Anesthesia For Operative Delivery pt3 Flashcards
Do spinally administered opioids increase or decrease PONV occurrence?
Both.
Can decrease occurrence due to decreased sensations that trigger PONV.
What is the dose of Fentanyl for SAB?
10 - 25mcg
Is early or late respiratory depression seen with fentanyl?
early: lipophilic = rapid onset, shorter acting
What is the typical dose of morphine (astramorph, duramorph) for SAB?
100 - 200 mcg
What is the onset and duration for morphine administered spinally?
Onset: 30 - 60 min
Duration: 12 - 24 hrs
hydrophilic = slower onset
Will respiratory depression be seen earlier or later with morphine administered via SAB?
Later (6-18 hrs after)
How is the pruritus associated with SAB morphine treated?
- Nalbuphine(nubaine) or Butorphanol(stadol)
- Naloxone or Naltrexone
What is an “epi wash”?
coating the syringe with epinephrine and squirting out before drawing up drugs
What is the purpose of epinephrine added to spinal anesthesia dose?
- Can prolong block by 15% or more via vasoconstriction
- 0.1-0.2mg (100-200mcg)
What dose of Precedex is utilized in spinals?
5-10 mcg
What is the purpose of Precedex as a spinal additive?
- Prolongs sensory & motor blockade
- Post-op pain control
- Minimizes shivering
What are the main adverse effects associated with spinally administered dexmedetomidine?
Bradycardia & Hypotension
Epidural medication doses are approximately _____ times that of spinal doses.
5 - 10x greater than spinal doses
Are spinals or epidurals better for C-sections?
Spinals (more reliable and dense)
epidurals have a gradual onset and can be less dense or “patchy”
IV anesthetics such as ______ or ______ are commonly used as adjuncts to epidurals for patients undergoing unplanned c-section.
ketamine ; precedex
2% Lidocaine is just as fast as chloroprocaine when what additive is added to it?
Na⁺ Bicarbonate
What dose of 1% Lidocaine is utilized for epidural blocks for c-sections?
Trick Question. Concentrations less than 2% Lidocaine are inadequate for c-section anesthetics.
What metabolizes chloroprocaine?
Pseudocholinesterases
What drug can decrease the efficacy of epidural morphine? Why?
2-Chloroprocaine
- Antagonizes μ and κ opioid receptors
Which concentration of bupivacaine IS NOT utilized in epidurals?
0.75%
(Only for spinals)
What concentration of bupivacaine is used for epidurals (for surgical anesthesia)?
0.5%
for dense block for surgical anesthesia (C-sx)
What concentration of ropivacaine is common for epidurals (for surgical anesthesia)?
0.5%
Compare the cardiac toxicity profiles of ropivacaine & bupivacaine?
Ropivacaine is less cardiotoxic than bupivacaine
Between fentanyl and morphine, which opioid administered neuraxially provides for a more dense block?
Fentanyl
What dose of dexmedetomidine is typically used in epidurals (for surgical anesthesia)?
4-5 mcg/mL of precedex
Ex. 20mL + 80 - 100mcg Precedex
How does Na⁺ bicarb helps speed up onset?
Shifts local anesthetic to more non-ionized state.
very useful speeding up “dose up” from epidural to avoid GETA.
Your patient has an epidural in place and is being converted from a normal labor to a c-section. The epidural is unilateral, how can this be fixed?
Replaced the catheter if possible
Your patient has an epidural in place and is being converted from a normal labor to a c-section. The epidural is patchy, how can this be fixed?
- Supplement w/ adjuncts (ex. 50mcg Fentanyl can be used for hotspots)
How much local anesthetic will you typically use to “dose up” an epidural for a c-section (surgical anesthesia)?
10 - 15mls
What is the Allis Test?
Pinch patient with clamps to assess quality of epidural anesthesia.
- If the patient can’t feel clamps then you’re good for surgical incision.
Why should your epidural dosing be less with a combined spinal epidural (CSE) ?
Hole through dura mater can result in medication going from epidural to intrathecal space.
What are three reasons that one might have to convert to general anesthesia for a c-section?
- Fetal Distress (fetal bradycardia)
- Maternal Hemorrhage w/ hypovolemia
- Neuraxial Anesthetic not possible
What are some reasons that neuraxial anesthesia may not be possible for c-section patients?
- Outright refusal
- Infection
- Coagulopathy / thrombocytopenia
If an epidural is not dense enough what can be administered to help? What must be done if the block is not adequate?
- If not dense enough, may need additional IV anesthesia or inhaled N2O
- If not adequate, may need to convert to GETA
2% lidocaine used in epidurals generally provides ____ onset and a _____ duration of action?
2% lidocaine used in epidurals generally provides rapid onset and a short duration of action?
Chloroprocaine is typically not used for neuraxial anesthesia because?
Chloroprocaine has a very short duration of action
Bupivacaine used in an epidural generally has a ____ onset and a ____ duration of action?
Bupivacaine used in an epidural generally has a intermediate onset and a long duration of action?
Ropivacaine used in an epidural generally has a ____ onset and a ____ duration of action?
Ropivacaine used in an epidural generally has a intermediate onset and a long duration of action?
What is the epidural dose of fentanyl?
50-100mcg
What dose of morphine is typically administered in an epidural?
1-3mg
