Bier block uses
-short (60 mins) procedures
-superficial wrist and hand surgeries (ex
: carpal tunnel)
-rapid onset and recovery
What type of anesthesia is a bier block considered?
Bier block IV placement and gauge
-IV as distal as possible on affected side
-small gauge IV (22)
How high should the cuff be inflated?
-150 mmHg greater than SBP
-usually to 300 mmHg
How do we check the double tourniquet cuffs are working?
Absence of a pulse
What cuffs should be up / down when injecting the LA?
Distal cuff down (so LA get get there)
Proximal cuff up
General sequence of events for a Bier block
-place 22g IV
-check cuffs are working (no pulse)
-elevate extremity and wrap with esmarch distal to proximal all the way up to distal cuff
-inflate distal then proximal cuffs to 300 mmHg
-deflate distal cuff
-inject LA over 5 mins
-once patient c/o pain the distal cuff is inflated and the proximal cuff is deflated
What LA is used? How much?
50 ml of 0.5% lidocaine
Why does the LA need to be injected slowly?
So as not to overcome the tourniquet pressure (otherwise the medication would not be localized to the surgical site)
What s/sx could indicate lido toxicity?
Perioral numbness, metallic taste in the mouth
Other SE include: dizziness, tinnitus, bradycardia, seizures
Why is lido 0.5 % the LA of choice?
-high therapeutic index
-always plain lido (NO epi)
How long does the tourniquet need to stay inflated for to prevent toxicity?
-At least 20-30 mins (sources vary)
-This gives the tissues time to take up the LA
What size syringe should be used to inject the lido? Why?
Reduces the pressure in the syringe when the barrel is pushed
How should the cuff be deflated?
-Cyclically so LA is leaked into the systemic circulation slowly
-deflated in 10 second intervals with 1 min reinflation x 3
Bier block complications
-Engorgement of the pt's extremity (pt with arteriosclerosis)
-Hematoma (hence we use a small gauge IV)
Bier block contraindications
-ischemic vascular disease
-traumatic lacerations, crush injuries
-severe post-op pain issues
-extremity fx (pain limits exsanguination)