paravertebral block.pptx anesthetic consideration

anesthetic implications of paravertebral blocks

1. Erector spinae plane block paravertebral block Moderator : Dr Shikha Sharma Presenter : Dr Tanvi sharma

2. Thoracic paravertebral block (TPVB) Technique of injecting local anesthetic alongside the thoracic vertebra close to where the spinal nerves emerge from the intervertebral foramen. Produces unilateral, segmental, somatic, and sympathetic nerve blockade, effective for anesthesia and in treating acute and chronic pain of unilateral origin from the chest and abdomen

3. Thoracic Paravertebral Space Anatomy It is bound posteriorly by the superior costotransverse ligament anterolaterally by the pleura, medially by the vertebrae and intervertebral foramina, and superiorly and inferiorly by the ribs. Communicates with the epidural space medially and with the intercostal space laterally. The TPVSs on either side of the thoracic vertebra also communicate with each other through the epidural and prevertebral space.

4. Mechanism of Block & Distribution of Anesthesia Produces ipsilateral somatic and sympathetic nerve blockade Multiple injection technique is preferable over single, large-volume injection. Segmental contralateral anesthesia :10%

5. TECHNIQUE Sitting position (preferred) ,lateral, or prone position. Surface landmarks are identified and skin markings are made 2.5 cm lateral to the midline ( transverse process )of the vertebra. Strict asepsis should be maintained a 22-gauge tuohy needle is recommended with depth markings or depth guard

6. Loss-of-Resistance Technique The skin and underlying tissue is infiltrated with lidocaine 1%, and the block needle is inserted perpendicular to the skin in all planes to contact the transverse process of the vertebra The depth at which the transverse process is contacted varies (3–4 cm) . the depth is deeper at the cervical and lumbar spine level and shallower at the thoracic levels. During needle insertion it is possible to miss the transverse process and puncture the pleura. therefore, search and make contact with the transverse process before advancing the needle too deep . Maximum depth :4 cm thoracic and 5 cm cervical / lumbar levels The needle is then walked above or bellow (safer) the transverse process and gradually advanced until a loss of resistance is elicited as the needle traverses the superior costotransverse ligament .

7. Predetermined Distance Technique : TPVB can also be performed by advancing the needle by a fixed predetermined distance (1 cm) once the needle is walked off the transverse process, without eliciting loss of resistance. Advantage: low risk of pneumothorax

8. CONTRAINDICATIONS Infection at the site of injection Allergy to local anesthetic drug Neoplastic mass occupying the paravertebral space Coagulopathy, or patients on anticoagulant ( relative contraindication) Kyphoscoliosis ,deformed spines , previous thoracic surgery.(Caution)

9. Local anesthetic Long-acting local anesthetic drug Bupivacaine or levobupivacaine 0.5% and ropivacaine 0.5%. For single-injection :20–25 ml Multiple-injection 4–5 ml of local anesthetic is injected at each level planned TPVS : well vascularized space leading to rapid absorption . epinephrine (2.5–5.0 mcg/ml) can be used to reduce systemic toxicity. The duration of anesthesia 3–4 h, analgesia : (8–18 h). For continuous pain relief : infusion of bupivacaine or levobupivacaine 0.25% or ropivacaine 0.2% at 0.1–0.2 ml/kg/h is started after the initial bolus injection and continued for 3–4 days or as indicated.

10. COMPLICATIONS Vascular puncture (3.8%) Hypotension (4.6%) : rare because sympathetic blockage is UL, may unmask hypotension, caution in hypovolemic or hemodynamically labile. Pleural puncture (1.1%), managed conservatively. Clues ( loss of resistance as the needle enters chest cavity, cough, onset of sharp chest or shoulder pain, or sudden hyperventilation) Pneumothorax (0.5%) local anesthetic toxicity Inadvertent epidural, subdural, or intrathecal injection and spinal anesthesia Ipsilateral or bilateral horner syndrome

11. Key points Perform TPVB with the patient in the sitting position. •  Surface landmarks should always be identified and marked with a skin marker. •  Use needles with depth markings to facilitate estimation of the depth of insertion. •  It is imperative to search and make contact with the transverse process before advancing the needle any farther. •  The depth at which the transverse process is contacted varies in the same patient at different thoracic levels. It is deepest in the cervical, upper and lower thoracic, and shallowest in the midthoracic region. •  The needle should not be advanced more than 1.5 cm beyond the contact with the transverse process. •  Avoid directing the needle medially to prevent inadvertent epidural or intrathecal needle misadventure

12. Lumbar paravertebral block lumbar paravertebral space (LPVS) anterolaterally : psoas major muscle; medially :vertebral bodies, the intervertebral discs, and intervertebral foramen with its contents; and posteriorly : transverse process and the ligaments . LPVS is occupied primarily by the psoas major muscle. local anesthetic is injected anterior to the transverse process into a triangular space between the two parts of the psoas major muscle containing the lumbar spinal nerve root.

13. TECHNIQUE Sitting, lateral, or prone position. Surface landmarks identified Iliac crest :L3-L4 interspace. Skin markings are made 2.5 cm lateral to the midline advance the needle by a fixed predetermined distance (1.5–2.0 cm) beyond the transverse process, perpendicular to the skin until the transverse process is contacted. The depth : (4–6 cm) once the transverse process is identified, the marking noted and the depth marker is adjusted so that it is 1.5–2.0 cm beyond the skin–transverse process depth The needle is withdrawn to the subcutaneous tissue and reinserted at a 10- to 15-degree superior or inferior angle so that it slides off the superior or inferior edge The needle is advanced by a further 1.5–2.0 cm beyond the contact with the transverse process or until the depth marker is reached. After negative aspiration the local anesthetic is injected

14. INDICATIONS LPVB is commonly used in combination with TPVB (T10 through L2) for surgical anesthesia during inguinal herniorrhaphy. It can be also effective for rescue in patients with severe pain after total hip replacement. diagnostic purpose evaluation of groin or genital pain Contraindications for LPVB are similar to TPVB Complications: intravascular, epidural, or intrathecal space injection medial angulation should be avoided. Intraperitoneal injection or visceral injury Motor weakness involving the ipsilateral quadriceps muscle may result if the L2 spinal nerve is blocked (femoral nerve L2–L4).

15. USG GUIDED a low-frequency ultrasound transducer (2–5 MHz) with a divergent beam and a wide field of vision. . The transverse process is seen as a hyperechoic structure, anterior to which there is a dark acoustic shadow which completely obscures the TPVS 

16. Transverse scan Place the transducer lateral to the spinous process with the orientation marker directed to the patient’s right side 

17. Transverse scan short axis needle insetion Teqnique is similar to that when surface anatomy landmarks are used Transverse scan with inplane needle insertion/intercostal approach Block needle is inserted in plane of usg beam from lat to medial direction

18. Sagittal scan in plane approach Block needle inserted along plane of usg Following injection there is anterior displacement of pleura , widening of space

19. ERECTOR SPINAE PLANE BLOCK The “erector spinae” comprises a group of muscles including the iliocostalis, longissimus, and spinalis muscles. They run bilaterally from the skull to the pelvis and sacral region, and from the spinous to the transverse processes, extending to the ribs. Block is not useful as sole anesthesia , mainly used for postoperative pain relief for thoracoabdominal surgeries and chronic pain Drug is deposited underneath ESM And overlying transverse process. INDICATIONS BREAST SURGERY , thoracic procedures , abdominal and pelvic procedures Rib fractures , thoracoabdomen neuralgia , cancer pain , CRPS

20. Anterior or ventral ramus of T2 to T5: Motor (Intercostal muscles) and sensory (anterior and lateral chest wall, and parietal pleura) Anterior or ventral ramus of T6 to T12: Motor (abdominal muscles) and sensory (anterior and lateral abdominal wall,and parietal peritoneum) Posterior or dorsal ramus of T2 to T12: Somatic motor and sensory information to and from skin and deep muscles Procedure Using Ultrasound Guidance   Position : sitting, lateral decubitus, or prone . T eqnique : high-frequency linear USG probe 10 to 15 mhz is placed in the paramedian sagittal plane , 2.5 to 3 cm lateral to the spinous process of thoracic vertebrae at the level of block .  LA in the fascial plane between the ESM above and the transverse process below. Is injected 22-gauge, 50-mm needle used Dose : diluted local anesthetic (20 to 30 mL of 0.2% ropivacaine or 0.25% bupivacaine) elevation of ESM can be seen by USG

21. Thank you