Fundamentals of Ultrasound Guided Peripheral Regional Anesthesia Techniques

Fundamentals of Ultrasound Guided Peripheral Regional Anesthesia Techniques

Joseph McVicker, CRNA, MS

1

Retired Navy Nurse CorpsUniversity South AlabamaGeorgetown University East Carolina University

I have not been reimbursed nor received benefits from any company or individual other than the NCANA for this presentation.Technology and images presented in this presentation are not an endorsements for a specific company or product. There are for illustrative and demonstration purposes only.Conflict of Interest

List the benefits of U/S guidance for peripheral regional anesthesia.Discuss commonly used machine controls and methods to improve ultrasound imaging to obtain optimal view.Identify the images of peripheral nerves, nerve plexuses, and adjacent anatomy for common upper and lower extremity nerve blocks.

Objectives

Inadequate pain relief after surgery may delay surgical recovery, decrease patient satisfaction, increase length of stay, raise risk of hospital readmissions and increase overall healthcare costs (Patacsil et al, 2016).Why PNBs?

Jason Patacsil DNP SP Literature review April AANA Journal5

Peripheral Nerve Blocks play an important role in anesthesia and analgesia for ambulatory surgery.Either obviates need for GA or decrease anesthetic requirement.Faster Discharge; more quickly Street Fit.Part of multimodal approach to pain management and decrease need for intraoperative and post operative opiates.Less PONV.Less postoperative pain.PNBs

Traditional approaches rely on strong knowledge of anatomy and physical assessment.Require motor stimulation and movement. (Pain?)Potential for intravascular injection (cant see).Adjacent structure injury.Nerve stimulators with insulated needles provide evidence of proximity at time of injection. Higher incidence of failure than U/S guided. Usual practice not to move needle after injection started (risk injury to nerve, movement to intravascular).

Traditional PNB Techniques

Pain: movement of affected extremity. Electrical stimulation pain minimized or obviated by decreasing the Pulse width to 0.1 or 0.3 avoid 1.0 ms unless seeking paresthesia with needle.7

Visualize surrounding structuresValidate external landmarks Not a substitute for knowledge of anatomyReal time needle guidance!Avoid injury to adjacent structures Steering NeedleVisualize other structures to provide local anesthesia prior to placing block needle (Fascia tough and painful with blunt needle.)More accurate inject local anesthetic can see tissue displacement and see spread of local.

Benefits of Ultrasound Techniques

Steering Avoidance of vascular structures8

U/S machines are smaller and more portable.Less Expensive than larger and more cumbersome ancestors.Quality of modern software provides improved imaging.Familiarization with the machine and controls will improve quality and outcomes.

Ultrasound Machines

Equipment Preparation

Still use the stimultor when teaching. Confirms that you are where you want to be. Eventually will discard the stimulator in favor of U/S image10

Lipid Rescue: 1.5 ml /kg or about 100ml over one minute then infusion of 15ml/kg/hour or 1000ml/hour. Max 2 repeat boluses. Can double infusion. Max total/cumulative dose is 12mg/kg or 840ml for a 70 kg person.11

Pt. Identifiers.Informed Consent for regional anesthesia (Correct Site).Mark/Initial Block location on the patient.When positioning patient possible to get wrong side errors. Propose adding a block band to the extremity to ensure site being blocked is on the same extremity.Procedural Time Out/ Facility Protocol.Include the patient. Sedate after the time out!Informed Consent

When positioned the surgeons mark may not be visible for the time out, And more than one block requires anesthetists initials on each sight.12

Linear array transducers scan a plane through the body that can be viewed as a Real-time, two-dimensional image on the screen. (Patients are 3D).Doppler used to identify pulsatile fluid filled structures.Commonly superimposed on B-mode image.2D or B(Brightness)-mode

2D is an important concept as we will be blocking a 3D patient13

Depth ControlDepth: Depth controls the distance over which the B-Mode images the anatomy. To visualize deeper structures, increase the depth.If there is a large part of the display which is unused at the bottom, decrease the depth.

14

B-Mode Gain increases or decreases the amount of echo information displayed in an image. It may brighten or darken the image if sufficient echo information is generated. B-Mode Gain

Increases the number of focal zones or moves the focal zone(s) so that you can tighten up the beam for a specific area.A graphic caret corresponding to the focal zone position(s) appears on the right edge of the image on the Logiq e U/S machine. Focus (Logiq e)

Doppler Mode: Identifies vascular structures. Differentiate between arterial and venous structures.The use in this application is solely to facilitate location of adjacent neuronal structures and avoidance of vascular injury.

Doppler Mode

17

Hyperechoic: Bones, Fascia & TendonsHypoechoic: Muscle, Fat, Small Veins and ArteriesAnechoic: Large Arteries and VeinsVariable: Nerves above Clavicle-Hypoechoic, Below Clavicle-Hyperechoic Anisotropy: Non-perpendicular angulation skews the return of the waves returning to the transducerEchogenicity

Bones will have an anechoic shadow due to inability of U/S waves to penetrate18

Brachial Plexus Anatomy

Not pictured Phrenic Nerve origenC3,4,5 passes anterior to the brachial plexus, superficial to the C-8, T-1 roots and then proceeds deep to the clavicle. Additionally, the brachial plexus may have a branch that contributes to the phrenic nerve. Almost 100% ipsilateral block of phrenic nerve at this level.19

Most beneficial PNB for outpatient shoulder surgery (Lin, Choi, Hadzic, 2013).Primary anesthetic with MAC or Adjunct to GA.Duke Surgery Center primarily ISB catheter/MAC.NHCL/NHCCP Single Shot ISB/GAInterscalene Nerve Block

With prolonged blockade also prolonged block of the phrenic nerve.20

Block at level of Nerve Trunks. U/S probe placed where palpate in classic techniqueScanning the neck above clavicle helps with anatomyHypoechoic (above the clavicle)Deep to the posterior margin of the SCMBetween anterior and middle scalene musclesClassic Stop Light appearance at this level

Interscalene Nerve Block

Accessory muscles of ventilation. Caution in people with lung disease. Almost 100% 21

Interscalene Block Technique

Note the location of the transducer. Slightly caudad to the level of C6. Identify the plexus at the level of the supraclavicular block, The plexus is just lateral to the subclavian artery. 22

Interscalene Block Images

Scan cephalad until the nerve structures coalesce into the three major trunks. Inject local in the direction of the most superior trunk. This will preferentially block the shoulder. Note Depth Markers. Yellow Focus markers.If open Biceps tendonesis incision will be made consider intercostobrachial blockade or ask surgeon to infiltrate incision at time of closure. Frequent complaints of pain in this region post operatively with good functioning ISB.Primary indication for shoulde and proximal humerus. Question whether adequate for elbow surgery. Some advocacy for lower approach 2-3 cm aboce clavicle for elbow.23

Supraclavicular Block Technique

24

Supraclavicular Block Images

Needle always from lateral to medial. Needle visualization and STRICT in plane technique to avoid Pneumothorax or vascular injury. Stay above the level of the first rib.Note Anechoic region around the nerves and again the depth of the needle relative to the lung, absence of echoes behind the first rib ribConsider intercostobrachial block if tourniquet used for procedure.The Spinal of the Arm, good for surgeries at elbow and above. NYSORA advocates the with U/S guidance that low approach to ISB is acceptable for hand and wrist surgery.Anecdotally more frequent need to block ulnar nerve at elbow or supplement ulnar distribution on operative field when ISB performed for wrist and hand procedures.

25

Block at the level of the CordsCords are adjacent to the axillary artery at this levelLateral, posterior and medialNerves more dense at this level, longer latencyDecreased incidence of PTX and vascular injuryNo need to supplement the musculocutaneous as with the axillaryInfraclavicular Block

Parasagittal plane below clavicle medial to corachoidHyperechoic cords? Not always, sometimes Hypoechoic.Goal to approach from cephalad to posterior aspect of the axillary artery to proximity of the posterior cord. Increased success in this approach for single injection.Infraclavicular Block

Rotate the transducer to obtain the best round view of the axillary artery. Use caution to avoid vascular injury. Difficult to compress this area. Keep vascular structures and tip of needle in view at all times.27

Infraclavicular Block Technique

Small curvilinear low frequency transduce better for this block in muscular males. 28

Infraclavicular Block Images

29

Infraclavicular Block Images

Redline fascia of Pect Minor muscle. Ideal picture with no pressure distortion of structure as seen on previous slide. Blue =ideal local spread. Note that there about 10% of the time you will encounter an anatomic septum preventing anterior spread of the local to the medial cord. Withdraw and redirect the needle to pass the artery at 12 o'clock position stopping at 2 o'clock and inject 5 ml of local. Keep transducer pressure constant during injection ensure compression of venous structures30

Medial aspect of upper arm, for surgery below the elbow.Musculocutaneous has left the sheath at this levelLike other brachial plexus blocks need a tourniquet ring if not providing significant sedation or general anesthesia.Very shallow.

Axillary Nerve Block

Axillary Block Anatomy

Femoral Block Technique

NAVL!33

Femoral Block Images

Needle approach from lateral to medial. According to MARAA U/S improves femoral nerve block by decreasing latency, improving sensory component and reducing LA volume needed. Primarily for procedures of the knee joint. Infrapatellar surjery involving the tibia and fibula necessitate Sciatic nerve block for complete analgesia.34

Large Hyperechoic nerve.Primarily blocked for procedures knee and long bones of the lower extremity.Can be accessed at popliteal fossa ankle procedures.

Sciatic Nerve Block

Still need to block saphenous component for procedures on anteromedial aspect of skin35

Sciatic Nerve Block Technique

Line between the greater trochanter and the ischial tuberosity. Sciatic nerve bisects this line. Large curvilinear probe for wide angle view and deeper structures.36

Sciatic Block Images

Nerve is located between anterior surface of the gluteus maximus and posterior surface of quadratus femoris muscles. Needle direction lateral to medial. High Frequency curvilinear probe37

Popliteal Fossa Block

Note lateral to medial approach to avoid vascular structures. Attempt as high as possible to ensure getting both branches of the nerveNormally used in conjunction with saphenous or adductor canal block38

Block in the medial thigh.In conjunction with sciatic nerve block for lower extremity surgery (further discuss Sciatic approach)Primarily Sensory and provides innervation to knee superficial medial anesthesia below the knee.Contents: FA/FV, Saph. N., Nerve to Vastus Medialis, Medial Cutaneous, Post Br. Obturator.Preserves the Quadricep Strangth & BalanceAdductor Canal

Vastus Medialis is the only motor nerve39

ADDUCTOR CANALSartoriusVastus MedialisFAAC

Anterior to left Sartorius on top Vastus medialis on left, if move more caudad artery drops out of the sub sartorial plane and descending genicular artery continues adjacent to saphenous.40

Infiltration within the posterior capsule of the kneeUltrasound guided Infiltration technique15 20 ml local between artery and femur under ultrasound guidanceUses for ACL*, TKA, etc.Will demonstrate during hands on.

* not beneficial patellar graft is harvested.

iPACK Nerve Block

Provides medial relief. Inferior lateral knee pain no well controlled. Most TKA pain is medial. Preserves motor component when used with adductor canal blocks. Success considered in attenuation not elimination of pain41

Transversus Abdominis Plane BlockProvides anesthesia for T10-L1 nerves. No relief for surgery above the umbilicus.Somatic innervation to the lower anterior abdominal wall by nerves in the fascial plane between the TA and IOM.No visceral component.Provides relief for Hysterectomy, Hernia, Lap Procedures.May be used diagnostically for chronic pain.

TAP Block Technique Patient positioned supine. Can be done under general anesthesia. Arms Abducted. Costal Margin, Iliac Crest, Axillary line. Needle direction medial to lateral. In plane technique. Distinct Needle Pop. NS test injection. 20-30 ml local anesthesia per side.

Note the spread of the local anesthetic remote from needle placement. This confirms proper fascial placement. No hemodynamic instability, Not good for incisions above umbilicus. May use continuous technique.43

TAP Block Technique

Transducer perpendicular to the needle. Medial to lateral approach. Less likely to enter peritoneum.44

TAP U/S Image

The local should be seen spreading between the fascia away from the needle if it forms a fluid pocket the location of the needle is not correct.45

Liposome Injection of Bupivacaine. Extended Release.December 14, 2016 FDA approval for TAP Block use.Rescinded warning letter for off label advertising.Dosing for TAP. One 20ml vial diluted to 40-60 ml.No more Local after administration of TAP for 72 Hours.

Exparel/ TAP

ReferencesBeaussier, M., Sciard, D., & Sautet, A. (2016). New modalities of pain treatment after outpatient orthopaedic surgery. Orthopaedics & Traumatology, Surgery & Research : OTSR, 102(1 Suppl), S121-4. doi:10.1016/j.otsr.2015.05.011 [doi]

Buckenmaier, C., & Bleckner, L. (2009). In Redding J. (Ed.), Military advanced regional anesthesia and analgesia, handbook (First ed.). Washington, DC: Office of the Surgeon General at TMM Publications.

Food and Drug Administration. (2015). Removal of warning letter; TAP block approval. Retrieved from http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/EnforcementActivitiesbyFDA/WarningLettersandNoticeofViolationLetterstoPharmaceuticalCompanies/UCM477250.pdf

Lin, E., Choi, J., & Hadzic, A. (2013). Peripheral nerve blocks for outpatient surgery: Evidence-based indications. Current Opinion in Anaesthesiology, 26(4), 467-474. doi:10.1097/ACO.0b013e328362baa4 [doi]

Patacsil, J. A., McAuliffe, M. S., Feyh, L. S., & Sigmon, L. L. (2016). Local anesthetic adjuvants providing the longest duration of analgesia for single-injection peripheral nerve blocks in orthopedic surgery: A literature review. American Association of Nurse Anesthetists Journal, 84(2), 95.