Regional Nerve Blocks
Josh MajorAnesthesia Clerkship
History of Peripheral Nerve Block
• 1880’s: William Stewart Halstad and Richard John Hall describe injecting cocaine into peripheral sites during minor surgery
• 1914: Heinrich Braun describes techniques for every region of the body.
• 1922: Regional Anesthesia: It’s Technic and clinical Application written by Gaston Labot at the Mayo Clinic– Definitive regional anesthesia textbook for 30 years.
Indications for Regional Nerve Block
• Pain control post-op associated with surgical procedures– Improved patient satisfaction due to decreased
pain, opioid use and side effects and decreased incidence of sleep disturbance
• Useful in patients in whom general anesthesia is contraindicated or prevent undesired effects
Contraindications
• Absolute Contraindications:– Infection at site of block– Patient refusal– Allergy to local anesthetic
• Relative Contraindications:– Medical anticoagulation or coagulopathy in
deeper nerve blocks
Types of Nerve Blocks
• Single Shot: one time injection of local anesthetic to target nerve
• Continuous Perineural Blockade: percutaneous insertion of a catheter directly adjacent to target nerves
Upper Extremity Blocks
Upper Extremity Blocks
• Interscalene Block – Indication: Surgery or manipulation of the shoulder
• Supraclavicular Block – Indication: Elbow, forearm and hand surgery
• Infraclavicular Block – Indication: Provide anesthesia to the arm and hand
• Axillary Block – Forearm and hand surgery
Lower Extremity Blocks
Lower Extremity Blocks
• Femoral Nerve Block – Indication: Knee arthroscopy, femoral shaft fractures, total knee repair and ACL reconstruction
• Obturator Nerve Block – Indication: Knee surgery, rarely blocked on it’s own
• Sciatic Nerve Block – Indication: Can be used together with a femoral or saphenous block for any procedure below the knee that doesn’t need a thigh tourniquet
Choices of Local Anesthetic
• Depends primarily on required duration of anesthesia
• Different anesthetic drugs have varying durations
• Blockade may last up to 24 hours• Epinephrine can be added to improve onset of
action and prolong drug action
Major Nerve Block Drugs
Drug with Epinephrine 1 : 200,000
Usual Concentration (%)
Usual Volume (mL)
Maximal Dose (mg)
Usual Onset (min)
Usual Duration (min)
Lidocaine 1-2 30-50 500 10-20 120-240Mepivacaine 1-1.5 30-50 500 10-20 180-300Prilocaine 1-2 30-50 600 10-20 180-300Bupivacaine 0.25-0.5 30-50 225 20-30 360-720Levobupivacaine 0.25-0.5 30-50 225 20-30 360-720
Ropivacaine 0.2-0.5 30-50 250 20-30 360-720
Major Nerve Blocks
Ultrasound Guidance
• Allows direct visualization of the nerve, needle, and anesthetic distribution
• Commonly used as an adjunct to regional anesthesia techniques
• Can be useful in decreasing complications• Facilitates placement of blocks in patients with
challenging anatomy
Complications
• Block Failure• Perineural Hematoma• Infection• Nerve Injury• Intravascular Injection• Intraneural Injection• Excessively Dense Block
References• Miller, M.D., Eriksson, L.I., et al. (eds.). Miller’s Anesthesia, 7th Edition. Philidelphia: Churchill Livingston
2009.