Exam 1 Spinal & Epidural Neuraxial Anesthesia [5/28/24] Flashcards
List the 3 major anesthesia techniques
- General Anesthesia
- MAC
- Regional Anesthesia
S1
Regional anesthesia has 2 classifications. What are they and its subclasses?
Central neuraxial
1.Spinal
2.Epidural
3.Combined spinal and epidural [CSE]
4.Caudal: this is peds specific.
Peripheral blocks
1.upper extremity blocks
2.lower extremity blocks
3.trunchal: top block, interfascial block, perivertibral, pectoral nerve block 1 and 2.
S1
What cannot be given through the spinal?
Reglan and Zofran `
3
What are the clinical Indications for neuroaxial anesthesia?
- Surgical procedures involving the lower abdomen, perineum, and lower extremities
- Orthopaedic surgery [alot of spinals]
- Vascular surgery on the legs
- Thoracic surgery (adjunct to GETA) [usually epidurals]
S5
What are the 6 benefits for neuraxial anesthesia?
Reduces the following:
1. Postoperative ileus
2. thromboembolic events
3. PONV
4. Respiratory Complications
5. Bleeding
6. Narcotic Usage
Reduces PIT RBN (say it like Pit rubbin’)
S6
What causes PONV?
What are the risk factors?
- PONV occurs due to induction medication like anesthetic gasses & opioids.
- Factors for increased PONV:
1.Females
2.NON-Smokers
4.Age 40 and higher
S6
List the other benefits of neuraxial anesthesia.
- Great mental alertness
- Less urinary retention*
- Quicker to eat, void, and ambulate
- Avoid unexpected overnight admission from complications of general anesthesia
- Quicker PACU discharge times*
- Preemptive anesthesia
- Blunts stress response from surgery
BM QUAP
S7
If using neuraxial anesthesia, and the pt needs to be put to sleep but needs to maintain respiratory drive what can be administed?
- Propofol
- 100-300 mcg/kg
S7
What are the relative contraindication for neuroaxial anesthesia
- Deformities of spinal column [issues w/positioning]
- Spinal stenosis, kyphoscoliosis, ankylosing spondylitis
- scoliosis, lordosis, kyphosis
- Preexisting disease of the spinal cord [residual weakness]
- Exacerbate a progressive, degenerating disease
- Multiple Sclerosis, post polio syndrome
- Chronic headache/backache
- Inability to perform SAB/Epidural after 3 attempts
S8
Why are chronic headaches/backaches a relative CI for neuroaxial anesthesia?
- A complication of neuroaxial anesthesia is post-dural puncture heacache.
- if pt has backpain, and we are sticking needes in the back it might worsen the pain
S8
What are the absolute CI for neuroaxial anesthesia?
- Coagulopathy
- Patient refusal
- Evidence of dermal site infection
- known coag disoder or on anticoagulants
- Severe or critical valvular heart disease
- HSS [idiopathic hypertrophic subaortic stenosis]
- Operation >duration of LA
- Increased ICP
- Severe CHF
S9-10
What are the coagulation problems that are absoulte contraindications for neuroaxial anesthesia
- INR > 1.5
- PLT < 100,000
- PT: 24-28 seconds
- PTT: 50-64 seconds
- BT: 6-14 min
- Known coag disorder or taking anticoags.
PT, PTT, BT 2X THE NORMAL
slide 9
Normal PT
12 - 14 seconds
S9
Normal INR
0.8 - 1.1
S9
Normal aPTT
25 - 32 seconds
S9
Normal Bleeding Time [BT]
3 - 7 minutes
S9
Normal Platelets
150,000 - 300,000 mm3
S9
List the factors involved in the coagulation cascade
* Intrinsic
* Extrinsic
* Common
- Intrinsic: 12→ 11→9 →8
- Extrinsic: 3→7
- Common: 10 + 5 →2 →1←13
S9
PT/INR measures?
PTT measures?
- PT/INR = extrinsic
- PTT = intrinsic
S9
PT = PLAY TENNIS OUTSIDE = EXTRINSIC
PTT = PLAY TABLE TENNIS INSIDE = INTRINSIC
What happens when we get injured?
Hemostasis:
1.Vascular effect - Body has vascular constriction.
2.Primary mechanism: where PLT is activated.
* PLT activation occurs by extrinsic methods.
* VWF (Factor VIII) pulls platelets to come closer and work together. This makes the PLT sticky. This forms a PLT plug [not strong].
3.Secondary mechanism: intrinsic/extrinsic/common pathway.
S9
What does the bleeding time look at?
- Examines PLT activation and adhesion.
- longer BT = problem with PLTs.
S9
What severe valvular heart diseases are absolute CI for neuroaxia anesthesia?
- Aortic stenosis <1cm2
- Mitral stenosis <1cm2
S10
List the valve area for AS for the following:
* Mild
* Moderate
* Severe
* Critical
- Mild: ≥1.5
- Moderate: 1.0 - 1.5
- Severe: 0.7 - 1.0
- Critical: < 0.7
cm2
What is the average course of valvular aortic stenosis in adults
- Age 35-40: increasing obstuction, myocardial overload
- Age 60: onset of severe symptoms **
- Age 63: average age of death.
S10
What are the s/sx of severe or critical AS? What are its survival rates?
- Angina - 5yrs
- Syncope - 3yrs
- Heart failure - 2 yrs, the worst [NYHF 3 or 4]
S10
Why is aortic stenosis a contraindication?
- Main issue for anesthesia is loss of afterload, SVR, and HR.
- W/general anesthesia, SVR is dropped.
- W/regional anesthesia esp spinal = Death Spiral
DEATH SPIRAL: decrease SVR →hypotension → ischemia → decrease CO →worsened BP →angina.
S10
What is the death spiral that occurs due to AS?
- hypotension causes myocardial ischemia
- ischemia contractile dysfunction
- decreases CO
- worsening hypotension
- increased ischemia
S10
Compare & Contrast the following characteristics of spinals and epidural:
* Onset
* Spread
* Nature of block
* Motor block
* Hypotension
S11
Compare & Contrast the following characteristics of spinals and epidural:
* Onset
* Duration
* Placement level
* Difficulty of placement
* Dosing
* Concentration
* LA toxicity
* Gravity influence
* Manipulation of dermatome spread after dosing
S10
What is the placement and needle size for spinals?
- Placement: L3-L4, L4-L5, L5-S1 but we as SRNAs do L4-L5
- Smaller needle: 25-27g
S12
What is the placement and needle size for epidurals?
- Placement: anywhere there is epidural space
- bigger needle: 18-19 g
- can do epidurals by thoracic but draw back is accidentally hitting the spinal cord.
S12
Baracity affects epidurals or spinals?
What does hyper, hypo, and iso -baric mean?
- Affects spinals
- hyperbaric: sinks
- hypobaric: floats
- isobaric: stays in place
S12
Positioning affects epidurals or spinals?
How would you postion a pt with right hip pain?
- Affects epidurals
- pain in right buttock - turn to right side to have LA stay on that side.
S12