Fundamentals & Physiology
This type of pain dominates the first stage of labor and is poorly localized
Visceral pain
These drugs provide poor and unreliable analgesia in labor but are widely available
IV/IM opiates
This is the most commonly used method of labor analgesia in the U.S
epidural
Most common maternal side effect of neuraxial opioids
pruritis
Minimum platelet threshold generally considered acceptable for neuraxial anesthesia
70,000
Pain from the second stage of labor is transmitted via these nerve roots
S2-4
Name commonly used opioids for labor analgesia
fentanyl, morphine, nalbuphine, butorphanol, or remifentanil
Neuraxial analgesia does NOT increase this delivery outcome
Cesarean rate
Approximate incidence of hypotension with low-dose neuraxial analgesia
About 10%
How much longer on average does epidural analgesia extend the 2nd stage of labor
7 minutes
Name two common referred pain locations during labor
iliac crests, buttocks, or thighs
This opioid has an ultra-short half-life and is delivered via PCA infusion
remifentanyl
The main advantage of combined spinal–epidural over epidural alone
faster onset of analgesia
Treatment for local anesthetic systemic toxicity
IV lipid emulsion
Best anesthesia option if emergent cesarean and no epidural is in place
General anesthesia
How quickly should a combined spinal-epidural provide sufficient analgesia?
Within 5-10 min
Why should mixed agonist-antagonists be avoided in patients on chronic opioids
risk of precipitating withdrawal and reduced effect of analgesia
This fetal heart rate abnormality is more common with combined spinal–epidural
fetal bradycardia
What is the incidence of an epidural hematoma
1 in 250,000
Why neuraxial anesthesia is preferred in preeclampsia
avoidance of hypertensive response from intubation during general anesthesia
Why is the risk of spinal epidural hematoma higher in epidural vs spinal techniques
larger catheter size
What kind of fetal heart tracing can butorphanol cause?
pseudo-sinusoidal
Proposed mechanism for fetal bradycardia after intrathecal opioids
rapid pain relief → ↓epinephrine → unopposed oxytocin/norepinephrine → increased uterine tone
Most dangerous neonatal effect of maternal opioid use
respiratory depression
Why can’t proper epidural catheter placement be definitively confirmed immediately after combined spinal–epidural placement
Spinal component masks pain until it wears off