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Flashcards in ITE OB 3 Deck (53)
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1
Q

Why do pts shiver during labor after an epidural?

A

redistribution of core heat to periphery
- blunting of Autonomic thermoregulatory function

but shivering will occur irrespective of whether neuraxial anesthesia is used or not

2
Q

the P50 of adult hgb is ___mmHg, and the P50 of fetal hgb is ___ mmHg which is Left shifted, greater affinity for O2

A

26 mmHg

19 mmHg

3
Q

Early _______in pregnancy (before 15 weeks) compared to late pregnancy has higher risk of pregnancy loss, rupture of membranes, club foot.

A

amniocentesis

4
Q

In the first stage of labor, maternal oxygen consumption increases by __%, and in the second stage of labor, by __%. This is driven by hyperventilation, pushing of infant, uterine contractility.

A

40,

75%

5
Q

arterial partial pressure of oxygen (PaO2) is increased in pregnancy to ___ mmHg, compared to normal nonpregnant levels at __ mmHg, starting in the first trimester of pregnancy

A

105 mmHg

100mmHg

6
Q

Pregnancy leads to a respiratory (acidosis/alkalosis) with compensatory metabolic (acidosis/alkalosis) . On ABG, this is represented as:

A

respiratory alkalosis

metabolic acidosis

pH slightly increased
decreased PaCO2, serum HCO3, base excess

7
Q

1st and 2nd most common cause of pregnancy related deaths in US

A

CV conditions

Infection

8
Q

Biophysical profile (BPP) includes: (5)

A
  1. Non stress test
  2. fetal breathing
  3. fetal movement
  4. fetal tone
  5. amniotic fluid vol
9
Q

Biophysical profile (BPP) is performed starting at ___ weeks

A

32-34

10
Q

BPP is considered reactive when _ fetal heart rate accelerations of __ beats/min for __ seconds, within a 40 min time period.

A

2 FHR accelerations

15 beats/min
15 seconds

11
Q

Pregnant women with a cord injury above __ spinal level will have an increased risk of preterm labor.

A

T11

12
Q

_____ anesthesia can be safely performed in pregnant pts with severe valvular disorders

A

epidural

- safely titrated

13
Q

In pts with severe mitral stenosis, which peripartum period is the most tenuous?

A

the period directly after delivery

- autotransfusion: blood in uterus is being placed back into maternal circulation

14
Q

Fetal oxygen saturation via fetal pulse oximetry is typically between __% and __%, and (has/has not) been able to predict fetal acidosis.

A

35-65%

has NOT

15
Q

There is a 5x increase incidence of pulmonary thromboembolism, which is multifactorial, but mainly d/t _______

A

caval compression by the gravid uterus

- leading to increased venous stasis -> DVT and PE

16
Q

Amniotic fluid embolisms (inflammatory process) usually present ___ (time) after vaginal delivery

A

8 minutes

17
Q

Fetal weight above ____ grams is an independent predictor of unsuccessful TOLAC

A

4000 g

18
Q

_____, a synthetic prostaglandin E1, unlike carboprost, does NOT carry the risk of bronchoconstriction

A

Misoprostal

19
Q

Asthma is an (relative/absolute) contraindication to carboprost, a synthetic prostaglandin F2-alpha

A

relative

- controlled asthmatics w/ no recent exacerbations can receive it safely

20
Q

If left untreated, umbilical cord prolapse can lead to ___ and ____. It is an indication for emergent C/S.

A

umbilical cord compression and fetal asphyxia

21
Q

Risk factors of umbilical cord prolapse (4)

A
  1. low birth weight
  2. multiparity
  3. multiple gestations
  4. artificial ROM
22
Q

Amniotic fluid embolism is also referred to as _____

A

anaphylactoid syndrome of pregnancy

- amniotic fluid in systemic circulation results in massive inflammatory release and DIC

23
Q

Clotting is broken up into two phases ____ and ___. Platelets are important for both.

A

Primary and secondary hemostasis

24
Q

Primary hemostasis is the formation of ____

A

initial platelet plug

- Unstable

25
Q

Secondary hemostasis is the formation of the ____

A

fibrin clot

- stable

26
Q

Alveolar dead space is reduced during ACTIVE labor secondary to ____

A

significant increase in Cardiac output (40%)

- lungs are well perfused, (and ventilated)

27
Q

Alveolar dead space consists of alveolar units that are _______

A

ventilated but not perfused

- air is inhaled, but does not participate in gas exchange

28
Q

If a pt is at high risk of previous alloimmunization and potential antibody presence, should a type and cross be obtained?

  • Emergent sx?
  • Nonemergent sx?
A

emergent - type + screen sufficient

Nonemergent - type + cross

29
Q

umbilical (artery/vein) is more representative of acid base status of the fetus. Usually have a pCO2 of __ and a PO2 of ___

A

artery

pCO2: 50
PO2: 20

30
Q

umbilical (artery/vein) is more representative of acid base status of placental function. Usually have a pCO2 of __ and a PO2 of ___

A

vein

pCO2: 40
PO2: 30

31
Q

The effects of adrenergic agents in pregnancy (ie. phenylephrine) are (increased/decreased) in pregnancy

A

decreased (blunted)

32
Q

Maternal cardiac output returns to normal after ____ (time)

A

2 weeks

33
Q

Lambert-Eaton syndrome involves _____, which is similar to magnesium toxicity (inhibits calcium ion influx).

A

autoantibodies targeting presynaptic calcium channels to inhibit calcium ion influx, and thus prevents ACh release

34
Q

Pre-eclamptic pt in labor gets _____ IV for seizure prophylaxis. If they get toxic levels, they have (hyper/hypo)reflexia, and (tachycardia/bradycardia)

A

Magnesium.
hyporeflexia
bradycardia

35
Q

Myasthenia gravis involves autoantibodies to _____

A

post-synaptic ACH receptors at the NMJ

36
Q

Pregnancy is a hypercoagulable state d/t increases in mainly ____ and ____

A

factor VII and fibrinogen

37
Q

Subarachnoid hemorrhage during pregnancy should be treated _____

A

the same as nonpregnant females. (mortality 40%)

- only after treatment, should you they continue until term gestation

38
Q

____ repair is seen in pts with vascular defects (pulmonic/tricuspid atresia or ventricular defects such as single ventricle)

A

Fontan repair

39
Q

_____ repair is associated with the highest prevalence of arrhythmias during pregnancy

A

Fontan repair

40
Q

Why is neuraxial anesthesia with meticulous attention to preload the preferred method for C/S in pts with valvular abnormalities compared to GA?

A

Avoids adverse effects of myocardial depressant medications and positive pressure ventilation

41
Q

____ is the largest risk factor when considering the passage of meconium, leading to possible aspiration. This can be prevented by ______

A

Gestational age,

using the earliest gestational age

42
Q

When measuring umbilical cord blood sample, it is important to recall that umbilical arteries are carrying blood (towards/away) from the fetus and that a normal sample will appear _____.

A

Away, venous

43
Q

Umbilical venous blood gas will appear _____, since it is carrying maternal arterial blood (towards/away) from fetus

A

Arterial, towards

44
Q

Uterine blood flow is determined by _______. With ______ being the single most important factor in determination of blood flow.

A

BP divided by uterine vascular resistance

45
Q

Hyperventilation of mom will result on hypocarbia, which results in a (right/left) shift and reduce oxygen delivery to fetus

A

left shift

46
Q

Aortocaval compression by gravid uterus can decrease cardiac output by _%.

A

25%

47
Q

Ephedrine, an indirect sympathomimetic, is generally avoided In pregnant pts as it can increase risk of _____

A

Fetal acidosis

48
Q

Nitrous oxide is usually avoided in obstetric pts d/t inhibition of _____

A

Methionine synthase,

  • involved in folate metabolism and DNA synthesis.
  • inhibition can lead to miscarriage
49
Q

The 1st and 2nd most common cause of non-obstetric surgery is _____ and _____

A
  1. Cholestasis,

2. appendicitis

50
Q

Primary pulmonary Hypertension in pregnancy is ____.

A

Very very bad. High maternal mortality. Pregnancy is discouraged, termination is advised.

51
Q

Nitrous oxide in pts with pulmonary HTN is _____

A

Avoided, as it can increase pulmonary vascular resistance, leading to RHF

52
Q

Anesthetic requirements (MAC) are decreased by up to __% in pregnancy

A

40%

53
Q

Acute CP distress following the evacuation of a molar pregnancy has been attributed to _______ in more than half of cases.
This presents as CP, cough, tachycardia, hypoxemia, diffuse rales, b/l pulmonary infiltrates.

A

Trophoblastic embolization (trophoblastic cells entering venous outflow from uterus during evacuation)