesia associated with lower incidence at 7 days and 30 days postoperatively

Minor morbidities: Block et al state that epidural analgesia (regardless of agent, location of catheter placement, or type and time of pain assessment) provided better postoperative analgesia, compared with parenteral opi­oids; another study found incidence of severe pain significantly lower with epidural, compared to intramuscu­lar (IM), narcotics; common assumption that RA associated with less PONV than GA generally correct (although newer GAs may cause less PONV); procedure specific (eg, reduction in PONV seen with breast pro­cedures and paravertebral blocks, less so with knee arthroscopy; significantly lower incidence in shoulder and hand surgeries); no studies show superiority of GA over RA for any of these outcomes

Specific type of RA: study looking at thoracic epidural anesthesia, spinal anesthesia, and lumbar epidural anesthe­sia found spinal anesthesia and thoracic epidural anesthesia most beneficial; no benefits with lumbar epidural an­esthesia compared to GA; benefit seen for neuraxial anesthesia vs GA, but when neuraxial combined with GA, no benefit over GA alone

Surgical population: no real benefits of RA for general, urologic, or vascular procedures; most benefits with ortho­pedic surgery

Specific procedure: meta-analysis which looked at elective total hip replacement found reduced intraoperative blood loss, lower incidence of DVT, and fewer thromboembolic events (eg, PE) with RA (neuraxial block) vs GA; Liu et al looked at benefits of central neuraxial block vs GA in ambulatory patients; found lower pain scores, less nausea, and less need for postoperative analgesia; same study looked at benefits of peripheral nerve blocks vs GA; found improved anesthesia induction time, postanesthesia care unit (PACU) time, VAS scores in PACU, nausea, and PACU bypass; Hadzic et al found more PACU bypass, better VAS scores, and lower incidence of PONV with RA (interscalene block) in outpatient rotator cuff repairs; same group looked at hand and wrist sur­gery; found significant benefits for pain reduction and PONV with RA; Mulroy et al compared spinal, epidural, and GA for knee arthroscopy; found satisfactory anesthesia for outpatient knee arthroscopy with either GA or epidural; therefore, choice of anesthetic technique dependent on patient’s desire to be alert and participatory during procedure; conclusions  —  speaker sees significant benefits of RA over GA; benefits procedure-, patient population-, and anesthetic-specific

Suggested Reading

Block BM et al: Efficacy of postoperative epidural analgesia: a meta-analysis. JAMA 290:2455, 2003; Borgeat A et al: Postoperative nausea and vomiting in regional anesthesia: a review. Anesthesiology 98:530, 2003; Bröking K, Waurick R: How to teach regional anesthesia. Curr Opin Anaesthesiol 19:526, 2006; Capdevila X et al: Effect of patient-controlled perineural analgesia on rehabilita­tion and pain after ambulatory orthopedic surgery: a multicenter randomized trial. Anesthesiology 105:566, 2006; Capdevila X et al: Effects of perioperative analgesic technique on the surgical outcome and duration of rehabilitation after major knee surgery. Anesthe­siology 91:8, 1999; Chelly JE et al: Training of residents in peripheral nerve blocks during anesthesiology residency. J Clin Anesth 14:584, 2002; Guay J: The effect of neuraxial blocks on surgical blood loss and blood transfusion requirements: a meta-analysis. J Clin Anesth 18:124, 2006; Hadzic A et al: A comparison of infraclavicular nerve block versus general anesthesia for hand and wrist day-case surgeries. Anesthesiology 101:127, 2004; Hadzic A et al: Training requirements for peripheral nerve blocks. Curr Opin An­aesthesiol 15:669, 2002; Ilfeld BM et al: Continuous infraclavicular brachial plexus block for postoperative pain control at home: a randomized, double-blinded, placebo-controlled study. Anesthesiology 96:1297, 2002; Ilfeld BM et al: Continuous interscalene bra­chial plexus block for postoperative pain control at home: a randomized, double-blinded, placebo-controlled study. Anesth Analg 96:1089, 2003; Ilfeld BM et al: Portable infusion pumps used for continuous regional analgesia: delivery rate accuracy and consis­tency. Reg Anesth Pain Med 28:424, 2003; Ilfeld BM, Enneking FK: Continuous peripheral nerve blocks at home: a review. Anesth Analg 100:1822, 2005; Konrad C et al: Learning manual skills in anesthesiology: Is there a recommended number of cases for anes­thetic procedures? Anesth Analg 86:635, 1998; Liu SS et al: A comparison of regional versus general anesthesia for ambulatory anes­thesia: a meta-analysis of randomized controlled trials. Anesth Analg 101:1634, 2005; Morin AM et al: Postoperative analgesia and functional recovery after total-knee replacement: comparison of a continuous posterior lumbar plexus (psoas compartment) block, a continuous femoral nerve block, and the combination of a continuous femoral and sciatic nerve block. Reg Anesth Pain Med 30:434, 2005; Mulroy MF et al: A comparison of spinal, epidural, and general anesthesia for outpatient knee arthroscopy. Anesth Analg 91:860, 2000; Richman JM et al: Does continuous peripheral nerve block provide superior pain control to opioids? A meta-analysis. Anesth Analg 102:248, 2006; Singelyn FJ et al: Effects of intravenous patient-controlled analgesia with morphine, continuous epidu­ral analgesia, and continuous femoral nerve sheath block on rehabilitation after unilateral total-hip arthroplasty. Reg Anesth Pain Med 30:452, 2005; Swenson JD et al: Outpatient management of continuous peripheral nerve catheters placed using ultrasound guidance: an experience in 620 patients. Anesth Analg 103:1436, 2006.