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%