Hypertensive disorders Flashcards
What are the classifications of hypertension severity?
Mild: 140-149, 90-99
Moderate: 150-159, 100-109
Severe: >160, >110
What are the three causes of hypertension in pregnancy?
Non proteinuric pregnancy induced HTN
Chronic HTN
Pre Eclampsia
Explain Non proteinuric pregnancy induced HTN
HTN rising for the first time in the second half of pregnancy in the absence of proteinuria
NO adverse pregnancy outcomes
What is the risk of Non proteinuric pregnancy induced HTN
That it goes on to become pre eclampsia (in 1/3)
What is pre eclampsia?
Hypertension of min 140/90 on 2 separate readings min 4h apart
+
Proteinuria of min 300mg protein in 24h collection of urine
Arising de novo after 20 wk gestation and resolving spontaneously within 6wk postpartum
What are RF for pre eclampsia?
First pregnancy or >10 yrs since baby Prior pre eclampsia FH pre eclampsia Age >40 BMI >35 Booking diastolic > 80 Multiple pregnancy
Why does pre - eclampsia occur?
Development of abnormal placenta
- Thromboblast invasion is patchy and poor
- Spiral arteries retain muscular walls
- This means placenta is POORLY PERFUSED > ischaemia
Uteroplacental ischaemia causes oxidative and inflammatory stress
This causes endothelial dysfunction, vasospasm, activation of coagulation system
Maternal body responds to poorly infused placenta by raising BP
What occurs to the CV system in PET?
Marked peripheral vasoconstriction > increase TPR (opposite of what should happen in pregnancy) > HTN
HTN+ loss of endothelial integrity causes OEDEMA
What occurs in the renal system in PET?
glomeriloendotheliosis
= impaired glomerular filtration, selective protein loss
Reduction in plasma oncotic pressur, exacerbate oedema
What occurs to the haem system in PET?
Diffuse vascular damage = laying down fibrin, platelet adherence
What occurs to the liver in PET?
Endothelial cell injury causes thrombi formation in microvasc
This causes reduced BF to liver
Liver injury
Liver enzymes released
Stretched liver capssule
What is HELLP?
Haemolyis
Elevated Liver enzymes
Low Platlets
Severe form of pre eclampsia
High total loss rate
What occurs to the Neuro system in pre eclampsia?
Vasospasm + cerebral oedema = seizures
Cerebral irritation = Clonus, hyperreflexia
What is eclampsia?
Presence of tonic clonic seizures in a woman with pre eclampsia in absence of other identifiable causes
What is the clinical presentation of pre eclampsia?
Headache (frontal)
Vision changes (blurring, scotoma due to decreased retinal blood flow)
Oedema - face and hands, widespread (due to endothelial injury + HTN)
Epigastric pain (reduced blood flow to liver > liver injury > liver enzymes released)
Malaise
What are signs of pre eclampsia ?
HTN
Epigastric teenderness
Hyperreflexia, clonus
Oliguria, proteinuria
What are complications of pre eclampsia?
Haemorrhagic stroke
Placental abruption
IUGR
What are maternal Ix for pre eclampsia?
FBC (low platelet count, high Htc)
Clotting
Renal profile
Liver profile
Repeat proteinuria quantification
What are foetal Ix in pre eclampsia?
Abdo USS (foetal size, amniotic flayed volume, doppler) CTG (foetal distress)
What is the cure of pre eclampsia=
ENDING the pregnancy by delivering the baabyby
How do you manage PET?
LABETALOL PO if >150/100 (or nifedipine/methyldopa)
What kind of medication is labetalol?
Alpha blocker
What drug is given for eclampsia?
IV magnesium sulphate - neuroprotector
Causes cerebral vasodilation > reduces ischaemia generated by cerebral vasospasm
What medication is given to prevent PET in high risk women?
ASPIRIN 75mg daily
What is other management you must consider in women in pre eclampsia (given the other things she is at risk of?
- Premature delivery > IM corticosteroids
- VTE > Clexane (LMWH) + stockings
- epidural if labour (helps control BP)
What are indications of administration of IV magnesium sulphate?
- Severe HTN + proteinuria
- Eclamptic fit
- Any Symptoms (headache, visual disturbance, epigastric pain, liver tenderness)
What agents do you offer in chronic (NON PET) HTN?=
Labetalol (alpha blocker)
Nifedipine
Methydopa
When do you treat chronic HTN?
If HTN > 150/100
What is foetal growth restriction?
Failure of a foetus to achieve full genetic growth potential
When is a baby considered small for gestational age (SGA)?
Baby below the 10th centile
How can we categorise causes for SGA?
Reduced foetal growth potential
Reduced foetal growth support
What are causes of Reduced foetal growth potential
\
Aneuploiody Single gene defect Structural abnormality (e.g. renal genesis) Intrauterine infection Foetal infection
What are causes of reduced foetal growth support?
DECREASED BLOOD TO BABY
- Reduced uteroplacental perfusion (poorly implanted, sickle cell)
- Reduced foetoplacental perfusion (single umbilical artery, twin to twin transfusion)
What do we also call Reduced foetal growth potential ?
Symmetrical
What do we also cause reduced foetal growth support, and why?
Asymmetrical
Because of reduced blood flow to foetus due to uteroplacental insufficiency
This means more oxygenated blood from umbilical vein travels through ductus venous and liver gets little blood
This produces an ASYMMETRICAL foetus with brain sparing but reduced abdominal girth
What does chronic foetal hypoxia present as on foetal blood test?
FOETAL ACIDOSIS (resp + metabolic)
How do you detect and monitor SGA?
- Accurate assessment of foetal gestation
- Recognition of foetal smallness (on growth chart, from CRL, HC, BPD, AC, FL)
What are RF for FGR?
History of prior FGR
Multiple pregnancies
heavy smoker, drug user
Underlying maternal medical condition (HTN, DM, heart disease, APS)
What is prognosis for FGR foetuses after delivery?
VERY GOOD if it was due to placental insufficiency
Infants catch up to peers
Because feeding is no longer dependent on placental ciculation
Who are WOMEN CLASSIFIED As HIGH RISK of PET (i.e. will need aspirin)
- Prior PET/HTN in gestation
- Chronic HTN
- CKD
- DM
- AI disease
How long do you give aspirin for in high risk PET women?
12 to 36 week gestation to birth
What is a common way of assessing proteinuria on the wards in PET?
SPOT protein : creatinine ratio
After birth, how do you monitor a woman with gestational HTN?
Measure BP:
- Daily for first two days
- At least once days 3-5
How do you change antiHTN tx after birth?
Change to ATENOLOL
What PET women do you recommend birth in <34 weeks?
SEVERE HTN refractory to tx
