4 Advantages Major Intra-abdominal surgery Ambulatory Surgery Cardiac diseaseVascular surgeryPulmonary resection/rib fracturesObstetric PatientsChronic PainOncologic Surgery?
5 Types of Regional Anesthesia TopicalLocal/FieldIV block- “Bier Block”Peripheral Nerve block (named after the nerve)Plexus block (eg lumbar, brachial)Central Neuraxial (spinal, epidural)
6 Topical Anesthesia Application of local anesthetic to mucous membrane UsesAwake oral or nasal intubationSuperficial surgical procedureAdvantageEasy to doDisadvantagePotential for large doses leading to toxicity
7 Airway blocks Injection of LA to block airway nerves Uses: facilitation of awake intubationAdvantage: complete lack of sensation in the airway, blunting of airway reflexesDisadvantage:Potential for injury/injection of surrounding major vascular structures or CSFMore invasive than topicalization
12 Local/Field Anesthesia Application of local subcutaneously to anesthetize distal nerve endings (small local area or field)Uses:Suturing, minor superficial surgery, line placementAdvantages:minimal equipment, technically easy, rapid onsetDisadvantages:potential for toxicity if large field
13 “IV” Block – “Bier” Block Injection of local anesthetic IV for anesthesia of an extremityUsesAny short surgical procedure on a distal extremityAdvantagesTechnically simple, minimal equipment, rapidDisadvantagesDuration limited by tolerance of tourniquet pain, toxicity
15 Peripheral/Plexus Nerve Block Injecting local anesthetic near the course of a named nerve or plexusUses:Surgical procedures in the distribution of the blocked nervePain control of a specific areaAdvantages:More bang for your buck (more coverage with less LA)Less narcoticPatient can either be sedated or fully awake and functionalLimb specificDisadvantages:technical complexity, neuropathy
16 Single shot vs Catheter Fast placementSmaller introducing needleMore complex placement- two step processDuration of anesthetic not limited to duration of drug action
17 Setup/methodOften in a designated “block” room or space with dedicated teamSuppliesMonitor vitalsSedationCan use ultrasound guidance or nerve stimulationPositioning!Localize nerve based on anatomy, confirm location with deviceCommunicate with patientInject and/or or thread catheterTest dose
18 Nerve stimulatorProvides short, low frequency electric impulse to elicit defined muscle responseBased on known innervation of nerveCan use transcutaneously to plan approachCan use with needle during blockGood response at low output indicates close proximity to the nerveInject localShould lose response as conduction blocked
19 Ultrasound vs Stimulator USStimulatorBenefitDirect visualizationReal-time visualizationHard-to-find landmarksDrawbackOsseous or gas-filled structures impede signalTakes up an extra handCan be misleading (need to see tip)BenefitConfirm correct nerve functionAttaches to needle in useDrawbackNo visualization of neighboring structuresRequires assistant’s handsDiscomfortUnreliable in neuropathy
21 Upper Extremity Plexi Cervical Plexus Brachial Plexus Ventral Rami of C1-C4Located deep to the SCM in the neckAdvanced regional techniqueBrachial PlexusVentral rami of C5-T1Responsible for cutaneous and muscular innervation of upper limb
22 Brachial plexus blocks LevelPotentialDrawbackUsesInterscaleneRoots, TrunksSpares inferior trunkShoulder, upper armSupraclavicularTrunks, DivisionsRisk for pneumoEntire arm, including handInfraclavicularCordsPectoral discomfortEntire arm, good for catheter
23 Interscalene Block Patient position Anatomical landmarks Supine with head rotated 30 degrees to C/L sideAnatomical landmarksDetermine interscalene groove (AS & MS) at the level of C6 where the nerves emerge from behind the scalene muscles (be careful of the EJ!).Do not confuse the interscalene groove with the AS/SCM groove.
29 Axillary Nerve Block Advantages Provides anesthesia for forearm & wristFewer complications than a supraclavicular blockLimitationsNot for shoulder or upper arm surgeryMusculocutaneous nerve lies outside of the sheath and must be blocked separatelyComplicationsIntravascular injectionElevated bleeding time increases risk for hematoma
30 Axillary Block Position Head turned away from arm being blocked Abduct to 90ºForearm is flexed to 90ºPalpate brachial artery for pulse
33 Femoral Nerve Block (L2-L4) Uses:Knee arthroscopy in combination with intra- articular local anestheticGood for femoral shaft fractures, ACL, TKA with multimodal regimenLimitations:Not reliable for posterior knee, lower leg or upper thighComplications:Arterial punctureAbdominal cavity puncture
34 Femoral block landmarks “NAVL” Draw a line between the ASIS and the pubic tubercleDetermine location of femoral arteryIntroduce needle one cm lateral to artery
36 Sciatic Nerve Block (L4-5, S1-3) Uses:Nearly complete blockade of the foot and ankleWhat does the sciatic nerve turn into?Limitations:Not a good block for upper thigh or hipAdvantages:Easy to palpate anatomic landmarksNo major vessels near the nerve
44 Lower Plexus Blocks Lumbar Plexus L2-L4 Form the obturator, lateral femoral cutaneous, and femoral nervesProvides sensory and motor innervation to anterior lower extremityLumbosacral plexus L4-L5, S1-S3Primarily forms the sciatic nerveProvides motor and sensory innervation to posterior lower extremityRarely done
46 Lumbar Plexus block Uses: Disadvantages Potential complications Obturator, femoral, and lateral femoral cutaneous nerves in the belly of the psoas muscleKnee, thigh and hipCatheter frequently used to extend blockDisadvantagesNot useful for lower leg or footCannot use real-time ultrasoundPotential complicationsBleeding from psoas muscle bedIncreased systemic absorption of local anesthetic from increased vascularity
47 Lumbar plexus Positioning Lateral decubitus positioning with the blocked side upFoot of the side being blocked should be over the dependent leg so the twitches of the patella can be seen.
48 Lumbar plexus Landmarks Locate both iliac crests and and draw a line between them, this is usually the location of L4 (Tuffier’s)Generally, the plexus will be 4cm lateral to the spinous process along this line.
49 TAP block Transversus abdominis plane block Good for abdominal surgerySingle shot (less frequently catheter)Can be used as rescueLA spread between internal oblique and transversus abdominus musclesAnesthetize anterior rami of T7-L1
51 Paravertebral blockAnesthetize thoracic spinal nerves within paravertebral space above L1Thoracic, chest wall, breast, rib fxUnilateral or bilateralUsually single shot, catheter possibleLandmark or ultrasoundComplications?
55 EpiduralInjection of local anesthetic +/- adjunct into the epidural space (lumbar, thoracic, caudal)Usually catheter is left in place for continued infusionUseful for intraoperative and post-operative pain control as well as labor analgesiaBenefits: decreased ileus, pain control without respiratory depression, improved perfusionPotential drawbacks: hypotension (sympathectomy), pruritis, possible wet tap, potential for epidural hematoma or vascular injection, one-sided or patchy block
57 Spinal Injection of local anesthetic +/- adjunct into spinal space Usually single shot procedureCan combine with epidural (CSE)Lumbar ONLYComplete motor and sensory blockFast to perform, quick onset, relatively short duration depending on choice of anesthetic, rarely failsMore pronounced hypotension, possible spinal HA, possible high spinal