Exam 1- Neuraxial Principles Pre-Test Flashcards
(21 cards)
What is the outermost layer surrounding the spinal cord?
Dura Mater
*Surrounding the spinal cord in the bony vertebral column are three membranes (from deep to superficial):
Pia Mater
Arachnoid Mater
Dura Mater
The dural sac terminates at what level?
S2 in Adults
S3 in Infants
What are the cardio-accelerator nerve fibers?
- T1, T2, T3, T4
The effects of neuraxial blocks on blood pressure are similar in some ways to the combined use of intravenous α1- and β-adrenergic blockers on cardiac output: decreased stroke volume and heart rate caused by blockade of the peripheral (T1-L2) and cardiac (T1-T4) sympathetic fibers as well as adrenal medullary secretion.
What are the absolute contraindications of Neuraxial anesthesia?
(8)
- Coagulopathy
- Severe Valvular Heart Disease
- Operation > Duration of Anesthetic
- Increased ICP
- Severe CHF
- Patient refusal
- Localized sepsis
- Allergy to any of the drugs planned for administration.
Sensory blockade of which dermatome level is necessary for C-section/upper abdominal surgery?
- T4
For isobaric solution, what is the most important factor in determining the spread of the local anesthetic in a subarachnoid (Spinal) 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 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
Patients with emphysema will present with which pulmonary pressure-volume loop?
- Loop A
Parturients will present with which pulmonary pressure-volume loop?
- Loop D
Pregnancy causes restrictive patterns because of the effect of the growing fetus on pulmonary pressures.
What is the dermatome level for the umbilical area?
- T10
Label the conditions involved with Loops A, B, C, and D
The subarachnoid space ends at ___________
The end of the Dural Sac
Relative Contraindications to Neuraxial Anesthesia
- Deformities of spinal column
- Preexisting disease of the spinal cord
- Chronic headache/backache
- Inability to perform within 3 attempts
