OB Flashcards
Means before birth
Antepartum
Means difficult labor
Dystocia
Means twins, triplets, etc
Multiple gestation
Means during the act of birth
Intrapartum
Means has had multiple gestations
Multiparous
Normal labor
38-40 weeks
Never completed a pregnancy beyond 20 weeks
Nulliparous
Another name for pregnant patient
Parturient
Means after birth
Postpartum
Preterm labor
<37 weeks
Means first pregnancy
Primapara (primip)
Age of viability
~24 weeks
When should you consider immediate intubation after birth?
If <28 weeks and not pink and active
What does gravida mean?
Total number of pregnancies, regardless of the outcome
What does parity mean?
The number of live births OR number of completed pregnancies that lasted more than 20 weeks
A woman is pregnant for the first time and is 12 weeks along. What is her GP status?
G1 P0
A woman is currently pregnant and 25 weeks along. She has had 6 miscarriages and only 1 live birth. What is her GP status?
G8 P1
A women is pregnant for the second time and delivered twin stillbirths in her first pregnancy at 19 weeks. What is her GP status?
G2 P0
What do oxytocic (uterotonic) drugs do?
Promote uterine contraction
Drugs that decrease uterine bleeding after delivery and induce labor in pregnant patients
Oxytocic drugs
- Pitocin
- Hemabate
- Methergine
- Cytotec
Examples of oxytocic drugs
- Pitocin
- Hemabate
- Methergine
- Cytotec
Effects of pitocin
- Stimulates uterine contraction
2. Induce labor
When is pitocin dosed in c-sections and why?
AFTER the baby and placenta are delivered because a contracted uterus does not bleed as much
Most common side effect of pitocin
Hypotension
Side effects of pitocin
- Hypotension
- N/V
- Chest pain
- EKG changes/arrhythmias
- SOB
- Myocardial ischemia
- Pulmonary edema
- Death
What is important to remember about pitocin?
It should be dosed slowly due to the side effects
How is pitocin dosed?
IV, slowly
What is the traditional protocol for dosing pitocin?
- 20-40 units in the IV bag after delivery of the baby and placenta
- 20 units in each subsequent liter of IV fluid
What is the ED90 of Pitocin for c-sections?
0.35 units for non-laboring patients
3 units for laboring patients
What is the newer Pitocin dosing protocol?
“The rule of threes”
- Give 3 units over 30 seconds
- If there is no response to Pitocin after 3 doses of 3 units (over 9 minutes), move to another uterotonic
- Give 3 units/hr for maintenance
What happens if your 3 units over 30 seconds of pitocin does not work?
Repeat the dose twice, with 3 minutes between each dose
Why should you move to another uterotonic if Pitocin does not work after 3 doses of 3 units?
It could cause more side effects but not uterine tone
Popular uterotonic if pitocin is ineffective
Hemabate
Dose of
Carboprost (Hemabate)
1 mL IM (250mcg)
When is Carboprost contraindicated?
In asthmatics
When is methylergonovine (Methergine) contraindicated?
Hypertension (preeclampsia)
When is Methergine used?
If Pitocin is ineffective
Dose of Methylergonovine
1 mL IM (200 mcg)
When is Misoprostol (Cytotec) used?
If there is persistent uterine bleeding despite Pitocin, Methergine and Hemabate administration
How is Cytotec administered?
Rectally (200mcg)
Drugs that promote uterine relaxation
Tocolytic drugs
- Magnesium
- Beta 2 agonists (terbutaline)
- Calcium channel blockers (Nicardipine, Nifedipine)
- Volatile agents
- Nitroglycerin
Effects of tocolytic drugs
- Uterine relaxation to prevent labor
2. Promote uterine bleeding
When does Nitroglycerin cause significant drops in blood pressure?
To treat HTN or relieve angina in patients with CAD at smaller doses (<50 mcg)
Why does NTG have less of an effect on blood pressure in pregnant patients?
- OB patients have increased circulating blood volume
2. Vessels are already dilated in well hydrated patients
Doses of NTG for uterine relaxation
250-500 mcg, even up to 1000 mcg
Normal fetal heart rate
120-160 bpm
Bradycardic fetal HR
<120 bpm
Tachycardic fetal HR
> 160 bpm
Why is fetal HR variability considered normal?
It is associated with fetal movement
What can cause absence of variability in a fetal HR?
- Fetal distress
2. General anesthesia
Variability that occurs every heart beat
Short term variability
Variability anywhere from a difference in 6-25 bpm
Long term variability
Common causes of fetal tachycardia
- Lack of nourishing blood supply
2. Resultant effects of some drugs
Drop in fetal heart rate
deceleration
Decrease in HR occurs at the onset of uterine contraction and pretty much returns to baseline by the end of the contraction
Early (Type I) deceleration
The decrease in HR occurs after the onset of the contraction
Late (Type II) decelerations
The decrease in HR is variable in intensity, duration and timing
Variable (Type III) decelerations
Most likely cause of Type I deceleration patterns
Vagal response (compression of the fetal head)
Most likely cause of Type II deceleration pattern
Fetal hypoxia (uteroplacental insufficiency)
Most threatening type of decel
Type II with variability loss
Most likely cause of Type III deceleration patterns
Umbilical cord compression and decompression
Normal respiratory rate for newborns
30-60 breaths/min
Newborn monitoring associated with survival
1 minute Apgar score
Newborn monitoring associated with neurologic outcome
5 minute Apgar score
Normal fetal pH
> 7.25
Amount of fluids that should be given prior to a neuraxial block
1000-1500 mL
Why should dextrose be used with caution during delivery?
It can lead to fetal hypersecretion of insulin and fetal acidosis
Important test to have before delivery
Type and screen
NPO status during delivery
Modest liquids are allowed for uncomplicated labor, with stricter restrictions for higher risk pregnancies
Drugs to avoid before the baby is delivered
- NSAIDs
- Versed
- Narcotics
Why should NSAIDs be avoided during delivery?
They can suppress uterine contractions and promote closure of the ductus arteriosus
Why is versed avoided before the baby is delivered?
It can cross the placenta.. possible post delivery fetal apnea??
-Want the mother to remember
Why are narcotics avoided before the baby is delivered?
Post delivery fetal apnea??
1mcg/kg on induction of GA does not appear to affect Apgar scores
Analgesic options for spontaneous vaginal delivery
- Epidural
- Spinal
- Obstetrician nerve blocks
- IV Nubain (Nalbuphine)
- Nitrous oxide
Most popular analgesic option for spontaneous vaginal delivery
Epidural
When is it acceptable to place an epidural?
- After the pt receives an adequate fluid bolus
- Normal platelet count
- “Adequate cervical dilation?” (may cause prolonged labor??)
Most common local anesthetic for labor epidurals, and why
Marcaine due to motor sparing quality
When is a spinal block an option in OB?
If the patient is going to have a C-section or if the patient is in the late stages of labor and is expected to deliver soon
Dose of marcaine for a spinal block
3-6 mg to prevent significant motor block
Local anesthetic injected into the vaginal submucosa
Paracervical nerve block
When is a paracervical nerve block used?
To relieve 1st stage labor pain
Adverse effect of paracervical nerve blocks
Higher incidence of fetal bradycardia
Transvaginal and perineal infiltration of local anesthetic
Pudendal nerve block
When is a pudendal nerve block used?
To relieve 2nd stage labor pain
What is Nubain?
A narcotic agonist-antagonist that has not appeared to be very effective
What can Nubain be used for other than analgesia?
To treat itching from duramorph
Benefits of nitrous oxide for spontaneous vaginal delivery
The patient starts breathing in the gas at the start of a contraction and breaths it off by the end of it
How should a patient be managed if they are hurting at some point after their epidural was started?
5-8mL local anesthetic bolus to increase block density, preferably with a stronger local anesthetic (≈5mL 2% lidocaine)
How should a patient be managed if they still feel pain on one side after an epidural?
- Have patient lay on side that’s hurting
- Pull the epidural catheter back 1-2 cm, or
- Pull the epidural catheter and start another one
Airway equipment should include:
- Smaller diameter ETT (for edema)
- Short laryngoscope handle (to avoid large breasts)
- LMA and videoscope ready
General outline of a c-section (9)
- Pt arrives in OR
- Antibiotics are administered
- Analgesic method is carried out
- Pt placed in LUD
- Vasopressors are given w/spinals
- Surgery begins, baby is delivered w/in 3 minutes of uterine incision
- Pitocin is given
- Zofran and decadron are administered
- Additional drugs for pain control are given
General outline of a c-section (9)
- Pt arrives in OR
- Antibiotics are administered
- Analgesic method is carried out
- Pt placed in LUD
- Vasopressors are given w/spinals
- Surgery begins, baby is delivered w/in 3 minutes of uterine incision
- Pitocin is given
- Zofran and decadron are administered
- Additional drugs for pain control are given
Most common cause of N/V during a c-section
Hypotension from the spinal block
Prophylactic dose (ED50 and ED90) of a phenylephrine infusion for preventing hypotension during a spinal for a C-section
0.31-0.54 mcg/kg/min
Causes of N/V for normotensive patients
- Dominance of the parasympathetic system
2. Vagal stimulation with the surgeon in the abdomen
Treatment of nausea in the presence of normotension
Robinul
Why is Robinul preferred over atropine to treat nausea?
Atropine crosses the placenta
Why is Robinul preferred over atropine to treat nausea?
Atropine crosses the placenta
What is the first and second question you should ask for a non-emergent C-section?
- Do they have an epidural?
2. Does it work?
What would you like to know prior to an emergent C-section? (other than if they have an epidural and if it works)
How is their airway?
Anesthetic options for a C-section
- Spinal
- Epidural
- CSE-Combined Spinal Epidural
- General anesthesia
Case outline for a c-section under spinal anesthesia (4)
- Perform a spinal with marcaine and duramorph
- Dose pressors as needed and place pt in LUD
- Administer Pitocin after the baby and placenta are delivered
- Give zofran and consider Toradol prior to leaving OR
How long does duramorph (intrathecal) provide analgesia for?
12-24 hours
What is the purpose of intrathecal duramorph?
Postop pain control
What is a total spinal?
A neuraxial block that rises above the cervical region and produces respiratory arrest and unconsciousness
True/false. The patient has a higher chance of staying conscious following a high epidural level when compared to a high spinal level (and why is it true or false?)
True. The epidural space only extends to the foramen magnum
When does “total spinal” happen with an epidural?
After bolus of saline
What are anesthetic options for a non-emergent C-section with mallampati I airway with a patchy spinal block?
- General anesthesia, or
2. Consider using N2O/ketamine to supplement the block
How would you manage a Non-emergent C-section, working epidural in place
Dose to T4 gradually with lidocaine (or chloroprocaine)
How would you manage Emergent C-section, working epidural in place
Dose epidural to T4 immediately with 20mL 3% chloroprocaine and bicarb
How would you manage Non-emergent C-section, “patchy” epidural
- Try to dose the epidural up to T4, or
- Supplement the block with ketamine or nitrous oxide, or
- Pull the epidural catheter and perform the spinal with a reduced dose, or
- Perform general anesthesia with an RSI
How would you manage Emergent C-section, “patchy” epidural
- If the airway looks easy, RSI with general anesthesia
- If the airway looks difficult, can consider trying to dose the epidural to T4 with 3% chloroprocaine and using ketamine and/or N2O to supplement the block (as an alternative to intubating with a videoscope)
How would you manage Working epidural at the start of a C-section; pain 30 minutes into the procedure
5-10mL epidural bolus of lidocaine or chloroprocaine
How would you manage Non-emergent C-section, Mallampati IV airway, “patchy” spinal block
- First try N2O/ketamine to supplement the block, or
2. Consider GA with a videoscope if the ketamine/N2O fails
Spinal was performed, patient is uncomfortable after the baby is out
Give IV fentanyl
High spinal, patient is anxious, but still conscious and breathing
- Reverse Trendelenburg
- Possible assist ventilation (and possible N2O)
- Blood pressure support
- Prepare for intubation
High spinal, patient is unconscious and apneic
- Intubate
2. Resuscitate
Emergent C-section, no epidural, Mallampati I airway
RSI with GETA
Emergent C-section, no epidural, obese and Mallampati IV airway
RSI with videoscope and GETA with LMA as backup
Non-emergent C-section, unable to intubate (even with a videoscope)
Awaken the patient
Emergent C-section, unable to intubate (even with a videoscope)
Place an LMA and hold cricoid pressure until the patient can be intubated
Case outline for a C-section under epidural anesthesia
- Give abx as soon as the patient arrives to the OR
- Raise epidural block up to T4
- Place pt in LUD
- Administer Pitocin after baby and placenta are delivered
- Dose duramorph in the epidural prior to epidural catheter removal
- Give zofran and consider toradol
Duration of duramorph epidurally
18-26 hours
Post-op pain control options for c-sections under epidural
- Duramorph 2-4 mg
- Order an epidural PCA
- Order an IV PCA
Most common method of post op pain control for C-section epidurals
Duramorph
Advantages to C-sections under GA
- Can get started quickly
- No sympathectomy
- Avoid risk of epidural hematoma in pts with low platelet counts or bleeding disorders
Disadvantages to C-sections under GA
- Increased fetal exposure to drugs
- Mother is exposed to airway risk, including aspiration
- Mother is not awake for birth of her child
When should you induce the patient for general anesthesia C-section?
After the patient is prepped, draped and the surgeon is ready
Indications for C-sections under general anesthesia
- Emergencies where there are fetal decels with no block in place and not enough time to do a spinal
- Hypotension and won’t tolerate sympathectomy
- Contraindication to neuraxial or if they request GA
- When a spinal or epidural attempt fails
- If the pt is apneic due to a high spinal
Condition where the placenta covers the cervical os
Placenta previa
Classic symptom of placenta previa
Painless vaginal bleeding
Condition where the placenta detaches from the uterus, leading to massive bleeding
Placental abruption
Condition where the placenta grows through the uterine wall, causing massive bleeding from both organs
Placenta accreta
Agent of choice in non-hemorrhaging, normotensive parturients
Propofol
Agent of choice for induction of internally bleeding or hypotensive parturients
Ketamine
Ketamine dose used to supplement a patchy epidural or spinal block
0.25 mg/kg
Case outline for a C-section under GA
- Give abx as soon as the patient arrives in the OR
- Induce the patient when the surgeon is ready
- Place pt in LUD
- Paralyze the pt if needed
- Administer Pitocin after the baby and placenta are delivered
- Give Zofran, start dosing fentanyl and give reversal
- Place on an IV PCA for postop pain control
True/false. Fasiculations are more intense in pregnancy due to progesterone
False, they are less intense
Option for postop pain control for C-section under general anesthesia
IV PCA only
Options for postop pain control for C-section under spinal
- Intrathecal duramorph
2. IV PCA
Options for postop pain control for C-section under epidural
- Epidural duramorph
- Leave the epidural catheter in postop
- IV PCA
Options for postop pain control for C section under CSE
- Leave the epidural catheter in postop