physiological changes Flashcards
Blood plasma
increase due to oestrogen and progesterone resulting in water and salt retention via RAAS activation
RBC change
increase - not completely in proportion to plasma
Maternal anaemia
as a result of not complete proportional increase in RBC production alongside plasma v
blood volume change?
overall increase to prepare for blood loss during delivery
is there a change in the oxygen carrying capacity of the blood
yes - increase
HCT change?
overall decrease as RBC increase is less than PV increase
signs of hypovolaemic shock
tachycardia and hypotension - watch out for DIC
preload
increase
stroke volume
increase
CO
increasE
PVR
decrease to facilitate vasodilation - this results in a decrease in BP in the first trimester
when does BP return to normal aka prepregnancy
second trimester
what causes decrease PVR
oestrogen and progesterone
cause of maternal hypotension in second trimester
baby compressing aorta
coagulatbility unchanged t or f
hypercoagulable due to high levels of oestrogen
aids haemostasis during delivery and minimises PPH
protein S
decreased
protein C and antithrombin III
no change
which clotting factors are increased
ANY THAT WILL IMPROVE HAEMOSTASIS - minus plasminogen - but this should assist in fibrinolysis when needed during delivery
anabolic phase when
first twenty weeks
respiratory rate
increase
peak flow
no change
oxygen conc of arteries
increase
CO2
decrease
tidal volume
the tide is high and I’m holding on (increase) just like their belly
minute volume
increase
vital capacity
unchanged
functional residual capacity
decreased - less functional residual capacity because they got a belly
- happens at the third trimester as the uterus is sitting underneath the diaphragm
progesterone is responsible for which changes in the respiratory system of mothers
stimulates the respiratory centres
increases the sensitivity of chemoreceptors to CO2, leading to a small increase in resp rate
promotes relaxation of the bronchial smooth muscle
2,3-DPG increase of decrease during pregnancy
increase as this will increase oxygen transfer in the periphery
will shift the oxygen dissociation curve to the right favouring unloading of oxygen int he periphery and aiding placental oxygen transfer
GFR
increase
serum creatinine and urea
fall due to increased blood flow resulting in increased filtration and excretion
extra cals needed
in third trim you need an extra 300 cals cause its catabolic
