Very high risk of hypoxia in pregnancy due to?
1. Decreased FRC
2. Increased O2 consumption
3. Increased A-a gradient
In maternal respiratory changes the mother may have airway edema which could lead to what?
1.Difficult intubation, high risk of bleeding
−Use smaller size tubes (6-7 mm)
With maternal respiratory changes, what does the mother have increased sensitivity to?
With maternal respiratory changes, what is decreased for the mother?
Increased sensitivity to LA
Decreased MAC for all GA
MAC --> Minimum Alveolar Concentration
Is pregnancy a restrictive or obstructive lung condition?
note FRC decreasing
Note FRC second from bottom.
in order: Vital Capacity
Total lung capacity
non pregnant/Left - FRC 1700
Pregnant at term/ right - FRC 1350
What happens with maternal hematologicall changes during pregnancy? (3 answers)
increased hgb, increased clotting factors, increased GFR
A.Physiological anemia of pregnancy
What happens during pregnancy when Estrogen INCREASES renin activity?
1.Estrogen INCREASES renin activity --> 75% increase in blood volume (dilutional effect)
2.Low crit is good for placental blood flow
−Give iron or folic acid
What happens to the clotting factors during pregnancy?
INCREASED clotting factors (VII, fibrinogen)
1.Hypercoagulable state helps to prevent blood loss during labor
Name all the maternal hematological changes?
Increased clotting factors
Decreased platelet count (10%)
Decreased folate level
Decreased plasma acetylcholine esterase activity (returns to normal 2-4 weeks postpartum)
What happens to renal and GI systems during pregnancy?
A.INCREASED GFR and renal plasma flow
B.DECREASED BUN and creatinine
C.DECREASED renal threshold for glucose and amino acids --> glycosuria and proteinuria
D.DECREASED LES pressure, INCREASED acid and INCREASED intragastric pressure --> reflux (heart burns)
E.INCREASED gastrin secretion
F.Slow gastric emptying
G.Increase risk of aspiration
What to give for slow gastric emptying during pregnancy?
1.Give metochlorpromide (Reglan) to
−INCREASES gastric emptying (move forward)
−Tighten up LES
What happens to maternal endocrine system during pregancy?
A. INCREASES TBG, INCREASES total T3 and T4
B.No change in free T3 and T4
C.Insulin resistance due to placental lactogen
E.INCREASES endorphins at term
What is the 1° site of nutrient and gas exchange between mother and fetus?
What are the two fetal components of the placenta and what are their purposes?
1.Cytotrophoblast − inner layer of chorionic villi. Cyto makes cells
2.Syncytiotrophoblast − outer layer of chorionic villi; secretes HCG (Human Chorionic Gonadotropin)
What is the maternal component of the placenta?
1.Decidua basalis − derived from the endometrium. Maternal blood in lacunae
Uterine blood flow is what during pregnancy?
Uterine blood flow is _______ dependent during pregnancy.
What are causes of decreased perfusion pressure during pregnancy? (7)
A.Causes of decrease perfusion pressure
1.Supine position: aortocaval compression
7.LA in high doses
What drugs can cross placental barrier?
A.Drugs passage across placental barrier
1.Smaller molecular weight, lipid soluble and non-ionized can pass
Uterine Blood Flow
___ BP ___blood flow
___SVR ___blood flow
uterine contraction ___BF
DECREASE BP DECREASED blood flow
INCREASED SVR DECREASED blood flow
uterine contraction DECREASED blood flow
alpha stimulant DECREASED blood flow
Uterine blood flow equation
What is classified as fetal bradycardia?
< 120 bpm
If maternal BP is decreased what will happen to uterine blood flow causing fetal hypoxia and decreased fetal HR?
1.Decrease mom’s BP --> decrease uterine BF --> fetal hypoxia --> decrease fetal HR
When maternal BP is increased with associated increase in SVR, what happens to fetal HR?
1.Increase mom’s BP (with associated increase in SVR) --> decrease fetal HR
Uterine and Placental Blood Flow
Maternal BP is the ONLY factor that influence blood flow through placenta