Hypertensive disorders Flashcards
Chronic Hypertension or essential hypertension
Hypertension identified at booking or before 20 weeks. This includes women who are normotensive because on antihypertensives. Sometimes a complication of renal disease.
PIH
New hypertension (> 140/90) presenting after 20 weeks without proteinuria, organ dysfunction or uteroplacental dysfunction.
PET
Hypertension developing after 20 weeks with proteinuria, or organ dysfunction (hepatic, renal, neurological, haematological complications) or placental dysfunction.
Eclampsia
Onset of convulsions associated with PET.
HELLP
Condition often associated to PET, characterised by haemolysis, elevated liver enzymes, low platelets
Labetalol
- dose/route
- side effects
- contraindications
- interactions
- midwifery implications
- difference with other medications
max 2.4g/24hrs PO, max 160mg/hr IV infusion
side effects: hypotension, tiredness, weakness
Contraindications: asthma, COPD, Raynaud’s disease, liver problems
Interactions: alcohol, antidepressants, anti diabetics, antihistamines, corticosteroids -> hypotensive effect
Implications: neonatal glycaemia, resp depression, jaundice. Safe during BF
Difference with other meds: 1st line antihypertensive
Nifedipine
- dose/route
- side effects
- contraindications
- interactions
- midwifery implications
- difference with other medications
max 90mg/24hrs PO
side effects: headache, flushing, dizziness, oedema, hypotension
contraindications: reduces awareness of hypos in diabetics
Interactions: avoid with grapefruit juice, erythromycin and insulin
Implications: also used for tocolysis (not MR) safe during BF
Difference with other meds: avoid before 20/40 as teterogenic
Methyldopa
- dose/route
- side effects
- contraindications
- interactions
- midwifery implications
- difference with other medications
max 3g/24hrs PO
side effects: sedation, depression, fluid retention, headache, GI disturbances, hepatic disorders
contraindications: hx of depression, liver and renal impairment, pheochromocytoma
interactions: alcohol, corticosteroids, iron, salbutamol, anxiolytics
implications: not for postnatal as risk of PND
difference with other meds: safe in asthmatic patients.
Doxazosin
- dose/route
- side effects
- contraindications
- interactions
- midwifery implications
- difference with other medications
max 16mg/24hrs PO
side effects: flu like symptoms, vertigo, sleep disturbances
contraindications: cardiac conditions, severe hepatic impairment
interactions: similar to other alpha blockers
implications: avoid if BF
Enalapril
- dose/route
- side effects
- contraindications
- interactions
- midwifery implications
- difference with other medications
max 40mg OD PO
side effects: renal impairment, hypotension, nausea, D+V, altered liver function
interactions: calcium channel blocker, beta blockers, methyldopa
implications: can cause skull defects in utero, oligohydramnios, neonatal hypotension
difference with other meds: PN only
Risk factors for CHT
- advanced age
- FHx
- Black ethnicity
- obesity
- lack of exercise
- high cholesterol
How many women with CHT develop PET?
1 in 4
(superimposed PET)
Severe hypertension is…
> 160/110
When does PIH typically go away?
within 6 weeks of birth
Differential diagnoses for hypertension (in the absence of proteinuria and organ dysfunction)
Pheochromocytoma –> neuroendocrine tumour
Coarctation of the aorta –> narrowing of aorta
Cushing’s syndrome –> excess cortisol
Conn’s syndrome –> excess aldosterone
Symptoms of PET
- nausea and/or vomiting
- severe pain below ribs
- severe, persistent headache, not resolved by mild analgesia
- rapid swelling of face, hands, feet
- visual disturbances
Signs of PET
- hypertension
- proteinuria (PCR > 30)
- oedema
- raised LFT
- altered mental status
- raised creatinine
- oliguria < 25ml/hr
- FGR
- placental abruption
MATERNAL complications of PET
- eclampsia
- HELLP
- pulmonary oedema
- stroke
- renal/hepatic failure
- multi-organ failure
- Disseminated intravascular coagulation (DIC)
- adult respiratory distress syndrome
- death
FETAL complications of PET
- IUGR
- oligohydramnios
- prematurity
- placental abruption
- fetal distress
- IUD
- neonatal respiratory distress syndrome
What % of women with PET also develop HELLP syndrome?
10-20%
Signs of HELLP
- hypertension
- proteinuria
- epigastric/ right upper quadrant pain
- generalised oedema
- gastro-intestinal bleed
- oliguria
Symptoms of HELLP
- malaise
- fatigue
- nausea and vomiting
- headache
Bloods used with S+S to diagnose PET + HELLP
FBC
Hb < 105 could indicate heamolysis (HELLP)
Platelets < 100 indicates dangerously low platelet count (HELLP)
(normal cut off is 150)
Bloods used with S+S to diagnose PET + HELLP
U&Es
Creatinine > 73 indicates renal impairment
Uric acid (depends on gestation, normal from 140-380, raised indicates kidney impairment)
eGFR < 90% indicates renal impairment
Bloods used with S+S to diagnose PET + HELLP
LFT
ALT > 40-70 indicates hepatic impairment (HELLP)
LDH > 600 indicates hemolysis (HELLP)
Bloods used with S+S to diagnose PET + HELLP
clotting
when abnormal indicates hepatic impairment
Bloods used with S+S to diagnose PET + HELLP
sFlt/PIGF ratio
+ when can this test be carried out?
> 38 but < 85, 1:5 chances of developing PET in 1 week
85, 1:2 chances of developing PET
singleton pregnancy between 20 - 34+6 weeks
Diagnostic tests for HELLP
- feel abdomen for enlarged liver
- liver USS, CT, MRI
When should IV MgSO4 be given?
- eclamptic fit
- birth is planned < 24hrs with symptomatic severe PET
- HELLP (LDH> 500)
Preconception care
- refer women medicated for CHT to cons Obs/ obstetric physician for pre-pregnancy counselling
- change medication to Labetalol or Nifedipine, stop statins and other meds contraindicated in pregnancy
- target BP 135/85
- support to change lifestyle
High risk factors for developing PET
- hypertensive disease in prev. pregnancy
- chronic hypertension
- chronic kidney disease
- autoimmune disease: SLE or APS
- type 1 or 2 diabetes
Moderate risk factors for developing PET
- booking proteinuria 1+ more or PCR > 30
- 1st pregnancy
- mat age > 40
- pregnancy interval of 10+ years
- BMI > 35
- FHx in mother/sister
- multiple pregnancy
When is Aspirin pxd?
ANY high risk factor
1+ moderate risk factor
150mg every evening from 12-36 weeks
Alongside aspirin, what else are high risk women advised to take?
800 IU Vit D + Calcium daily
AN care in community for CHT and PIH well controlled
- appts every 1-4 weeks initially, then 2 weekly from 32-36 weeks, then weekly or more especially if BP > 135/85
- routine check: BP, urine, discuss S+S
- Measure fundal height, metal movements
- Any concern –> MAU
PET bloods
CTG
USS referral - USS for fatal growth, amniotic fluid volume and UAD at 28, 32, 36 weeks
AN care in hospital (PET)
- MDT approach (senior ops, neonatologist, senior anaesthetist)
- Full-PIERS tool to calculate adverse maternal outcomes
- 4 holy obs (o2 may give warning of pulmonary oedema)
- fluid balance (min output 100mls/4hrs), daily weights
- PET bloods (at least 2-3 x week)
- PCR if clinically indicated
- Antihypertensives, corticosteroids if birth <34/40
- daily CTG with Dawes-Redman from 25-26/40
- daily or weekly USS depending on placental insufficiency
- TEDs and LMWH
Intrapartum care PET
- timing generally from 37/40 to balance risks to baby vs worsening PET
- IOL not offered before 40-41/40 if CHT or PIH well controlled
- Decision to deliver once woman stable
- PET bloods + clotting taken 6hrly in severe PET
- epidural might help BP control but ensure good level of platelets
- do not preload before epidural
-1 hourly obs - MgSO4 if fetes < 32/40
- fluid management –> not necessary if PU > 30ml/hr and stable BP. If necessary, max 80ml/hr intake unless ongoing fluid loss
- lower threshold for Foley catheter if epidural
- do not routinely limit duration of 2nd stage, unless severe hypertension when operative birth might become necessary
- observe for s+s of severe PET and request urgent medical r/w if concerns
- cEFM to ensure fatal wellbeing
Intrapartum care for HELLP
similar to PET
- regular PET bloods with clotting and LDH (can even be 2hrly)
- timing of delivery is based on rapid progress of disease
- expedite before platelets < 80 because of risks with regional analgesia
Immediate PN care
- 3rd stage Oxytocin –> 5IU + 5IU
- 4hrly obs unless BP stable for over 24hrs (talk to Dr)
- continue with antihypertensives except for methyldopa
- if labetalol use in pregnancy –> hypoglycaemia obs for baby
- caution with NSAIDS for increased BP effect and for inhibiting platelets aggregation
Discharge to community
- plan for follow up care, including frequency of BP checks, treatment
- GP appt at 2 weeks and 6 weeks
- women should be aware of increased risk of hypertension and associated cardiovascular morbidity later on in life –> lifestyle changes needed
- women should be aware of increased risk of recurrent hypertensive disorders in future pregnancies
- offer appt with obstetrician at 6-8 weeks if severe PET
- contraceptive advice
Small for gestational age (SGA)
EFW or AC < 10th centile
Fatal growth restriction (FGR)
failing to reach genetically predetermined growth potential.
increased risk of adverse perinatal outcome, EFW < 3rd gentile, AC or EFW growth velocity reduction > 50 centiles, abnormal dopplers
Why babies are small…
- constitutional
- placenta-mediated (hypertensive disorders, renal disease, autoimmune disease)
- non-placenta mediated (chromosomal, fatal infection/CMV, toxoplasmosis, COVID)
Uterine artery dopplers
PET and FGR associated with inadequate quality and quantity of the maternal vascular response to placentation.
Raised uterine artery dopplers = impedance to flow in uterine arteries is increased
usually assessed at 20/40 USS in Oxford
other places assess between 20-24/40 only if high-risk
tools to determine fetal wellbeing biometry
- measure head circumference, abdominal circumference, femur length
- calculate EFW
- growth velocity (EFW, AC)
umbilical artery dopplers Absent end diastolic flow
when the blood flow is absent during diastole. This means that the blood flow to the placenta is markedly decreased.
umbilical artery dopplers Reversed end diastolic flow
when there is a reversed flow during diastole. This is indicative of an increase in resistance in placental blood flow. it’s the most severe classification of abnormal dopplers and is associated with significant fatal mortality.
