Ensuring the success of regional blocks

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Ensuring the success of regional blocks

  1. 2. ENSURING THE SUCCESS OF REGIONAL BLOCKS Dr P Narasimha Reddy, MD,DA Professor & HOD Dept of Anesthesiology & Critical Care NRI Medical College & General Hospital Chinakakani, Guntur Dist, A.P.
  2. 3. Introduction <ul><li>Regional anesthesia was popular </li></ul><ul><li>Tragic incident in Britain. </li></ul><ul><li>It was an art </li></ul><ul><li>Now it is a scientific and business like </li></ul>
  3. 4. <ul><li>Answerable to patient’s problems </li></ul><ul><li>Continuous search to improve safety and surety </li></ul><ul><li>Inventions like PNS and imaging techniques </li></ul>
  4. 5. History <ul><li>1884- Karl Koller –cocaine </li></ul><ul><li>1889- Karl Ludwig- infiltration </li></ul><ul><li>1884-William Halstead-LA directly into nerves </li></ul><ul><li>1885-L.Corning-accidental-epidural </li></ul><ul><li>1898-August Bier-spinal anesthesia </li></ul>
  5. 6. <ul><li>1912-Kulen Kampff-supra.cl.block on himself </li></ul><ul><li>1912-Von Perthes-PNS </li></ul><ul><li>1944-AP Winni-perivascular technique </li></ul><ul><li>1978-La-Grange-doppler u/s to locate nerves </li></ul><ul><li>1992-Fried &Fritz- axillary block with u/s </li></ul>
  6. 7. Regional Blocks - Advantages <ul><li>Simple </li></ul><ul><li>Economical </li></ul><ul><li>Complete analgesia </li></ul><ul><li>Reduced stress response </li></ul><ul><li>Good relaxation </li></ul><ul><li>Less blood loss </li></ul><ul><li>Less blood transfusions </li></ul>
  7. 8. Contd… <ul><li>Good operating field </li></ul><ul><li>Conscious patient </li></ul><ul><li>Less action on immune system </li></ul><ul><li>Post –op analgesia </li></ul><ul><li>Minimal stay in hospital </li></ul><ul><li>Less incidence of DVT </li></ul><ul><li>Early bowel recovery </li></ul><ul><li>Early ambulation </li></ul>
  8. 9. Disadvantages <ul><li>Failures </li></ul><ul><li>Neurological problems </li></ul><ul><li>Anxious patients </li></ul><ul><li>Action on free radicals – more </li></ul>
  9. 10. <ul><li>Anatomy </li></ul><ul><li>Pharmacology </li></ul><ul><li>Complications and side effects </li></ul><ul><li>Technique of blocks </li></ul>Pre-requisites
  10. 11. Select your patient <ul><li>Patient – Exclude- </li></ul><ul><li>Over anxious </li></ul><ul><li>Needle phobia </li></ul><ul><li>Anti psychotic therapy </li></ul><ul><li>Language barrier </li></ul><ul><li>Morbid obesity </li></ul><ul><li>Severe arthritis </li></ul><ul><li>Degenerative nerve disorders & </li></ul><ul><li>Adolescent group </li></ul><ul><li>Success depends on your patient </li></ul>
  11. 12. Select Your Surgeon <ul><li>Good sympathetic, understanding </li></ul><ul><li>Delicate hands and movements </li></ul><ul><li>No pulling </li></ul><ul><li>No pressure on the patient & </li></ul><ul><li>Not much of retraction </li></ul>
  12. 13. Select Your Block <ul><li>Logical selection </li></ul><ul><li>Depends on site, duration & speed of surgeon </li></ul><ul><li>Eg., ISB for shoulder surgeries </li></ul><ul><li>AXB for fore arm and hand surgery </li></ul><ul><li>Missing nerves can be blocked separately </li></ul>
  13. 14. Select Your Drug <ul><li>Depending on duration of surgery </li></ul><ul><li>Post – op analgesia </li></ul><ul><li>Use enantiomers than racemic mixtures </li></ul><ul><li>Use less toxic drugs </li></ul><ul><li>Ropivacaine is more sensory blocker </li></ul><ul><li>Bupivacaine not used in Biers block </li></ul>
  14. 15. Contd… <ul><li>Adjuvants : </li></ul><ul><li>Sedatives – </li></ul><ul><li>Titration </li></ul><ul><li>Verbal contact </li></ul><ul><li>No drug prevents toxicity of LA </li></ul>
  15. 16. <ul><li>Vaso constrictors – </li></ul><ul><li>Epinephrine 1 in 2-2.5 lakhs </li></ul><ul><li>Freshly prepared solution </li></ul><ul><li>Prolongs block </li></ul><ul><li>Reduced toxicity </li></ul><ul><li>Used as a marker </li></ul><ul><li>Use full also with Bupivacaine </li></ul>Contd…
  16. 17. <ul><li>Soda - bicarb – </li></ul><ul><li>1 ml for 10 ml of Xylocaine </li></ul><ul><li>0.1ml for 10ml of Bupivacaine </li></ul><ul><li>Hyaluronidase – </li></ul><ul><li>Used in ophthalmic practice & field blocks </li></ul>Contd…
  17. 18. <ul><li>Additives : </li></ul><ul><li>Many drugs are being added to local anaesthetics – </li></ul><ul><li>Tramadol </li></ul><ul><li>Buprenorphine </li></ul><ul><li>Clonidine </li></ul><ul><li>Neostigmine </li></ul>Contd…
  18. 19. <ul><li>Ketamine </li></ul><ul><li>Fentanyl </li></ul><ul><li>Epinethrine </li></ul><ul><li>They prolong the block, prevent patchy </li></ul><ul><li>Analgesia, depth of block quick onset of </li></ul><ul><li>sensory & motor block </li></ul>Contd…
  19. 20. Select Your Equipment <ul><li>Glass syringes are better than disposable </li></ul><ul><li>Short bevelled needles are better </li></ul><ul><li>Disposable kits are more useful </li></ul>
  20. 21. Select Your Technique <ul><li>By facial clicks : </li></ul><ul><li>Nerves will be in fascial sheath </li></ul><ul><li>Anesthetist must feel the click when he enters the sheath </li></ul><ul><li>Well appreciated with short bevel needles </li></ul><ul><li>Success rate is 60-65% </li></ul>
  21. 22. <ul><li>By Paresthesias : </li></ul><ul><li>Moore said “no paresthesia – No anesthesia” </li></ul><ul><li>It is an abnormal sensation </li></ul><ul><li>It indicates needle tip near the nerve or nerve injury </li></ul><ul><li>Exaggerated paresthesias are undesirable & dangerous </li></ul><ul><li>Success rate is 70-90% </li></ul>Contd…
  22. 23. <ul><li>By Trans arterial injection : </li></ul><ul><li>Good indication that needle is in the sheath </li></ul><ul><li>Stan et al – safe with minimal complications & high success rate </li></ul><ul><li>Complications : </li></ul><ul><li>- Intra arterial injection </li></ul><ul><li>- Haematoma </li></ul><ul><li>- Needle can be deep into muscles </li></ul>Contd…
  23. 24. <ul><li>By peri-vascular injection : </li></ul><ul><li>Suggested by Winni </li></ul><ul><li>Ronie & Thomson opposed </li></ul><ul><li>Patridge, Katz and Bernischke demonstrated septae but they are thin </li></ul><ul><li>Anatomical land marks are very important </li></ul><ul><li>All these techniques depend on normal anatomy, but there are many anatomical variations </li></ul><ul><li>Skill & experience of anaesthesist will not work here </li></ul><ul><li>Success rate is 60-65% </li></ul>Contd…
  24. 25. <ul><li>Anatomical variations : </li></ul><ul><li>Tuffiers line crosses between L3-L4 or L5-S1 </li></ul><ul><li>Termination of cord </li></ul><ul><li>Root size </li></ul><ul><li>Volume of CSF </li></ul><ul><li>7 major configurations of B plexus </li></ul><ul><li>61% defer from right to left </li></ul>Contd…
  25. 26. <ul><li>Peripheral Nerve Stimulator : </li></ul><ul><li>It is better than blind injection </li></ul><ul><li>Popularized by Dr. P. Raj </li></ul><ul><li>Success Rate 93% </li></ul>Contd…
  26. 27. <ul><li>Advantages : </li></ul><ul><li>Less latency </li></ul><ul><li>Less nerve injury </li></ul><ul><li>Less quantity of LA </li></ul><ul><li>Getting motor response with less than 0.5 mA </li></ul>Contd…
  27. 28. <ul><li>Pitfalls of PNS : </li></ul><ul><li>Correct polarity of the stimulating needle </li></ul><ul><li>Positive electrode – secured to the patient </li></ul><ul><li>Loose connections and flat batteries must be avoided </li></ul><ul><li>Motor response must be in the distal group of muscles </li></ul>Contd…
  28. 29. <ul><li>Disadvantages : </li></ul><ul><li>Nerve stimulator settings have no consisting relationship to the proximity of the nerve </li></ul><ul><li>Neuropathies, diabetes, toxic neuropathy, chemotherapy, radiation, demyelinating disorders, multiple sclerosis, peripheral vascular disease, old age can mute the response </li></ul>Contd…
  29. 30. <ul><li>Amputees </li></ul><ul><li>Difficult to locate the nerves </li></ul><ul><li>Nerve damage can occur </li></ul><ul><li>Parasthesias after the block </li></ul><ul><li>Compartmental syndrome </li></ul>Contd…
  30. 31. <ul><li>Single Vs Multiple injections : </li></ul><ul><li>It is not clear weather single Vs multiple stimulation & injection are superior to single injection </li></ul><ul><li>AXB – 2, 3, 4 injections have high success rate </li></ul><ul><li>Neuroproxia is 1-7% </li></ul>Contd…
  31. 32. <ul><li>Continuous Catheter Technique : </li></ul><ul><li>Very exciting & developing area </li></ul><ul><li>Nerve is located with PNS using conductive needles </li></ul><ul><li>Catheter is passed 2 to 3 cm beyond the needle </li></ul><ul><li>STIMUCATH are used to locate the nerves & to find epidural space </li></ul><ul><li>This technique is used in particular places </li></ul>Contd…
  32. 33. <ul><li>Percutaneous Electrical Guidance (PEG): </li></ul><ul><li>New technique developed by W.Urmey </li></ul><ul><li>Noninvasive </li></ul><ul><li>Indentation of skin with cylindrical smooth tipped probe </li></ul><ul><li>The needle is passed through the channel in the probe </li></ul><ul><li>GROSSI proposed a new concept of anesthetic line </li></ul>Contd…
  33. 34. Imaging Technology <ul><li>In 1978 Doppler U/s was used to locate the nerves </li></ul><ul><li>Fluoroscopy & U/s was used to locate the vessels </li></ul><ul><li>Software is available to image the nerves </li></ul><ul><li>Modern machines are affordable, portable with better resolution and penetration </li></ul>
  34. 35. <ul><li>Advantages : </li></ul><ul><li>Direct visualization of nerves </li></ul><ul><li>Direct visualization of other structures </li></ul><ul><li>Direct & indirect visualization of LA spread </li></ul><ul><li>Re-position of needle in case of misdistribution of LA </li></ul><ul><li>Avoidance of side effect </li></ul>Contd…
  35. 36. <ul><li>Avoidance of painful muscle contractions due to PNS </li></ul><ul><li>Faster onset </li></ul><ul><li>Longer duration of blocks </li></ul><ul><li>Improved quality </li></ul><ul><li>Blocks under GA </li></ul><ul><li>Neuropathies & Amputees </li></ul>Contd…
  36. 39. <ul><li>Basic Views : </li></ul><ul><li>Nerves can be imaged in short or long axis </li></ul><ul><li>Short Axis (SAX) – when probe is aligned perpendicular to the axis of the nerve, the nerve is seen in cross section </li></ul><ul><li>Long Axis (LAX) – when probe is aligned parallel to the axis of the nerve </li></ul><ul><li>Short Axis View is preferred due to easy identification of nerves, more stable view & allows to visualise circumferential spread of LA. This is called “Doughnut” sign </li></ul>Contd…
  37. 41. <ul><li>Needle Approaches : </li></ul><ul><li>In plane (IP) – long axis of the needle is oriented to the long axis of the probe </li></ul><ul><li>Entire needle can be seen </li></ul><ul><li>Out of plane (OOP) – the long axis of the needle is the oriented perpendicular to long axis of the probe </li></ul><ul><li>Only part of the needle is seen </li></ul>Contd…
  38. 42. <ul><li>Successful imaging of nerves : </li></ul><ul><li>Use lot of gel </li></ul><ul><li>Adjust gain, frequency and focus on U/s machine so that muscles appear fairly dim and nerves will be denser </li></ul><ul><li>Nerves run along the borders of other structures i.e., muscles </li></ul><ul><li>When scanning transversely slide change in angle of U/s probe along any axis results in better quality image </li></ul>Contd…
  39. 43. <ul><li>Interscalene groove trunks appear hallow like vessels without flow. But they appear mottled when followed peripherally </li></ul><ul><li>U/s cross section of nerve looks like a bundle of straws viewed end on </li></ul><ul><li>Follow a survey pattern using land marks are border of tissues </li></ul><ul><li>Using orientation on the screen </li></ul>Contd…
  40. 44. <ul><li>Many potential targets on screen move with U/s probe back and forth and get oriented to tissues i.e., nerves </li></ul><ul><li>Tendons & ligaments can move with nerves – when move the limb </li></ul><ul><li>Vessels - color Doppler, press </li></ul><ul><li>Repeated views of nerves on U/s machine </li></ul>Contd…
  41. 45. <ul><li>Equipment : </li></ul><ul><li>U/s machine (high resolution U/s) with compound imaging multi-frequency linear array probes and recording capabilities </li></ul><ul><li>22G insulated needles are various lengths – 2” to 6” </li></ul><ul><li>High frequency and high resolution – low penetration 10-14 MHz </li></ul><ul><li>Broadband transducers 5-12, 8-14 MHz offers excellent resolution </li></ul>Contd…
  42. 46. <ul><li>Linear array transducers parallel sound beam HRUS software </li></ul><ul><li>Peripheral nerves – Hypo or hyper echoic, depending on size, sonographic frequency & angle of U/s bean </li></ul><ul><li>Longitudinal view – relatively hyper echoic band, multiple discontinuous, hypo echoic stripes separated by hyper echoic continuous lines </li></ul>Contd…
  43. 47. <ul><li>Failures in U/s : </li></ul><ul><li>Injection of LA into adjacent compartments </li></ul><ul><li>Injection can enter the muscles </li></ul>Contd…
  44. 48. <ul><li>Avoiding failures : </li></ul><ul><li>Your attention must be on the target on the screen </li></ul><ul><li>Never inject all the drug at a time </li></ul><ul><li>Reposition the needle at least twice or thrice during the injection </li></ul>Contd…
  45. 54. <ul><li>Should anesthetist use ultrasound guided nerve blocks? </li></ul><ul><li>What about training? </li></ul><ul><li>- Learning curve </li></ul><ul><li>- first with PNS and later ultra sounding of the nerve ( dream ticket) afterwards directly with ultrasound. </li></ul>
  46. 55. Conclusion <ul><li>Not as a first case </li></ul><ul><li>Centralize your equipment </li></ul><ul><li>Select proper block </li></ul><ul><li>Good knowledge of anatomy </li></ul><ul><li>No about potential complications on treatment </li></ul>
  47. 56. <ul><li>Select right patient </li></ul><ul><li>Pick the right surgeon </li></ul><ul><li>Be confident about your block </li></ul><ul><li>But still if you fail </li></ul><ul><li>Failures are the stepping stones for success </li></ul>Contd…
  48. 57. <ul><li>What about the future of regional anesthesia? </li></ul>

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