Ocular and Bier Blocks Flashcards Preview

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Flashcards in Ocular and Bier Blocks Deck (36):
1

What is a Bier block?

A double tourniquet IV regional block.

2

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)

3

mL of lidocaine 0.5% Bier Block

30 - 40 mL

4

mL of lidocaine 1% Bier Block

12 - 15 mL

5

First step of Bier Block

Elevate and wrap arm with esmarch to exsanguinate extremity

6

Second step of Bier Block

Test tourniquet cuffs then inflate proximal tourniquet 50 -100 mmHg above MAP keeping distal tourniquet deflated.

7

Third Step of Bier Block

Unwrap arm and inject 40 mL of Lidocaine 0.5% max dose of 3 mg/kg

8

What is onset of Bier Block?

Immediate

9

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.

10

There is no postoperative analgesia in Bier Blocks. T/F

True

11

There is a motor block with Bier Blocks. T/F

False

12

What provides innervation to lacrimal gland and posterior eye?

Ciliary Ganglion

13

What nerve provides sensory afferent information in the eye?

Trigeminal nerve

14

What muscle turns the eye down and out?

Superior Oblique

15

What muscle turns the eye up and in?

Superior Rectus

16

What muscle turns the eye in towards the nose?

Medial (Internal) Rectus

17

What muscle is responsible for cross eyed or downward and inward?

Inferior Rectus

18

What muscle turns the eye outward?

Lateral (External) Rectus

19

What muscle turns the eye up and outward?

Inferior Oblique

20

What nerve provides sensory input to the brain for what the eye is seeing?

Optic Nerve

21

What reflex is activated by posterior globe pressure, muscle stretch, or surgical manipulation of the eye?

The oculocardiac reflex

22

What cranial nerves pathways are responsible for stimulation and response of the oculocardiac reflex?

CN V Trigeminal Afferent
CN X Vagus Efferent

23

What are the symptoms of the oculocardiac reflex?

Profound bradycardia and slowing of the impulse conduction through the AV node

24

What is treatment of oculocardiac reflex?

STOP STIMULATION
Ensure adequate oxygenation and ventilation
Atropine IVP 0.01-0.02 mg/kg but pretreatment does not always prevent
Local anesthetic infiltration

25

Best way to PREVENT oculocardiac reflex stimulation?

Retrobulbar or peribulbar blocks

26

Patient cannot go into full cardiac arrest with oculocardiac reflex. T/F

False patient may need CPR

27

How many mL of Local anesthetic for Retrobulbar block?

5 mL

28

What nerve is anesthetized to prevent oculocardiac reflex?

Trigeminal CN V Afferent pathway

29

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

30

How many mL of LA for Peribulbar blocks?

10 mL = 2 x 5 mL

31

Which is the deeper eye block? Peribulbar or retrobulbar?

Retrobulbar block

32

Which is the safer eye block? Peribulbar or Retrobulbar

Peribulbular

33

Where does the Afferent pathway send information before efferent pathway?

Medulla oblongata

34

How can an eye block lead to respiratory arrest?

By inadvertent injection into the CSF which will cause a high neuroaxial blockade requiring intubation

35

How can an eye block cause seizures?

By inadvertent intra-arterial injection of local anesthetic

36

Most common complication in eye blocks?

Oculocardiac reflex