Hypertension in pregnancy Flashcards
blood pressure is proportional t systemic vascular resistance and cardiac output
blood pressure falls in second trimester
when is nadir reached?
22-24 weeks
after nadir, what happens?
steady rise until term
after delivery what happens to blood pressure?
falls but then subsequently rises and peaks around day 3/4
hypertension. what does bp have to be over on 2 occasions?
140/90
DBP >110
or >30/15 compared to booking visit
what 2 factors makes HTN likey to be pre exising?
if its before 20 weeks gestation, or BP has not returned to normal within 3 months of delivery
pregnancy induced hypertension, how long does it take to resolve
6 weeks
15% of gestational hypertension go on to ?
pre eclampsia
3 things in pre eclampsia?
hypertension, proteinuria (>0.3g/l), oedema. lack of oedema doesn’t exclude diagnosis
pre eclampsia risk factors?
1st child, obesity, history, diabetes, obesity, kidney disease
buz diffuse vascular endothelial dysfunction
pathogenesis - abnormal formation of placenta and trophoblast invasion. failure of vascular remodelling
2 stages of pre eclampsia?
stage 1 - abnormal placental perfusion
2 - maternal syndrome
pre eclampsia is a multi system disorder** it affects…
CNS, renal, hepatic, haematological, cardio, placental
symptoms of pre eclampsia?
headache, visual disturbance, epigastric RUQ pain, nausea, vomiting, rapidly progressive oedema
3 main signs?
hypertension, proteinuria, oedema
risk factors?
family history, history, obesity, first child, over 40, obese, diabetes,CKD, connective tissue disease, thrombophilia
when to admit?
BP>170/110 or >140/190 with proteinuria
significant symptoms - headache visual disturbance, abdominal pain
abnoral biochemistry
proteinuria (jd)
need for antihypertensive therapy (gr)
signs of fetal compromise
Inpatient assessment - blood pressure 4 hourly, urinalysis,, input/output, UPCR, bloods - minimum 2 per week
with an MAP of over 150, there is a significant risk of cerebral haemorrhage
y
how do you calculate MAP?
2d + s / 3
control of blood pressure DOES NOT reduce the risk of pre eclampsia
.
what class of drug is nifedipine?
calcium channel blocker
labetalol?
alpha and beta blocker
who can you not give labetalol to?
asthmatic patients
methyl dopa - what class of drug?
alpha agonist
who can you not give metal dopa to?
patients with depression
hydralazine?
vasoconstrictor
what do steroids promote?
fetal lung surfactant production
steroids reduce RDS by 50% if administered 24-48 hours before delivery
can administer up to 36 weeks
what steroid would you use?
betamethasone
tonic clonic seizure occurring with features of pre eclampsia?
eclampsia
who is eclampsia more common in?
teenagers
management?
control blood pressure, stop seizures, fluid balance, delivery
what do you use to control blood pressure?
IV LOL HI IV labetalol, hydralazine
prophylaxis/seizure treatment?
magnesium sulphate
if persistent consider?
diazapam
main cause of death from pre eclampsia?
pulmonary oedema
what is used to prevent seizures in women with pre eclampsia?
magnesium sulphate
what does aspirin inhibit?
COX
what pathway is COX involved in?
production of TXA2
when would you commence aspirin treatment in a high risk patient?
before 12 weeks
placental ischaemia leads to widespread endothelial damage and dysfunction
.
what happens to spiral arteries?
fail to adapt to become high capacitance, low resistance vesslels.
lack of blood to placenta leads to
oxidative stress. PGI2:TXA2 imbalance.
get endothelial activation. increased permeability, expression CAM, prothrombotic factors, platelet aggregation, vasoconstriction
.
