Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Basics of Anesthesia > Week 2 - Spinal and Epidural Anesthesia > Flashcards

Week 2 - Spinal and Epidural Anesthesia Flashcards

1
Q

What is the anatomy of the spine?

A

Cervical (7)

Thoracic (12) - spinous processes point more down

Lumbar (5) - spinous processes are more outward facing

Sacrum and Coccyx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What layers do you pass through to reach the epidural space?

A 
Skin
Subcutaneous tissue
Supraspinous ligament
Interspinous ligament
Ligamentum flavum
Epidural space
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where does the spinal cord end in an adult and peds?

A

Adult = L1

Peds = L2-3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What spinal levels give a nice straight shot to the spinal space and are easily palpated?

A

L2-3

L3-4

L4-5

*having pt flex back opens the space even more (position is very important)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where is the epidural spinal space accessed with Caudal anesthesia?

A

at the sacral hiatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How do you assess the level of neuraxial anesthesia?

A

-Use cold (ice or alcohol) or skin prick/pinch

  • assess bilateral level using a comparative patch of skin (like arm)
  • sensation of pain is usually first modality to disappear; it is followed by the loss of sensations of cold, warmth, touch, deep pressure, and finally loss of motor function (although variation among pts and different nerves is considerable)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What type of nerve conduction is blocked with neuraxial anesthesia?

A

Sympathetic nerve conduction (not parasympathetic, except pelvic splenic nerves)

  • spinal sympathetic blockade 2-4 dermatomes above sensory level
  • epidural sympathetic blockade at level of block
  • vasomotor blockade leads to venous and arterial dilation (in elderly with cardiac dx, SVR may decrease 25% – 15-18% in healthy pt)
  • decrease in HR seen with blockade of cardio-accelerator nerves from T1-4
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What spinal level does the dural sac end?

A

S2 in adults and lower in children

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What spinal level innervates the uterus and bladder? Peritoneum?

A

The necessary level for anesthesia may be higher than incision site

Uterus and bladder is innervated by T10 (umbilicus line)
Peritoneum has innervation as high as T4 (nipple line)

*abd surgery including c-section may need as high as T4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the effect of a T5 level block? S2-S5 block?

A

T5 level will block motor and superficial sensory to entire abdomen

S2 to S5 (Saddle Block) will block the perineum and anal area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the three most important factors in determining the distribution of spinal local anesthetics?

A

Baricity

Position of patient after, during, and just after injection

Dose of anesthetic injected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the advantages to neuraxial anesthesia?

A

Fairly predictable and simple procedure with practice

Avoidance of GA (avoidance of airway issues, aspiration, recovery time, PONV…)

Postop pain control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the disadvantages to neuraxial anesthesia?

A

Patient cooperation is needed

Sympathectomy?

May take additional time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Epidural vs Spinal

A

Spinal takes less time to perform, produces more rapid onset of better-quality sensorimotor block and is associated with less pain during surgery

Epidural offers lower risk of PDPH, less hypotension, ability to prolong the blockade via an indwelling catheter and the option of using it for postop pain control

*don’t forget the option of combined spinal/epidural

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the contraindications for neuraxial anesthesia?

A

The only absolute contraindication is patient refusal

  • can the pt tolerate decreases in SVR or preload? (hypovolemia, shock, severe aortic or mitral stenosis) – Aortic stenosis is an absolute contraindication for spinal
  • increased ICP increases risk of brain herniation with removal of CSF
  • coagulopathy or thrombocytopenia increases risk of epidural hematoma
  • sepsis and infection at puncture site increases the risk for meningitis
  • patients with pre-existing neuropathy or CNS disease may not be able to distinguish block effects and disease effects (LA may be more toxic to abnormal nervous tissue)
  • abnormal spine anatomy (scoliosis, hx of back surgery) may make spinal difficult
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the paramedian approach to neuraxial anesthesia

A
  • Needle is inserted through the skin at a point about 1.5 cm lateral to the mid point of the spinous process immediately below the level of the desired block
  • Needle is advanced perpendicular to the skin, through the underlying fat and muscle, until it strikes vertebral lamina
  • It is then withdrawn slightly, redirected cephalad and medially, and walked off the lamina until it pierces the ligamentutm flavum and enters the epidural space
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

When is the paramedian approach to neuraxial anesthesia used?

A

Thoracic epidurals and difficult lumbar spinal/epidural

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a “wet tap”?

A

You were intending on an epidural anesthetic and got CSF

*expect PDPH and know that epidural local anesthetic could enter spinal space through dural puncture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How do you treat hypotension as a result from neuraxial anesthesia in a healthy patient if decrease in BP is less than 30%?

A
  • Fluid bolus 500mL to 1L
  • Observe
  • Consider pressors (ephedrine, Neo)
  • Consider Trendelenburg

Responds: Continue bolus as needed until BP normalizes

No Response, frequent med bolus, or symptomatic:

  • HR <70 –> Ephedrine 10-20 mg, consider epi
  • HR >80 –> Phenylephrine 100-200 mcg, consider norepi
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How do you treat hypotension as a result from neuraxial anesthesia in a healthy patient if decrease in BP is greater than 30%?

A

HR <70: Ephedrine 5-10mg, repeat in 2-3 min, Fluid bolus 500-1L, Consider Trendelenburg

HR >80: Phenylephrine 50-100mcg, repeat in 2-3 min, Fluid bolus 500-1L, Consider Trendelenburg

Responds: continue bolus as needed
No Response, frequent med bolus, or symptomatic:
-HR <70 –> Ephedrine 10-20 mg, consider epi
-HR >80 –> Phenylephrine 100-200 mcg, consider norepi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How do you treat hypotension as a result from neuraxial anesthesia in a patient with cardiac disease, hx of CVA or CNS disorder if decrease in BP is less than 30%?

A

HR <70: Ephedrine 5-10mg, repeat in 2-3 min, Fluid bolus 500-1L, Consider Trendelenburg

HR >80: Phenylephrine 50-100mcg, repeat in 2-3 min, Fluid bolus 500-1L, Consider Trendelenburg

Responds: continue bolus as needed
No Response, frequent med bolus, or symptomatic:
-HR <70 –> Ephedrine 10-20 mg, consider epi
-HR >80 –> Phenylephrine 100-200 mcg, consider norepi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How do you treat hypotension as a result from neuraxial anesthesia in a patient with cardiac disease, hx of CVA or CNS disorder if decrease in BP is greater than 30% and pt is symptomatic?

A

HR <70 –> Ephedrine 10-20 mg, no response double dose, consider epi push and infusion

HR >80 –> Phenylephrine 100-200 mcg, no response double dose, consider Phenylephrine infusion, consider norepi infusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the side effects of neuraxial anesthesia?

A 
Hypotension
Bradycardia
Respiratory effects -- Short of breath
N/V
Urinary retention
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is spinal bradycardia the result of?

A

Unopposed parasympathetic tone resulting from blockade of T1 through T5 cardioaccelerator sympathetic fibers, but it is primarily caused by decreased preload

Decreased preload contributes to bradycardia by activating a group of reflexes that respond to a stretch of intracardiac volumes and/or pacemaker receptors – rapid decrease in LV volume has been speculated to cause severe bradycardia and asystole via paradoxic activation of the Bezold-Jarisch reflex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How do you treat bradycardia caused by neuraxial anesthesia?

A

Mild to Moderate Bradycardia: 0.4-1.0 mg atropine IV – repeated every 5 minutes (not to exceed 2mg)

Severe Bradycardia refractory to atropine: 5-10mcg epinephrine IV and the dose incrementally increased every minute until achievement of the desired effect

*Should asystole ensure – 1mg epinephrine should be administered without delay and chest compressions

26
Q

What are the respiratory effects of neuraxial anesthesia?

A

Pt may complain of shortness of breath with a high spinal blockade due to paralysis of abdominal and intercostal muscles

*may be an issue with those who have respiratory pathophysiology

27
Q

What are the GI effects of neuraxial anesthesia?

A

Nausea and vomiting occur after spinal anesthesia approx. 20% of the time
-risk factors include blocks higher than T5, hypotension, opioid admin, and history of motion sickness

High vagal tone due to unopposed parasympathetic activity leads to increased GI peristalsis – can be treated with atropine

28
Q

What are the renal effects of neuraxial anesthesia?

A

Has little direct effect on renal function

May lead to urinary retention due to paralysis of bladder function

29
Q

The choice of local anesthetics and adjuncts to use for neuraxial anesthesia depends on what?

A

Duration of action of the drug – how long do you need the spinal to last?

How high of a spinal you need

30
Q

What effect does the baricity of the solution have on neuraxial anesthesia?

A

Baricity (density) of the solution plays a factor in the spread of local anesthetic for intrathecal injection

31
Q

Define:

  • Hyperbaric Solution
  • Isobaric Solution
  • Hypobaric Solution
A

Hyperbaric - solution that is denser than CSF (specific gravity >1.0069) usually contains dextrose to accomplish this — “Sinks” with gravity

Isobaric - “Stays in general vicinity of block” not gravity dependent

Hypobaric - “Floats up”, used in Jack Knife position, lateral position for hip repair

32
Q

What is the dose of Lidocaine (5% in 7.5% dextrose) for a spinal to T10? To T4?
What is the onset and duration?

A

T10: 50-60 mg
T4: 75-100 mg

Onset: 3-5 min
Duration: 60 min (plain) and 75 to 100 min (epi 0.2mg adjunct)

33
Q

What is the dose of Tetracaine (0.5% in 5% dextrose) for a spinal to T10? To T4?
What is the onset and duration?

A

T10: 6-8 mg
T4: 10-16 mg

Onset: 3-5 min
Duration: 70-90 min (plain) and 100-150 min (epi 0.2mg adjunct)

34
Q

What is the dose of Bupivacaine (0.75% in 8.5% dextrose) for a spinal to T10? To T4?
What is the onset and duration?

A

T10: 8-10 mg
T4: 12-20 mg

Onset: 3-5 min
Duration: 90-120 min (plain) and 100-150 min (epi 0.2mg adjunct)

35
Q

What is the dose of Ropivacaine (0.5% in dextrose) for a spinal to T10? To T4?
What is the onset and duration?

A

T10: 12-18mg
T4: 18-25 mg

Onset: 3-5 min
Duration: 80-110 min (plain)

36
Q

What is the dose of Levobupivacaine for a spinal to T10? To T4?
What is the onset and duration?

A

T10: 8-10 mg
T4: 12-20

Onset: 3-5 min
Duration: 90-120 min (plain) and 100-150 min (epi 0.2mg adjunct)

37
Q

What is the dose of Chloroprocaine (2%, 3% isobaric?) for a spinal to T10? To T4?
What is the onset and duration?

A

T10: 30 mg
T4: 45-60 mg

Onset: 3-5 min
Duration: 60-90 min (plain) and up to 130 (170?) min (epi 0.2mg adjunct)

38
Q

What is the dose of Mepivicane (2% isobaric?) for a spinal to T10? To T4?
What is the onset and duration?

A

T10: 40 mg
T4: 45-60 mg

Onset: 3-5 min
Duration: 90-120 min (plain)

39
Q

What is the onset and duration of 2-Chloroprocaine 3% administered epidurally in 20-30mL volumes?

A

Onset: 10-15 min

Duration Plain: 45-60 min

Duration 1:200,000 Epi (0.1mg to 20mL): 60-90 min

40
Q

What is the onset and duration of Lidocaine 2% administered epidurally in 20-30mL volumes?

A

Onset: 15 min

Duration Plain: 80-120 min

Duration 1:200,000 Epi (0.1mg to 20mL): 120-180 min

41
Q

What is the onset and duration of Mepivacaine 2% administered epidurally in 20-30mL volumes?

A

Onset: 15 min

Duration Plain: 90-140 min

Duration 1:200,000 Epi (0.1mg to 20mL): 140-200 min

42
Q

What is the onset and duration of Bupivacaaine 0.5-0.75% administered epidurally in 20-30mL volumes?

A

Onset: 20 min

Duration Plain: 165-225 min (2 hr 45 min to 3hr 45 min)

Duration 1:200,000 Epi (0.1mg to 20mL): 180-240 min (3-4 hr)

43
Q

What is the onset and duration of Etidocaine 1% administered epidurally in 20-30mL volumes?

A

Onset: 15 min

Duration Plain: 120-200 min (2 hr to 3 hr 20 min)

Duration 1:200,000 Epi (0.1mg to 20mL): 150-225 min (2.5 hr to 3 hr 45 min)

44
Q

What is the onset and duration of Ropivacaine 0.75-1.0% administered epidurally in 20-30mL volumes?

A

Onset: 15-20 min

Duration Plain: 140-180 min

Duration 1:200,000 Epi (0.1mg to 20mL): 150-200 min

45
Q

What is the onset and duration of Levobupivacaine 0.5-0.75% administered epidurally in 20-30mL volumes?

A

Onset: 15-20 min

Duration Plain: 150-225 min (2 hr 30 min to 3 hr 45 min)

Duration 1:200,000 Epi (0.1mg to 20mL): 150-240 min (2 hr 30 min to 4 hrs)

46
Q

What is the dosing of Fentanyl for:

  • Intrathecal or Subarachnoid single dose
  • Epidural single dose
  • Epidural continuous infusion
A

Intrathecal/Subarachnoid Single Dose = 5-25 mcg

Epidural Single Dose = 50-100 mcg

Epidural Cont Infusion = 25-100 mcg/hr

47
Q

What is the dosing of Morphine for:

  • Intrathecal or Subarachnoid single dose
  • Epidural single dose
  • Epidural continuous infusion
A

Intrathecal/Subarachnoid Single Dose = 0.1-0.3 mg

Epidural Single Dose = 1-5 mg

Epidural Cont Infusion = 0.1-1 mg/hr

48
Q

What is the effect of adding epinephrine to local anesthetics for neuraxial anesthesia?

A

Thought to prolong block duration by decreasing local anesthetic uptake

Effect is seen greatest with lidocaine, mepivacaine, and 2-Chloroprocaine, least effect with bupivacaine and ropivicaine

49
Q

What is the effect of adding bicarb to local anesthetics for neuraxial anesthesia?

A

Speed onset and quality by producing more rapid intraneural diffusion by increasing concentration of non-ionized free base

50
Q

What is the effect of adding opioids to local anesthetics for neuraxial anesthesia?

A

Work on pre and post synaptic non-specific opioid receptors (mu, kappa, & delta) in the spinal cord

Provides post op analgesia

There is also vascular uptake from the vascular system which can cause systemic side effects – resp depression, N/V, itching

***Use with caution with additional IV/PO narcotics

51
Q

Compare and Contrast the properties of neuraxial opioids (Lipophilic vs Hydrophilic):

  • Onset of analgesia
  • Duration of analgesia
  • CSF spread
  • Site of action
  • Side effects
A

Lipophilic Opioids (Fentanyl, sufentanil):

  • Rapid Onset (5-10 min)
  • Shorter duration (2-4 hr)
  • Minimal CSF spread
  • Spinal and systemic site of action

Hydrophilic Opioids (Morphine, hydromorphone):

  • Delayed onset (30-60 min)
  • Longer duration (6-24 hr)
  • Extensive CSF spread
  • Primarily spinal site of action
  • N/V: lower incidence with lipophilic than hydrophilic
  • Pruritus: lipophilic < hydrophilic
  • Resp Depression: primarily early/minimal delay in lipophilic and both early and delayed possible with hydrophilic
52
Q

What factors affect the level of a neuraxial block?

A
  • Baricity, dose and volume of drug injected
  • Position of pt with hyperbaric or hypobaric solution
  • Site of injection
  • Height (extremely tall or short)
  • Spinal column anatomy
  • Increased abdominal pressure (obesity, pregnancy) leading to decreases CSF volume
53
Q

What are possible complications of neuraxial anesthesia?

A
  • Neurologic Injury (rare, from direct needle trauma, spinal cord ischemia, introduction of bacteria, or epidural hematoma) – Cauda Equina Syndrome and Transient Neurologic Symptoms (TNS)
  • Spinal Hematoma (rare, coagulation defects are principle risk factor)
  • Total Spinal (LA spreads high enough to block entire spinal cord and brainstem - leads to profound bradycardia/hypotension, respiratory arrest)
  • Post Dural Puncture Headache (treat with hydration, laying flat, caffeine, epidural blood patch)
54
Q

What is the recommended time the following drugs should be stopped prior to neuraxial procedure/catheter removal and restarted after the procedure/catheter removal?
-ASA, NSAIDS, Clopidogrel, Prasugrel, Ticagrelor

A

ASA and NSAIDS don’t need to be stopped

Clopidogrel: 7 days before and restart after catheter removal

Prasugrel: 7-10 days before and restart 6 hours after

Ticagrelor: 5 days before and restart 6 hours after

55
Q

What is the recommended time the following drugs should be stopped prior to neuraxial procedure/catheter removal and restarted after the procedure/catheter removal?
-Warfarin, Heparin (IV), Heparin (subQ), LMWH, Fondaparinux

A

Warfarin: 5 days before (normal INR) and restart after catheter removal

Heparin IV: 4-6 hours before and restart 1-2 hours after

Heparin SubQ: no need to stop

LMWH: 12 hours before (prophylactic) 24 hours before (therapeutic) and restart 4 hours after

Fondaparinux: 36-42 hours before and restart 6-12 hours after

56
Q

What is the recommended time the following drugs should be stopped prior to neuraxial procedure/catheter removal and restarted after the procedure/catheter removal?
-Dabigatran, Rivaroxaban, Apixaban

A

Dabigatran: procedure contraindicated per manufacturer

Rivaroxaban: 22-26 hours

Apixaban: 26-30 hours

57
Q

Which medications cause TNS and cauda equina syndrome? Which is usually permanent?

A

TNS: hyperbaric lidocaine use (mepivacaine has also been indicated), addition of phenylephrine to 0.5% tetracaine, surgery in lithotomy position

Cauda Equina Syndrome: intrathecal catheters and 5% hyperbaric Lidocaine

58
Q

Who is at higher risk for Post Dural Puncture Headache? How would you try and prevent and treat PDPH?

A
  • Younger
  • Females
  • Pregnant

Treatment:
-supine positioning, hydration, caffeine, oral analgesics, epidural blood patch

59
Q

What are the layers of the spinal cord? Where dose CSF reside?

A 
Pia Mater (inner most)
Arachnoid Mater
Dura Mater (outer most)

*CSF resides is the subarachnoid space between pia mater and arachnoid mater

60
Q

What are the layers of the spinal cord? Where dose CSF reside?

A 
Pia Mater (inner most)
Arachnoid Mater
Dura Mater (outer most)

*CSF resides is the subarachnoid space between pia mater and arachnoid mater

61
Q

What arteries supply blood to the spinal cord?

A

Two posterior spinal arteries supply posterior 1/3

Anterior spinal artery supplies the anterior 2/3

Artery of Adamkiewicz = largest feeder artery to anterior system

62
Q

What does the speed of neural blockade depend on?

A

Size, surface area, and degree of myelination of nerve fibers

Basics of Anesthesia (35 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions