Ulnar
Intravenous Regional Anesthesia
Indications
Brief minor surgery up to one hour of the hand, forearm, foot, or ankle (e.g. Carpal tunnel release, Wrist fracture)
Anatomy
Nerves of Brachial Plexus blocked:
Ulnar
Median
Radial
Musculocutaneous
Arteries Occluded:
Radial
Ulnar
Equipment
20-22Gauge
angiocath x 2
Extension tubing x 2
Esmarch elastic bandage
Cotton batting (Webroll)
Double cuff tourniquet
Pressure source
Tape
Local anesthetic
50-100cc syringe
4x4 gauze
Technique
Perform with patient in supine position
Administer supplemental oxygen
Monitor:
Blood pressure
EKG
Pulse oximeter
Insert
20-22Gauge PIV into dorsal hand vein of the arm to be anesthetized
Also need to establish a second PIV in nonoperative arm for administration of fluids and drugs prn.
Attach extension tubing and tape securely into place
Place cotton batting on upper arm
Apply tourniquet with overlap placed on outer arm to avoid nerve sheath compression
Palpate radial and ulnar arteries to establish baseline
Elevate arm to promote venous drainage
Ask patient to grasp cotton roll tightly in fist
Apply wide Esmarch rubber bandage from fingertips to tourniquet in distal to proximal fashion
Inflate
Distal cuff to further exsanguinate limb, then inflate Proximal tourniquet to
300mmHG or 2.5x patient’s systolic BP, then deflate distal cuff.
If during surgery pt. c/o tourniquet pain, inflate Distal tourniquet then and only then may you deflate the Proximal tourniquet
Remove esmarch and assess radial and ulnar pulses for occlusion
Inject Local anesthetic while observing for venous engorgement
Forearm discolors, pt. c/o “pins & needles” sensation while LA onsets approximately 5min.
Remove PIV
If surgery >1hour, leave PIV in place, may re-inject after 90min.
Local Anesthetics
Lidocaine 0.5%
Most commonly used
Methylparaben free
Typically 50cc, onset 1.5 - 5minute, duration 1 – 4hours
Prilocaine 0.5%
Methylparaben free
Observe for Methemoglobinemia
Typically 50cc, onset 2 - 15minute, duration 1 – 4hours
Bupivacaine 0.25%
Methylparaben free
Slower onset
onset 5 -15minute, duration 1.5 – 8.5hours
Use of bupivacaine for IV regional anesthesia has been associated with local anesthetic toxicity and death and is not
recommended
Epinephrine should not be added to local anesthetic.
Durations of local anesthestics are dependent on tourniquet time and drug redistribution
Block Assessment
Assess pallor of skin
Pale/pasty coloring is indicative of adequate exsanguinations.
Extensive mottling is indicative of inadequate exsanguinations.
Assess anesthesia of applicable nerves:
1 - Ulnar Nerve – C8
2 - Median Nerve – C7
3 - Radial Nerve – C6
Musculocutaneous (not pictured) sensory to anterior forearm
Advantages of IV Regional Anesthesia
Ease of administration
Rapid onset
Muscle relaxation
Rapid recovery
Controllable extent of anesthesia
Possible Disadvantages
Rapid recovery may lead to postoperative pain
Difficulty in providing a bloodless field
Necessity of exsanguination in the case of a painful injury (eg, fracture)
Complications
Tourniquet pain (usually after 45 minutes)
Treatment:
IV analgesia or sedation
Inflation of distal tourniquet over anesthetized tissue and deflation of proximal tourniquet
Systemic toxicity
Most common
Minimal tourniquet time is 20minutes
Cyclic deflation of the tourniquet at 10-second intervals has been shown to increase the time to peak
arterial lidocaine levels that may decrease potential toxicity.
Allergic reactions
May occur with the use of local anesthetics containing preservatives, i.e. Methylparaben, or with ester
local anesthetics
Compartment syndrome (Rare)
Loss of limb (Rare)