Exam 1 - Neuraxial Principles Pre-Test Flashcards
What is the outermost layer surrounding the spinal cord?
Dura mater
Surrounding the spinal cord in the bony vertebral column are three membranes (from innermost to outermost): the pia mater, the arachnoid mater, and the dura mater.
The dural sac terminates at what level?
S2
so anything past s2 is no longer considered spinal procedure!
What are the cardio-accelerator nerve fibers?
T1-T4!
What is an absolute contraindication of spinal anesthesia? select 3.
A. pt refusal
B. multiple sclerosis
C. chronic headache/backache
D. dermal site infection
E. deformities of spinal column
F. BT: 15 mins
A. Patient refusal
D. evidence of dermal site infection
F. coagulopathy (INR >1.5, plts <100k, PT >28 secs, aPTT >64 secs, BT >14 mins)
Also:
- severe or critical valve heart dz
- HSS
- operation > duration
- increased ICP
- severe CHF (EF <40%)
Sensory blockade of which dermatome level is necessary for upper abdominal surgery?
T4
For isobaric solution, what is the most important factor in determining the spread of the local anesthetic in a subarachnoid block?
- Dose
The dose, volume, and concentration are inextricably linked (Volume × Concentration = Dose), but dose is the most reliable determinant of local anesthetic spread (and thus block height) when compared with either volume or concentration for isobaric and hypobaric local anesthetic solutions. Hyperbaric local anesthetic injections are primarily influenced by baricity.
_______ is an ultra–short-acting ester local anesthetic and is metabolized by pseudocholinesterase.
- Chloroprocaine
The blood that resides in the venous system is approximately ____% of the total blood volume
- 75%
The effects of Bezold-Jarisch reflex are manifested as ________, ________, and __________.
- Bradycardia
- Hypotension
- Coronary Dilation
The Bezold-Jarisch reflex responds to noxious ventricular stimuli sensed by chemoreceptors and mechanoreceptors within the LV wall by inducing the triad of hypotension, bradycardia, and coronary artery dilatation
The diaphragm is innervated by ______, _________, ________.
- C3
- C4
- C5
The incidence of cauda equina syndrome is linked to high dose of which local anesthetic?
- Lidocaine
The rate of cauda equina syndrome is approximately 0.1 per 10,000 and invariably results in permanent neurologic deficit. The lumbosacral roots of the spinal cord may be particularly vulnerable to direct exposure of large doses of local anesthetic, whether it is administered as a single injection of relatively highly concentrated local anesthetic (e.g., 5% lidocaine)
______ is the resulting metabolite of ester local anesthetics.
- Para-aminobenzoic acid (PABA)
Which local anesthetic has high affinity to cardiac toxicity?
- Bupivacaine
Two mL of hyperbaric bupivacaine 0.75% concentration is equivalent to how many mg?
- 15 mg
Functional residual capacity is a combination of which lung volumes?
- ERV
- RV