Week 12 - Non-OB Surgery in the OB Patient Flashcards Preview

Advanced Principles of Anesthesia > Week 12 - Non-OB Surgery in the OB Patient > Flashcards

Flashcards in Week 12 - Non-OB Surgery in the OB Patient Deck (15)
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1
Q

What are common causes for non-OB surgery in an OB patient?

A
  • Trauma (most common cause of maternal death, highest fetal risk due to placental disruption)
  • Abdominal Surgery
  • Neurosurgery
  • Cardiac Surgery
  • Fetal Surgery
2
Q

What are the maternal and fetal risk factors undergoing anesthesia?

A

Maternal: physiologic changes, anatomical changes, psychological changes

Fetal: teratogenic potential, maintenance of adequate placental blood flow, premature delivery

3
Q

What are the goals/objectives for non-OB anesthesia in an OB patient?

A
  • First and foremost ensure maternal safety
  • Avoid teratogenic drugs
  • Avoid intrauterine asphyxia (deprivation of oxygen) – optimize/maintain utero-placental blood flow and delivery
  • Prevent induction of pre-mature labor (avoid stimulation of the myometrium – tocolytics may be used)
  • Optimize and maintain normal maternal physiological function
4
Q

How is anesthesia pharmacology affected during pregnancy?

A
  • MAC is reduced by 30% under influence of progesterone and endogenous endorphins
  • Decrease in plasma cholinesterase levels by 25% from early pregnancy
  • NDMRs have prolonged duration of action
  • Increased sensitivity to local anesthetics
5
Q

What is teratogenicity?

A

The observation of any significant change in the function or form of a child secondary to maternal treatment

  • depends on dosage, route of administration, and the timing of fetal exposure
  • genetic predisposition may also play a role
6
Q

What trimester is preferred for surgical intervention? Why?

A

Second trimester

-it is the period after much organogenesis has taken place and it minimizes risk for preterm delivery or miscarriage

7
Q

Why should NSAIDs be avoided during pregnancy?

A

First trimester may increase abortion rates

Third trimester can cause closure of the ductus arteriosus which is reliant upon PGE2 to remain patent

8
Q

What is fetal asphyxia and how can it be avoided?

A

Fetus is deprived of oxygen causing unconsciousness or death

Maintaining maternal oxygenation and hemodynamic stability is of utmost importance (avoid: hypoxia, extreme hypercarbia or hypocarbia, hypotension, uterine hypertonia)

*most serious risk to fetus during maternal surgery

9
Q

When is intraop electronic fetal monitoring appropriate?

A
  • The fetus is viable
  • It is physically possible to perform intraop monitoring
  • A health care provider w/ OB surgery privileges is available and willing to intervene during surgery for fetal indications
  • When possible, the woman has given informed consent to emergency c-section
  • The nature of the planned surgery will allow the safe interruption or alteration of the procedure to provide access to perform emergency delivery
10
Q

What is the anesthetic approach for non-OB surgery before 24 weeks?

A
  • Postpone surgery until second trimester
  • Request pre-op assessment by OB
  • Use non particulate antacid preop
  • Monitor and maintain oxygenation, CO2, normotension, and euglycemia
  • Use regional anesthesia for postop pain when appropriate
  • Document fetal heart tones before and after procedure
11
Q

What is the anesthetic approach for non-OB surgery after 24 weeks?

A
  • Postpone surgery until post partum if possible.
  • Obtain OB consultation and discuss use of tocolysis
  • Aspiration prophylaxis of choice (reglan, bicitra, RSI)
  • Maintain uterine displacement
  • Monitor and maintain oxygenation, CO2, normotension and euglycemia
  • Consider use of FHR monitoring intraoperatively (know that most of the meds used for GA surgery will decrease baseline variability – utilize baseline HR)
  • Monitor uterine contraction and FHR post op
  • No outcome differences in GA vs RA (but.. RA can avoid potential effects of anesthetic drugs on fetus/sensitivity in mother)
12
Q

What are general anesthetic considerations in non-OB surgery in an OB patient?

A
  • Be prepared for possible difficult airway
  • Full pre-oxygenation w/ de-nitrogenation
  • Aspiration precautions
  • Decreased MAC requirements
  • Monitor NMB
  • Treat hypotension quickly (fluids, phenylephrine or ephedrine)
  • Extubate fully awake
13
Q

What are regional anesthetic considerations in non-OB surgery in an OB patient?

A
  • Biggest risk is hypotension if using neuraxial blockade (increased risk of higher block due to LA increased sensitivity and reduced capacity of the epidural space due to increased venous pressure)
  • Pre load with IV fluids
  • Treat promptly (or even prophylactically) w/ ephedrine or phenylephrine
  • If peripheral RA, use lowest dosage of LA possible
14
Q

What are laparoscopic considerations in non-OB surgery in an OB patient?

A
  • May need higher peak pressures due to upward displacement of diaphragm
  • Changes trendelenberg or reverse trendelenberg can have significant resp and CV effects
  • Pneumoperitineum pressure should be limited to 15 mmHg
  • Maintain CO2 of 32-35 to decrease risk of resp acidosis
15
Q

In trauma, shock may not be clinically evident until how much maternal blood volume is lost?

A

25-30%

-maternal blood is shunted away from fetus to preserve vital organs