Exam 3: Labor Anesthesia & Analgesia Pt. 1 Flashcards
What does SROM stand for?
Spontaneous Rupture of Membranes
What does AROM stand for?
Artificial Rupture of Membranes
Also known as Amniotomy - the OB provider artifically breaks the water
Is OA or OP preferred for delivery?
OA (Baby’s Occiput Anterior)
OA: Back of the baby’s head is facing anterior - best way to deliver.
OP: another way to phrase = “sunny-side-up” (baby is facing up)
What is CLE, DPE, and CSE?
Continuous labor epidural
Dural Puncture Epidural
Combined spinal epidural
What do the expanded numbers for the Gs and Ps mean?
numbers after the P:
- How many term
- how many preterm
- how many abortions
- how many living children
i.e. G2P0101
2 pregnancies, P: (0 term) (1preterm) (0 abortions) (1 living child)
Theodore Please Absorb Lichens
Once the amniotic sac ruptures, you should give birth within ____ hours becasue the risk for infection increases substantially
12 hours
What is the first stage of labor called?
Latent phase and active phase (1a and 1b)
How long will the first stage of labor last for a woman having her first baby?
If Primiparous, 8 - 12 hours typically.
How long will the first stage of labor last for a woman having already had a child before?
If Multiparous, 5 - 8 hours typically.
What three things characterize the Latent phase of the first stage of labor?
- Cervical Effacement
- Minor (2-4cm) cervical dilation
- Contractions q5-7 min w/ 30 sec duration
What characterizes the active phase of the first stage of labor?
- Cervical dilation ramps up to 10cm
- Contractions q2-5min w/ 50-70sec duration
the woman cannot start pushing until the cervix is complete (10cm)
How long does the 2ⁿᵈ stage of labor last?
Typically 15 - 120 min
What characterizes the 2ⁿᵈ stage of labor?
- Full (10cm) cervical dilation
- Contractions q 2min w/ 60-90s duration
- Fetal Descent
- Ends with Delivery of fetus
The 2ⁿᵈ stage of labor is considered prolonged if it lasts more than….
3 - 4 hours
What can cause prolonged 2nd stage of labor?
Cephalopelvic disproportion (large head)
Risks of prolonged 2nd stage of labor
- risk of fetal trauma
- severe umbilical cord compression possible
- maternal trauma (physical and emotional)
- increased risk for postpartum hemorrhage
- increased risk for infection
- increased admission to NICU
How long does the 3rd stage of labor last?
15 - 30 min
When does the 3rd stage of labor begin and end?
Begins after fetal delivery, ends with the delivery of the placenta
The 3rd stage of labor is prolonged if it lasts more than ….
30 minutes
What is the 4th stage of labor?
1st hour postpartum
In what stage of labor is the highest risk of uterine atony and post-partum hemorrhage present?
4th stage
What are some reasons labor pain varies to each individual?
- Complex type of pain
- has genetic influence
- can be because of pelvic siize and shape
- can be d/t fetal presentation
- could be d/t natural labor vs induction of labor vs augmented labor
most women c/o severe pain during contraction and with pushing
women say augmented labor with pitocin is more painful earlier on
What causes pain via mechanoreceptor stimulation in the 1st stage of labor?
Stretching and distention of lower uterine segment and cervix
What causes the visceral pain associated with the 1st stage of labor?
Small, unmyelinated C-fibers entering spinal cord at T10 - L1
difficult to treat with opioids because of the diffuse nature, but these fibers can be blocked!
What spinal levels are primarily affected during the latent phase of the 1st stage of labor?
T10 - T12
What spinal levels are primarily affected during the active phase of the 1st stage of labor?
T12 - L1
What type of pain becomes more predominant in the 2ⁿᵈ stage of labor?
What are the characteristics of this pain?
Somatic Pain is more prominent (visceral pain is still there though)
- Sharp, easily localized
- Caused by stretching & compression of pelvic/perineal structures
What type of nerve fibers are responsible for the somatic pain characteristic of the 2ⁿᵈ stage of labor?
Aδ fibers of the pudendal nerve
What spinal levels are relevant to the somatic pain associated with the 2ⁿᵈ stage of labor?
T12 - S4
What non-pharmacological modality could help with labor pain management?
Intradermal sterile water injections
- inject water under the dermus
- gate control theory (releasing endorphines)
- physical distraction
creates a noxious stimuli to distract the body
What inhaled anesthetic can a patient use to “self-anesthetize”?
N₂O
What receptors does N₂O work on?
- Inhibits: NMDA glutamate
- Stimulates: dopaminergic, opioid, and α 1 and 2
How much does N₂O depress uterine contractility?
Trick question. It does not.
Does N₂O causes neonatal depression?
No
What nerve block is often used in conjunction with N₂O ?
Pudendal nerve block
What are adverse effects associated with N₂O?
N/V, Dizziness, Paresthesias, Xerostomia
Combination of N₂O and ____ can result in hypoxia, LOC changes, and loss of airway reflexes.
Opioids
Volatile anesthetic agents will cause uterine smooth muscle ____ in a dose-dependent modality.
relaxation
Preeclampsia and hypertension prevent this use of this drug.
Ketamine
What is the obstetric dose of ketamine?
0.2 - 0.5 mg/kg
What is the IV onset & duration of ketamine?
Onset: 30 seconds
Duration: 5-10 min
What is the IM onset & duration of ketamine?
Onset: 2-8 min
Duration: 10 - 20 min
What is the ketamine infusion loading dose and rate?
Loading: 0.2 mg/kg (over 30 min)
Infusion: 0.2 mg/kg/hr
What are the neonatal consequences of benzodiazepines?
- Neonatal respiratory depression
- Neonatal hypotonicity
- Neonatal impaired thermoregulation
usually give benzos after the baby is born
What is the IM dose of meperidine?
50 - 100mg IM q4hours
What is the IV dose of Meperidine?
12.5-25 mg IV q2-4 hours
What is the weight based dose of IV morphine?
0.05 - 0.1 mg/kg IV
What is the weight based dosing of IM morphine?
0.1 - 0.2 mg/kg IM
What is the active metabolite of morphine than can accumulate in the neonate?
Morphine-6-glucuronide
What is the PCA dosing of remifentanil?
20 - 40mcg (lockout of 2-3 min)
What is the IV/IM dose of butorphanol?
1-2mg IV/IM q3-4 hours
Most common OB med b/c there is less side effects to fetus and mom
What is the dose of nalbuphine?
5 - 20 mg IV/IM/SQ
What opioid can result in significant fetal bradycardia?
Nalbuphine
Why is toradol typically not used in labor?
- Suppresses uterine contractions
- Premature constriction of fetal DA
- Inhibits PLT aggregation
Pregnancy Unravels….Duh
What nerve block is typically provided by the OBGYN during the 1st stage of labor?
Paracervical Block
- goal is the block transmission through the paracervical ganglion (actual cervix, not neck lol)
What are the two fetal complications that can occur with paracervical block?
Fetal LAST (more severe)
Fetal Bradycardia (more common)
Risk of paracervical injection into fetal scalp
What nerve block is an alternative to pharmacologic pain management in the 2ⁿᵈ stage of labor?
Pudendal nerve block
Side effects and risks of pudendal nerve block
- minimizes urge to push
- risk of injection into pudendal artery (LAST risk)
- fetal trauma or injection of LA risk
What form of anesthesia covers both 1st and 2ⁿᵈ stage of labor?
Neuraxial
Epidural veins are decompressed in what position?
Lateral lying
Harder to place.
Why is there an increase for cephalad spread of neuraxial LA in pregnant patients?
Due to apex of thoracic curvature shifting from T8 to T6.
Also from epidural vein engorgement.
