Perioperative Medicine
The Future of Anesthesiology
Pain Management
Goel A, Azargive S, Weissman JS, et al. Perioperative Pain and Addiction Interdisciplinary Network (PAIN) clinical practice advisory for perioperative management of buprenorphine: results of a modified Delphi process. Br J Anaesth. 2019;123(2):e333-e342. doi:10.1016/j.bja.2019.03.044
Bottom line: Buprenorphine is a partial mu receptor agonist with high binding affinity and mimics antagonist properties at higher doses. that is used for chronic pain and opioid use disorder management. This expert consensus document used a modified Delphi process to determine a practice advisory for perioperative management of Buprenorphine.
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Major points:
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1. It is almost always appropriate to continue buprenorphine at the preoperative dose for the perioperative period.
2. Pain management should incorporate non-opioid adjunct analgesia (especially regional anesthesia techniques) and consult chronic pain management team or addiction medicine based on the underlying indication for the medication. In the setting of poor pain control, can consider reducing buprenorphine dose.
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3. Opioid management of postoperative pain can be via hydromorphone, morphine, and fentanyl. Sufentanil isn't recommended to overcome the binding effects of buprenorphine due to lack of familiarity with this medication.
Schwenk ES, Viscusi ER, Buvanendran A, et al. Consensus Guidelines on the Use of Intravenous Ketamine Infusions for Acute Pain Management From the American Society of Regional Anesthesia and Pain Medicine, the American Academy of Pain Medicine, and the American Society of Anesthesiologists. Reg Anesth Pain Med. 2018;43(5):456-466. doi:10.1097/AAP.0000000000000806
Bottom Line: Subanesthetic ketamine has reversible antagonism of the NMDA receptor and also has effects on multiple other receptors. These guidelines were created to guide ketamine use during the perioperative period and for acute pain.
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Major points:
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1. Acute pain indications include those who have expected severe postoperative pain, opioid tolerant or opioid-dependent patients, or those with acute exacerbation of a chronic condition, and those with increased risk for opioid-related respiratory depression such as OSA.
2. Ketamine boluses for acute pain and perioperative analgesia (as adjuncts to opioids) should not exceed 0.35 mg/kg for boluses and 1 mg/kg for infusions.
3. Ketamine should be avoided in those with poorly controlled CVS disease, pregnancy, active psychosis, sever hepatic dysfunction, elevated ICP and intraocular pressure.
Humble SR, Dalton AJ, Li L. A systematic review of therapeutic interventions to reduce acute and chronic post-surgical pain after amputation, thoracotomy or mastectomy. Eur J Pain. 2015;19(4):451-465. doi:10.1002/ejp.567
Bottom Line: This systematic review included 32 RCT studies to evaluate how effective our interventions are at preventing chronic pain in the high-risk operations of amputation, mastectomy and thoracotomy.
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Major points:
1. Gabapentinoids, anti-depressants, local anesthetics and regional anesthesia can potentially reduce neuropathic pain.
2. Ketamine and intercostal cryoanalgesia aren't as effective at reducing chronic pain.
3. Those who are high risk for chronic surgical pain undergoing amputation, thoracotomy and mastectomy should use high doses of medications initiated prior to surgery and continued for several weeks.
Dunn LK, Durieux ME. Perioperative Use of Intravenous Lidocaine. Anesthesiology. 2017;126(4):729-737. doi:10.1097/ALN.0000000000001527
Bottom line: This article explains how lidocaine has the prolonged effect of reported benefits of reduction in pain, nausea, ileus duration, opioid requirement, and length of stay despite low blood concentrations of lidocaine. It also reviews the surgeries in which the benefit of perioperative lidocaine infusion has been established.
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Major points
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1. Some of the pro-inflammatory effects of surgery that contribute to postoperative complications may be attenuated by lidocaine by the local anesthetics ability to block priming of PMN's at very low doses.
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2. Perioperative lidocaine infusion may be beneficial for open and laparoscopic abdominal procedures, radical prostatectomy, mastectomy, thoracic, major spine surgery.
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3. There may be less benefit in patients undergoing laparoscopic renal surgery, obstetric patients, total abdominal hysterectomy, cardiac surgery, hip surgery.
Barreveld A, Witte J, Chahal H, Durieux ME, Strichartz G. Preventive analgesia by local anesthetics: the reduction of postoperative pain by peripheral nerve blocks and intravenous drugs. Anesth Analg. 2013;116(5):1141-1161. doi:10.1213/ANE.0b013e318277a270
Bottom line: This review included 89 studies and examined the role of preventive analgesia which is a reduction in postoperative pain that persists for more than 5.5 half-lives of a drug.
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Major points:
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1. Nerve blocks improve postoperative analgesia when compared to placebo, PCA and intraarticular local anesthesia.
2. There has been no studies comparing IV lidocaine to a regional anesthetic (epidural or peripheral nerve block) but there is postoperative analgesic associated with IV lidocaine and should be considered when regional techniques are contraindicated or not performed.
3. For regional techniques; the total dose of local anesthetic (mass) rather than volume or concentration is most important for the efficacy of the block. Timing of the block (pre or post) around the time of incision isn't important.
Foo I, Macfarlane AJR, Srivastava D, Bhaskar A, Barker H, Knaggs R, Eipe N, Smith AF. The use of intravenous lidocaine for postoperative pain and recovery: international consensus statement on efficacy and safety. Anaesthesia. 2020 Nov 3. doi: 10.1111/anae.15270. Epub ahead of print. PMID: 33141959.
Bottom line: This consensus statement (based on the authors recommendations), developed following a death from a lidocaine infusion error, explores whether post-operative IV lidocaine infusions are effective, safe, and appropriate (as their use is ‘off-label’). It culminates in 15 recommendations focused primarily on infusion safety, which are more conservative than current infusion practices.
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Major points:
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1. The quality of evidence for post-operative lidocaine infusions (used for pain and enhanced recovery) is low and these recommendations are conservative in comparison to current practice. The use of lidocaine requires individualized patient assessment, careful consideration of the risks and benefits – especially in the case of any relative contraindications (cardiac disease, renal or hepatic impairment, electrolyte abnormalities, seizure disorders, pregnancy/breastfeeding, or neurological disorders).
2. Safe dosing for IV lidocaine infusions involves dosing based on ideal body weight, a maximum bolus dose of 1.5mg/kg, a maximum infusion rate of 1.5mg/kg/hr, avoidance in patients less than 40 kg, avoidance of rates greater than 120mg/h, avoidance within 4 hours of nerve blocks or surgical infiltration, and running the infusion for no more than 24 hours.
3. The authors advocate for running IV lidocaine infusions in a monitored setting with emergency equipment immediately accessible (including 20% lipid emulsion), and administering the infusion through a locked pump connected to a dedicated intravenous line.
Bravo M, Bakal O, Rivas E, Mascha EJ, Pu X, Mosteller L, Rodriguez-Patarroyo F, Essber H, AlGharrash A, Turan A. Effect of Intravenous Acetaminophen on Mean Arterial Blood Pressure: A Post Hoc Analysis of the EFfect of Intravenous ACetaminophen on PosToperative HypOxemia After Abdominal SurgeRy Trial. Anesth Analg. 2021 Dec 1;133(6):1532-1539. doi: 10.1213/ANE.0000000000005429. PMID: 33856395.
Bottom line: Clinicians should not withhold use of intravenous (IV) acetaminophen for concerns of hypotension in postoperative patients with acute pain. IV acetaminophen was found to not lower mean arterial pressure (MAP) by a clinically meaningful amount in postoperative patients for abdominal surgery.
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Major points:
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1. There was a decrease in MAP from baseline values after each acetaminophen dose by a mean change of −1.03 (95% confidence interval [CI], −1.60 to −0.47) mm Hg, P < .001) over the placebo group, in a linear mixed effects model.
2. This is a sub-study of the eFfect of intravenous ACetaminophen on posToperative hypOxemia after abdominal surgeRy (FACTOR) trial (NCT02156154) which looked at the differences in MAP between post-operative patients randomly assigned to receive either 1g of acetaminophen IV Q6H or placebo.
3. 212 patients were excluded from the original 570 patients in the FACTOR study leaving 358 patients, 182 of whom received acetaminophen and 176 received placebo. Patients were excluded primarily on the basis of gaps in monitoring.
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4. The primary outcome was the MAP difference between MAP 5 minutes before study drug administration (baseline) and MAP 30 minutes post study drug administration; continuous non-invasive blood pressure monitoring was used (the ViSi Mobile device by Sotera Wireless, Inc, San Diego, CA).
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5. There was no interaction of age, race, sex, ASA physical status, hypertension, surgery type, or opioid use with the effect of acetaminophen on MAP change.
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6. Although average MAP was not clinically lower in patients in the IV acetaminophen group, they were more likely to have at least one decrease of 10 mm Hg or more in MAP in comparison to the placebo group (26% vs 15%, P = .007).