OB: Labor Analgesia Flashcards
Many _____ & ____ _____ throughout history
- Princess and the Pea
- Upper class women have more pain than “savages”
- “Modern women” have more pain than “savages” because “the church and culture taught them to expect it.”
social and medical connotations
Less than ___% of pregnancies end on the EDD
10%
In the US approximately ____% occur preterm (<37 weeks) and 5-7% remain undelivered postterm (>42 weeks)
13%
Cause for onset of labor
remains unknown
Three (4) stages of labor
Dilation
Expulsion
Placental
(4th) Stabilization
Stage 1 has three phases
_____ (0-3 cm)
_____ (4-7 cm)
_____ (8-10 cm)
Latent (0-3 cm)
Active (4-7 cm)
Transitional (8-10 cm)
First stage of labor
__________ pain
_____ level
visceral
T10 - L1
Second stage of labor
_____ pain
_____ level
Somatic
S2 - S4
3 components of labor and delivery (3 P’s)
Powers (uterine contraction, maternal voluntary expulsive efforts)
Passageway (pelvis, soft tissues)
Passenger (fetus)
Passenger - Fetal size and relationship of the fetus to the ____ ____ affect labor progress
maternal pelvis
Passenger - lie (3)
Transverse
Oblique
Longitudinal
Passenger - presentation (3)
Cephalic
Breech
Shoulder
Passenger - P____
Position
Station - Palpation of the ____ ____ ____ of the fetus
leading bony point
3 general methods to control pain in labor
nonpharmacologic
neuraxial
non-neuraxial
Nonpharm methods
Antenatal health education
Support persons
Relaxation techniques
Massage
Reflexology
Hypnosis
Aromatherapy
Acupuncture/acupressure
Hydrotherapy
TENS
Sterile water injection
neuraxial methods
Epidural
Spinal
CSE
non-neuraxial methods
Nitrous
Volatile anesthetics
Non-opioids
Opioids
Sterile Water Injection
Injection of small ___ ____ of sterile water
0.1mL blebs
Sterile Water Injection
Ideal number of injections ____
unknown
Sterile Water Injection
Counterirritation - ____ ____ theory
Gate control
Sterile Water Injection
Not recommended for ____ ____
active labor
Inhalational Agent for analgesia -
Nitrous
___% blended
Used much more often in Canada & UK
____ effective than epidural
____ nausea
50%
Less
More
Inhalational Agent for analgesia -
Volatile anesthetics
Smooth muscle _____
Provider/equipment _____
relaxation
limitations
Non-opioid Analgesia and Sedation -
Acetaminophen
____ IV decreased VAS scores and need for rescue meds
___ ____ in neonates
1 g
No change
Non-opioid Analgesia and Sedation -
______
Few studies
Can increase HR/BP
Ketamine
Non-opioid Analgesia and Sedation -
Benzodiazepines
______ cross placenta
Maternal ____
easily
amnesia
Non-opioid Analgesia and Sedation -
Phenothiazines
____ cross placenta
____ fetal HR variability
Easily
decrease
Non-opioid Analgesia and Sedation -
Barbiturates
____ cross placenta
Neonatal ____
Easily
depression
Opioid Analgesia
Meperidine
Most used and researched
_____ analgesia
Reduced _____
Neonatal depression
poor
variability
Opioid Analgesia
Morphine
____ satisfaction than meperidine
More requests for _____ doses
Less
additional
Opioid Analgesia
Fentanyl
Good pain relief
Context-sensitive half-life requires ____ ____ mom/baby after prolonged use
extended monitoring
Opioid Analgesia
Remifentanyl/Alfentanyl/Sufentanyl
____ ____ ____ to support use
No strong evidence
Neuraxial Analgesia for Labor Indications
____ request
Maternal
Neuraxial Analgesia for Labor Indications
Anticipation of ____ delivery (malposition, multiple gestation…)
operative
Neuraxial Analgesia for Labor Indications
____ _____/____ risk for precipitous, high-risk or emergency delivery (pre-e, nonreassuring FHT…)
Obstetric disease/High
Neuraxial Analgesia for Labor Indications
_____ conditions (obesity, difficult airway, MH)
Maternal
Neuraxial Analgesia for Labor Indications
Maternal _____ disease
coexisting
(severe cardiac or respiratory disease)
Absolute Contraindications of Neuraxial Analgesia for Labor
Patient refusal
Uncooperative patient
Moderate/severe bleeding conditions
Anticoagulation
Uncontrolled hemorrhage/severe hypovolemia
Epidural site infection
Unskilled/inexperienced anesthesia provider
Relative Contraindications of Neuraxial Analgesia for Labor
Elevated ICP
Documented LA allergy
Untreated systemic infection
Preexisting neurologic deficit
Informed consent difficulties (language)
Severe fetal depression
Severe maternal cardiac disease
Skeletal abnormalities
Some types of back surgery
Neuraxial Technique Choice - Maternal coexisting disease such as (2)
Severe valvular heart disease
Intracranial mass/neurologic disease
Neuraxial Technique Choice - Obstetric considerations such as (3)
Likelihood of surgical delivery
Stage of labor
Fetal abnormalities
Neuraxial Technique Choice - Anesthetic considerations such as (3)
Difficult airway
Timing
PDPH
Benefits of Epidural Analgesia - Decreased maternal ______
catecholamines
Benefits of Epidural Analgesia - Decreased maternal ______
hyperventilation
Benefits of Epidural Analgesia - Ability to rapidly transition to ___ ____ for emergencies
epidural anesthesia
Preparation:
eval and consent
aspiration prophylaxis
labs
IVs
monitoring
positioning
emergency drugs and equipment
Evaluation and Consent
History
Relevant _____ exam
_____ consent
Recognition of ____ _____
physical
informed
risk factors
Aspiration Prophylaxis
____ Liquids
All pregnant women are considered a ….. ____ ____
ASA guidelines – no solid food during ____ labor, no consensus on amount of liquid
What other factors could increase risk of aspiration?
Clear
full stomach
active
Labs
plts?
crossmatch?
generally not needed
monitoring
BP
FHT
EKG? generally not needed, but must be used during epidural
Pulse ox?
Emergency Drugs & Supplies
pressors
airway
Choice of Local Anesthetics - Bupivacaine
Advantages
_____ block
_____ duration of action
Lack of _____
Limited placental transfer
Differential
Long
tachyphylaxis
Choice of Local Anesthetics - Bupivacaine
Disadvantages
_____ onset time
____ and ____ toxicity
slower
CV and neuro
Choice of Local Anesthetics - Bupivacaine
Concentration and dose
0.0625%-0.125% sometimes up to ____
__-__mL
0.25%
12-20
Choice of Local Anesthetics - Lidocaine
Not routinely used for maintenance of labor analgesia
____ sensory/motor discrimination
Popular as a ____ ___
Little
test dose
Choice of Local Anesthetics - Chloroprocaine
_____ toxic
___% used for rapid expansion for cesarean
least
3%
Choice of Local Anesthetics - Chloroprocaine
____ duration
Increased motor block
Interfere with action of ____ & ____ (more in peripheral blocks)
least
bupivacaine and opioids
Choice of Local Anesthetics - Ropivacaine
Less ____toxic
0.1-0.2% Infusions
Less ____ block
More _____
Lidocaine works as well and is cheaper
cardio
motor
expensive
Adjuvants - opioids
____ & ____ opioid receptors
Lipophilic > Morphine
Spinal and supraspinal
Adjuvants - epinephrine
- Vasoconstriction, decreased clearance
- ___ agonism
- Disadvantages: ___ agonism (systemic), Increased ___ block
α2
β2
motor
Adjuvants - clonidine
α2 agonism
___ ____ in motor block
____ ___ warning in OB
No increase
Black Box
Adjuvants - neostigmine
In animals
____ ____ in human study
Did increase ____
Didn’t work
nausea
Analgesia for Vaginal Delivery
Second stage of labor pain - ____ fibers at __-__
somatic
S2-S4
Analgesia for Vaginal Delivery - Recently placed epidurals may benefit from sacral top offs
5-10mL of ______ ______ with _____ _____
Given in sitting position
0.5-1% Lidocaine with 100 mcg fentanyl
Analgesia for Vaginal Delivery - Instrumented vaginal delivery
May need a ____ block
__-__ mL of 2% Lidocaine with epi, 0.25% bupivacaine, or 3% 2-chloroprocaine
denser
5-10
Neuraxial Anatomy - Reduction of _____ gap
intervertebral
Neuraxial Anatomy - Widening of hips creates a ___ ____ ____ when lateral
head down tilt
Neuraxial Anatomy - ____ ____ of the pelvis can move the line at the iliac crests higher
Forward rotation
Neuraxial Anatomy - Higher apex of thoracic _____
kyphosis
Neuraxial Anatomy - Engorgement of ____ veins
epidural
Neuraxial Anatomy - Difficult to ID ____ ____
ligamentum flavum
Types of Maintenance (5)
Epidural vs CSE
Continuous spinal
Intermittent Bolus
Continuous Infusion
PCEA
Maintenance of Continuous Spinal Analgesia -
Narcotic helps provide analgesia without ____ ____ ____
excessive motor block
Maintenance of Continuous Spinal Analgesia
Bupivacaine - ___-___ plus 1-2 mcg/mL fentanyl rate of ___-___
Disconnect ____ option
May opt for clinician administered top off doses
Special caution for sterile technique
0.8-0.125%
1-1.5 mL/hour
PCEA
Maintenance of Continuous Spinal Analgesia
LABEL ____ LABEL
LABEL
Ambulation in Labor - Advantages (3)
Maternal satisfaction/autonomy
Decreased dystocia
Decrease risk of DVT
Ambulation in Labor - Disadvantages (5)
Falls with slight motor block
Hypotension
Increased workload
Increased need for top off doses
Mediolegal
Side effects - hypotension
Up to ___% of parturients
Initial dose or bolus
_____ blockade
Fluid loading or use of prophylactic pressors may decrease risk, but _____ prevents
Can lead to fetal _____
80
Sympathetic
nothing
distress
Side effects - pruritis
Time limited __ minutes
____ can sedate
____ 5-10mg
Ondansetron
90
Benadryl
Nubain
Complications
failed analgesia
unintended dural puncture
back pain
excessive motor block
urinary retention
maternal hyperthermia
fetal heart rate abnormalities
accidental IV injection
meningitis
epidural hematoma/abscess
neurologic deficits
