Labor Analgesia Flashcards
Duration of 2-chloroprocaine
Short
Do the moms usually like morphine more than meperidine?
No
They have less satisfaction and ask for more doses
How to decrease risk of hypotension with neuraxial analgesia?
What totally prevents it?
Decrease risk by fluid loading or use of prophylactic pressors
But nothing prevents it
Components of informed consenst for neuraxial technique
Risks
Benefits
Expectations: reduction in pain but may feel pressure
Advantages of Bupivacaine
- Good differential block
- Long duration
- Lack of tachyphylaxis
- Limited placental transfer
What receptor do clonidine act on when used regionally?
Hint… same as they always do…..
Are they good to use?
Alpha2 agonism
Causes no increase in motor block but they have a black box warning that we need to know about although MBG doesnt even konw what its for and i cant find what its for either
Longggg list of complications with neuraxial analgesia
- Failed analgesia
- unintended dural puncture
- Back pain
- Excessive motor block
- Urinary retention
- Maternal hypothermia
- Fetal HR abnormalities
- Accidental IV injection
- Meningitis
- Epidural hematoma/ abscess
- Neuro deficits
4 stages of labor
- Dilation
- Expulsion
- Placental
- Stabilization
Indications for neuraxial analgesia for labor
- Maternal request
- Anticipation of operative delivery (malposition, multiple gestation)
- Obstetric disease/ high risk for precipitous, high risk of emergency delivery (pre-ecclampsia, nonreassuring FHT)
- Maternal conditions (obesity, difficult airway, MH)
- Maternal coexisting disease (cardiac or respiratory)
How do opioids act when used in regional?
Act on both spinal and supraspinal opioid receptors
*increase potency
*won’t change duration or density of block
(from LA handout)
Relative contraindications of neuraxial analgesia for labor
- Elevated ICP
- Documented LA allergy
- Untreated systemic infection
- Preexisting neuro deficit
- Informed consent difficulties (language)
- Severe fetal depression
- Severe maternal cardiac disease
- Skeletal abnormalities
- Some types of back surgery
Monitoring necessary for neuraxial placement
At minimum:
- BP
- FHT (before and after)
- EKG and pulse oximetry our book says too
Cons of using Volatiles in labor pain control
Smooth muslce relaxation and Provider/equipment limitation
How does sterile water injection work?
Counterirritation
Gate control theory
Which LA interferes with action of Bupivacaine and opioids?
2-Chloroprocaine
Advantages of ambulation during labor
Maternal satisfaction/autonomy
Decreased dystocia
Decreased risk of DVT
Maintenance of continuous spinal analgesia
- Bupivacaine 0.08-0.125 plus 1-2 mcg/mL fentanyl at rate of 1-1.5 ml/hour
- Disconnect PCEA option and may opt for clinical administered top off doses
- STERILE
Concentration of 2-chloroprocaine used for rapid expansion in cesarean
3%
Concentration/Dose of Bupivacaine
0.0625-0.125% sometimes up to -.25%
Although MBG says they use 0.5%?
12-20 ml
Should you label your spinal catheter?
Yes please
Which opioid provides good pain relief for laboring moms?
What do you need to monitor?
Fentanyl
CSHT requires extended monitoring of baby and mom after extended use
What 4 factors related to passenger effect labor?
- Fetal size
- Fetal lie
- Presentation
- Position
What is considered pre-term?
<37 weeks
Aspiration prophylaxis considerations in neuraxial
- Clear liquids allowed
- All pregnant women are a full stomach
- No solid food during active labor but no consensus on amount of liquid
- Obesity, diabetes, and sedation are all additional risk factors
Are barbiturates good for labor pain and sedation?
Nah
- Easily cross placenta
- Cause neonatal depression
Sacral top offs in recently placed epidurals for vaginal delivery
5-10 mls of 0.5-1% lidocaine with 100 mcg of fentanyl
Given in sitting position
Does your patient need an IV before or after neuraxial placement?
Before
Obstetric considerations that affect neuraxial technique choice
Likelihood of surgical delivery
Stage of labor
Fetal abnormalities
Is neostigmine a good adjuvant in regional?
In animals yes, in humans nope
Increased nausea
Can also cause fetal bradycardia
also FYI - for GA if you give it fast it can cause an increase in ACh which can cause contractions
What percent of pregnancies end on expected due date?
Preterm?
Post-term?
Prob dont need to know this but…..
<10% on EDD
~ 13% pre-term
~5-7% post-term
How long does pruritis last associated with neuraxial analgesia?
90 minutes?
What hemodynamic effects can ketamine cause?
Increase HR and BP
Which way do you want their head to be facing when they come out? as in front or back of mom?
Back
What type of pain and where does it occur in first stages of labor?
Visceral pain
T10-L1
Drugs for pruritis
- Avoid benadryl (causes sedation)
- Nubain 5-10 mg
- Ondansetron (8 mg *book)
Didnt we learn in another class that you can put some narcan in there to help with the itching or did i make that up??
yup that sounds familiar
Concentration of ropivacaine used for infusions
0.1-0.2%
Effect of epidural analgesia on maternal catecholamines?
Hyperventilation?
Both decreased
What type of pain occurs and where in second stage of labor?
Somatic pain
S2-S4
Which LA is popular as a test dose, has little sensory/motor discrimination, and is not routinely used for maintenance of LEA?
Lidocaine
What presentation is optimal?
Cephalic- head down
What may you need for instrumented vaginal delivery?
Denser block
5-10 mls of 2% lidocaine with epi, 0.25% bupivacaine, or 3% 2-chloroprocaine
Disadvantages of bupivacaine
Slower onset time
CV and neuro toxicity
Which opioid is the most widely used but provides poor analgesia and reduced variability and neonatal depression?
Meperidine
Are remi, al, and su good choices for pain relief for laboring moms?
No strong evidence to support use
anatomic changes in pregnancy that can affect neuraxial placement (6)
- Reduction in intervertebral gap
- Widening of hips creating a head down tilt when lateral
- Forward rotation of the pelvis can move the line at iliac crest higher–> important because you might think you are at L4 or L5 but actually closer to L2
- Higher apex of thoracic kyphosis
- Engorgement of epidural veins
- Difficult to ID ligamentum flavum
What is considered post-term?
>42 weeks
3 phases of Stage 1 Labor and their amount of Dilation
- Latent: 0-3 cm
- Active: 4-7 cm
- Transitional: 8-10 cm
Side effects of neuraxial analgesia
- hypotension
- pruritis
- urinary retention
Name some non-pharmacologic methods of pain control that we spent reading hours about that she said we dont really need to know about
- Antenatal health education
- Support persons
- Relaxation techniques
- Massage
- Reflexology
- Hypnosis
- Aromatherapy
- Acupuncture/acupressure
- Hydrotherapy
- TENS
- Sterile water injection
Maternal coexisting diseases that effect neuraxial technique choice
Severe valvular heart disease
Intracranial mass/neuro disease
Is acetaminophen good for labor pain?
Yes, 1 g IV reduced VAS pain scores and need for rescue meds with no change in neonates
Which type of opioids are best to add to your regional?
More lipophilic opioids
Not morphine
Which LA is less cardiotoxic and has less of a motor block, but is expensive and you might as well just use lidocaine?
Ropivacaine
Benefits of epidural analgesia
- Decreased maternal catecholamines
- Decreased maternal hyperventilation
- Ability to rapidly transition to epidural anesthesia for emergencies
Is sterile water injection indicated for active labor?
No
what emergency equipment should always be available with neuraxial placement?
Pressors (ephedrine, neo)
Emergency airway equipment
Are phenothiazines good for labor pain and sedation?
Easily cross placenta
Decrease fetal HR variability so no
Which LA is least toxic and has increased motor block making it a good choice for C-sections?
2-Chloroprocaine
Hypotension r/t neuraxial analgesia in parturients can lead to fetal _________
distress
Pros and cons of Nitrous oxide use
How much do you use?
Use 50% Nitrous
Cons:
- Less effective than epidural
- More nausea
Dont see any pros here…
How much water do you give in sterile water injections and how many times?
give 0 bc this is stupid
0.1 ml blebs
Ideal number unknown
Disadvantages of ambulation during labor
Falls with slight motor block
Hypotension
Increased workload
Increased need for top-off doses
Medicolegal issues
MOA of using epinephrine in regional
alpha2 agonism
beta2 agonism (systemic)- slows delivery
Result is vasoconstriction and decreased clearance and increased motor block
Absolute contraindications for neuraxial analgesia for labor
- Patient refusal
- Uncooperative - dont stick a nut
- Moderate/severe bleeding conditions
- Anticoagulation
- Uncontrolled hemorrhage/ severe hypovolemia
- Epidural site infection
- Unskilled/inexperienced anesthesia provider
Are benzos good for labor pain and sedation?
Not really since they easily cross placenta and cause maternal amnesia
And make for a floppy baby according to her last lecture
Anesthetic considerations affecting neuraxial technique choice
- Difficult airway
- Timing
- PDPH
If cephalic presentation is best, what are the other possible presentations that are suboptimal?
- Breech- butt first
- Shoulder first
What percent of parturients have hypotension during neuraxial analgesia?
When usually?
80%
During initial dose or bolus
What is responsible for hypotension associated with neuraxial analgesia?
Sympathetic blockade
Advantage of using narcotics in continuous spinal analgesia
Analgesia without excessive motor block
What labs should you get before neuraxial placement?
Platelets and crossmatch
3 components of labor and delivery (3 Ps)
- Powers- contractions, maternal voluntary expulsive efforts
- Passageway- pelvis, soft tissues
- Passenger- fetus
what is the advantage of a combined spinal-epidural (CSE) over a conventional labor epidural (LEA)?
*quiz*
faster onset
components of the ideal local anesthetic for labor
*quiz*
- rapid onset
- minimal side effects
- long duration
- differential blockade
effective blockade for both stages of labor requires coverage from ___ to ___
*quiz*
T10-S4
is anticipated operative delivery an indication or contraindication for neuraxial labor analgesia?
*quiz*
indication
Which maternal position reduces risk of vascular injection?
Sitting or lateral?
Lateral due to better draining of epidural veins
