Recommended
More Related Content
Similar to SPINAL & EPIDURAL ANAESTHESIA DR OYETUNDE.pptx
Similar to SPINAL & EPIDURAL ANAESTHESIA DR OYETUNDE.pptx (20)
Recently uploaded
Recently uploaded (20)
SPINAL & EPIDURAL ANAESTHESIA DR OYETUNDE.pptx
- 1. SPINAL ANAESTHESIA Presenter: Dr Oyetunde O.R. Supervising SR: DR Ajelabi A. Supervising Consultant: Dr Ibrahim
- 2. OUTLINE Pre-test Introduction/Definition Brief history Relevant anatomy Indications Contraindications Procedure Complications Conclusion Post -test
- 3. Pre-test 1. Name 5 surgical procedures which are suitable for a subarachnoid block? 2. What level do the following end: - spinal cord? - dural sac? 3. What type and size of spinal needle is recommended for a subarachnoid block? 4. How are Local anaesthetic drugs rendered “Heavy”
- 4. INTRODUCTION • Spinal anaesthesia (or spinal anesthesia), also called spinal block, subarachnoid block, intradural block, is a form of neuraxial regional anaesthesia involving the injection of a local anaesthetic or opioid into the subarachnoid space, generally through a fine needle, usually 9 cm (3.5 in) long. • Epidural anaesthesia is a central neuraxial block technique with many applications; can be used as an anaesthetic, as an analgesic adjuvant to general anaesthesia, and for postoperative analgesia in procedures involving the lower limbs, perineum,pelvis, abdomen and thorax.
- 5. INDICATIONS In Orthopaedic surgery; on the pelvis, hip, femur, knee, tibia, and ankle, including arthroplasty and joint replacement In Plastic surgery e.g Vascular surgery on the legs In General surgery; Hernia (inguinal), Haemorrhoidectomy
- 6. INDICATIONS-2 In O&G e.g Caesarean sections, Hysterectomy, examinations under anaesthesia, Labour and postoperative analgesia (epidural), In Urology ; Transurethral resection of the prostate and transurethral resection of bladder tumours, Nephrectomy and cystectomy (in combination with general anaesthesia).
- 7. CONTRAINDICATIONS Absolute Patient refusal Sepsis at site of lumbar puncture Severe coagulopathy Relative Hypovolaemia Aortic stenosis Neurological disease Patients on anticoagulants.
- 10. IMPORTANT LANDMARKS Spinal cord: L1/L2 – Adults L2/L3 - Children Dural: S2 Lumbar puncture: L3/4 – L4/5 Anterior sup. iliac spines: L4/ 5 space Tuffier's line: A line drawn between the highest points of the iliac crests (the intercristal line) crosses the L 4 spinous process.
- 11. SPINAL NEEDLES Traditional spinal needles have a stilette and a bevelled tip. They range in size from 18 G – 29G. The standard lengths are 90mm and 100mm. The ideal needles for spinal anaesthesia are 25G , 26G and 27 G. Needle with a Pencil tip (like a pin) and an opening 2 – 3 mm from the tip is recommended . They push through the dura rather than cutting through it. This results in less leakage of CSF and an incidence of spinal headache of less than 1%.
- 13. Epidural needles: Multiple types have been designed (Tuohy, Hustead, Crawford, Weiss, etc.), Tuohy being the most used one. These are usually 17 or 18 G and 3.5 inches long (up to 6 inches for obese patients).
- 14. EPIDURAL ANAESTHESIA SITES: Cervical Thoracic Lumbar Caudal(Excellent for perianal operations )
- 15. Spinal tray: 2 ml plastic syringe – for the lidocaine 1% skin infiltration. 5 ml plastic syringe – for the bupivacaine 0.5%. 26 G pencil point needle (90 mm) 18 G blunt drawing up needle. 26 G (40 mm) needle for lidocaine infiltration. Galley pot + Betadine solution (alcoholic povidone iodine). Sterile drapes.
- 16. Bupivacaine 0.5% plain (or heavy) in 4 ml sterile ampoule (The denser (hyperbaric) bupivacaine is produced by the addition of glucose (80 mg/mL) to isobaric or plain bupivacaine). Small pack of gauze squares. Sterile gloves. OTHERS 16 or 18 G intravenous cannula + intravenous fluid infusion. A crash cart : with facilities for resuscitation Monitors (Pulse oximetry, ECG, BP). Oxygen via mask or nasal prongs. Equipment for GA
- 17. DRUGS-1 Amides - lidocaine, bupivacaine, prilocaine, levobupivacaine, mepivacaine, ropivacaine Esters – procaine, tetracaine, cocaine, amethocaine, chloroprocaine Mode of action – reversible blockade of sodium channels
- 18. DRUGS- 2
- 19. Why Bupivacaine is preferred in spinal anaesthesia: The duration of anesthesia is significantly longer with Bupivacaine (90-150mins) than with any other commonly used local anesthetic. There is a period of analgesia that persists after the return of sensation, during which time the need for strong analgesics is reduced.Onset of action is 5- 8minutes.
- 20. • Additives to local anaesthetics: • Adrenaline (1:200,000)/5mcg/ml, max 200mcg • Opioids – fentanyl, morphine • Ketamine • Clonidine • Sodium Bicarbonate • etc
- 21. PRE-ANESTHETIC EVALUATION History: comorbidities, any history of reaction to local anesthesia or any other allergies Physical examination : vital signs, inspection for local infection at the spinal anaesthesia site, any spinal deformity, scoliosis, kyphosis etc Laboratory Evaluation: CBC, EUCR, ECG, other relevant in investigations Preoperative plans: informed consent, optimize patient's parameters, NPO, GXM blood , premedications, secure IV cannula etc
- 22. TECHNIQUE- 1 •Fluid Preloading: 2 16/18 G intravenous cannula are inserted and intravenous infusion of normal saline or lactated ringers is commenced, so that 500 – 1500 ml has been infused by the time the spinal injection has been completed. This compensates for the expected peripheral vasodilation. •Monitors are connected •Correct positioning : a knowledgeable assistant who understands how to position the patient is invaluable.
- 23. TECHNIQUE- 2 There are two positions – sitting and lateral. The sitting position; is useful in the morbidly obese or the pregnant patient as it is easier for the patients to maintain flexion and easier for the anaesthetist to stay in the midline.
- 25. TECHNIQUE-3 The sitting position; is ideal for a saddle block. A small volume of “heavy” bupivacaine is injected and the patient is kept sitting for 5 minutes to allow the LA to sink down and block the sacral roots. Left lateral position; consider wherever possible. Ask the patient to “curl up in a foetal position” or arch his/her back like a cat or “push your back out towards me”.
- 26. TECHNIQUE-4 The assistant embraces the patient with one arm behind the neck and the other behind the knees. Good flexion is paramount. The back should be vertical – a pillow between the knees may facilitate this. Elevate the operating table so that, when seated, your eye is on the same level as the spinal needle insertion site. This helps you to stay in the midline.
- 27. TECHNIQUE-5 ASEPTIC PROCEDURE • Clean the skin over the injection site with chlorhexidine solution from in to out • Paint the skin with alcoholic povidone iodine from in to out and drape the patient.
- 28. TECHNIQUE- 6 Identify the intercristal/ Tuffier's line (L4) and infiltrate lidocaine 1% using the 21 G long needle. Inform the patient you are about to do this as they will instinctively pull away and it may be difficult to coax them into fully flexing again. Infiltrate to a depth of 2 –3 cm but the subcutaneous tissues are not particularly sensitive. What is sensitive however are the periosteum and nerves. Keep away from both.
- 29. TECHNIQUE- 7 Insert the 21G needle in a slightly cephalad direction and pass the 26G pencil point spinal needle through it. The key to success is staying in the midline. This can prove difficult in obese patients as the spines may not be palpable. If the needle strays from the midline it can pierce a nerve root causing the patient to complain of pain – usually in the leg. Take note of which leg as this will guide the redirection of the needle.
- 30. TECHNIQUE-8 At a variable depth of 3 – 7 cm (average 4 cm) a definite “gripping” resistance will be felt – just like trying to push a needle through a rubber eraser. This is the ligamentum flavum. Advance the needle a few more millimetres and you should feel a “give” as you perforate the dura. Continue for 2-3 mm and withdraw the stilette. CSF should appear at the hub. Slowly inject 2 – 4 ml of LA.
- 31. TECHNIQUE - 9 If bone is struck, reinsert the needle in a more cephalad direction. If a nerve root is struck, you have deviated from the midline. If blood appears in the hub, you have probably pierced an epidural vein. If the CSF is blood stained but the blood clears, it is safe to inject. If you are unable to reach the subarachnoid space despite optimum flexion, make another attempt at an adjacent interspace.
- 32. TECHNIQUE- 10 With the 26 G needle it is common to get a passive flow of CSF but be unable to aspirate it. Try rotating the needle 90° and pushing it in another couple of millimetres. Once you can obtain a passive flow of CSF go ahead and inject the LA. Roll the patient supine and assiduously monitor the cardiovascular and respiratory parameters.
- 33. MEASURING THE HEIGHT OF A BLOCK Always check the height of the block before allowing the surgeon to start. Place the subarachnoid block and roll the patient supine. Ask him to lift his leg off the bed. If the quadriceps is weak, we can assume he will eventually get a good block to L2. Take an alcohol swab or block of ice (not a needle prick) and touch the ice on the back of the patients hand to give him an idea of the cold sensation you are trying to elicit. Then start at the feet and move proximally until the patient says feels cold. Consult a dermatome diagram to determine the upper level of the block.
- 34. ANATOMY OF EPIDURAL SPACE Boundaries: Superiorly-Dural mater at foramen magnum Inferiorly-Sacrococcygeal membrane Anterior-posterior longitudinal Ligament/vertebral bodies & discs Laterally-Pedicles /intervertebral foraminae Posteriorly-Ligamentum flavum EPIDURAL BLOCK
- 35. Contents • Fat • Dural sac • Spinal nerves • Vessels- ant. & post. Spinal arteries; valveless veins of Batson • Connective tissue
- 36. SITES: Cervical, Thoracic, Lumbar, Caudal INDICATIONS: Lumbar/Caudal; operative procedures as for spinal + analgesia in labour, postoperative pain relief, chronic pain management. Thoracic;postoperative pain management (e.g thoracototomy,), analgesia in trauma. Cervical; chronic pain therapy,
- 37. PRE PROCEDURE • Monitoring: ECG, NIBP, Oximetry • IV cannula- 18/16 • Preload with crystalloid • Epidural pack-18G Tuohy needle, catheter with filter,syringes • Drugs- plain bupivacaine(0.5-0.75%), ropivacine (0.75-1%), ephedrine, phenylephedrine,others
- 38. Technique • Aseptic procedure • Identify the space- loss of resistance to saline or air • Insert catheter • Test dose- 3ml 2% lidocaine plus adrenaline 1: 200,000 • Then marcaine 10-15ml to establish block • Adjuvants- opioids, others
- 40. Factors which determine block: • Dose/volume • other drugs • Baricity • weight/height/age • Speed of injection • Position after injection
- 41. EFFECTS OF SPINAL ANAESTHESIA • Blocks spinal nerve roots • + cord level • CVS: Hypotension • Bradycardia • ↓ Blood loss • ↓Risk of DVT • RS: ↓Cough/ventilation (O2 supplement) • GIT: Contracted bowel • GUS: Urinary retention
- 42. EARLY COMPLICATIONS Trauma to nerves/blood vessels/pleura Breakage of needles/catheters. Local anaesthetic toxicity /intravascular injection Failure of technique High/total spinal block Hypotension / Bradycardia Phrenic nerve block Injection of the wrong solution particularly through catheter RISK AND COMPLICATIONS OF SPINAL/EPIDURAL ANAESTHESIA
- 43. RISK AND COMPLICATIONS Late Complications • Postdural puncture headache • Urinary retention • Neurological damage ; Trauma,Haematoma, Infection,Arachnoiditis,Cord ischaemia • Cerebral herniation • Infection • Bleeding •Radiculopathy •Low back ache
- 44. SUMMARY Golden rules of spinal anaesthesia, always: - Discuss the procedure with the patient - Discuss with the surgeon - Discuss potential complications/side effects and document in the notes/charts - Perform the procedure best suited for the patients
- 45. • Perform the procedure in an appropriate setting + resuscitation drugs and equipment • Have an iv access • Monitor with standard techniques • Fractionate doses greater than 5ml • Document procedure performed and complications • Know the anatomy and technique well • Be prepared to fail – back up plan
- 46. POST-TEST 1. Name 5 surgical procedures which are suitable for a subarachnoid block? 2. What level do the following end: - spinal cord? - dural sac? 3. What type and size of spinal needle is recommended for a subarachnoid block? 4. How are Local anaesthetic drugs rendered