OB Part 2

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OB Part 2
2014-03-29 10:17:40
BC Nurse Anesthesia

OB part deux
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  1. 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
  2. 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
  3. Pain pathway during 1st stage of labor
    • T10-L1
    • visceral pain from uterine contractions and resulting cervical dilation and effacement
  4. Pain pathway during 2nd and 3rd stages of labor
    • S2-3
    • pain caused by descent (pushing out) of fetus and placenta
  5. At what anatomic level is a labor epidural usually placed?
    L2-3 or L3-4
  6. T or F, nearly all opioid analgesics readily cross the placenta and can affect the fetus (respiratory depression / acidosis and sedation)
  7. T or F, epidurals slow the progress of labor
    F, was previously believed to be true
  8. 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
  9. T or F, epidurals are meant to eliminate all labor pain
    F, meant to help manage labor pain
  10. T or F, no anesthesia equipment or drugs are necessary to attempt an epidural
  11. Epidural absolute contraindications
    • Pt refusal
    • Coagulopathy / thrombocytopenia
    • Skin infection at injection site
    • Raised IC pressure
    • Hypovolemia
  12. 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
  13. Epidural catheter should extend ___ cm into the epidural space
    3-5 cm
  14. 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
  15. What will happen if the catheter is IV?
    • IV- increased HR and BP
    • IT- fast onset T8-10 spinal block
  16. Typical epidural bolus dose
     5 ml of 0.25% bupiv and 100 mcg fent
  17. Monitoring after epidural placement
    Monitor for hypotension for 15-20 mins initially then q2-3 hours for hypotension and adequate analgesia
  18. 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
  19. Dosing for an intrathecal catheter compared to epidural
    1/10 the mg volume dose
  20. For what type of pts are intrathecal opioids reserved for?  
  21. Is hypotension typically seen with spinal opioid administration?
    No as since there is no LA, there is sympathetic blockade
  22. Max volume to be injected into intrathecal space
    3 ml
  23. 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)
  24. SE of intrathecal narcotics
    itching and N/V, incidence increases with increased doses
  25. Almost any stressful situation in the fetus evokes the ____ response
    baroreceptor, manifests as peripheral VC and HTN and resultant bradycardia
  26. Examples of fetal stressors
    Hypoxia, uterine contractions, fetal head compression, fetal defecation
  27. Normal FHR range
    110-160 bpm
  28. Variable FHR is _____.
    normal and reassuring
  29. FHR accelerations are _______
    normal and reassuring
  30. Absence of FHR variability and accelerations is _____
    non reassuring
  31. 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
  32. 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
  33. 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 
  34. What causes variable decels?
    Umb cord compression
  35. 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
  36. What is considered severe bradycardia with FHR?
    60-80 bpm
  37. Sensory level required for c-section for any regional anesthetic
  38. SE associated with T4 sensory blockade
    VD, potential bradycardia (cardiac accelerator fibers originate from 1st - 5th thoracic spinal nerves)
  39. A fluid bolus of ___ is recommended prior to T4 level block
    1L - 1.5 L
  40. 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
  41. What would tingling or weakness in the hands indicate?
    Low cervical blockade
  42. How can you assess what accessory respiratory muscles are still functioning with a suspected high block?
    Ask pt to lift head off of pillow
  43. Dose and type of LA used for spinal for c-section
    Hyperbaric bupiv 0.75%, 10.5 - 15 mg
  44. Airway management for crash c-section
  45. Why is spinal preferred over epidural for scheduled c-section?
    • Faster placement
    • Consistent and dense sensory and motor blockade
  46. 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)
  47. How is the lido alkalinized?
    at 1 ml of sodium bicarb 8.4% per 10 ml of lido
  48. 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
  49. NPO for elective c-section
    6 hours for ANY anesthetic
  50. Why is GETA more risky in the parturient vs. the non parturient?
    Increased risk of aspiration and 8x greater incidence of difficult airway
  51. RSI doses of prop and succ
    • prop 2 ml / kg
    • succ 1.5 ml / kg
  52. T or F, short term low concentrations of volatiles are associated with decreased uterine activity, increased uterine bleeding, and neonatal depression
  53. Extubation of the parturient
  54. Normal neonate RR
    30-60 / min
  55. What 5 criteria are assessed during Apgar scoring?
    color, heartbeat, respiration, response to stim (crying), activity
  56. Normal Apgar score
  57. what does an Apgar score of 4-6 mean?
    what about 0-3?
    • 4-6 moderate impairment
    • 0-3 needs resuscitation
  58. 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
  59. How long should elective surgeries be postponed in the parturient?
    6 weeks after delivery (2/2 aspiration risk)
  60. 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
  61. Placentra previa
    • Prevents or blocks fetal delivery
    • Presents as painless vaginal bleeding
  62. T or F, all parturients with vaginal bleeding are presumed to have placenta pre via until proven otherwise
  63. Placental accreta
    Placenta adheres to uterine surface
  64. Placental increta
    Placenta adheres to uterine muscle
  65. Placental percreta
    Placenta completely invades uterine muscle and surrounding tissue
  66. H/o ____ or previous c-section increases risk of placenta accrete, increta, percreta
    Placenta previa
  67. Management of placenta previa with active bleeding, unstable pt / fetus
    • Immediate c-section
    • Prepare for large blood loss
  68. Abruptio placentae
    -what is it?
    • premature separation of the placenta from the uterine wall
    • painful vaginal bleeding
  69. Uterine rupture
    -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
  70. Tx of uterine rupture
    Open hysterectomy with aggressive volume management
  71. Causes of post partum hemorrhage
    • Most commonly uterine atony
    • previous use of tocolytic agents
    • multiple gestation
    • retained placenta
    • lacerations
    • uterine inversion
  72. Is RA acceptable in pts with hypovolemia?
  73. Oxytocin
    • 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
  74. 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
  75. Umbilical cord prolapse
    Can lead to cord compression and ultimately fetal demise
  76. Most common cause of umbilical cord prolapse
    premature or artificial rupture of membranes
  77. 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
  78. Dystocia
    • ineffective labor typically caused by inadequate uterine contractions or abnormal fetal presentation
    • will ultimately require anesthetic intervention
  79. When during pregnancy can correction of breech position be attempted (version)?
    after 36 weeks
  80. 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
  81. Amniotic fluid embolism
    • > 80% mortality rate
    • amniotic fluid enters maternal circulation causing a severe anaphylactic rxn
  82. S/sx of amniotic fluid embolism
    • sudden resp distress
    • CV collapse
    • bleeding
  83. Risks for amniotic fluid embolism
    • version
    • pushing on uterus during c-section
  84. PDPH characteristics
    • fronto-occipital
    • aggravated by sitting up or straining (coughing)
    • diminished by laying supine
  85. 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
  86. Gold standard for treatment of PDPH
    epidural blood patch
  87. When should an epidural blood patch be given?
    24-48 hours after dural puncture
  88. In what pts is an epidural blood patch recommended for?
    H/A interferes with ADLs
  89. How does an epidural blood patch work?
    Creates a blood clot over the hole in the dura stopping or slowing the CSF leak
  90. How is an epidural blood patch performed?
    • 15-20 ml of autologous blood is injected into the epidural space
    • inject at previous puncture site
  91. Characteristics of a reassuring fetal HR tracing
    • Rate= 130-140 bpm
    • variability
    • Decels coincide with contractions (mirror image) and are short in duration