Paraspinal Blocks a new paradigm in truncal analgesia Ki Jinn Chin, MBBS (Hons), MMed, FRCPC Associate Professor Toronto Western Hospital University of Toronto Online Resources https://youtu.be/lockhd 80EU A brief how to guide to the ESP block https://youtu.be/hmuevx1xn3e Anatomy and technique of the ESP block https://youtu.be/yrscgnv4f2o Introduction to the ESP and other paraspinal blocks (RA UK Annual Meeting May 2017) 1
Thoracic / Abdominal Analgesia = Epidural Block Paraspinal Blocks are not new = Intercostal Block = Thoracic Paravertebral Block 2
Paraspinal Blocks = Intercostal Block = Thoracic Paravertebral Block * Pleura New Paradigm = Ultrasound Guidance Ultrasound guided TPVB Safer Easier? Tracking needle tip not always easy Small target area Imaging in real patients can be difficult Anesth Analg 2016;122:1186 91 Total complications = 0.70% (99% CI: 0.17 1.86%) Pleural puncture = 0% (99% CI: 0 0.35%) LAST = 0.23% (99% CI: 0.01 1.11%) HR / BP = 0.47% (99% CI: 0.07 1.50%) 3
Injection lateral to the spine & neuraxis Injection into a musculofascial plane or muscle The New Paradigm in Paraspinal Blocks Erector Spinae Plane Block Retrolaminar Block Nerve targets Paraspinal Intercostal Blocks The Retrolaminar Block 4
Retrolaminar Block Paravertebral Lamina Technique US Guided Retrolaminar Block 3 cases of multiple rib fractures Catheter inserted Infusion of 0.125% bupivacaine Opioid sparing 5
Retrolaminar block Trapezius Transversospinalis mm. Trapezius Transversospinalis mm. Fluid spread Lamina Lamina Lamina Lamina Cranial Caudal Cranial Caudal 25 cases of major breast surgery Continuous catheter infusion for up to 3 days 84% required no intraoperative opioids 100% required no postoperative opioids Promising alternative to TPVB More investigation needed N = 30 modified radical mastectomy Landmark guided continuous TPVB vs retrolaminar block at T4 for 72 h Higher intraoperative remifentanil dose in retrolaminar group No postoperative opioids required in any patient Optimal dosing? More block PCA demands in retrolaminar group (3ml bolus, 4 ml/h infusion) Larger volumes? 6
The Erector Spinae Plane (ESP) Block Mauricio Forero Reg Anesth Pain Med. 2016 Sep-Oct;41(5):621-7 Sanjib Adhikary 7
Reg Anesth Pain Med. 2016 Sep-Oct;41(5):621-7 Evolution of the technique 2 cases of chronic thoracic pain 2 cases of VATS Cadaveric investigation T1 T5 T8 The Erector Spinae Plane (ESP) block Forero et al. Reg Anesth Pain Med 2016; 41: 621 7. Cranial ESM (reflected) TP TP TP rib Spinal nerve root rib Origin of dorsal ramus Ventral ramus rib Injection deep to ESM stains ventral rami and foraminal areas Confirmed in subsequent clinical cases that this is the optimal plane for injection 8
Performing the ESP block Patient position Transducer linear vs curved Sitting Lateral Prone Performing the ESP block SP TP rib Lamina 9
Performing the ESP block Trapezius Trapezius Rhomboid M Rhomboid M ESM ESM rib rib TP TP pleura TP ESM Shallow needle trajectory Strike TP Withdraw very slightly TP ESM TP ESM TP Linear spread of LA lifting ESM off TP 10
Applications Thoracic surgery Thoracic trauma Superficial back surgery Courtesy of Julia Lapalma (LASRA Argentina) Courtesy Mario Fajardo Paraspinal Blocks Voodoo or Science? 11
Principles of Mechanism of Action Local anesthetic solution tracks extensively within tissues The paraspinal muscles are more porous than we think Only a small amount of local anesthetic is required to effect an analgesic block Principles of Mechanism of Action Local anesthetic solution tracks extensively within tissues M.F. Rojas Gomez 12
Principles of Mechanism of Action Muscles and connective tissues are more porous than we think Video courtesy of LASRA Argentina (Carlos Salgueiro & Vidal Ezequiel) Mechanisms of action Pleura and endothoracic fascia Sympathetic Anterior ganglion cutaneous branch Rami communicantes Lateral Ventral ramus cutaneous branch Dorsal ramus Intercostal nerve Posterior cutaneous branches Spread occurs Laterally (into intercostal space) Anteriorly (into paravertebral space) Sympathetic chain Viscera Dorsal ramus Back Ventral ramus Lateral cutaneous branches Anterior cutaneous branches Courtesy of Maria Fernanda Rojas Gomez 13
Is it important to target transverse process vs rib? Trapezius Trapezius Rhomboid M Rhomboid M ESM ESM rib rib TP TP pleura Is it important to target transverse process vs rib? Intercostal Paraspinal Nerve Block Cedric Roue et al. Anaesthesia 2015; 71, 110 13 Paraspinal mm. LA rib ICM pleura 14
Local and Regional Anesthesia 2015; 8: 79 84. Analgesia comparable to TEA Similar respiratory function Similar ICU and hospital length of stay Likely to work well for ventral rami / somatic pain 15
23/01/2018 Is it important to target transverse process vs rib? Injection closer to the midline = more likely to get spread into neural foramina and epidural space Sympathetic chain Epidural and neural foraminal spread of injectate Epidural and neural foraminal spread of injectate Intercostal spread Transversospinalis group of mm. Erector spinae mm. ERECTOR SPINAE PLANE BLOCK Pfeiffer et al 2005 Midline RETROLAMINAR BLOCK 16
Level Retrolaminar Block ESP Block Level Retrolaminar Block ESP Block Level Retrolaminar Block ESP Block Cadaver #1 #2 #3 #1 #2 #3 T1 T2 T3 T4 T5 T6 T7 T8 Epidural Space Cadaver #1 #2 #3 #1 #2 #3 T1 T2 T3 T4 T5 T6 T7 T8 Neural Foramina 20 ml at the level of T5 Cadaver #1 #2 #3 #1 #2 #3 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 Intercostal Space 17
Paraspinal Blocks Voodoo or Science? Midpoint Transverse process to Pleura (MTP) & Multiple Injection Costotransverse (MIC) Block 18
USG injections posterior (superficial) to the superior costotransverse ligament Anaesthesia 2017 5mL at each level T2 T7 the intertransverse connective tissue complex Multiple Injection Costotransverse (MIC) Block 5 x 4mL Nielsen MV, Moriggl B, Chin KJ, Hoermann R, Nielsen TD, Bendtsen TF, Børglum J 19
SCTL Dorsal ramus Ventral ramus ITL TP Tip TP Tip 20
The MTP / MIC block A modification of the TPVB Results in spread to paravertebral space Spread in erector spinae plane also noted Multiple injection or singleinjection technique? The erector spinae muscles extend from C spine to L spine T4-5 C7-T2 T7-8 ESM L2-3 21
C7-T2 Case series of 4 patients + 1 cadaver 3 laparoscopic, 1 conversion to open L2-3 Case series of 3 patients 2 cases of rescue following deep abdominal pain in PACU 1 case of elective preop insertion of bilateral catheters, postop intermittent manual boluses Rapid relief of pain Duration variable = 2 to 6 hours T7 TP Erector spinae Fluid opening the ESP Cranial Caudal 22
23/01/2018 Bilateral ESP catheters at T8 Infusion 0.1% bupivacaine @ 6ml/h ESP in abdominal surgery Relatively simple and safe Can target specific area Requires access to back Unilateral block Variable intensity & duration Catheter easily inserted Early stage; more evidence needed 23
Clinical Applications of Paraspinal Blocks (for now) Thoracic trauma or surgery Abdominal / urologic surgery Where TEA or TPVB is contraindicated or undesirable or declined Why choose to perform a paraspinal block? Technically easier Theoretically safer Pleural puncture Epidural hematoma Epidural abscess May be as effective as TEA or TPVB Unique advantages J Anesth. 2016 Dec;30:1003 7. 2017 May 15;8(10):254 256. 24
Why choose to perform a paraspinal block? Extensive cranio caudal spread from single injection point Muscle plane vs. Fat filled space 20 ml TPVB T1 T5 C7-T2 T8 T8 L2-3 Anesthesiology. 2013;118:1106 12. Why choose to perform a paraspinal block? Amenable to catheter insertion Amenable to injection of liposomal bupivacaine Entire spine potentially accessible Cervical Thoracic Lumbar AA Case Rep 2018 ESM 25
Limitations and Risks Variable intensity Variable duration Insert catheter whenever possible Vascular reabsorption? LAST is a real risk Add epinephrine Respect maximum LA doses (hydrolocate with non active fluid) Monitor patient Theoretically minimal risk of Pneumothorax Visceral injury Nerve injury Epidural hematoma Epidural abscess Hypotension? Unanswered questions How reliable are paraspinal blocks? Optimal technique? Optimal dosing? How do they compare to TEA? TPVB? Efficacy and safety Population dependent? How do they compare to each other? Anesthetic vs analgesic block? How to maximize duration? Additives? Optimal dosing regimen for catheters? Infusion? Rate? Intermittent boluses? Volume? 26
ESP block beyond thoraco abdominal analgesia? Upper limb Spine ESM Lower limb Paraspinal Blocks Present Conclusions Alternative to thoracic epidural / paravertebral / intercostal blocks Sound anatomical basis Simpler Safer (Almost) as effective Opioid sparing (not eliminating) Use as part of multimodal analgesia 27