3Anatomy of the intercostal nerve They are 12 pairs of thoracic anterior primary rami.Intercostal nerves 3–6 (the ‘typical’ intercostal nerves)
4Anatomy of the intercostal nerve They enter their intercostal spaces across the anterior aspect of the corresponding superior costotransverse ligament to lie below the intercostal vessels, first between the posterior intercostal membrane and the pleura and then, at the rib angles, between the internal intercostal and the innermost intercostal muscles.Near the margin of the sternum, each nerve passes in front of the internal thoracic vessels and sternocostalis muscle and pierces the internal intercostal muscle, anterior intercostal membrane and the overlying pectoralis major to become an anterior cutaneous nerve of the thorax.
5Atypical intercostal nerves The 1st intercostal nerve (T1) Passes across the front of the neck of the 1st rib, lateral to the superior intercostal artery, to enter into the composition of the brachial plexus.The 2nd intercostal nerve: its lateral cutaneous branch crosses the axilla to supply the skin of the medial aspect of the upper arm (intercostobracbial nerve).The 7th to 11th intercostal nerves enter the abdominal wall between the interdigitations of the diaphragm with transversus abdominis.The 12th thoracic (subcostal) nerve runs along the lower border of the 12th rib below the subcostal vessels, passes behind the lateral arcuate ligament to run in front of quadratus lumborum then passes between transversus abdominis and internal oblique.
6Indications of intercostal nerve block Any pain from chest wall and upper abdominal wall like:Cancer pain.Rib fractures.Chronic painful inflammation like herpes zoster.
8Technique of intercostal nerve block Patient is in prone position.By index finger displace the skin over rib in the posterior axillary line .Needle inserted perpendicular to skin until bony contact with the desired rib is made.The needle is walked off the lower edge of rib until bony contact is lost, the needle is advanced 3-5 mm deeper.
9Complications of Intercostal block Pneumothorax:Occur relatively in 1% to 2% of patients.Local anesthetic toxicity:Because of rapid absorption from this site.Infection.
11Interpleural BlockUnilateral perioperative analgesia : Cholecystectomy, renal or breast op.Upper extremity ischemic and neuropathic pain, thoracic herpes zoster, pancreatitis, and thoracic cancer pain.
12Anatomy & technique Lat. Or semiprone position. Ipsilateral arm should hang across the body, retract the scapula anteriorly.Endpoint for entry into the interpleural space is detection of negative interpleural pressure.5~8th intercostal space, selected rib, 8~10cm lat. to the midline.Perpendicular to the skin, over rib, and walked cephalad until contact the sup. Edge of rib is lost.Passive loss of resistance.
13Dosing Supine ; intercostal block with less sympathetic block Head up : Upper abdominal visceral painHead down : upper thoracic and cervical spreadLt. Side : pancreatic, gastric, or splenic painRt. Side : hepatic, gallbladder painTherapeutic dose : 20~30ml of 0.25~0.5% bupivacaine over 2~3minutes
14ComplicationTraumatic injury : Pneumothorax (2%), catheter malposition.Systemic effect from drug : Inflammation of pleural membranes, local anesthetic toxicity(1.3%), Pleural effusion (0.4%).Etc. : Horner’s syndrome, phrenic n. palsy, bronchopleural fistula formation, injury to the neurovascular bundle.
16Common Indications SURGICAL ANESTHESIA: POSTOPERATIVE ANALGESIA: Breast surgeryHerniorrhaphyChest wound explorationPOSTOPERATIVE ANALGESIA:Thoracic surgeryBreast surgeryCholecystectomyRenal and ureteric surgeryHerniorrhaphyAppendectomyVideo-assisted thoracoscopic surgeryMISCELLANEOUSFractured ribsTherapeutic control of hyperhydrosisLiver capsule pain after blunt traumaAcute postherpetic neuralgia
17Regional Anatomy Wedge shaped area on both sides of vertebra BOUNDARIES:Anterior/lateral: Parietal pleuraPosterior: Superior costo- transverse ligamentMedial: Postero-lateral aspect of the vertebral body, intervertebral disc and the intervertebral foramenCOMMUNICATIONS:Intercostal space laterally.Epidural space medially.Paravertebral space on the other side via the prevertebral and epidural space.
18Patient position & landmarks Position : Sitting or lateral decubitus, with kyphotic attitude supported by a attendant.Landmarks :Spinous processes along the midlineTip of scapula : T10Paramedian line 2.5 cms lateral to midline
19TechniqueAt thoracic level : Spinous process of upper vertebrae is at level of transverse process of lower spine.Needle Insertion Point: 2.5 cm lateral to the tip of spinous process.Saggital section through the thoracic paravertebral space showing a needle that has been advanced above the transverse process.
20Technique Procedure consists of 3 maneuvers Contacting transverse processes of individual vertebrae (depth 2-4 cms).Withdrawing needle to skin level and reinserting it 10 deg caudal or cranial.Inserting needle 1 cm deeper than level of transverse processes.Called “Walking Off” (Cranially/Caudally)
22Technique (Continuous Thoracic paravertebral block) The same method can be modified and a catheter can be placed in the paravertebral space for giving more prolonged postoperative analgesia.A Touhy’s needle is used for the procedure and a catheter is inserted 5 cms beyond the tip of the needle.Catheter is ideally inserted 1-2 segmental levels below the thoracotomy incision.
24Local Anesthetic: 3-4 ml/ level for multiple level block, ml for single level, and 0.1 ml/kg/h. Appropriate drugs: bupivacaine %, ropivacaine %, or lidocaine 1%; with epinephrine (2.5 μg/ml).Mechanism and Spread of Anesthesia: 15 ml bupivacaine 0.5% in TPVs produces unilateral somatic block over 5 (range: 1-9) dermatomes, and sympathetic block over 8 (range 6-10) dermatomes.Possible areas of spread:May remain localizedMay spread to contiguous levels above and belowIntercostal space laterallyEpidural space, mostly unilateral and insignificant, in up to 70%Single ml injection as effective as multiple 3-4 ml/site.Increasing volume may predispose to bilateral anesthesiaIf a wide block (≥ 5 dermatomes) is desired, preferable to do multiple injections, or 2 injections several dermatomes apart
25Contraindications ABSOLUTE Infection at the site of needle insertion. Empyema.Allergy to local anesthetic drugs, andTumor occupying the TPVS.RELATIVECoagulopathyKyphoscoliosis (chest deformity may predispose to pleural or thecal puncture)Patient with previous thoracotomy: TPVB may be obliterated by scar tissue and adhesion of lung to chest wall
26Complications and ways to avoid them Infection- A strict aseptic technique should be usedHematoma- Avoid multiple needle insertions in anticoagulated patientsLocal anesthetic toxicity- Rare - Large volumes of long-acting anesthetic should be reconsidered in older and frail patients - Consider using chloroprocaine for skin infiltration to decrease the total dose/volume of the more toxic, long-acting local anestheticNerve injury- Local anesthetic should never be injected when a patient complains of severe pain or exhibits a withdrawal reaction on injectionTotal spinal anesthesia- Avoid medial angulation of the needle, which can result in an inadvertent epidural or subarachnoid needle placement - Aspirate before injection (for blood and CSF)Quadriceps muscle weakness- This can occur when the levels are not accurately determined and the levels below L1 are blocked (femoral nerve; L2-4)Paravertebral muscle pain-Paravertebral muscle pain, resembling a muscle spasm, is occasionally seen, particularly in young, muscular men and when a larger gauge Tuohy needle is used - Injection of local anesthetic into the paravertebral muscle before needle insertion and the use of a smaller gauge (e.g. 22 gauge) Quincke tip needle is suggested to avoid this side effect
28Anatomy of transversus abdominis plane (TAP) The anterior abdominal wall (skin, muscles, parietal peritoneum) is innervated by the anterior rami T7 to T12 and L1.Terminal branches of them course through the lateral abdominal wall within a plane between the internal oblique and transversus abdominis muscles.Injection of local anesthetic within the TAP produce unilateral analgesia to the skin, muscles, and parietal peritoneum.
29Indications of TAP block For supplementary anesthesia or analgesia for lower abdominal surgery like:Inguinal hernia.Cesarean section.
30Technique of transversus abdominis block Needle is inserted at triangle of Petit bounded by the latissimus dorsi muscle posteriorly, the external oblique muscle anteriorly and the iliac crest inferiorly.A needle is inserted perpendicular to enter TAP plane after two pops.The first pop: penetration of the external oblique fascia.The second pop: penetration of internal oblique muscle.
31Ulrasound guided technique for TAP block Patient is placed in a supine position and the abdomen is exposed between the costal margin and the iliac crest.Identify the three muscular layers of the abdominal wall: the external oblique (most superficial), the internal oblique and transversus abdominis muscles.Among the three muscles, the internal oblique muscle is the most prominent layer.
32Ultrasound guided TAP block (cont) Needle is inserted in-plane with the transducer, in an antero-posterior direction.Choosing an insertion point some distance away from the transducer improves needle shaft and tip visualization.Deposit local anesthetic deep to the fascial layer that separates the internal oblique and transversus abdominis muscles.
34Anatomy Innervation of the inguinal region lumbar plexus nerves: Ilioinguinal, Iliohypogastric nerves (L1).Genitofemoral nerve (L1,L2).These nerves coarse anteriorly near an important landmark for the block , the anterior superior iliac spine.The ilioinguinal nerve lies between the transversus abdominis muscle and the internal oblique muscle initially and then penetrates the internal oblique muscle some distance medial to the anterior superior iliac spine.The iliohypogastric nerve lies between the internal and external oblique muscles near the anterior superior iliac spine.The genitofemoral nerve follows a different coarse, and it is this nerve that must often be supplemented intraoperatively.All these nerves continue anteriorly in a medial orientation and become superficial as they terminate in the skin and muscles of the inguinal region.
35Course of the ilioinguinal, iliohypogastric, and genitofemoral nerves. Course of the ilioinguinal, iliohypogastric, and genitofemoral nerves. The circle indicates area infiltrated with local analgesic for each block. The centre of the circle (dotted line) indicates the point of insertion of the needle for each nerve block.
36Technique of inguinal block The anterior superior iliac spine (ASIS) should be marked while the patient is supine. Another mark should be made approx. 3 cm. medial and inferior to the ASIS.A skin wheal is created, and a 8-cm, 22-gauge needle is inserted in a cephalolateral direction to contact the inner surface of ilium. 10 mm of local anesthetic is injected as the needle is slowly withdrawn through the layers of the abdominal wall.The needle should then reinserted at a steeper angle to ensure penetration of the three muscle layers.From the previously placed skin wheal, the injection is extended toward the umbilicus, creating a subcutaneous field block.
38Anatomy for celiac plexus block Celiac plexus is situated retroperitoneally in paravertebral areolar tissue at anterolateral edge of the first lumbar vertebra on both sides.It lies posterior to the stomach and pancreas, anterior to the crura of diaphragm and the aorta.The numbar of ganglia varies from 1 to 5 on both sides.It receives afferent fibers of both sympathetic and parasympathetic from viscera.The celiac plexus provides innervation to most of the gut from the lower esophagus to the level of the splenic flexure of the colon.
39Indications of celiac plexus block Cancer from upper abdomen: cancer stomach or pancreas.Chronic non malignant pain from upper abdomen
40Classic retrocrural technique (deep splanchnic approach) Triangle is made between 3 points: spine between T 12 & L 1 and lower edges of 12th rib on both sides.Needle is inserted just cauded to 12th rib 7 cm lateral to midline, 45 degree from horizontal plane & 15 degree cephaled until bony contact with L1 vertebral body is made.Needle is withdrawn & redirected laterally about 1-2 cm, at this point aortic pulsations may be felt and the local anesthetic is injected retroaortic.
43Anatomy of superior hypogastric nerve The superior hypogastric plexus is a retroperitoneal structure that extends bilaterally anterior to the vertebral column between L5 and S1 vertebral bodies.It is formed by pelvic visceral afferents and efferent sympathetic nerves from branches of the aortic plexus, and fibers from the splanchnic nerves.It divides into two lateral portions which travel inferiorly to end as inferior hypogastric plexus.
44Indications of superior hypogastric block Any pain from:Lower urinary tract: bladder & urethra.Lower GIT: descending colon & rectum.Female genital tract: uterus, vagina & vulva.Male genital tract: prostate, penis &testes.Perineum.
45Technique of superior hypogastric block The patient will be in prone position.Needle is introduced 6 cm lateral to spine of L4.Directed 45 degrees medial and caudal until its tip comes anterior to vertebral body of L5 under fluoroscopic guidance.
47Anatomy of the ganglion Impar The ganglion impar is the only unpaired autonomic ganglion in the body.Marks the end of the two sympathetic chains.Located retroperitonially anterior to the sacrococcygeal joint.
48Indication of ganglion Impar block Any pain from:Perineum.Distal rectum & anus.Distal urethra.Distal third of vagina & vulva.Prostate & testes.
49Technique of ganglion Impar block The patient in the prone position.Needle is inserted in the sacral cornu to pierce the dorsal sacrococcygeal ligament at the midline.The needle is then advanced to pierce the ventral sacrococcygeal ligament, felt as a loss of resistance.
50QUESTIONS Patient position in intercostal nerve block can be: Prone.Lateral.Supine.All of the above.One of important indications of paravertebral block:Patients in whom neuroaxial techniques may be containdicated owing to hypotension or coagulopathy.Infection at site of injection.Allergy to local anesthetic.Tumor in paravertebral space.
51Triangle of Petit boundaries are: Latissmus dorsi, iliac crest, external oblique.Latissmus dorsi, internal oblique, transversus abdominis.External oblique, internal oblique, latissmus dorsi.Transversus abdominis, iliac crest, external oblique.Nerves that supply inguinal region:Ilioinguinal, iliohypogastric, genitofemoralLateral cutaneous nerve of thigh, ilioinguinal, obturator.Iliohypogastric, genitofemoral, sciaticFemoral, dorsal nerve of penis, ilioinguinal.Celiac plexus is situated retroperitoneally at anterolateral edge of:L1L4L5S1