Midterm Flashcards
(145 cards)
Blood volume changes
-increase by 50%
4L to 5.5 L
RBC changes
- RBC volume increases only about 25% which results in a dilutional anemia
- blood flows faster due to lower viscosity
cardiac output changes
increases 40% mostly due to increases in stroke volume and not so much heart rate
vasculature changes
- decreased systemic vascular resistance resulting in systolic decrease 5 points and diastolic decrease 10 points
- gravid uterus can compress vena cava resulting in supine and orthostatic hypotension, varicose veins, edema, and hemorrhoids
heart sound findings
normal to find systolic ejection murmur and S3
regional blood flow changes
-increased flow to kidneys and uterus
respiratory changes
- increase in oxygen consumption and minute ventilation (tidal volume x RR)
- tidal volume increased more than respiratory rate
metabolic acidosis
- increase in minute ventilation exceeds oxygen consumption leading to respiratory alkalosis and hyperoxemia
- leads to metabolic acidosis
- decreased bicarb on labs is normal
dyspnea of pregnancy
- lower CO2 trigger to breathe
- can feel short of breath often which is normal
gastrointestinal changes
changes mediated by progesterone
- increased appetite, food cravings
- increased cholesterol concentration
- increases colon transport time
- decreased gallbladder emptying time
- nausea, decreased swallowing
- decreased gastric and lower esophageal sphincter tone
- bleeding gums
renal changes
- increased urine outflow
- can overwhelm absorption ability
- can find protein in urine
- ureters are dilated due to decreased peristalsis from progesterone and effect of fetal head on ureter
metabolic changes
- increased insulin resistance, serum triglycerides, lipolysis
- increased cortisol
endocrine changes
- pregnant women create ketones in 4-6 hrs versus a normal 2 days and need to eat 300-500 more cal/day (esp. fat/protein)
- increase in aldosterone where lack of can lead to preeclampsia
hematological changes
- platelet numbers stay stable
- clotting factors increase
- iron stores decrease due to increase RBC production
- WBC not reliable indicator of infection if pregnant
weight changes
- frequently weight loss in 1st semester due to N/V
- by 20 wks nearly all have reached or passed baseline weight
- expected gain 1#/wk after 20 weeks
- if not expected weight loss after delivery then retaining fluid somewhere
oxygen transport to fetus
- want large surface area and decreased thickness to increase O2 diffusion across placenta
- hemochorial placenta is most efficient at O2 delivery but has increased blood loss when placenta delivers
placenta versus lungs
- placenta receives 60% CO and lungs receive 100%
- placenta metabolically active and uses 30% O2 delivered, lungs use <5%
- V/Q mismatch in placenta is normal and pathologic in lungs
fetal compensation for O2
- CO enhanced at a rate 10X greater than an adult
- hemoglobin is higher
- blood with higher O2 saturation is shunted to essential vascular beds
fetal hemoglobin
contains a gamma chain that does not allow it to respond to DPG and decrease O2 affinity, therefore fetal hemoglobin has higher O2 affinity
fetal circulation
- placenta acts as small intestine, kidneys, lung
- blood in IVC has 2 different streams with minimal mixing
fetal circulation after birth
- increase in systemic pressure causes foramen ovale to close
- ductus arteriosus becomes the ligamentum arteriosum
- ductus venosus becomes ligamentum venosum
- left umbilical vein becomes ligamentum teres
- umbilical arteries become lateral umbilical ligaments
immunological changes in pregnancy
- can become septic easier
- viral, bacterial, and fungal infections are more severe
goals of prenatal care
- reduce maternal and fetal morbidity/mortality
- reproductive life planning
- promote lifelong health behaviors
individual care model
- 1 patient per 1 MD
- majority of practices