Obs - hypertensive disorders Flashcards
How does blood pressure change in pregnancy and why?
reduces slightly in 2nd trimester: 30/15mmhg (or 15-20)
because of reduced SVR - systemic vascular resistance
how does protein excretion change in pregnancy?
increases but <0.3g/24h
what point in pregnancy do you see PREGNANCY INDUCED hypertensive disorders arise?
after 20 weeks - so well into 2nd trimester
this means if BP high before then, it was not induced by pregnancy -> Chronic HTN
what is the origin / aetiology of pre-eclampsia?
‘not completely understood’
placental in origin
Stage 1 (development): incomplete trophoblast invasion
reduction in flow of blood in Spiral artery and Uteroplacental circulation
Stage 2 (manifestation):
Ischaemic placenta +
Exaggerated inflammatory response ->
Endothelial cell damage (virchow’s -> clotting) ->
increased vessel permeability (proteinuria + oedema) ->
vasoconstriction (HTN, Eclampsia, Liver damage)
define pre-eclampsia
Pre-eclampsia is a disorder of pregnancy characterized by hypertension (>140/90) & proteinuria (>0.3g/24h)
list risk factors for pre-eclampsia?
nulliparity
previous pre-eclampsia
family hx pre-eclampsia
older mothers
chronic HTN
DM
Kidney disease
Twin pregnancy
what are the types of pre-eclampsia
Mild : 140/90 - 149/99
Moderate: 150/100 - 159/109
Severe - >160/110
how may pre-eclampsia present?
Asymptomatic
Headache, drowsiness, nausea and vomiting
visual disturbances
epigastric pain
what examination would you conduct for pre-eclapmsia?
Bedside:
BP - may not be high
Urine dip - protein (exclude infection with MC&S)
Fundoscopy - disc oedema
Neuro exam - reflex, eye movement
Abdo exam - epigastric tenderness (dic, liver failure, hellp)
Others:
24 hour urine collection
Protein:creatinine ratio >30
complications of pre-eclampsia?
Maternal:
- Eclampsia - grand mal seizures
- > death due to brain vessel spasm + hypoxia
- > placental abruption
- Renal failure
- Pulmonary oedema
- HELLP syndrome (which has complications eg: DIC, abruption, renal failure)
- DIC
- Liver failure
more sever if earlier onset
Fetal:
IUGR, Stillbirth, Preterm delivery
If closer to term, less effect on growth. all gestatoins have equal risk abruption.
what is drug of choice in prophylaxis and treatment of eclampsia
magnesium sulphate - MgSO4
how would pulmonary oedema be managed?
furosemide and oxygen
list some fetal complications of pre-eclampsia? depending on date acquire?
IUGR - main problem if PET <34 wks
causing need for Preterm birth
Placental abruption
if PET around term:
Stillbirth
Placental abruption
what ivx would tell you some1 with pre-eclampsia is deteriorating?
fall in platelets - hellp
Low Hb - haemolysis (low haptoglobin too - haematocrit may be low or normal)
increased ALT - hellp, liver damge
increased LDH - haemolysis, liver damage
increased uric acid - very key feature!
how would you then monitor a baby?
US - fetal growth and weight
CTG
Umbilical artery doppler - key to outline prognosis
how is PET mitigated?
All pregnant women have regular BP and urinalysis checks - come to the DAU
Aspirin 75mg before 16 weeks in at risk women
uterine artery doppler 23 weeks (not routine)
where are PET patients managed? what is regular monitoring?
- Mild AND moderate -> OUTpatient care
Assess DAU
-> No proteinuria and mild/moderate htn are managed as outpatients and BP/urinalysis checked twice (▪ Mild: 1/week – Moderate: 2/week)
weekly, with USS every 2-4 weeks
2. Admission criteria in suspected PET A -> Symptoms B -> Proteinuria 2+ ore more on dipsticks, or >0.3g/24h collection C -> Diastolic BP >160/110mmHg D -> Suspected fetal compromise
Admission is necessary with severe htn and where there is proteinuria
-> New proteinuria of 2+ should be admitted with or without HTN
Severe: manage in specialist unit with neonatal facilities
how is PET managed? aim BP?
think this includes GHTN? review
Antihypertensives are given if BP reaches 150/100mmHg
Mod:
Labetalol
Severe:
1st - Oral Nifedipine
2nd - IV labetalol (usually contraindicated in severe)
+ IV MgSO4 - prevent eclampsia
+ Steroids
aim BP: 140/90
what is the mechanism of MgSO4?
what sx does toxicity cause?
mechanism - increases cerebral perfusion
toxicity - respiratory depression, hypotension
when do we deliver in pregnancy related HTN diseases?
Gestation htn - IOL 40wks
Mild PET - ‘deliver’ 37wks
Mod PET - deliver 34-36wks
Sev PET - deliver 34-36wks - more urgent, soon as steroids completed and BP stabilised
if sev with complications / fetal distress - deliver any gestation
delivery <34 wks - c-section
delivery >34 wks - IOL
when does PET resolve?
within 24 hours post delivery
BP reach highest level 5days post birth
BUT may get worse!
what does postnatal care of PET involve?
monitor closely -
bloods
urine output
BP - give labetalol. need long-term monitoring at GP
refer to renal clinic if persisting
How does pre-existing hypertension present in pregnancy?
BP is already or rises above 140/90 before 20 weeks
may increase more in late pregnancy
may notice clinical signs of the cause: eg renal bruit, radiofemoral delay
proteinuria at booking - if kidney disease
what are the causes of pre-existing hypertension in pregnancy?
Primary - essential HTN - Most common
Secondary - obesity, kidney disease (eg CKD),
- rare; phaeo, cushings, aortic coarctation - heart disease
management of pre-existing hypertension in pregnancy?
1st - labetalol
2nd - nifedipine
Low dose aspirin - mitigate pre-eclampsia risk
deliver by 40 weeks
take them off ACEinhibitors! (remember they would be on these if pre-existing htn)
comlications and prognosis of pre-existing hypertension in pregnancy?
BP may drop in 2nd term
- may not need labetalol at that time
Risk of Pre-eclampsia
What are the side effects of IV mgSO4 use?
how to monitor use?
Toxicity ->
respiratory depression and hypotension
Monitor: respiratory rate, SaO2, deep tendon reflexes (usually lost in TOXICITY)
how to treat resp depression in mgso4 use?
calcium gluconate
what findings on Umbilical artery doppler are worrying and indicate delivery?
Reduced End diastolic flow on UAD
how is gestational HTN treated?
05/2021
Similar to pre-eclampsia
But first line for both Mod/Severe is Oral Labetalol
Same kind of monitoring with wholistic tests and Umbilical artery dopplers
-> they dont have proteinuria - so monitor to ensure it stays this way -> their main risk is developing PET
How do we manage chronic hypertension HTN in pregnancy?
Pre-Pregnancy Advice:
1. Change ACE inhibitors or ARBs or chlorothiazide to:
Labetalol (or nifedipine 2nd line)
(due to increased risk of congenital abnormalities)
o Target BP < 150/100 mm Hg if uncomplicated hypertension
Monitoring: A. ultrasound foetal growth, B. amniotic fluid volume assessment C. 2x umbilical artery Doppler-> 28-30 and 32-34 weeks D. BP and proteinuria Lifestyle advice: Advice keeping dietary salt intake low
Delivery:
If not severe (<160/100): Deliver after 37wks
If severe: steroids, early delivery
