Flashcards in Ocular and Bier Blocks Deck (36):
What is a Bier block?
A double tourniquet IV regional block.
Tools required for Bier Block?
Lidocaine 0.5 - 1%
IVs x 2 -> 1 surgical side and 1 on other side for sedation
Tourniquet x 2 (blue/red and know which cuff is at which location)
mL of lidocaine 0.5% Bier Block
30 - 40 mL
mL of lidocaine 1% Bier Block
12 - 15 mL
First step of Bier Block
Elevate and wrap arm with esmarch to exsanguinate extremity
Second step of Bier Block
Test tourniquet cuffs then inflate proximal tourniquet 50 -100 mmHg above MAP keeping distal tourniquet deflated.
Third Step of Bier Block
Unwrap arm and inject 40 mL of Lidocaine 0.5% max dose of 3 mg/kg
What is onset of Bier Block?
Fourth Step of Bier Block
Inflate distal cuff after 30 minutes and deflate proximal cuff. DO NOT DEFLATE CUFF IF SURGERY ENDS EARLIER THAN 20 MINUTES.
There is no postoperative analgesia in Bier Blocks. T/F
There is a motor block with Bier Blocks. T/F
What provides innervation to lacrimal gland and posterior eye?
What nerve provides sensory afferent information in the eye?
What muscle turns the eye down and out?
What muscle turns the eye up and in?
What muscle turns the eye in towards the nose?
Medial (Internal) Rectus
What muscle is responsible for cross eyed or downward and inward?
What muscle turns the eye outward?
Lateral (External) Rectus
What muscle turns the eye up and outward?
What nerve provides sensory input to the brain for what the eye is seeing?
What reflex is activated by posterior globe pressure, muscle stretch, or surgical manipulation of the eye?
The oculocardiac reflex
What cranial nerves pathways are responsible for stimulation and response of the oculocardiac reflex?
CN V Trigeminal Afferent
CN X Vagus Efferent
What are the symptoms of the oculocardiac reflex?
Profound bradycardia and slowing of the impulse conduction through the AV node
What is treatment of oculocardiac reflex?
Ensure adequate oxygenation and ventilation
Atropine IVP 0.01-0.02 mg/kg but pretreatment does not always prevent
Local anesthetic infiltration
Best way to PREVENT oculocardiac reflex stimulation?
Retrobulbar or peribulbar blocks
Patient cannot go into full cardiac arrest with oculocardiac reflex. T/F
False patient may need CPR
How many mL of Local anesthetic for Retrobulbar block?
What nerve is anesthetized to prevent oculocardiac reflex?
Trigeminal CN V Afferent pathway
When do you angle the needle during the retrobulbar block and in what direction?
Once past the axis of the globe and angle it superiorly and medially
How many mL of LA for Peribulbar blocks?
10 mL = 2 x 5 mL
Which is the deeper eye block? Peribulbar or retrobulbar?
Which is the safer eye block? Peribulbar or Retrobulbar
Where does the Afferent pathway send information before efferent pathway?
How can an eye block lead to respiratory arrest?
By inadvertent injection into the CSF which will cause a high neuroaxial blockade requiring intubation
How can an eye block cause seizures?
By inadvertent intra-arterial injection of local anesthetic