Abstracts and Highlight Papers of the 33rd Annual European Society of Regional Anaesthesia & Pain Therapy (ESRA) Congress 2014: Invited Speaker Highlight Papers

Abstracts and Highlight Papers of the 33rd Annual European Society of Regional Anaesthesia & Pain Therapy (ESRA) Congress 2014: Invited Speaker Highlight Paperss and Highlight Papers of the 33rd Annual European Society of Regional Anaesthesia & Pain Therapy (ESRA) Congress 2014: Invited Speaker Highlight Papers ESRA1-0001 Symposium: Evidence of regional anaesthesia EVIDENCE OF CONTINUOUS REGIONAL ANESTHESIAVS SINGLE SHOT Ilfeld B. Anesthesiology, University California San Diego, San Diego, USA. Technique overview: While single-injection peripheral nerve blocks provide multiple benefits in both acute and chronic pain states, the maximum duration of 8-24 hours for currently available local anesthetics is often far less than required. Multiple techniques to extend duration have been reported, such as the additives buprenorphine, naloxone, clonidine, and dexamethasone. However, these agents may result in undesired side effects, and do not reliably extend action beyond 24 hours. In the past two decades, there has been an increasing interest in providing “continuous peripheral nerve blocks” (CPNB)— also called “perineural local anesthetic infusions”. This technique involves the percutaneous insertion of a catheter directly adjacent to the peripheral nerve(s) supplying an affected surgical site (as opposed to a “wound” catheter placed directly at a surgical site. Local anesthetic is then infused via the catheter providing potent, site-specific analgesia. Therefore, CPNB provides an alternative option when a prolonged neural blockade is desired. Since its first description in 1946, CPNB has evolved from an experimental case report involving a needle inserted through a cork taped to a patient’s chest, to a well-validated analgesic technique accepted by the medical community with products designed solely for its application. Benefits of CPNB: There is now a plethora of evidence demonstrating the benefits of a CPNB over a single-injection peripheral nerve block when analgesia is desired longer than the duration of a typical single-injection bolus of local anesthesia. Randomized, controlled trials provide evidence for continuous interscalene, infraclavicular, femoral, psoas compartment, sciatic, and paravertebral nerve blocks. Although definitive data is lacking, it appears that nearly all benefits derived from CPNB results from the induced analgesia. Examples include decreased opioid consumption, decreased opioid-related side effects, fewer sleep disturbances, and improved patient satisfaction with analgesia. Lastly, compared with a single-injection peripheral nerve block, CPNB may decrease the time to readiness to discharge, and in some cases, time to actual hospital discharge. Complications: Because there are inherent risks with CPNB, the majority of published series limit this technique to patients expected to havemoderate postoperative pain of a duration greater than 24 h that is not easily managed with oral opioids. However, CPNB may be used following mildly painful procedures—defined here as usually well managed with oral opioids—to decrease opioid requirements and opioid-related side effects. Because not all patients desire, or are capable of accepting, the extra responsibility that comes with the catheter and pump system, appropriate patient selection is crucial for safe perineural local anesthetic infusion. Combining a perineural catheter with a portable infusion pump, outpatients may experience the same level of analgesia previously afforded only to those remaining hospitalized. However, compared with single-injection peripheral nerve blocks, CPNB requires additional considerations. Since some degree of postoperative cognitive dysfunction is common following surgery, investigators often require patients to have a “caretaker” at least through the first postoperative night. Whether a caretaker for one night or for the entire duration of infusion is necessary remains unresolved. If catheter removal at home is expected, then a caretaker willing to perform this procedure must be available at the infusion conclusion if the patient is unwilling or unable to do this themselves (e.g. psoas compartment catheter). Complications that could bemanaged routinely within the hospital may take longer to identify or be more difficult to manage in medically unsupervised By agreement, the journal has printed the abstracts from author proofs, which have not been copyedited by the publisher or RAPM editorial office. Regional Anesthesia and Pain Medicine • Volume 39, Number 5, Supple Copyright © 2014 American Society of Regional Anesthesia and Pain patients at home with CPNB. Related to this, investigators often exclude patients with known hepatic or renal insufficiency, in an effort to avoid local anesthetic toxicity. For infusions that may effect the phrenic nerve and ipsilateral diaphragm function (e.g. interscalene or cervical paravertebral catheters), patientswith heart or lung disease are often excluded since continuous interscalene local anesthetic infusions have been shown to cause frequent ipsilateral diaphragm paralysis. Although the effect on overall pulmonary function may be minimal for relatively healthy patients, conservative application of this technique is warranted until additional investigation of hospitalized, medically supervised, patients documents its safety. Discharge and Home-Care: CPNB requires additional patient and caretaker education prior to discharge. Because most patients have some degree of postoperative cognitive dysfunction, most investigators educate both the patient and his/her caretaker at the same time prior to discharge. Although currently uninvestigated, there is consensus among practitioners that both verbal and written instructions should be provided, along with contact numbers for health-care providers who are available throughout the infusion duration.Along with standard postoperative outpatient instructions, topics reviewed usually include infusion pump instructions, expectations regarding surgical block resolution, breakthrough pain treatment, specific instruction not to drive or operate machinery, catheter site care (sponge bath instead of shower), limb protection, what to do if local anesthetic leaks from under the protective dressing, signs and symptoms of possible catheter-related complications, and catheter removal plan. Dislodgement: Unlike single-injection peripheral nerve blocks, a continuous block may be unexpectedly truncated prior to expected termination. The most common complication during ambulatory perineural infusion is simply inadvertent catheter dislodgement. The reported incidence of dislodgement varies greatly between 0 and 30%, and ismost likely related to the anatomical location, equipment type, and technique used to secure the catheter. Every effort to optimally secure the catheter must be made to maximize patient benefits. Measures have included the use of sterile liquid adhesive (e.g. benzoin), sterile tape (e.g. “Steri-Strips”), securing of the catheter-hub connection with either tape or specifically designed devices (e.g. “Statlock”), subcutaneous tunneling of the catheter, and the use of 2-octyl cyanoacrylate glue. Using a combination of these maneuvers, investigators have reported a catheter retention rate of 95-100% for 6-9 days of ambulatory infusion. Patient contact and catheter removal: Unlike single-injection peripheral nerve blocks, practitioners usually have daily (or frequent) contact with patients during the infusion. Although not systematically investigated, practitioners may want to consider documenting each patient contact, as is standard-of-care for inpatients. The optimal frequency of contact with ambulatory patients is currently unknown, and probably is dependent upon multiple factors such as patient comorbidities and surgical procedure. Multiple investigators have suggested that patients be contacted daily by telephone, while others have provided twice-daily home nursing visits in addition to telephone calls. Also unlike single-injection peripheral nerve blocks, the perineural catheter requires removal. Investigators have reported catheter removal for ambulatory patients by various techniques: some discharge patients with written instructions, others have insisted on a health-care provider performing this procedure, while others have patients’ caretakers (or occasionally the patients themselves) remove the catheters with instructions given by a provider over the telephone. While there are no data documenting the superiority of any one technique, one survey revealed that with instructions given by phone, 98% of patients felt comfortable removing their catheter at home. Of note, only 4% would have preferred to return for a health-care provider to remove the catheter, and 43% responded that they would have felt comfortable with exclusively written instructions. Practitioners may consider providing nonsterile gloves for patients having their catheters removed at home. The presence of a blue/silver catheter tip identified by the person removing the catheter confirms complete removal (depending on catheter design), and should be documented in the medical record. Liposome Bupivacaine. Bupivacaine liposome injectable suspension (EXPAREL; Pacira Pharmaceuticals, Inc., Parsippany, NJ) consists of ment 1, September-October 2014 e1 Medicine. Unauthorized reproduction of this article is prohibited. ESRA Abstracts Regional Anesthesia and Pain Medicine • Volume 39, Number 5, Supplement 1, September-October 2014 multivesicular liposomes in a honeycomb-like formation (DepoFoam) with numerous aqueous chambers that contain bupivacaine. The proprietary DepoFoam technology, which provides steady, reliable, and prolonged drug release, is well established, having been used to encapsulate other analgesic (e.g., morphine), antineoplastic (e.g., cytarabine), antibiotic (e.g., gentamicin, tobramycin), and antiviral agents (e.g., zalcitabine, acyclovir), as well as peptide