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Local Anesthesia and Additives. R3 김세희. Intrathecal agent : Transient Neurologic Symptoms. Transient radicular irritation Freedman et al Factors associated with TNS Lidocaine use, outpatient status, lithotomy position. Intrathecal Agent : Transient Neurologic Symptoms. Freedman et al
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Intrathecal agent: Transient Neurologic Symptoms • Transient radicular irritation • Freedman et al • Factors associated with TNS • Lidocaine use, outpatient status, lithotomy position
Intrathecal Agent: Transient Neurologic Symptoms • Freedman et al • Not associated with TNS • Bupivacaine, age, sex, use of pencil-point needles
What are the Alternatives to Intrathecal Lidocaine ? • Mepivacaine • Addiction of epinephrine and opioids • Meperidine • Low-dose hypobaric lidocaine • Ropivacaine
Mepivacaine • Reliable intrathecal anesthetics • Ligouri and colleagues • Intraoperative anesthesia • 45mg dose knee arthroscopy • 7.4% TNS incidence • Intrathecal fentanyl • 30mg mepivacaine knee arthroscopy
Addiction of Epinephrine and Opoids • Extend the duration of anesthesia • Fentanyl, morphine sulfate • Meperinde • Alone, intrathecal anesthetic agent for postpartum sterilization procedure • 60mg similar 70mg of hyperbaric 5% lidocaine • 1.5mg/kg effective sensory anethesia for 2hr
Newer Agents • Levobupivacaine • Clonidine • Ketorolac • Ketamine
Levobupivacaine • Less cardiotoxic than racemic bupivacaine • Peripheral nerve blockade, lumbar epidural anesthesia • Indistinguishable from racemic bupivacaine • Postoperative epidural infusion • Low incidence of dense motor blockade at 24hr
Clonidine • Increase the duration of anesthesia and analgesia for all regional anesthetic techniques • Site of analgesia action • Periphery, spinal level, brain stem • Analgesia for patient with neuropathic pain • Intraoperative epidural anesthesia • Prolonged by 50% to 100% with the addition of 150ug • Bupibacaine SA : 75-150ug clonidine prolong anesthesia, analgesia by 30% tourniquet pain reduce
Clonidine • Epidural analgesia with clonidine, local anesthtic, diamorphine • Decreased incidence of phantom limb pain • IV regional anesthesia • With clonidine 150ug to lidocaine • Decrease tourniquet pain , no significant change in hemodynamics • Peripheral nerve block : extended by 50% to 100%
Ketorolac • Added to local anesthetic for various regional anestheic technique • excellent analgesic adjuvant • Significant difference in tourniquet pain and postoperative analgesic requirement in IV ketorolac and placebo • Local antiinflammatory action at the site of mediator synthesis
Ketamine • Not new but rediscovered • Cook • Compared the addition of epinephrine, clonidine, ketamine to bupivacaine for postoperative caudal analgesia • Duration of analgesia • Ketamine (12.5hr), clonidine(5.8hr), epinephrine(3.2hr) • Extended the duration of local anesthetics and to enhance the activity of epidural morphine • Gantenbein and colleague • Inhibit the bupivacaine metabolism
Interesting Place for Local Anesthtics • Catheter technique • Increasingly popular to extend postoperative analgesia • Prolonged anesthesia and postoperative analgesia • Inhibit tachyphylaxis • 0.125% to 0.25% bupivacaine and 0.2% ropivacaine • Intraperitoneal lidocaine • Primary anesthetic technique and for postoperative analgesia after mini-laparotomy and laparoscopy • Reduction pain score, level of metabolic markers of stress • Intra-articular injection of local anesthetics for knee surgery • Analgesia, primary anesthetic technique anethesia • Preoperative injection 20ml 2% lidocaine, bupivacaine
Toxicity of Local Anesthetics • Determinig toxicity of local anesthetics • Lipid solubility and protein binding • Dwell time or the amount of time that a local anesthetic occupies the cardiac sodium channel • Bupivacaine • 1.5s dwell time • Fast-in, slow outprofile • Lidocaine • 0.15s dissociation time • Rapidly in and out of cardiac sodium channel
Toxicity of Local Anesthetics • Levobupivacaine • R isomer longer dwell time in cardiac sodium channel than S isomer (levobupivacaine) • Less cardiotoxicity • Ropivacaine • Isomeric formulation of pure S ropivacaine • Increased margin of cardiac safety