ACROSS THE LIFESPAN EXAM WITH QUESTIONS AND
EXPERT VALIDATED ANSWERS 2023
1. How does pregnancy affect minute ventilation?: Progesterone is a respiratory
stimulant, it increases minute ventilation by up to 50%
-Vt increases by 40%
-RR increases by 10%
2. How does pregnancy affect the mother's ABG?: Progesterone = RR stimulant
- it ‘ minute ventilation up to 50% (tv > RR rate)
’ mom's PaCO2 falls = respiratory alkalosis
Renal compensation eliminates bicarb to normalize blood pH
A small “ in physiologic shunt explains the mild ‘ in PaO2
WHICH then ‘s the driving pressure of O2 across placenta = IMPROVES fetal gas
exchange
Arterial pH = no change (or slight ‘)
-PaO2 = ‘ (104-108)- d/t HYPERVENT & slight “ in physiologic shunt
-PaCO2 = “ (28-32) -HCO3
= “ (20)
3. How does pregnancy affect the oxyhemoglobin dissociation curve?: Right shift (‘
P50) ’ facilitates O2 unloading to the fetus
4. How does pregnancy affect the lung volumes + capacities?: “ FRC 2/2 “ ERV + RV
‘ O2 consumption + “ FRC hastens onset of hypoxemia.
Failure to reverse hypoxemia ’ brain death of the mother + fetus
5. How does CO change during pregnancy + delivery?: Compared to pre-labor:
1st stage labor: CO ‘ 20%
2nd stage labor: CO ‘ 50%
3rd stage labor: CO ‘ 80%
-returns to pre-labor values in 24-48 hrs
-returns to pre-preg values in ~2 wks
,-twins cause CO to ‘ 20% above a single fetus pregnancy
6. How do BP + SVR change during pregnancy?: ‘ BV + “ SVR = net effect on MAP
Progesterone causes ‘ NO ’ vasodilation + “ response to angiotensin + NE
7. Who is at risk for aortocaval compression? How do you treat it?: Pregnant women
In supine, a gravid uterus compresses both the vena cava + the aorta. This “ venous return
arterial flow to the uterus + LE. “ CO compromises fetal perfusion + cause the mother to los
consciousness. Tx: LUD: elevate mother's right torso 15º
8. How does the intravascular fluid volume change during pregnancy?: ‘ 35%
-plasma volume ‘ 45%
-Erythrocyte volume ‘ 20%
9. What hematologic changes accompany pregnancy?: ‘ clotting factors: 1, 7, 8, 9, 10,
12
Anticoagulants:
-Protein S “
-no ³ Protein C
‘ fibrin breakdown
“ 11 + 13 antifibrinolytic system
10. How does MAC ³ during pregnancy?: “ by 30-40% probably 2/2 ‘ progesterone
11. How does pregnancy affect gastric pH + volume?: ‘ V + “ pH 2/2 ‘ gastrin
12. How does pregnancy affect gastric emptying?: Before onset of labor: no change
After onset of labor: slowed
13. How does pregnancy affect uterine BF?: Non-pregnant: 100mL/min
Term: up to 700mL/min or 10% CO
-some texts say up to 800-900 mL/min
14. What conditions can reduce UBF: Uterine BF is NOT auto regulated. Therefore, it is
dependent on MAP, CO, + uterine vascular resistance
1. “ perfusion: maternal hypoTN
-sympathectomy
-hemorrhage
-aortocaval compression
2. ‘ resistance
-uterine contraction
-HTN conditions that ‘ UVR
15. Uterine BF equation: UBF = (uterine a. P - uterine v. P) / uterine vascular resistance
,16. Discuss the use of phenylephrine + ephedrine in the laboring patient.: Classic: neo
‘ UVR + “ placental perfusion
More recent: Neo is as efficacious as ephedrine in maintaining placental perfusion + fetal
pH in healthy mothers.
-mothers who received neo had higher fetal pH (less fetal acidosis)
17. Which law determines which drugs will pass through the placenta?: Fick's
principle
Characteristics that factor transfer:
-Low molecular weight
-High lipid solubility
-Nonionized
-Nonpolar
18. Fick's equation: Rate of diffusion =
(Diffusion coefficient x SA x [ ] gradient b/t mom/fetus) / membrane thickness
19. Define the 3 stages of labor.: Stage 1: Beginning of regular contractions to full
cervical dilation (10 cm)
Stage 2: Full cervical dilation to delivery of the fetus
Stage 3: Delivery of the placenta
20. How does uncontrolled labor pain affect the mother and fetus?: 1. ‘ maternal
catecholamines ’ HTN ’ “ UBF
2. Maternal hyperventilation ’ L shift of oxyhgb curve ’ “ deliver of O2 to fetus
21. Compare + contrast the pain that results from the first + second
stage of labor.: First stage:
-Pain begins in the lower uterine segment + cervix -T10-L1 posterior n
roots Second stage:
-Adds pain impulses from vagina, perineum, + pelvic floor
-S2-S4 posterior n roots
22. Compare + contrast the regional anesthetic techniques that can
be used for 1st + 2nd stage labor pain.: Neuraxial techniques
T10-L1 level for stage 1
Extend to S2-S4 for stage 2
23. Describe the "needle through the needle" technique for CSE.: Epidural space ID
w/epidural needle
Spinal needle is placed through epidural needle.
LA is injected into the intrathecal space
Epidural catheter is threaded through the epidural needle
, 24. Compare + contrast bupivicaine + ropivicaine for labor: Both long duration
amides Bupi:
-racemic mixture
-minimal tachyphylaxis
-low placental transfer
-‘ sensory blockade
-‘ cv tax w/R-enantiomer
-cv tox before seizures
-0.75% CI via epidural 2/2 risk of toxicity w/IV injection Ropiv:
-S-enantiomer of bupi + sub of propyl group
-“ risk cv tox v bupi
-“ potency v bupi
-“ motor block v bupi
25. Discuss the use of 2-chloroprocaine for labor.: -Useful for emergency C/S when
epidural is already in place (very fast onset)
-Metabolized by pseudocholinesterase in the plasma - minimal placental transfer
-Antagonizes opioid receptors (mu & kappa) and “ the efficacy of epidural morphine
-Risk of arachnoiditis when used for spinal 2/2 preservatives
-Solutions w/o methylparaben + metabisulfite do not cause neurotoxicity
26. Discuss the consequences of an epidural that is placed in the subdural space.:
w/in 10-25 min after the epidural is dosed, the pt will experience symptoms of an
excessive cephalad spread of LA.
Subdural space is a potential space that holds a very low volume.
27. What is the treatment for a total spinal?: May result from:
-epidural dose injected into the subarachnoid space
-epidural dose injected into the subdural space
-a single shot spinal after a failed epidural Treatment:
-vasopressors
-IVF
-LUD
-Elevate the legs
-intubation if LOC
28. Discuss the fetal heart rate: Surrogate measure of overall fetal wellbeing.
Provides indirect method to assess fetal hypoxia + acidosis
EXPERT VALIDATED ANSWERS 2023
1. How does pregnancy affect minute ventilation?: Progesterone is a respiratory
stimulant, it increases minute ventilation by up to 50%
-Vt increases by 40%
-RR increases by 10%
2. How does pregnancy affect the mother's ABG?: Progesterone = RR stimulant
- it ‘ minute ventilation up to 50% (tv > RR rate)
’ mom's PaCO2 falls = respiratory alkalosis
Renal compensation eliminates bicarb to normalize blood pH
A small “ in physiologic shunt explains the mild ‘ in PaO2
WHICH then ‘s the driving pressure of O2 across placenta = IMPROVES fetal gas
exchange
Arterial pH = no change (or slight ‘)
-PaO2 = ‘ (104-108)- d/t HYPERVENT & slight “ in physiologic shunt
-PaCO2 = “ (28-32) -HCO3
= “ (20)
3. How does pregnancy affect the oxyhemoglobin dissociation curve?: Right shift (‘
P50) ’ facilitates O2 unloading to the fetus
4. How does pregnancy affect the lung volumes + capacities?: “ FRC 2/2 “ ERV + RV
‘ O2 consumption + “ FRC hastens onset of hypoxemia.
Failure to reverse hypoxemia ’ brain death of the mother + fetus
5. How does CO change during pregnancy + delivery?: Compared to pre-labor:
1st stage labor: CO ‘ 20%
2nd stage labor: CO ‘ 50%
3rd stage labor: CO ‘ 80%
-returns to pre-labor values in 24-48 hrs
-returns to pre-preg values in ~2 wks
,-twins cause CO to ‘ 20% above a single fetus pregnancy
6. How do BP + SVR change during pregnancy?: ‘ BV + “ SVR = net effect on MAP
Progesterone causes ‘ NO ’ vasodilation + “ response to angiotensin + NE
7. Who is at risk for aortocaval compression? How do you treat it?: Pregnant women
In supine, a gravid uterus compresses both the vena cava + the aorta. This “ venous return
arterial flow to the uterus + LE. “ CO compromises fetal perfusion + cause the mother to los
consciousness. Tx: LUD: elevate mother's right torso 15º
8. How does the intravascular fluid volume change during pregnancy?: ‘ 35%
-plasma volume ‘ 45%
-Erythrocyte volume ‘ 20%
9. What hematologic changes accompany pregnancy?: ‘ clotting factors: 1, 7, 8, 9, 10,
12
Anticoagulants:
-Protein S “
-no ³ Protein C
‘ fibrin breakdown
“ 11 + 13 antifibrinolytic system
10. How does MAC ³ during pregnancy?: “ by 30-40% probably 2/2 ‘ progesterone
11. How does pregnancy affect gastric pH + volume?: ‘ V + “ pH 2/2 ‘ gastrin
12. How does pregnancy affect gastric emptying?: Before onset of labor: no change
After onset of labor: slowed
13. How does pregnancy affect uterine BF?: Non-pregnant: 100mL/min
Term: up to 700mL/min or 10% CO
-some texts say up to 800-900 mL/min
14. What conditions can reduce UBF: Uterine BF is NOT auto regulated. Therefore, it is
dependent on MAP, CO, + uterine vascular resistance
1. “ perfusion: maternal hypoTN
-sympathectomy
-hemorrhage
-aortocaval compression
2. ‘ resistance
-uterine contraction
-HTN conditions that ‘ UVR
15. Uterine BF equation: UBF = (uterine a. P - uterine v. P) / uterine vascular resistance
,16. Discuss the use of phenylephrine + ephedrine in the laboring patient.: Classic: neo
‘ UVR + “ placental perfusion
More recent: Neo is as efficacious as ephedrine in maintaining placental perfusion + fetal
pH in healthy mothers.
-mothers who received neo had higher fetal pH (less fetal acidosis)
17. Which law determines which drugs will pass through the placenta?: Fick's
principle
Characteristics that factor transfer:
-Low molecular weight
-High lipid solubility
-Nonionized
-Nonpolar
18. Fick's equation: Rate of diffusion =
(Diffusion coefficient x SA x [ ] gradient b/t mom/fetus) / membrane thickness
19. Define the 3 stages of labor.: Stage 1: Beginning of regular contractions to full
cervical dilation (10 cm)
Stage 2: Full cervical dilation to delivery of the fetus
Stage 3: Delivery of the placenta
20. How does uncontrolled labor pain affect the mother and fetus?: 1. ‘ maternal
catecholamines ’ HTN ’ “ UBF
2. Maternal hyperventilation ’ L shift of oxyhgb curve ’ “ deliver of O2 to fetus
21. Compare + contrast the pain that results from the first + second
stage of labor.: First stage:
-Pain begins in the lower uterine segment + cervix -T10-L1 posterior n
roots Second stage:
-Adds pain impulses from vagina, perineum, + pelvic floor
-S2-S4 posterior n roots
22. Compare + contrast the regional anesthetic techniques that can
be used for 1st + 2nd stage labor pain.: Neuraxial techniques
T10-L1 level for stage 1
Extend to S2-S4 for stage 2
23. Describe the "needle through the needle" technique for CSE.: Epidural space ID
w/epidural needle
Spinal needle is placed through epidural needle.
LA is injected into the intrathecal space
Epidural catheter is threaded through the epidural needle
, 24. Compare + contrast bupivicaine + ropivicaine for labor: Both long duration
amides Bupi:
-racemic mixture
-minimal tachyphylaxis
-low placental transfer
-‘ sensory blockade
-‘ cv tax w/R-enantiomer
-cv tox before seizures
-0.75% CI via epidural 2/2 risk of toxicity w/IV injection Ropiv:
-S-enantiomer of bupi + sub of propyl group
-“ risk cv tox v bupi
-“ potency v bupi
-“ motor block v bupi
25. Discuss the use of 2-chloroprocaine for labor.: -Useful for emergency C/S when
epidural is already in place (very fast onset)
-Metabolized by pseudocholinesterase in the plasma - minimal placental transfer
-Antagonizes opioid receptors (mu & kappa) and “ the efficacy of epidural morphine
-Risk of arachnoiditis when used for spinal 2/2 preservatives
-Solutions w/o methylparaben + metabisulfite do not cause neurotoxicity
26. Discuss the consequences of an epidural that is placed in the subdural space.:
w/in 10-25 min after the epidural is dosed, the pt will experience symptoms of an
excessive cephalad spread of LA.
Subdural space is a potential space that holds a very low volume.
27. What is the treatment for a total spinal?: May result from:
-epidural dose injected into the subarachnoid space
-epidural dose injected into the subdural space
-a single shot spinal after a failed epidural Treatment:
-vasopressors
-IVF
-LUD
-Elevate the legs
-intubation if LOC
28. Discuss the fetal heart rate: Surrogate measure of overall fetal wellbeing.
Provides indirect method to assess fetal hypoxia + acidosis
