OB Flashcards
How will you manage a pregnant patient with pseuodotumor cerebri for labor?
IT catheter placement with intermittent bolus
Can draw off CSF if needed
What are the airway considerations for a pregnant patient?
Difficult visualization due to engorgement of the nasopharyngeal vessels + Increased risk of bleeding –> smaller ETT
Large breasts make it hard to DL
FRC is decreased and O2 consumption is increased so faster time to desaturation (also faster denitrogenation)
Higher risk of aspiration due to upward displacement of the stomach and decrease LES tone. –> RSI
What are the CV considerations in pregnancy?
Increased stroke volume and cardiac output
Decreased SVR 2/2 progesterone
Decreased venous return supine from aortocaval compression
Increased plasma volume with dilutional decrease in Hct + fetus stealing oxygen –> increased risk of hypoxia
More dependent on SNS (increased cortisol, decreased beta receptors) –> less responsive to epi and isoproterenol, neo
What are the neuraxial considerations for pregnancy?
MAC is decreased by 40%, don’t need as much local
Increased CBF
Increased permeability of bbb
Engorgement of epidural veins and higher lumbar pressure –> increased spread of spinal or epidural
Enhanced sensitivity to local anesthetic due to decreased volume in the subarachnoid space
More susceptible to hypotension from block because increased SNS and therefore downregulation of beta receptors
What happens to rate of inhalational induction in pregnancy?
Higher CO output
Higher alveolar ventilation
Therefore: faster onset of soluble agents
Also, increased CBF and bbb permeability! Lower MAC requirements
A patient needs to go for crash c-section and is a full stomach, what do you do?
Bicitra
Famotidine in IV
Regina - for promotility and nausea
RSI
What are the considerations for bleeding in a pregnant patient?are they at increased risk?
They are in a procoagulant state due to induction of liver enzymes and increase in factors.
They also have decreased sensitivity to Protein C and S
Increased fibrin and plasmin, decreased antiothrombin III
Dilutional anemia which is protective for blood loss (oxygen carrying capacity)
What puts them at risk for bleeding?
Dilutional TCP and increased destruction of platelets
Higher fibrinolysis due to higher plasmin
What are the changes with NMB?
They have decreased plasma cholinesterase so may be more sensitive to NMBs
What is your airway management for a pregnant patient?
Pre meds for aspiration if time
Sniffing position
LUD and slight reverse T
Ramp
Preoxygenate
RSI with rocuronium (doesn’t cross the placenta), no cricoid since not proven to close esophagus and can obstruct your view
Video laryngoscopy + Bougie –> tube (2 attempts)
If can’t get it, BMV (call for help) and ensure NMB and not laryngospasm
then slide in LMA to ventilate (2 attempts), fail–> cric
If mom and baby are ok - wake the patient and do FO
Mom Ok and baby not? Intubate thru LMA, FO, mask the case
If baby and mom not ok –> cut the neck
Your OB patient codes, what do you do?
Start CPR slightly higher up SUPINE + LUD
Call for help
Get pads on
100% FiO2, secure the airway
Get IV access above the diaphragm
Get ready for c-section
Make sure any internal fetal monitors are removed before defib
You induce the OB patient and secure the airway, are you worried about anesthetic gases for the fetus?
If you keep MAC less than 1 and delivery is within 10 minutes, I am less worried about this
I would use Fentanyl at less than 1 Mcg/kg for induction for minimal fetal effect although this does cross the placenta
Explain the response to an AFE
At first, there is increase in pulmonary pressure and subsequent RV dilation and dysfunction, which in turn decreases CO (hypotension) and increases V/Q mismatch –> decreased oxygen saturation
Catecholamines contribute to HTN and uterine tachy
The heart arrests –> get the heart started back with epi and compressions and then you have pulmonary edema from improvement in RV fun and decrease in PVR. Then you get DIC
What are the anesthetic considerations for an OB patient undoing a surgery during the second trimester?
LUD
Maintain BP
Avoid hyperventilation since this can cause umbilical artery vasoconstriction
Avoid ketamine due to teratogens is and uterine hypertonic (early pregnancy)
FHR monitoring if after 24 weeks of gestation
Have OB on standby for c-section if needed
Treat pain well - stress = Preterm labor
You have a patient with pre-eclampsia in labor, what do you do?
Get labs - coags, LFTs, platelet count, Hct. Type and cross
Start magnesium for neuroprotection
Give betamethasone if baby is less than 34 weeks
Treat HTN with labetalol, hydralazine IV or nifedipine/methyl dopa
Esmolol drip
Nicardipine if severe and refractory
Don’t us nitroprusside - will drop preload and afterload and cyanide cross placenta
What will you do for seizure prophylaxis in PreE.
Bolus of magnesium 4-6 g IV, then drip at 2 g/h for 24 hours PP
Would you do neuraxial anesthesia on a patient with pre-E?
If platelets are above 80, yes because it will improve UPF through vasodilation, help with HTN and pain, avoid airway instrumentation.
You do neuraxial on a pre-E patient, but then the OB notices hemorrhage, what now?
I would induce and intubate with BP goals less than 140/90 with video laryngoscopy
Remember magnesium with prolong NMB because it blocks calcium and increases the sensitivity of the NMJ to acetylcholine
What do you do for difficult airway in a parturient
Awake FO or RSI
What if you can barely ventilate the patient?
Slide in an LMA
Intubate thru this using fiber optic and smaller tube
How would you follow Magnesium levels in a patient?
Serial Neuro checks : level of sedation and decreased DTRs
Mg levels
Renal function
Why do you want to use lower levels of NMB in a patient with pre-E?
Because the magnesium decreases acetylcholine release at the NMJ due to calcium antagonism
What would you do if you had a dysfunctional epidural catheter and a nonemergent c/s?
CSE and decrease the spinal dose by 20-30%
What is the pathophysiology of preeclampsia?
Thought to be due to poor placental perfusion with release of antiangiongenic factors and impaired endothelial function
What is the most important predictor of stroke in a pregnant patient?
SBP > 160
What is the differential diagnosis of headache in the parturient?
PDPH Migraine Preeclampsia Stroke SAH/ICH Meningitis Caffeine withdrawal Sleep deprivation Pneumocephalus Dehydration
What neuraxial techniques can cause exacerbation or multiple sclerosis?
Spinals
High concentration local anesthetic with epidural
Would you place an epidural in a patient with aortic stenosis?
Yes, recognizing that a drop in afterload could lead to coronary ischemia from decreased coronary perfusion.
I would increase preload by giving fluid bolus before epidural placement and have phenylephrine in the line for quick administration.
I would dose the epidural with lower concentrate local anesthetic slowly (aliquots of 3 ml) until desired analgesia to T10.
If a patient has fever and possible chorio, would you place and epidural? Why or why not?
I would to avoid airway instrumentation recognizing that
- Make sure she’s on appropriate antibiotics
- Provide fluid bolus to maintain adequate preload
- Slowly dose epidural for analgesia to T10 to avoid high sympathetic blockade and worsened hypotension with low concentration anesthetic
If the patient is having postpartum hemorrhage with boggy uterus, what would you do?
Make sure patient was getting pitocin, turn down volatile
Ask OB to massage the uterus
Make sure she’s getting 100% oxygen, check other vitals and support as necessary
Establish more access, consider arterial line
Send labs
Consider other uterotonics
What uterotonics agents are available?
Per rectum cytotec 800-100 micrograms
Methylergonovine –> coronary vasoconstriction,
Hemabate –> asthma
Dinoprostone - PGE2 –> decreased SVR
What can be done about continued postpartum hemorrhage to stop bleeding beside uterotonics?
Compression sutures
Ligation of uterine arteries
Uterine balloon
Hysterectomy
How would you assess for spinal hematoma or abscess?
Tenderness at site
Progressive weakness (regressive = residual block)
Sensory/Motor deficit, urinary incontinence, saddle anesthesia
Fever?
Get MRI
Consult neurosurgeon (decompression within 6-12 hours)
How would you prepare for TOLAC?
Counsel patient about risk of uterine rupture
Do delivery in OR and prepare for general anesthesia
Get a type and cross
Ensure adequate IV access
What other pain control options are there besides epidural?
IV narcotics, NSAIDs, Lamaze TENS Paracervical block for first stage Pudendal nerve block + perineal infiltration for second stage
What are the advantages of epidural analgesia?
Superior analgesia
Improved blood flow secondary to reducing circulating catecholamines
Safe option to avoid general
What are the risks for a paracervical block?
Fetal bradycardia
Decreased uteroplacental perfusion
What is the most common cause of postpartum foot drop?
Compression injury of the lumbosacral trunk due to prolong difficult delivery and baby’s head
Evaluate for weakness of ankle inversion/eversion and toe flexion.
If just weak in ankle eversion = peroneal nerve injury
How would you evaluate someone for autonomic neuropathy?
Ask about: Early satiety Prolonged postprandial fullness Bloating Postural hypotension Lack of sweating Painless MI Peripheral neuropathy Dysrhythmia Nocturnal diarrhea N/V Epigastric pain
What are the anesthetic concerns for autonomic neuropathy?
Increased risk of aspiration Increased risk of hypotension High incidence of silent ischemia Risk of hypothermia Impaired ventilatory response Sudden cardiac arrest due to anesthetic
What is terbutaline associated with?
Pulmonary edema
What’s the pathophysiology of tetanus uterine contraction after spinal or epidural placement?
Rapid onset of analgesia results in abrupt decrease in epinephrine because of deceased stimulation of beta receptors in the uterus leading to increased tone and reduced BF –> fetal hypoxia and bradycardia
What’s the differential for fetal bradycardia?
Uterine tachysystole
Nuchal cord
Maternal hypotension: aortocaval compression, neuraxial
Preeclampsia and therefore uteroplacental insufficiency
How would you treat fetal bradycardia in response to uterine tachysystole
Maternal supplemental oxygen LUD Fluid bolus/hypotension treatment D/c pitocin Administer 50-100 Mcg of NTG or 125-150 Mcg of terbutaline
How would you prepare for the delivery of a neonate with thick meconium?
Ensure self inflating bag attached to 100% oxygen
Neonatal oxygen mask, airway equipment (ETTs, emergency meds)
Warmer
Wall suction
Blankets
Don’t need to suction routinely even if not vigorous according to 2015 guidelines
What Apgar score indicate need for immediate resuscitation?
0-3
What is baseline fetal heart rate variability?
Defined as fluctuations in FHR more than 2 cycles per minute
What is the differential for lack of FHR variability?
Fetal hypoxia Congenital abnormalities Sleep cycle CNS depressants: magnesium! Tachy Betamethasone
Which variable decals do we worry about?
Severe prolonged (<60 bpm)
What is Rhesus isosensitization?
It occurs when the blood of an Rh positive baby mixes with the mother’s blood during trauma, delivery, miscarriage, amniocentesis causing the maternal production of IgG antibodies against the Rhesus D antigen
These antibodies can cross the placenta and cause fetal anemia and hydrops
How can you prevent Rhesus isosensitization?
Administer anti-Rh antibodies to the mother within 72 hours of a potentially sensitizing event which destroys fetal Rh + cells before the mother can make antibodies against them
What is Kleihauer-Betke test?
A test to detect and quantify the extent of fetomaternal hemorrhage
What are the ways to monitor a fetus status?
Biophysical profile
Fetal scalp ph
Noninvasive stress testing
What would you do if the FHT go down while you are inducing.
I would optimize the mother’s condition while calling for help-
LUD
give 100% oxygen
Analyze EKG
Auscultate the chest
Ensur IV access and give fluid bolus and vasopressors as indicated
Prepare for surgical airway/attempt intubation depending on her airway exam
How would prepare a patient for omphalocele surgery?
Maintain normothermia
Address respiratory insufficiency
Cover the viscera with sterile, saline-soaked dressings and wrap in plastic to minimize exposure and loss of fluid
Obtain IV access
Replace lose fluids and correct electrolyte/acid-base status
Decompress the stomach
Look for other congenital abnormalities
What is omphalocele?
Abdominal wall defect due to gut failing to return to the abdominal cavity
Associated with bladder exstrophy, cardiac abnormalities, Beckwith-Weidemann, trisomy 21
What are the concerns for nonobstetric surgery in a pregnant patient?
Aspiration, hemorrhage, thromboembolism, difficult airway, damage to uterus, hypercarbic induced fetal acidosis
Fetal asphyxia, IUGR, teratogenicity, neurocognitive defects long term, preterm labor and delivery
When do you want to operate on a pregnant patient if you had to?
Before 23 weeks in order to decrease risk of preterm labor and allow surgical access to abdomen
When do you administer betamethasone?
Between 24-34 weeks
Provides reduced incidence of RDS, IVH, and neonatal death if delivered before 30 weeks
