OB Part 2
Card Set Information
OB Part 2
BC Nurse Anesthesia
OB part deux
Describe the 3 stages of labor
stage 1= onset of "regular contractions" to 10 cm dilation of cervix
stage 2= complete dilation until delivery of the infant
stage 3= delivery of the placenta
Differentiate between the latent and active phases of the 1st stage of labor
latent= < 4 cm dilation of cervix
active= > 4 cm dilation of the cervix
Pain pathway during 1st stage of labor
visceral pain from uterine contractions and resulting cervical dilation and effacement
Pain pathway during 2nd and 3rd stages of labor
pain caused by descent (pushing out) of fetus and placenta
At what anatomic level is a labor epidural usually placed?
L2-3 or L3-4
T or F, nearly all opioid analgesics readily cross the placenta and can affect the fetus (respiratory depression / acidosis and sedation)
T or F, epidurals slow the progress of labor
F, was previously believed to be true
Most common SE r/t labor epidurals
hypotension 2/2 sympathectomy and resultant VD
IVF, ephedrine 5-10 mg or neo 40 mcg to effect
T or F, epidurals are meant to eliminate all labor pain
F, meant to help manage labor pain
T or F, no anesthesia equipment or drugs are necessary to attempt an epidural
Epidural absolute contraindications
Coagulopathy / thrombocytopenia
Skin infection at injection site
Raised IC pressure
Relative contraindications to epidural
Pre-existing neuro d/o (MS)
Fixed CO states (AS, HOCM, MS, CHB)
Anatomical abnormalities of the vertebral column
H/o previous back surgery
Epidural catheter should extend ___ cm into the epidural space
Purpose of test dose
Ensure catheter is not IV
Attempt aspiration 1st (does not negate intrathetal / IV placement)
Test catheter NOT needle!
3 ml of 1.5% lido with 1:200,000 epi
What will happen if the catheter is IV?
IV- increased HR and BP
IT- fast onset T8-10 spinal block
Typical epidural bolus dose
5 ml of 0.25% bupiv and 100 mcg fent
Monitoring after epidural placement
Monitor for hypotension for 15-20 mins initially then q2-3 hours for hypotension and adequate analgesia
Epidural bolus dose for inadequate analgesia
5-10 ml of 0.25% bupiv
If pt completely dilated and about ready to push maybe just use 50-100 mcg fent and avoid further LA to maintain max motor function
Dosing for an intrathecal catheter compared to epidural
1/10 the mg volume dose
For what type of pts are intrathecal opioids reserved for?
Is hypotension typically seen with spinal opioid administration?
No as since there is no LA, there is sympathetic blockade
Max volume to be injected into intrathecal space
Typical doses of intrathecal morphine and fent
What is the benefit of using both?
Morphine 0.15- 0.25 mg
Fent 12.5-25 mcg
Morphine has slow onset (30-60 mins) but a long DOA (4-6 hours) while
Fentanyl has a fast onset (1-3 mins) but a short DOA (1-2 hours)
SE of intrathecal narcotics
itching and N/V, incidence increases with increased doses
Almost any stressful situation in the fetus evokes the ____ response
baroreceptor, manifests as peripheral VC and HTN and resultant bradycardia
Examples of fetal stressors
Hypoxia, uterine contractions, fetal head compression, fetal defecation
Normal FHR range
Variable FHR is _____.
normal and reassuring
FHR accelerations are _______
normal and reassuring
Absence of FHR variability and accelerations is _____
What are early decels? Should we be worried about them?
Simultaneous to contractions and are the result of a vagal reflex to head compression
No, not associated with fetal distress, are considered reassuring
What are late decels? Should we be worried about them?
Onset of 10-30 seconds after contraction begins and end 10-30 seconds after the contraction ends. Sign uteroplacental insufficiency.
Yes, potentially life threatening to the fetus, NON reassuring
Most commonly encountered FHR during labor
Variable decels, vary in shape, depth, and duration
Acute fall in FHR and a variable recovery phase
May not bear a constant relationship to uterine contractions
Commonly use pts who have experienced premature rupture of membranes and decreased amniotic fluid volume
What causes variable decels?
Umb cord compression
When do variable decals become concerning?
With loss of variability, tachycardia, or late return to baseline
If not corrected may lead to acidosis and fetal distress
What is considered severe bradycardia with FHR?
Sensory level required for c-section for any regional anesthetic
SE associated with T4 sensory blockade
VD, potential bradycardia (cardiac accelerator fibers originate from 1st - 5th thoracic spinal nerves)
A fluid bolus of ___ is recommended prior to T4 level block
1L - 1.5 L
What are quiet respirations?
Pt may feel like she can't / isn't breathing adequately due to partial blockade of sensory innervation to thoracic region
Tell pt prior to block placement
What would tingling or weakness in the hands indicate?
Low cervical blockade
How can you assess what accessory respiratory muscles are still functioning with a suspected high block?
Ask pt to lift head off of pillow
Dose and type of LA used for spinal for c-section
Hyperbaric bupiv 0.75%, 10.5 - 15 mg
Airway management for crash c-section
Why is spinal preferred over epidural for scheduled c-section?
Consistent and dense sensory and motor blockade
How can a previously placed labor epidural be dosed for emergency c-section?
5 ml increments, to a total of 20 ml of
alkalinized 2% PF lido or
3% nesicaine (chloroprocaine)
How is the lido alkalinized?
at 1 ml of sodium bicarb 8.4% per 10 ml of lido
What if the labor epidural catheter migrated IV or intravascularly but was already dosed with 20 ml of LA?
Toxic blood levels or high spinal
NPO for elective c-section
6 hours for ANY anesthetic
Why is GETA more risky in the parturient vs. the non parturient?
Increased risk of aspiration and 8x greater incidence of difficult airway
RSI doses of prop and succ
prop 2 ml / kg
succ 1.5 ml / kg
T or F, short term low concentrations of volatiles are associated with decreased uterine activity, increased uterine bleeding, and neonatal depression
Extubation of the parturient
Normal neonate RR
30-60 / min
What 5 criteria are assessed during Apgar scoring?
color, heartbeat, respiration, response to stim (crying), activity
Normal Apgar score
what does an Apgar score of 4-6 mean?
what about 0-3?
4-6 moderate impairment
0-3 needs resuscitation
why are we worried about it?
what do we do about it?
can damage the neonate's lungs
attempt to remove it with suctioning PRIOR to first breath
How long should elective surgeries be postponed in the parturient?
6 weeks after delivery (2/2 aspiration risk)
Considerations for the parturient have non-obstetric surgery
aspiration risk- antacids and RSI
avoid teratogens (benzos, N20, ketamine)
maintain placental perfusion (tight HD control, oxygenation)
assess for preterm labor
FHR monitoring after 6-10 weeks gestation
RA preferred over GA
uterine displacement after 24 weeks
Prevents or blocks fetal delivery
Presents as painless vaginal bleeding
T or F, all parturients with vaginal bleeding are presumed to have placenta pre via until proven otherwise
Placenta adheres to uterine surface
Placenta adheres to uterine muscle
Placenta completely invades uterine muscle and surrounding tissue
H/o ____ or previous c-section increases risk of placenta accrete, increta, percreta
Management of placenta previa with active bleeding, unstable pt / fetus
Prepare for large blood loss
-what is it?
premature separation of the placenta from the uterine wall
-who's at risk
parturients with any h/o previous extensive uterine manipulation, esp VBACs
loss of uterine tone, bleeding, fetal distress
sudden painful event can overtake analgesic effects of a labor epidural
Tx of uterine rupture
Open hysterectomy with aggressive volume management
Causes of post partum hemorrhage
Most commonly uterine atony
previous use of tocolytic agents
Is RA acceptable in pts with hypovolemia?
20-30 U/ L wide open IV
stimulates contraction of uterine smooth muscle to IMPEDE uterine blood flow
number of oxytocin receptors peaks at term
What other drugs can be used to impede uterine blood flow and thus treat post partum hemorrhage
Methergine 0.2 mg IM, SE= HTN
Hemabate 0.25 mg IM, SE= mild BP increase
Umbilical cord prolapse
Can lead to cord compression and ultimately fetal demise
Most common cause of umbilical cord prolapse
premature or artificial rupture of membranes
Tx of umbilical cord prolapse
manually pushing the cord back up into the pelvis
parturient in knee- chest position and steep t-burg to help with fetal perfusion
ineffective labor typically caused by inadequate uterine contractions or abnormal fetal presentation
will ultimately require anesthetic intervention
When during pregnancy can correction of breech position be attempted (version)?
after 36 weeks
Why is an epidural typically placed during correction of breech position?
external manipulation can result in placental abruption /fetal distress requiring immediate c-section
Amniotic fluid embolism
> 80% mortality rate
amniotic fluid enters maternal circulation causing a severe anaphylactic rxn
S/sx of amniotic fluid embolism
sudden resp distress
Risks for amniotic fluid embolism
pushing on uterus during c-section
aggravated by sitting up or straining (coughing)
diminished by laying supine
T or F, increased PO fluid intake in the 1st 24 hours after dural puncture can decrease incidence of PDPH?
T, thought to help increase rate of CSF production
Gold standard for treatment of PDPH
epidural blood patch
When should an epidural blood patch be given?
24-48 hours after dural puncture
In what pts is an epidural blood patch recommended for?
H/A interferes with ADLs
How does an epidural blood patch work?
Creates a blood clot over the hole in the dura stopping or slowing the CSF leak
How is an epidural blood patch performed?
15-20 ml of autologous blood is injected into the epidural space
inject at previous puncture site
Characteristics of a reassuring fetal HR tracing
Rate= 130-140 bpm
Decels coincide with contractions (mirror image) and are short in duration