Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Anesthesiology > OB > Flashcards

OB Flashcards

1
Q

What happens to the MAC during pregnancy?

A

MAC ↓40% (b/c sedative effect of progesterone and surge of beta-endorphin during L&D)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What happens to sensitivity to anesthetic during pregnancy?

A

Enhanced sensitive to local anesthetics (dose ↓30%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What causes an increased risk during epidural anesthesia?

A

Obstruction of IVC by enlarging uterus distends epidural venous plexus and ↑risk intravascular injection during epidural anesthesia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What happens to the intravascular volume during pregnancy?

A

intravascular volume increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What happens to the plasma volume during pregnancy?

A

plasma volume increases (by 45%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What happens to the red blood cell production during pregnancy?

A

RBC production increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Increased intravascular volume, and increased plasma volume (45%) during pregnancy cause?

A

Relative anemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What happens to the CO in pregnancy?

A

CO increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What happens to the HR in pregnancy?

A

HR increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens to the SV in pregnancy?

A

SV increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens to the SVR in pregnancy?

A

SVR decreases due to progestrone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens to the MAP in pregnancy?

A

MAP decreases (because SVR decreases)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens to the response to adrenergic agents and vasoconstrictors in pregnancy?

A

response to adrenergic agents and vasoconstrictors is blunted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Aortocaval compression causes:

A

systemic hypotension + ↑uterine venous P + uterine arterial hypoperfusion + hypotensive effect of anesthesia → fetal asphyxia. 28-week or longer gestation should NOT be supine w/o L. uterine displacement. Place a wedge under the right hip to prevent.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens to the lung volume in pregnancy?

A

lung volume decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens to the FRC in pregnancy?

A

FRC decreases 20% (atelectasis when supine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What happens to the minute ventilation in pregnancy?

A

minute ventilation increases 50% because of increased TV by increased progestrone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What happens to the TV in pregnancy?

A

TV increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the compensatory mechanism in response to the change in minute ventilation?

A

Increased minute ventilation causes a compensatory respiratory alkalosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What happens to the PaO2 in pregnancy?

A

PaO2 decreases due to decreased FRC and increased O2 consumption. So you get rapid O2 desaturation during apnea. During 1st minute apnea PaO2 decreas 2.5X faster than non-preg. Thus, preoxygenation MANDATORY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What GI changes during pregnancy?

A

GERD and esophagitis common during pregnancy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is a pregnant woman’s food intake status?

A

Always consider full stomach regardless of NPO status

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Steps in pre-op prep for C-section - for the airway exam consider what?

A

Airway exam: airway edema and large breasts → more difficult intubate

24
Q

Steps in pre-op prep for C-section - for the GI consider what?

A

I. All considered full stomachs
II. Prophylaxis for aspiration: Bicitra (sodium citrate) 30 mL
III. For GERD, not NPO, or morbidly obese: ranitidine(anti H2 on parietal cells in stomach, decreasing gastric acid secretion), metoclopramide (gastroprokinetic)

25
Q

Steps in pre-op prep for C-section - for regional anesthesia consider what?

A

If giving regional anes, prehydrate w/ crystalloid 1000 mL IV, colloid 500 mL to prevent/minimize hypotension due to SNS block

26
Q

Identify reasons why the parturient is at a higher risk for aspiration versus the non-parturient.

A

A. Progesterone causes decreased gastric motility and increased gastric volume
B. Increased acid production, incompetent Lower esophageal sphincter (uterus press up against stomach)
C. All at increased risk of regurgitation thus aspiration. Thus always consider full stomach despite NPO status

27
Q

What type of anesthesia is used for C-section?

A

80-90% C-sec done w/ regional anesthesia (spinal anesthesia, epidural, combo)

28
Q

Advantages of regional anesthesia for C-section?

A

mother maintain own airway and spont. respiration, intact protective airway reflexes which decreases risk aspiration, neonate exposed to fewer drugs, mother awake for birth, option use neuroaxial (spinal or epidural) opioids for postop analgesia, decreases maternal mortality

29
Q

Disadvantages of regional anesthesia for C-section?

A

more time required, not useful in emergent situations, potential for failure then go to general anesthesia, complication in hypovolemic/hypotensive pt., requires T4 sensory level, potential for excessively high neural block causeing sev. hypotension and impaired spont. ventilation, potential for local anesthesia toxicity (epidural) → seizures, potential for post dural puncture headache.

30
Q

When to use general anesthesia in C-section?

A

Only if neonatal emergency or complication with regional (coagulopathy, hemorrhage, infxn near back)

31
Q

Advantages of general anesthesia in C-section?

A

rapid and reliable, control airway and ventilation, once intubated no worry of oversedation, potentially less hypotension

32
Q

Disadvantages of general anesthesia in C-section?

A

risk pulm. aspiration until ETT in place, potential for difficult airway, Rx-induced fetal depression (uncommon), higher maternal mortality

33
Q

What happens to the uterine blood flow during anesthesia?

A

Uterine blood flow is 10% of CO ( 500-700mL/min) and is critical to the fetus. A decreases in 50% causes fetal distress. Uteroplacental blood flow is dependent on maternal BP! (hypotensive mother means drop in unterine blood flow)

34
Q

What drugs affect uteroplacental blood flow?

A

Barbiturates and propofol cause small decrease in uterine BF

35
Q

How is uterine blood flow affected by respiratory gas tensions?

A

Uterine BF not significantly affected by respiratory gas tensions but extreme hypocapnia (PaCO2

36
Q

What do you do for maternal hypotension?

A

Correct maternal hypotension w/ either phenylephrine or ephedrine. Phenylephrine assoc. w/ less fetal acidosis then ephedrine.

37
Q

What causes uterine a. vasoconstriction?

A

Uterine a. vasoconstriction can result from endogenous catecholamine released from stress of labor OR hypertensive disorders of pregnancy. Uterine contractions cause compression of uterine arterial vessels cauing decrease in uterine BF

38
Q

Describe the mechanism of transfer of anesthetic drugs across the placenta.

A

Diffusion primary mechanism, all inhalation agents and most IV anesthetics cross placenta

39
Q

What influences a drugs ability to cross the placenta?

A

Ability to cross placenta influenced mostly by lipid solubility, as well as ionization and molecular weight. Increased solubility increases crossing. High lipid solubility correlations to non-ionized, so increased ionization decreases crossing (↑ionized ↓X), Molecular wt.

40
Q

Effect of opioids on neonate?

A

I. Morphine – more neonate respiratory depression comp. to others
II. Fentanyl – minimal neonatal effects tho crosses placenta
III. Remifentanil potential to produce respiratory depression in newborns

41
Q

Which drugs do NOT cross the placenta?

A

Muscle relaxants – highly ionized so do NOT cross placenta significantly

42
Q

What is “ion trapping”?

A

“ion trapping” – lower fetal pH so more basic drugs (local anesthetics, opioids) cross placenta in non-ionized form and are ionized in fetal circulation

43
Q

Preeclampsia criteria?

A

> 140/90 after wk 20
proteinuria >0.5g/day
edema

44
Q

In preeclamplsia what happens to the intravascular volume and SVR?

A

Incravascular volume decreases, SVR increases and HF symptoms (pulmonary edema) occur

45
Q

Treatment of preeclampsia?

A

delivery of fetus and placenta; symptoms abate w/in 48 hr of delivery (still risk seizures) Control HTN and correct hypovolemia before anesthesia.

46
Q

Anesthesia options for delivery in a case of preeclampsia

A

I. Epidural analgesia is the first choice for labor – check coag status (C/I = coagulopathy), prehydrate (colloid boluses more effective than crystalloid)
II. C-section – epidural (slow onset anes)
III. General anes if emergent – get arterial line, laryngoscopy/intubation can cause extreme ↑BP, use antiHTN (labetalol, hydralazine, SNP), magnesium can potentiate NDMR (thus reduce dose of NDMR)

47
Q

risks associated with anesthetic management of the preeclamptic and eclamptic parturient.

A

Difficult intubation b/c edema of airway, BP control w/ nitroglycerine, lidocaine, esmolol and remifentanyl, effect Mg on m. relaxants

48
Q

Advantages of epidural anesthesia in labor?

A

labor epidural can use for c-section as well, more gradual decrease in BP, epidural catheter allow better control over sensory level

49
Q

Disadvantages of epidural anesthesia in labor?

A

patchy block may require conversion to general anes, quantity of local anesthetic needed is much larger than that for spinal anes, potential for local anes tox

50
Q

Advantages of spinal anesthesia in labor?

A

easier perform, rapid onset, more intense “solid” block, NO risk local anes tox

51
Q

Disadvantages of spinal anesthesia in labor?

A

hypotension and bradycardia which is often rapid in onset

52
Q

Advantages of combo epidural and spinal anesthesia in labor?

A

rapid, reliable neural block + benefic epidural catheter

53
Q

Common pharmacologic properties of Lidocaine and Bupivacaine

A

Local anesthetics that bind and block voltage-gated Na channels from inside the cell and prevent depolarization. Both are Amides and metabolized by P-450 enzymes in the liver

54
Q

Bupivicaine is…

A

Bupivacaine binds more strongly than lidocaine (longer effect, duration 1.5-8 hr)
Has greater cardiotox. Preferred for spinal anesthesia.

55
Q

Lidocaine is…

A

Lidocaine is shorter-acting than bupivacaine (0.75-2 hr), faster onset.
Used for in-dwelling epidural catheter for C-sec.

56
Q

Describe the teratogenicity of anesthetic drugs

A

Human studies inconclusive as to anesthetic teratogenicity – best to minimize exposure.
I. 3rd-8th week = organogenesis, most susceptible to teratogens
II. Benzodiazepans- concern for cleft palate

57
Q

Describe effect of anesthetics on breast feeding

A

IV anesthesia for breast-feeding mothers has minimal effects on neonates – still avoid breast feeding 12-24 hr. after general anesthsia (breast pump and store milk pre-op)

Anesthesiology (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions