Hypertensive conditions - Essential HTN, Pre-eclampsia and eclampsia Flashcards
Describe the normal BP physiological changes in pregnancy
BP initially falls
Stabilises in 2nd trimester - usually 15mmHg lower than pre-pregnancy
Rises in third trimester
Reaches pre-pregnancy levels at term
Define pre-eclampsia
New hypertension presenting after 20 weeks (on more than 2 occasions >4hrs apart) AND significant proteinuria
What percentage of pregnancies are complicated by hypertension?
10-15%
What percentage of pregnancies are complicated by pre-eclampsia?
3-5%
How many UK pregnancies are complicated by eclampsia?
1 in 3000
Describe what happens in pre-eclampsia
Abnormal trophoblast invasion and differentiation in the 1st trimester
Failure of trophoblast cells to destroy the muscularis layer of the spiral arteries - Underdeveloped spiral arteries
Failure to transform into low resistance vessels
Reduction of blood flow to the intervillous space
Uteroplacental ischaemia - poorly perfused placenta
What happens as a result of the defective placenta?
Toxic factors release
Influence of ischaemia leads to endothelial damage, redistribution of fluid, protein leakage through kidneys, vasoconstriction, activation of the coagulation system
List some risk factors for pre-eclampsia
Obesity Age >40 Genetic predisposition - sister greater risk than mother Multiple pregnancy Primip Long birth interval Hydrops with large placenta Hydatidiform mole Triploidy
Pre-existing HTN CKD DM Antiphospholipid antibodies Connective tissue disease
List some clinical features of pre-eclampsia
HTN Proteinuria Oedema Headaches Visual disturbances Epigastric pain Clonus Rib pain Vomiting IUGR
What are some complications of pre-eclampsia
Maternal:
- Eclampsia (seizures)
- Cerebral haemorrhage
- Pulmonary oedema
- Pulmonary embolism
- Renal failure (AKI)
- HELLP syndrome, liver haemorrhage and rupture
- Disseminated intravascular coagulopathy
Foetal:
- Placental abruption
- Oligohydramnios
- Foetal growth restriction
- Increased risk of HTN
- Increased risk of stroke
What clinical picture is seen in HELLP syndrome
Haemolysis
Elevated liver enzymes
Low platelets
What is eclampsia
One or more tonic clonic seizure in association with features of pre-eclampsia and not attributable to any other cerebral pathology
What percentage of woman with eclampsia have symptoms of pre-eclampsia?
1/3
Describe the management of pre-eclampsia
Monitoring
VTE prevention - LMWH
Antihypertensive - labetalol
Delivery , nifedipine, methyldopa
Describe post natal care of pre-eclampsia
Usually resolves following delivery of placenta, however monitor mother for at least 24hrs post partum
Blood pressure monitored daily for first 2 days and then at least once 3-5day post partum and the need for antihypertensive should be assessed
What class of drug is labetalol?
Beta blocker
List the side effects of labetalol
Postural hypotension Fatigue Headache Nausea Vomiting Epigastric pain
What class of drug is nifedipine?
Calcium channel blocker
List the side effects of nifidipine
Peripheral oedema Dizziness Flushing Headache Constipation
What drug class is methyldopa
Alpha agonist
List the side effects of methyldopa
Drowsiness Headache Oedema GI disturbance Dry mouth Postural hypotension Bradycardia Hepatotoxicity
Which drug group of antihypertensive are contraindicated in pregnancy and why?
ACE inhibitors
Association of congenital abnormalities
What investigations should be done in pre-eclampsia
BP monitoring Urine dipstick 24hr urinary collection FBC - decreased Hb and platelets U&Es - increased urea, creatinine, urate and decreased urine output LFTs - increased ALT and AST
Which investigations should be done in eclampsia
FBC U&Es LFTs Clotting studies Blood glucose Neurological examination - clonus
Describe the immediate management of eclampsia
ABCDE assessment
Left lateral position
Secure airway and high flow O2 in non-rebreathe mask
2 large bore cannula
BP monitoring
Magnesium sulphate to stop seizures and also maintenance after as prophylaxis (4g in 100ml0.9% NaCl)
Control BP - labetalol and hydralazine (target MAP of <120mmHg)
Continuous CTG monitoring
Prompt delivery of baby and placenta if needed - caesearean section/vaginal delivery
Monitoring - fluid balance, BP
Describe the inpatient management of eclampsia
Regular symptoms review - headaches and epigastric pain
Bloods 72hr post partum - FBC, LFT, creatinine
Pre-conceptual counselling
Step down care to community when BP target reached and asymptomatic
Describe the community care after eclampsia
CT head if neurology
BP checked daily for 2 weeks post partum
Follow up at 6 weeks - BP, proteinuria, creatinine, FBC, FSTs and creatinine
What is hypertension
> 140/90 on two separate occasions
What is considered significant proteinuria?
Urine protein: creatinine ratio >30
24hr urinary protein >300mg
What is a hypertensive woman <20 weeks gestation considered to have and why?
Pre-existing/essential hypertension as BP usually falls in first trimester
Above what mean arterial pressure is maternal and foetal morbidity and mortality increased?
90
List some risks related to pre-existing/essential hypertension in pregnancy
Superimposed pre-eclampsia Placental abruption Foetal growth restriction Intracerebral haemorrhage Maternal cardiac failure Intracranial haemorrhage Maternal death
Describe pregnancy induced hypertension
BP >140/90 on two separate occasions
>20/40 gestation
No significant proteinuria
What are the different severities of pre-eclampsia?
Mild - BP 140/90 - 150/100
Moderate - BP 150/100 - 160/110
Severe - BP >160/110 or BP<160/110 but >2 signs/symptoms of severe pre-eclampsia
Describe the blood tests in pre-eclampsia and possible results
FBC - decreased Hb and platelets - <100 U&Es - creatinine >100 Uric acid - raised LFT - ALT>50 Clotting
Does the presence of hypertension and proteinuria always signify pre-eclampsia?
No - could be essential hypertension or renal disease - consider the gestation and onset
Is the presence of oedema a useful diagnostic sign?
No as can be normal in normal pregnancy
More specific if facial oedema however
Describe what happens to the liver in pre-eclampsia
Vasoconstriction in hepatic bed
Periportal fibrin deposits, haemorrhage and hepatocellular necrosis
Elevated liver enzymes
Rarely - hepatic infarction and rupture of liver capsule
Describe what happens to the brain in pre-eclampsia
Cerebral vasoconstriction Oedema Membrane destabalisation Focal ischaemia Seizures Haemorrhage
When can seizures from eclampsia occur
Antenatally - 38%
Intrapartum - 18%
Postnatally - 44% usually within the first 24-48hrs post partum
What is HELLP syndrome associated with?
Eclampsia DIC Placental abruption Acute renal failure Pulmonary oedema
What percentage of women with HELLP syndrome will require a blood transfusion or blood products?
50%
What is used to prevent pre-eclampsia?
150mg aspirin daily from 12 weeks in moderate-high risk women
How is pre-eclampsia screened for in high risk women?
1st and 2nd trimester uterine artery dopplers
Placental growth factor
1st trimester PAPP-A levels
What is PAPP-A
Pregnancy associated plasma protein
Produced by placenta
Describe recommended delivery in women with pre-eclampsia
C/S if <34 weeks
MgSO4 if <32 weeks for foetal neuroprotection
Vaginal delivery if >34 weeks, aim for short second stage and IV oxytocin for the 3rd stage
Which drugs should be avoided in the 3rd stage of labour with pre-eclampsia and why?
Ergometrine or synometrine - increases BP
What is the most important/most specific sign of pre-eclampsia to be elicited
Brisk tendon reflexes/clonus
Which drug is given to reverse the respiratory depressive effect of too much magnesium sulphate in eclampsia?
Calcium gluconate
How long should magnesium sulphate be continued postpartum?
24 hrs after delivery or after last seizure