Pre-eclampsia and eclampsia Flashcards
What is pre-existing hypertension?
Hypertension (BP>140/90) prior to 20wk GA, persisting >7wk postpartum.
What are 4 complications of essential hypertension?
Increased risk of gestational HTN
Abruptio placentae
IUGR
IUFD
What is gestational hypertension?
Development of hypertension (sBP >140 or dBP>90) after 20th wk GA in the absence of proteinuria in a woman known to be normotensive before pregnancy
What are 5 maternal risk factors of gestational hypertension?
Primigravida (80-90% of gestational HTN) Past history or family history of GA hypertension DM, chronic HTN, or renal insufficiency Obesity Extremes of maternal age (<18 or >35 yr)
What is pre-eclampsia
Preeclampsia is a disorder of widespread vascular endothelial malfunction and vasospasm that occurs after 20 weeks gestation and can present as late as 4-6 weeks post partum
It is clinically defined by hypertension and proteinuria, with or without pathologic edema.
What quantity is hypertension
> 140/90 on 2 occasions in 6 hours
What quantity is proteinuria
> 0.3g in a 24 urine sample
1+ or greater on dipstick
A protein to creatinine ratio of 0.3 or higher
Why is a trace of proteinuria ignored on dipstick
This is almost always due to contamination by vaginal discharges or antiseptic solution
What is pathological oedema
Oedema in the face, hands, abdominal wall, sacrum, vulva and lower limbs
What are the requirements for diagnosing severe pre-eclampsia
BP > 160/110 on 2 occassions in 6 hrs
Proteinuria of at least 3g/5g in 24hr sample
3+/4+ on dipstick
Oliguria from renal failure
Cyanosis from pulmonary oedema
Symptoms of impending eclampsia (headache, visual disturbances or epigastric pain)
Features of HELLP syndrome
What are 7 differential diagnosis for proteinuria in pregnancy?
1 - Pre-clampsia/eclampsia
2 - UTI
3 - Vaginal discharge, blood, mucus and meconium
4 - Renal disease eg glomerulonephritis or pyelonephritis
5 - Collagen vascular disease
6 - Sickle cell disease
7 - Orthostatic proteinuria in pregnancy
What is the pathophysiology of pre-eclampsia in the kidney?
Glomerulo-capillary endotheliosis, endothelial cells swollen and blocks capillary lumen
↓ renal blood flow
↓ glomerular function
↓ in creatinine clearance
Results in proteinuria and in severe cases oliguria
Acute tubular necrosis and then acute renal failure
What is the pathophysiology of pre-eclampsia in the brain?
Cerebrovascular haemorrhage, vasospasm* and oedema* -> increased neuronal activity -> convulsions
Headache, visual disturbances, nausea, vomitting and hyperreflexia are due to a central cause
What is the pathophysiology of pre-eclampsia in the liver?
Have periportal haemorrhages and hepatocellular necrosis
URQ pain due to swelling of Glisson’s capsule
Elevated transaminases (above 10% normal) are a feature of HELLP syndrome
What is the pathophysiology of pre-eclampsia on the cardio-respiratory systems?
Hypertension is a result of increased peripheral resistance from generalized vasospasm
Increased cardiac output may play a minor role
Cardiac failure and pulmonary oedema can occur so it is important to restrict IV fluids
Can also have adult respiratory distress syndrome
What haematological changes occur in pre-eclampsia
↓ plasma volume = ↓ regional perfusion = hypovolemic shock if APH or PPH occurs
HCT rises and severity and duration of pre-eclampsia continues
Microangiopathic hemolytic anemia ⟶ altered thromboxane/prostacyclin ratio ⟶ fibrin deposition, coagulation factors and platelet consumption ⟶ mesh formation ⟶ RBC hemolysis and thrombocytopenia.
What is the pathophysiology of pre-eclampsia in the uterus and placenta?
Uterus:
Uteroplacental perfusion ↓ by 55-60% 3-4wks before HTN ⟶ IUGR and perinatal mortality and morbidity
Placenta:
Possibility of placental abruption and DIC
Failure of trophoblast to invade spiral arteries of inner 1/3 of myometrium leading to acute atherosis (fibrinoid and foam cell deposition)
What are predisposing factors for pre-eclampsia?
Nulliparity Pre-clampsia in a previous pregnancy FHx of pre-eclampsia Extremes of age <18 or >40 Chronic renal disease DM Obesity
What is Eclampsia?
New onset of tonic-clonic/grand mal seizure activity and/or unexplained coma in the setting of pre-eclampsia
and in the absence of other neurologic conditions
Describe an eclampsia seizure
Tonic phase - may lose consciousness, facial twitching, eyes protrude, extremities flexed towards the body or extended away from it lasting 15 - 20 sec
Clonic phase - muscles contract and relax repeatedly lasting about 1 minute
What is the aetiology of pre-eclampsia?
Genetic - 7% incresed risk in daughters, single recessive gene. 20 - 30% of daughter devlope it. 11-37% of sisters develop it
Immunological
Abnormalities in renin-angiotensin-aldosterone pathway
Altered prostacyclin-thromboxane ratio
Endothelial dysfunction
What investigations do you do for pre-eclampsia
CBC - HB for MAHA and plt for thrombocytopenia
U&E - Cr for GFR, Uric acid gives fetal prognosis
LFT - elevated transaminases in HELLP syndrome
PT/PTT - thrombocytopenia, DIC, HELLP
MSU - to exclude differentials
24 urine sample - volume and proteinuria
What is the goal of management in a pre-eclamptic patient?
To control BP and prevent any complications of the disease
Preventing seizure activity
Monitoring for systemic complications (maternal and fetal) of the disease
To deliver the fetus by the earliest and safest means
Delivery is the only cure
What are 10 things initially done for management of mild pre-eclampsia?
1 - Admit for monitoring and investigations
2 - CBC, U&E, LFT, PT/PTT, GXM
3 - Ultrasound
4 - 24hr urine collection - creatinine and proteinuria
5 - CTG if >28wks
6 - Vitals and FHR ever 4 hrs
7 - Normal diet but avoid low salt diet
8 - Best rest
9 - DVT prophylaxis - heparin 5000u sc bd
10 - Corticosteroids if <34 wks - dexamethasone
