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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
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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
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Pain pathway during 1st stage of labor
- T10-L1
- visceral pain from uterine contractions and resulting cervical dilation and effacement
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Pain pathway during 2nd and 3rd stages of labor
- S2-3
- pain caused by descent (pushing out) of fetus and placenta
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At what anatomic level is a labor epidural usually placed?
L2-3 or L3-4
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T or F, nearly all opioid analgesics readily cross the placenta and can affect the fetus (respiratory depression / acidosis and sedation)
T
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T or F, epidurals slow the progress of labor
F, was previously believed to be true
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Most common SE r/t labor epidurals
Treatment?
- hypotension 2/2 sympathectomy and resultant VD
- IVF, ephedrine 5-10 mg or neo 40 mcg to effect
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T or F, epidurals are meant to eliminate all labor pain
F, meant to help manage labor pain
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T or F, no anesthesia equipment or drugs are necessary to attempt an epidural
F
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Epidural absolute contraindications
- Pt refusal
- Coagulopathy / thrombocytopenia
- Skin infection at injection site
- Raised IC pressure
- Hypovolemia
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Relative contraindications to epidural
- Uncooperative pts
- Pre-existing neuro d/o (MS)
- Fixed CO states (AS, HOCM, MS, CHB)
- Anatomical abnormalities of the vertebral column
- H/o previous back surgery
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Epidural catheter should extend ___ cm into the epidural space
3-5 cm
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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
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What will happen if the catheter is IV?
Intrathecal?
- IV- increased HR and BP
- IT- fast onset T8-10 spinal block
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Typical epidural bolus dose
5 ml of 0.25% bupiv and 100 mcg fent
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Monitoring after epidural placement
Monitor for hypotension for 15-20 mins initially then q2-3 hours for hypotension and adequate analgesia
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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
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Dosing for an intrathecal catheter compared to epidural
1/10 the mg volume dose
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For what type of pts are intrathecal opioids reserved for?
multips
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Is hypotension typically seen with spinal opioid administration?
No as since there is no LA, there is sympathetic blockade
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Max volume to be injected into intrathecal space
3 ml
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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)
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SE of intrathecal narcotics
itching and N/V, incidence increases with increased doses
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Almost any stressful situation in the fetus evokes the ____ response
baroreceptor, manifests as peripheral VC and HTN and resultant bradycardia
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Examples of fetal stressors
Hypoxia, uterine contractions, fetal head compression, fetal defecation
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Normal FHR range
110-160 bpm
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Variable FHR is _____.
normal and reassuring
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FHR accelerations are _______
normal and reassuring
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Absence of FHR variability and accelerations is _____
non reassuring
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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
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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
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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
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What causes variable decels?
Umb cord compression
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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
- NON reassuring
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What is considered severe bradycardia with FHR?
60-80 bpm
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Sensory level required for c-section for any regional anesthetic
T4
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SE associated with T4 sensory blockade
VD, potential bradycardia (cardiac accelerator fibers originate from 1st - 5th thoracic spinal nerves)
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A fluid bolus of ___ is recommended prior to T4 level block
1L - 1.5 L
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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
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What would tingling or weakness in the hands indicate?
Low cervical blockade
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How can you assess what accessory respiratory muscles are still functioning with a suspected high block?
Ask pt to lift head off of pillow
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Dose and type of LA used for spinal for c-section
Hyperbaric bupiv 0.75%, 10.5 - 15 mg
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Airway management for crash c-section
RSI GETA
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Why is spinal preferred over epidural for scheduled c-section?
- Faster placement
- Consistent and dense sensory and motor blockade
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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)
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How is the lido alkalinized?
at 1 ml of sodium bicarb 8.4% per 10 ml of lido
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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
- RSI GETA
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NPO for elective c-section
6 hours for ANY anesthetic
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Why is GETA more risky in the parturient vs. the non parturient?
Increased risk of aspiration and 8x greater incidence of difficult airway
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RSI doses of prop and succ
- prop 2 ml / kg
- succ 1.5 ml / kg
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T or F, short term low concentrations of volatiles are associated with decreased uterine activity, increased uterine bleeding, and neonatal depression
F
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Extubation of the parturient
AWAKE!!
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Normal neonate RR
30-60 / min
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What 5 criteria are assessed during Apgar scoring?
color, heartbeat, respiration, response to stim (crying), activity
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what does an Apgar score of 4-6 mean?
what about 0-3?
- 4-6 moderate impairment
- 0-3 needs resuscitation
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Meconium
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
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How long should elective surgeries be postponed in the parturient?
6 weeks after delivery (2/2 aspiration risk)
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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
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Placentra previa
- Prevents or blocks fetal delivery
- Presents as painless vaginal bleeding
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T or F, all parturients with vaginal bleeding are presumed to have placenta pre via until proven otherwise
T
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Placental accreta
Placenta adheres to uterine surface
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Placental increta
Placenta adheres to uterine muscle
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Placental percreta
Placenta completely invades uterine muscle and surrounding tissue
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H/o ____ or previous c-section increases risk of placenta accrete, increta, percreta
Placenta previa
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Management of placenta previa with active bleeding, unstable pt / fetus
- Immediate c-section
- Prepare for large blood loss
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Abruptio placentae
-what is it?
-s/sx?
- premature separation of the placenta from the uterine wall
- painful vaginal bleeding
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Uterine rupture
-who's at risk
-s/sx
- 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
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Tx of uterine rupture
Open hysterectomy with aggressive volume management
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Causes of post partum hemorrhage
- Most commonly uterine atony
- previous use of tocolytic agents
- multiple gestation
- retained placenta
- lacerations
- uterine inversion
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Is RA acceptable in pts with hypovolemia?
NO!
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Oxytocin
-dose
-uses
- 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
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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
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Umbilical cord prolapse
Can lead to cord compression and ultimately fetal demise
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Most common cause of umbilical cord prolapse
premature or artificial rupture of membranes
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Tx of umbilical cord prolapse
- immediate c-section
- manually pushing the cord back up into the pelvis
- parturient in knee- chest position and steep t-burg to help with fetal perfusion
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Dystocia
- ineffective labor typically caused by inadequate uterine contractions or abnormal fetal presentation
- will ultimately require anesthetic intervention
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When during pregnancy can correction of breech position be attempted (version)?
after 36 weeks
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Why is an epidural typically placed during correction of breech position?
- uncomfortable
- external manipulation can result in placental abruption /fetal distress requiring immediate c-section
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Amniotic fluid embolism
- > 80% mortality rate
- amniotic fluid enters maternal circulation causing a severe anaphylactic rxn
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S/sx of amniotic fluid embolism
- sudden resp distress
- CV collapse
- bleeding
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Risks for amniotic fluid embolism
- version
- pushing on uterus during c-section
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PDPH characteristics
- fronto-occipital
- aggravated by sitting up or straining (coughing)
- diminished by laying supine
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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
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Gold standard for treatment of PDPH
epidural blood patch
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When should an epidural blood patch be given?
24-48 hours after dural puncture
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In what pts is an epidural blood patch recommended for?
H/A interferes with ADLs
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How does an epidural blood patch work?
Creates a blood clot over the hole in the dura stopping or slowing the CSF leak
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How is an epidural blood patch performed?
- 15-20 ml of autologous blood is injected into the epidural space
- inject at previous puncture site
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Characteristics of a reassuring fetal HR tracing
- Rate= 130-140 bpm
- variability
- Decels coincide with contractions (mirror image) and are short in duration
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