Physiologic Changes in Pregnancy Flashcards
(25 cards)
How much total gain in plasma volume during pregnancy?
1.1 - 1.6 L
*Systemic vasodilation activates RASS system to hold onto fluid
What is tachycardia in pregnant women?
110-120
How much does cardiac output increase by in the third trimester? How?
30-50%
Increased heart rate
Retaining volume
Why does Creatinine go down?
With increased CO, kidney’s see more fluid, GFR is increased by 50%
How does pregnancy effect the respiratory system?
fetus displaced diaphragm by 5 cm
Decreases expiratory reserve volume
Decreases Function residual capacity
Progesterone- abdominal wall muscles relax, allows rib cage to expand more than usual - increased inspiratory volumes
Total lung capacity remains the same
Tidal volume overall increased
Why do you see slight hydroureter in pregnant women?
Increased progesterone
Decreased smooth muscle transit/ peristalsis
Decreased movement of ureter
= hydroureter
Pregnancy has increased metabolic demands and therefore requires an increased oxygen. How does the body accomplish this?
increased respiratory rate
need increased minute volume (tidal volume x respiratory rate)
Increased oxygen uploading- also means increased CO2 offloading - causes alkalosis
**RESPIRATORY ALKALOSIS**
Why GERD in pregnancy?
Progesterone and relaxin = relax smooth muscle > sphincter is more loose
Anemia definition in First and third trimester?
< 11
Anemia definition in second trimester?
< 10.5
Daily Fe recommendation during pregnancy?
40-200 mg daily elemental Fe
Usually 60 mg elemental Fe
Ferrous Sulfate = 325 mg tablet with 65 mg elemental Fe
What happens to cardiac output in pregnancy?
Increases
CO = HR x SR
(increased HR and increased volume)
What happens to systemic vascular resistance in pregnnacy?
Decreases by 21%
What happens to pulmonary vascular resistance in pregnancy?
Decreases by 34%
What is the usual acid-base status of pregnancy?
Slight respiratory alkalosis
Functional residual capacity in pregnancy
Decreases
FRC = after a regular breath, how much is left over in the lungs + residual volume (what you can’t get out of your lungs)
Think because the diaphram is displaced upward 5 cm (less room for residual air to sit in there), responsible for more shallow breathing
Inspiratory Capacity in Pregnancy
INCREASES
Progesterone and relaxin prevent smooth muscle from contracting (abdominal wall/rib cage) relaxes → inspiratory capacity increases because you can expand chest wall more than you ever could before
Residual Lung Volume in Pregnancy
DECREASES!
Think about the diaphram, it is elevated, less room for resdiual in there!
Tidal Volume in Pregnancy
Tidal Volume = the amount of air that moves in or out of the lungs with each respiratory cycle
TIDAL VOLUME INCREASES
Respiratory rate in pregnancy
Increased respiratory rate
increased minute volume = tidal volume x respiratory rate
tendency towards tachynpea > increased CO2 offloading > respiratory alkalosis
How much does plasma volume increase by in pregnancy?
1.5 L
Pulmonary Changes in Pregnancy - things that decrease
Residual Volume (RV)
Expiratory Reserve Volume (ERV)
Function Residual Capacity (FCR)
Total Lung Capacity (TLC)
Take the RV down to the ER(v) for some TLC because it’s FR(c)ee
Pulmonary Changes in Pregnancy - things that increase
Inspiratory Capacity (IC)
Tidal Volume (TV)
I See (IC) the TV
Pulmonary Changes in Pregnancy - things that DONT change
Vital Capacity (VC)
Inspiratory Reserve Volume (IRV)
