NURS 5450 Exam 2 - OB Anesthesia Study
Guide With Solution
A 31-year-old female with a 24-week gestation presents for an appendectomy.
- How does pregnancy complicate the management of this patient?
- What are the potentially detrimental effects of surgery and anesthesia on the
fetus?
When is the fetus most sensitive to teratogenic influences?
15-56 days???
What would be the ideal anesthetic technique for a 31-year-old female with a
24-week gestation needing an appy?
Are any special monitors indicated perioperatively for a 31-year-old female with a
24-week gestation needing an appy?
Fetal heart montior +/- TOCO
When should elective operations be performed during pregnancy?
NEVER
The cardiovascular changes in pregnant women are characterized by:
- An increase in intravascular fluid volume
- An increase in cardiac output (CO)
- A decrease in systemic vascular resistance (SVR)
At term, plasma volume ↑by ____%
45
,Erythrocyte volume ↑by ____%
20
Disproportionate plasma volume to erythrocyte volume increase results in the
relative _____ of pregnancy
anemia
The increased intravascular volume offsets the _______ ml of EBL associated with
vaginal delivery and the ________ ml of EBL associated with c-section
300-500; 800-1000
The increased intravascular volume in a pregnant woman's blood dilutes the
__________.
plasma protein concentration
What happens to cardiac output during pregnancy?
- 10% increase by the 10th week of gestation
- 40-50% by the third trimester
Why does cardiac output increase during pregnancy?
Result of a 25-30% increase in stroke volume and a 15-25% increase in HR
CO can increase by as much as ___% immediately following delivery.
80
Parturients with _______ (fixed valvular stenosis) at increased risk of increased cardiac
output after delivery.
cardiac disease
CO returns to near pre-pregnant values by ______ postpartum
,2 weeks
What causes the decrease in SVR in pregnant women?
Largely compensatory to offset the effects that would otherwise be seen with the
increases in blood volume and CO
How much does SVR decrease in pregnant women?
Overall SVR is reduced by 20%
Femoral venous pressure ↑due to ___ by the gravid uterus.
vena cava compression
What is the Aortocaval Compression that occurs in pregnancy associated with?
- Associated with the supine position which reduces venous return (preload) due to
vena cava compression by the gravid uterus
What causes the lower extremity venous stasis (ankle edema, hemorrhoids and
varicose veins) in pregnancy?
Aortocaval Compression
What is the acute presentation of aortocaval compression?
Diaphoresis, N & V, changes in cerebration (Supine Hypotension Syndrome), fetal
distress
Aortocaval Compression is ________ .
Potentially worsened by regional anesthetics (sympathectomy)
Aortocaval Compression
What are the pregnant woman's compensatory mechanisms for
aortocaval compression?
, - The increased IVC pressure below the gravid uterus results in diversion of a large
portion of the venous return to the paravertebral venous plexuses →azygous vein
→SVC thereby maintaining preload (regional anesthesia implications)
- Reflex peripheral SNS response which increases SVR and sustains B/P
Regional Implications of IVC Compression (image)
What is the symptomatic management of aortocaval compression?
- Left uterine displacement a.k.a. lateral tilt
- Oxygen
- Hydration
- Pressor agents as needed
Left uterine displacement a.k.a. lateral tilt (image)
What upper airway changes occur during pregnancy?
- Capillary engorgement of the upper airway
- Edematous vocal cords and arytenoids
- Weight gain +/-pre-existing obesity +/-short neck and large breasts
- CAREFUL instrumentation of airway (laryngoscopy, suctioning, oral (nasal) airway
placement)
- Smaller ETT tubes
What happens to minute ventilation during pregnancy?
- 50% overall increase (40% ↑in VT; 15% ↑RR)
- Mediated by ↑progesterone
- Resting PaCO2 ↓to 32 mm Hg from 40 mm Hg
Guide With Solution
A 31-year-old female with a 24-week gestation presents for an appendectomy.
- How does pregnancy complicate the management of this patient?
- What are the potentially detrimental effects of surgery and anesthesia on the
fetus?
When is the fetus most sensitive to teratogenic influences?
15-56 days???
What would be the ideal anesthetic technique for a 31-year-old female with a
24-week gestation needing an appy?
Are any special monitors indicated perioperatively for a 31-year-old female with a
24-week gestation needing an appy?
Fetal heart montior +/- TOCO
When should elective operations be performed during pregnancy?
NEVER
The cardiovascular changes in pregnant women are characterized by:
- An increase in intravascular fluid volume
- An increase in cardiac output (CO)
- A decrease in systemic vascular resistance (SVR)
At term, plasma volume ↑by ____%
45
,Erythrocyte volume ↑by ____%
20
Disproportionate plasma volume to erythrocyte volume increase results in the
relative _____ of pregnancy
anemia
The increased intravascular volume offsets the _______ ml of EBL associated with
vaginal delivery and the ________ ml of EBL associated with c-section
300-500; 800-1000
The increased intravascular volume in a pregnant woman's blood dilutes the
__________.
plasma protein concentration
What happens to cardiac output during pregnancy?
- 10% increase by the 10th week of gestation
- 40-50% by the third trimester
Why does cardiac output increase during pregnancy?
Result of a 25-30% increase in stroke volume and a 15-25% increase in HR
CO can increase by as much as ___% immediately following delivery.
80
Parturients with _______ (fixed valvular stenosis) at increased risk of increased cardiac
output after delivery.
cardiac disease
CO returns to near pre-pregnant values by ______ postpartum
,2 weeks
What causes the decrease in SVR in pregnant women?
Largely compensatory to offset the effects that would otherwise be seen with the
increases in blood volume and CO
How much does SVR decrease in pregnant women?
Overall SVR is reduced by 20%
Femoral venous pressure ↑due to ___ by the gravid uterus.
vena cava compression
What is the Aortocaval Compression that occurs in pregnancy associated with?
- Associated with the supine position which reduces venous return (preload) due to
vena cava compression by the gravid uterus
What causes the lower extremity venous stasis (ankle edema, hemorrhoids and
varicose veins) in pregnancy?
Aortocaval Compression
What is the acute presentation of aortocaval compression?
Diaphoresis, N & V, changes in cerebration (Supine Hypotension Syndrome), fetal
distress
Aortocaval Compression is ________ .
Potentially worsened by regional anesthetics (sympathectomy)
Aortocaval Compression
What are the pregnant woman's compensatory mechanisms for
aortocaval compression?
, - The increased IVC pressure below the gravid uterus results in diversion of a large
portion of the venous return to the paravertebral venous plexuses →azygous vein
→SVC thereby maintaining preload (regional anesthesia implications)
- Reflex peripheral SNS response which increases SVR and sustains B/P
Regional Implications of IVC Compression (image)
What is the symptomatic management of aortocaval compression?
- Left uterine displacement a.k.a. lateral tilt
- Oxygen
- Hydration
- Pressor agents as needed
Left uterine displacement a.k.a. lateral tilt (image)
What upper airway changes occur during pregnancy?
- Capillary engorgement of the upper airway
- Edematous vocal cords and arytenoids
- Weight gain +/-pre-existing obesity +/-short neck and large breasts
- CAREFUL instrumentation of airway (laryngoscopy, suctioning, oral (nasal) airway
placement)
- Smaller ETT tubes
What happens to minute ventilation during pregnancy?
- 50% overall increase (40% ↑in VT; 15% ↑RR)
- Mediated by ↑progesterone
- Resting PaCO2 ↓to 32 mm Hg from 40 mm Hg
