This document provides an overview of epidural anesthesia, including spinal anatomy, the epidural space, techniques for administering epidural anesthesia, indications and contraindications. Key points include: - Epidural anesthesia involves injecting anesthetic into the epidural space surrounding the spinal meninges. - The epidural space is located using the loss of resistance technique, then a test dose is administered before further doses. An epidural catheter may be inserted. - Epidural anesthesia can be used for surgeries involving the abdomen, thorax or neck. It provides postoperative and chronic pain management. Contraindications include increased intracranial pressure and coagulopathies. Complications include failed or high

1. Epidural anesthesia
Presenter: Brenda Richard
Supervisor: Dr Lugano

2. Overview
• Introduction
• Applied anatomy
• Technique
• Indications & contraindications
• Complications

3. Spinal Anatomy
 33 Vertebrae
◦ 7 Cervical
◦ 12 Thoracic
◦ 5 Lumbar
◦ 5 Sacral
◦ 4 Coccygeal
 High Points: C5 & L5
 Low Points: T5 & S2

4. Sagittal Section
• Supraspinous Ligament
• Outer most layer
• Interspinous Ligament
• Middle layer
• Ligamentum Flavum
• Inner most layer

5. Spinal Cord
• Spinal Cord
• Adult
• Begins: Foramen Magnum
• Ends: L1
• Newborn
• Begins: Foramen Magnum
• Ends: L3
• Terminal End: Conus Medullaris
• Filum Terminale: Anchors in sacral region
• Cauda Equina: Nerve group of lower dural sac

6. Epidural Space
• Potential Space that surrounds the spinal meninges
• Ligamentum Flavum
• Binds epidural space posteriorly
• Widest at Level L2 (5-6mm)
• Narrowest at Level C5 (1-1.5mm)

7. Spinal Meninges
 Dura Mater
◦ Outer most layer
◦ Fibrous
 Arachnoid
◦ Middle layer
◦ Non-vascular
 Pia
◦ Inner most layer
◦ Highly vascular
 Sub Arachnoid Space
◦ Lies between the arachnoid
and pia

8. Technique
• It is given in sitting or lateral position
• The epidural space is most commonly located by loss of resistance
technique. Another technique is hanging drop technique (rarely used
in current practice)
• Once the needle is confirmed in epidural space, a test dose of 2-3mls
of lignocaine 1-2% with adrenaline 5mcg/ml is given. If in 5mins there
are no signs of either spinal block or intravascular injection, further
dose can be injected 15-20mls.
• An epidural catheter is then passed through the needle(3-4cm of the
catheter should be in epidural space)

9. Standard Epidural needle is typically 17 to 18 gauge, 3-3.5inches long
and has a blunt bevel with a gentle curve of 15 to 30degrees. Tuohy
needle is the most commonly used
Placing a catheter into epidural space allows for continuous infusion or
intermittent bolus technique which is useful for intraoperative epidural
anesthesia and postoperative analgesia
Distances from Skin to Epidural Space
• Average adult: 4-6cm
• Obese adult: up to 8cm
• Thin adult: 3cm

10. Indications
All surgeries which can e performed under spinal anesthesia can be
performed under epidural block.
However in clinical practice epidural block in mainly used in
• Postoperative pain management
• Chronic pain management
Others include
• Upper abdominal surgery
• Thoracic surgery
• Neck surgery

11. contraindications
• Raised intracranial pressure
• Patient refusal
• Severe hypovolemia and hypotension
• Coagulopathy

12. Physiologic effects of epidural block
1. Cardiovascular system
Blockade of Sympathetic Preganglionic Neurons
• Send signals to both arteries and veins
• Predominant action is venodilation
• Reduces:
• Venous return
• Stroke volume
• Cardiac output
• Blood pressure
T1-T4 Blockade
• Causes unopposed vagal stimulation
• Bradycardia
• Associated with decrease venous return & cardioaccelerator fibers blockade
• Decreased venous return to right atrium causes decreased stretch receptor
response

13. 2. Respiratory system
• Healthy Patients
• Appropriate epidural blockade has little effect on ventilation
• High Spinal
• Decrease functional residual capacity (FRC)
• Paralysis of abdominal muscles
• Intercostal muscle paralysis interferes with coughing and
clearing secretions
• Apnea is due to hypoperfusion of respiratory center

14. Factors affecting the spread(level) of block
• Volume of the drug
• Age
• Length of vertebral column
• Patient position

15. Complications
• Failed epidural anesthesia
• High or total spinal anesthesia
• Nerve injury
• Postdural puncture headache
• Back pain
• Infection

16. References
• Morgan & Mikhail’s clinical anesthesiology 6th edition
• A short textbook of anesthesia Ajay Yadav 6th edition
• UpTodate