What are the steps for thoracic epidural placement without fluoroscopy?

Step-by-Step Instructions for Thoracic Epidural Placement Without Fluoroscopy

Thoracic epidural placement without fluoroscopy can be safely performed using proper technique and anatomical landmarks, though alternative regional blocks such as paravertebral or erector spinae plane blocks should be considered as first-line options for thoracic procedures due to their lower risk profile. 1

Patient Positioning and Preparation

• Position the patient in sitting or lateral decubitus position with shoulders and back flexed to open the interlaminar spaces 1, 2
• For difficult cases, the prone position may be used as an alternative approach 2, 3
• Identify the target thoracic level using anatomical landmarks (counting down from C7 prominence or up from the iliac crest) 1
• Mark the midline and the target interlaminar space 2
• Perform sterile skin preparation and drape the area 1

Ultrasound Guidance (Preferred Method)

• Use a low-frequency curvilinear probe (2-5 MHz) to identify the target interlaminar space between T9-T12 (lower thoracic levels are easier to access) 2, 3
• Obtain a paramedian sagittal view to identify the lamina and interlaminar space 2
• For mid-thoracic epidural access, consider using the paramedian cross (PX) view technique which has shown a 96% first-attempt success rate 3
• Mark the skin entry point at the junction of a line parallel to the vertebral column passing through the middle of the pedicle and the lower border of the vertebral body 4

Needle Insertion and Advancement

• Infiltrate the skin and deeper tissues with local anesthetic 1
• Insert an 18G Tuohy needle at the marked point with an inward angulation of approximately 38 degrees and upward angulation of about 63 degrees 4
• For real-time ultrasound-guided technique:
  • Advance the needle under direct ultrasound visualization until it reaches the posterior complex 2
  • Continue needle advancement using loss-of-resistance technique once the needle tip is visualized near the ligamentum flavum 2, 3
• For traditional technique:
  • Walk the needle off the lamina toward the midline at the height of the pedicle 4
  • Use loss-of-resistance technique with saline or air to identify the epidural space 5

Loss-of-Resistance Technique

• Attach a syringe filled with saline (preferred) or air to the Tuohy needle 1
• Apply constant or intermittent pressure on the plunger while slowly advancing the needle 1
• When the needle tip enters the epidural space, a sudden loss of resistance will be felt 1
• For ultrasound-guided drip infusion technique, observe the free flow of fluid into the epidural space when resistance is lost 3

Catheter Placement

• Hold the needle steady and insert the epidural catheter 3-5 cm into the epidural space 1
• Remove the needle carefully while holding the catheter in place 1
• Secure the catheter to the skin with adhesive dressing 1
• Consider administering a test dose (3-5 mL of lidocaine 1.5% with epinephrine 1:200,000) to rule out intravascular or intrathecal placement 1

Verification of Placement

• Assess for bilateral sensory changes after administration of local anesthetic 1
• Ensure there are no signs of intravascular injection (tachycardia, hypertension) or intrathecal injection (rapid onset of dense motor block, hypotension) 1, 6
• If available, consider using epidurography with contrast to confirm proper placement, though this requires fluoroscopy 5

Common Pitfalls and Complications

• Dural puncture: Recognize by free flow of CSF; may require repositioning at a different level 1, 6
• Vascular puncture: Withdraw needle immediately if blood is aspirated 1, 6
• Neurological injury: Avoid advancing the needle or catheter against resistance 1, 6
• Hypotension: Monitor blood pressure closely after local anesthetic administration 1, 6
• Failed block: Consider alternative approaches or regional techniques such as paravertebral block or erector spinae plane block if epidural placement is unsuccessful 1

Important Considerations

• Thoracic epidural placement has a higher technical difficulty compared to lumbar epidural placement 5
• First-pass success rates are significantly higher with fluoroscopic guidance (98%) compared to blind technique (74%), but fluoroscopy is not always available 5
• Real-time ultrasound guidance has shown first-pass success rates of 76.3% for lower thoracic epidurals and up to 96% for mid-thoracic epidurals using specialized techniques 2, 3
• For thoracic surgical procedures, consider alternative regional techniques such as paravertebral block or erector spinae plane block which have fewer side effects and complications 1