Prodigy- neuraxials Flashcards
Explain where the spinal cord starts, ends, whats below it
Starts at the foramen magnum → L1-L2
Ends as a tapered segment: conus medullaris
Below that is the cauda equina - bundle of nerve fibers that branch off and extend from L1-S5
What is the sacral hiatus?
An opening where the last sacral lamina is which is not completely closed
What colums transmit light touch and proprioception
Pain and temp?
What columns contain neurons that eventually enter the sympathetic chain?
dorsal colums
Lateral spinothalmic tract
lateral grey columns
What does the ARrtery of Adamkiewicz supply blood to?
The anterior 2/3 of the spinal cord
*Anterior Spinal Artery syndrome can result from clamping of the aorta and results in
→flaccid paralysis of lower extremities and blowel & bladder dysfunction
→ sensation is unchanged
where are the posterior spinal arteries derived from?
what do they supply?
the posterior cerebral circulation
posterior 1/3 of the spinal cord
Normal CSF production in ml/hr
how much per day
how much at any given time
21ml/hr
over 1/2 L /day
150ml @ any given time
What forms CSF?
choroid plexuses in the ventricles
What 2 drugs we use increases the absoprtion rate of CSF?
What increases vs decreases CSF secretion (1 each)
isoflurane (no effect on secretion)
→think blood:gas 143 , i love you, i want to absorb you
Fentanyl
→junkies want to absorb all the fentanyl
Des → increases secretion (adds fire to the flame)
Etomidate→ decreases secretion (less CSF pressure, makes your wanna vomit [evomidate]
Why can a healthy patient become solument after a spinal?
Bc it reduces the amount of sensory input htat goes to the reticular activating system (responsible for maintaining consciousness)
- less stimulation to that area, less awake
Why might you not want to do a spinal in someone who is already in extreme pain or who is under the influence of a lot of opioids or other CNS depressants?
the painful stimulus might be the primary sensory input maintaining their wakefulness and once the spinal takes effect and the pain is eleminated, the effects of their meds could result in CNS depression or unconsciousness
Where does the GI tract receive parasympathetic vs sympathetic innervation from?
what happens with neuraxial anesthesia nd the gut?
parasympathatic = vagus nerve
sympathetic = T5- L2
The sympathetic block leads to unopposed parasympahtic stimulation
→ general contraction of bowel
→ increased blood flow to bowel
→ increased peristalsis
T/f: neuraxial anesthesia preserves shivering and vasoconstriction in response to heat loss
false- it’s inhibited - throw a damn bair hugger on them
What can result from not letting the antiseptic solution dry before puncturing the skin?
Arachnoiditis
What are the two pops appreciated with a spinal anesthetic?
- ligamentum flavum
- dura
Why isnt a confinous spinal infusion used for labor?
risk of dural puncture (PDPH?) like your obviously puncturing the dura for a spinal…
T/F: height, weight, and BMI have little effect on the spread of local anesthetics injected into the subarachnoid space
True
i think the exception is if they are really tall or really short; like >6 foot, <5 foot
T/F: a pregnant patient will exhibit a higher level of sensory block than a non-pregnant patient with the same dose is adminsitered
True
increased IAP causes a decrease in CSF volume due to increased pressure in the epdiural space.
what does adding clonidine to a spinal do?
improves analgesia for about 2 hours for both intermediatea nd long-acting locals
+intensifies motor block
Why dont they use clonidine in spinals for obstetrics?
Black box warning! increased hemodynamic instability- hypotension, bradycardia
how much dex could you add to a epdiural and what would be the benifit?
1mcg/kg - shown to improve the quality and duration of the block
What guage are epidural needles typically?
length?
16-18g
3”
What is the purpse of the epidural needle being blunt and curved at the tip?
so it can pass through the ligments but wont pass as easily through the dura
What would signify you have a intravenous injection with a test dose
what about intrathecal injection?
time frames?
10BMP increase in HR or 15mmHg increase in BP
With an epidural, the first signs of sensory alteration typically occur at the dermatome level where the drug was injected within how many minutes?
when will the full extent of the block typically be reached?
5-10 mins
20-30mins
T/F: the additionan of epi to a local anesthetic is associated with an increase in the indicdenceof nausea?
True- epi and morphine
T/F: Fentanyl added to LA does isnt shown to increase the incidence of nauesa
does clonidine?
true
nope
Which syndrome causes persistent paralysis of the nerves, resulting in lower extremity weakness and bladder and bowel dysfunction?
A. Cauda equina syndrome
B. Horner’s syndrome
C. Postdural puncture headache syndrome
D. Transient neurologic syndrome
A
hich drug class would be least likely to increase the risk for postoperative urinary retention?
A. intravenous anesthetics
B. anticholinergics
C. opioids
D. sympatholytics
A
Which condition would you most expect to see in a patient with a midthoracic neuraxial anesthetic?
A. Significantly decreased tidal volume
B. Normal PaCO2
C. Significantly increased respiratory rate
D. Significantly decreased minute ventilation
B
Which local anesthetic would be prolonged the most by adding an adrenergic agonist?
A. Lidocaine
B. Procaine
C. Tetracaine
D. Ropivacaine
Not B
idk bc it says alpha 2 agonist prolong intermediate and long acting spinals equally
Ropi and tetracaine are long acting and lido is intermediate soooo
Which of the following statements regarding neuraxial anesthesia level is true?
A. Pinprick sensation is inhibited at a higher dermatome level than kinesthetic sensation
B. Cold sensation is blocked at the same dermatome level as pinprick sensation
C. Cold sensation is left intact by neuraxial anesthesia
D. Light touch sensation is blocked at a higher level than pinprick sensation
D
The coccyx is made up of four small bone segments that become fused into two bones by the age of:
A. 5-10 years
B. 25-30 years
C. 16-20 years
D. 11-15 years
Not D
You are preparing to place an epidural catheter in an obstetric patient who is taking metoprolol. Which of the following would be the best formulation for an epidural test dose?
A. Lidocaine and fentanyl
B. Lidocaine and phenylephrine
C. Lidocaine and metoprolol
D. Lidocaine and esmolol
Not D
The classic 3 mL test dose for epidural anesthesia contains
A. epinephrine 15 mcg
B. lidocaine 30 mg
C. epinephrine 30 mcg
D. lidocaine 15 mg
A
Which nerve fiber is responsible for transmitting pain, cold temperature, and touch?
A. A-alpha
B. A-delta
C. A-gamma
D. A-beta
B
The incidence of transient neurologic symptoms following a tetracaine spinal anesthetic is increased by
A. increasing the glucose concentration in the anesthetic
B. early ambulation
C. the addition of phenylephrine to the anesthetic
D. local anesthetic baricity
C
Following administration of a spinal anesthetic, a patient exhibits severe bradycardia. What is the first line of treatment you should employ?
A. Ephedrine 25 mg IV
B. Propofol 20 mg IV
C. Intravenous fluids 15 mL/kg IV
D. Atropine 0.4-0.6 mg IV
D
After administering a neuraxial anesthetic to a patient who has received large doses of opioids to treat the pain of a hip fracture, you would observe the patient most closely for
A. hyperventilation
B. decreased level of consciousness
C. urinary retention
D. bradycardia
B
A patient has experienced loss of consciousness due to an inadvertent total spinal block during epidural placement. The patient’s loss of consciousness is most likely due to
A. local anesthetic blockade of the cerebrum
B. local anesthetic systemic toxicity
C. supraventricular tachycardia
D. hypoperfusion of the cerebrum and brainstem
D
Which patient factor would have the most impact on the spread of an epidural block?
A. Height = 1.7 meters
B. Weight = 230 lbs
C. BMI = 30
D. Age = 74
D
Which effect would you be most likely to see as a result of thoracic epidural anesthesia?
A. Increased renal blood flow
B. Increased hepatic blood flow
C. Hyperperistalsis
D. Increased vital capacity
not D
