Hypertension in pregnancy Flashcards
what is the definition and criteria of pre-eclampsia?
pregnancy induced hypertension
with features of proteinuria, oedema and generalised multi-organ system dysfunction
A: Hypertension= > 140/90 or an >30/15 increase above baseline
B: Proteinuria > 300mg/24hrs
C: generalised oedema
what is the main maternal risk of pre-eclampsia?
DIC and seizures
what must you exclude if you detect proteinuria during pregnancy?
Exclude:
leucorrhoea-artifact (poorly collected sample, not MSU)
UTI
renal failure or dysfunction
how might we treat pre-eclampsia?
the only cure= immediate delivery of baby and placenta
when does pre-eclampsia symptomatically present in a pregnant woman?
LATE presentation!
Woman is usually asymptomatic but hypertensive
what are some predisposing factors for pre-eclampsia?
Positive family history Age extremes- young mother and older mother First pregnancy New paternity Assisted reproduction
Medical conditions such as chronic HT, renal disease, DM, autoimmune disease and thrombophillia
Pregnancy conditions- multiple pregnancies, gestational DM, gestational trophoblast disease, hydrops fetalis, trisomy 13
what is typically the time course of pre-eclampsia?
usually develops late in pregnancy and resolves post delivery
what is the difference between pregnancy induced hypertension and pre-eclampsia?
pre-eclampsia is a SUBSET of pregnancy induced HT.
Pre-eclampsia also involves proteinuria and multi-system organ failure and generalised oedema
what is the main organ that causes pre-eclampsia?
larger than expected placenta –> increased risk of pre-eclampsia
how might we monitor the severity of pre-eclampsia?
Headache papilloedema presence of visual disturbances worsening proteinuria thrombocytopenia
What is the problem with using ergometrine in inducing labour in pre-eclampsia? What do we use instead?
SE of ergometrine is HT and will EXACERBATE pre-eclampsia
oxytocin or syntocinin is used instead
what is a key treatment principle of pre-eclampsia?
pre-eclampsia is cured BY delivery but NOT AT delivery
what is a ddx we need to consider with pre-eclampsia?
phaeochromocytoma
what anti-hypertensive drugs can we use in pregnancy?
antihypertensives such as labetalol, hydralazine, nefidipine, methyldopa
what anti-convulsant drug do we normally use in pre-eclampsia?
magnesium sulfate 50% via IV syringe pump
how might we clinically monitor the SE of magnesium sulfate in a woman with pre-eclampsia
test for reflexes and look for clonus. in pre-clampsia, hyper-reflexia and clonus may be present.
if magnesium sulfate is used, it will cause hyporeflexia or reduce hyper-reflexia
too much magnesum sulfate will cause areflexia however
what are the clinical signs of magnesium sulfate toxicity in a pre-eclampsia patient?
areflexia and respiratory depression
what is the antidote for magnesium sulfate toxicity?
calcium gluconate
what are some maternal factors in a woman with preeclampsia favour a c-section?
primiparous mother unstable BP control cerebral irritability breech presentation immature fetus fetal growth restriction abnormal fetal doppler waveforms
what is the most common cause of seizure during pregnancy?
epilepsy!
but also can be eclampsia
how might you distinguish between a seizure caused by pre-eclampsia vs epilepsy in a pregnant woman?
bracelet will usually be worn on an epileptic woman
look for gum hypertrophy
look in handbag for anti-epileptic medications
what are the main clinical symptoms which may indicate imminent eclampsia?
headache
visual disturbances
clonus
what does HELLP syndrome stand for?
Haemolysis
Elevated Liver Enzymes
Low Platelet Count
what is the only evidenced based medication that may be used to prevent pre-eclampsia?
low dose aspirin
what is ‘eclampsia’?
Eclampsia is a generalised tonic-clonic seizure as a consequence of pregnancy-related cerebral hypoxia.
Describe the pathophysiology of pre-eclampsia?
In pregnancy states, adaptive changes to maternal blood flow do not occur causing generalised vasoconstriction, reduced blood volume and increased coagulability. As a result, there is reduced blood flow to the placenta going to the foetus, resulting in fetal growth restriction
from what gestation week do we normally dx pre-eclampsia?
from 20 weeks gestation
consider pre-existing HT or HT due to hyatidiform mole
what are some key ix we need to order to diagnose preeclampsia?
urine analysis looking for proteinuria (dipstick)
renal function UEC
LFTs
FBE looking for thrombocytopenia
how do we monitor fetal wellbeing in a woman who has just been diagnosed with preeclampsia?
CTG doppler ultrasound fetal movements amniotic fluid volume u/s of fetal growth
which antihypertensives do we NOT use in the case of preeclampsia and why?
ace inhibitors- teratogenicity
diuretics–> further reduces maternal blood volume
what drug do we use to prevent convulsions in a patient at high risk of eclampsia?
magnesium sulfate
what are the ongoing postpartum risks of preeclampsia for the mother?
recurrence in subsequent pregnancies
increased risk of CV disease, thromboembolism and hypertension
when is preeclampsia is a medical emergency requiring immediate hospital admission?
BLOOD PRESSURE > 170/110mmHg is a medical emergency and warrants admission + delivery
apart from IUGR what is another risk to fetus if the mother has preeclampsia?
placental abruption–> can cause fetal demise
what are the absolute maternal indications for delivery in preeclampsia?
HT > 170/110 or HT not responding to antihypertensives
severe proteinuria >5g/24 hrs
signs of neurological deficits
signs of pulmonary oedema
severe thrombocytopenia + DIC
markedly elevated and deranged LFTs
who is involved in the care of a woman who has been admitted to hospital with severe preeclampsia?
After establishing the diagnosis of severe preeclampsia, the woman should be admitted to an appropriate area of the hospital equipped for intensive nursing. The anaesthetic service should be informed and an obstetric physician may be consulted, but the primary responsibility for care must remain with the obstetric team. The paediatric team should be informed if the patient is preterm.
what are some management principles of severe pre-eclampsia
- admit the patient
- stabilise the patient
- control BP if you can with antihypertensives
- fluid status monitoring
- fetal wellbeing monitoring
- give magnesium sulfate for prophylaxis against convulsions
- organise teams- e.g. obstetrics, paediatrics, anaesthetic
- decide type of delivery e.g. vaginal or c-section depending on maternal/fetal factors
- use oxytocin NOT ergometrine for delivery of placenta
- postpartum ongoing followup and monitoring
what are the main clinical features of HELLP syndrome?
epigastric pain malaise N+V blurring vision headaches DIC
how do we manage the DIC associated with preeclampsia?
fresh frozen plasma
what are the maternal investigations required for preeclampsia?
FBE, urinary protein : creatinine ratio, serum uric acid, platelet count and hepatic transaminases
why do we need to consider fluid resuscitation in a woman with severe preeclampsia with imminent delivery of her child?
reduced intravascular space with increased venoconstriction
magnesium sulfate may cause a sudden drop in blood pressure and consequently CO as it is a venodilator
so have IV access and be on alert in case fluid resuscitation is required
what is your first aid management of a pregnant lady who is fitting?
- Prevention of injury. The woman should positioned so as to protect her from physical injury.
- Airway and oxygen. A rubber airway placed in her mouth will inhibit tongue-biting and protect the airway. Oxygen should be provided by means of a mask or nasal catheter. Artificial ventilation with bag and mask may be necessary in the early postictal phase, particularly if large amounts of diazepam were required.
- Posture. The woman should be nursed in the semiprone position to facilitate drainage of the airway and to minimise pulmonary aspiration.
- Anticonvulsant. Diazepam or clonazepam intravenously remains the most effective means of stopping a convulsion. Loading with 4 g magnesium sulfate should occur as soon as feasible.
- Transport. If the woman is to be transferred to hospital, it is desirable that a doctor or nurse accompany her in the ambulance.
what are some management considerations for a woman with severe preeclampsia who has been admitted to hospital for emergency delivery of her child?
- Fast the patient + ranitidine
- Fluid replacement with crystalloid solution so may require 2 x large bore IV lines
- Attempt reducing BP with anti-hypertensives
- Strict FLUID BALANCE monitoring and restriction- IDC
- Monitoring of magnesium sulfate toxicity- testing reflexes and conscious state
- Have platelets and FPP on hand, monitor platelet levels
- Continuous CTG for fetal wellbeing
- Corticosteroids if fetus is < 34 weeks gestation
- Warn the neonatal paediatrician in the case the baby is preterm
- Avoid ergometrine and prolonged pushing. Use oxytocin instead
- Post delivery mother must be on magnesium sulfate for 24 hours with close monitoring
Review in 6 weeks
what is your management of a pregnant lady with ‘mild’ preeclampsia?
Consider the gestational age
• If preterm, consider watch and wait till 38 weeks
• If nearly or at term, then deliver
• If any signs of fetal compromise= delivery required
Treat the HT:
• Anti-hypertensives such as nifedipine, labetalol and methyldopa, hydralazine
Antenatal reviews:
Increase antenatal monitoring of mother and baby (tests of fetal wellbeing) e.g. weekly reviews with investigations
how do we determine the severity of preeclampsia?
Severity is dictated by symptoms, clinical signs including BP, proteinuria, oedema, clonus
what is the diagnostic criteria for HELLP syndrome?
Haemolysis: schistocytes or red cell fragments on blood film, raised bilirubin, raised LDH greater than 600mIU/L, decreased haptoglobin
Elevated liver enzymes: AST and ALT greater than 70 IU/L
Low platelets: less than 100 x 109/L
how many beats of clonus is abnormal in routine monitoring in a preeclampsia pregnant woman?
> 2 beats clonus is abnormal
other than DIC and seizures, what are some other maternal complications to preeclampsia
placental abruption • disseminated intravascular coagulation (DIC) • HELLP Syndrome (Haemolysis, Elevated Liver enzymes, Low Platelets) • ascites • pulmonary oedema • acute renal failure • liver rupture • intracerebral haemorrhage
what is the therapeutic level of magnesium sulfate in a woman who is being managed for severe preeclampsia?
1.7- 3.5 mmol/L
what is the drug of choice to manage HT in severe preeclampsia? when might we not use this drug?
IV labetalol
Hydralazine remains the drug of choice for women with asthma or congestive heart failure.
what are some postpartum immediate management considerations for a woman who has preeclampsia?
Most women will show signs of recovery within the first 24 hours of delivery; however a minority will remain unstable or deteriorate after delivery. As the majority of eclamptic seizures occur after the birth, close monitoring should therefore continue until:
• BP is stable
• diuresis has occurred and urine output has normalized
• blood investigations (FBE, LFT’s, U and Es) are stable/improving.
Management of magnesium sulphate
• magnesium sulphate should be stopped at a minimum of 24 hours postpartum but may be prolonged if clinically indicated
• postpartum magnesium levels may be adequately assessed clinically (reflexes, respiratory rate) unless there is renal impairment/oliguria when serum levels should be performed 6 hourly
• continue to check hourly patellar reflexes until infusion is ceased.
out of the antihypertensives used during pregnancy, which is the one given in oral form?
nifedipine
given that we do not do a routine MSU at each antenatal visit, how might we detect preeclampsia?
BP looking at high blood pressure
AND
evidence of at least 1 maternal organ dysfunction or sign of fetal growth restriction
