Pre-eclampsia Flashcards
Discuss hypertension in pregnancy
-Incidence of types of HTN/PET/Eclampsia (4)
-Definitions of
-HTN
-Severe HTN
-Chronic HTN
- Incidence
-HTN 10-15%
-PET 3-5%
-Eclampsia 1% of all PET
-Most common cause of iatrogenic prematurity - Definitions
HTN: Systolic BP >=140 OR diastolic >=90 as measured on 2 occasions 4 hrs apart Or BP >160/100 on a single occasion
Severe HTN: = >170/110
Chronic HTN: Prior to 20/40 or if persisting > 3 months PP
Discuss chronic HTN noted in pregnancy
1. Definition (2)
2. Causes (4)
3. Investigations (4)
4. Risks for pregnancy (5)
5. Diagnosis of superimposed PET on chronic HTN (4)
- Definition
HTN>140/90 before 20 weeks or persisting after 3months PP - Causes
-95% is due to idiopathic HTN (essential HTN). Need to rule out secondary causes before giving this dx
-Renal causes: renal artery stenosis, CKD, DM, SLE
-Cardiac causes: Coarctation of the aorta
-Endocrine disorders: Phaeochromocytoma, Cushings, Conn’s, hyperparathyroidism - Investigations
-Check for end organ damage
-Check baseline Cr and proteinuria
-Echo
-Renal screening - Risk for pregnancy
-Development of PET 25%, 46% if severe HTN
-PTD 50% if superimposed PET
-SGA - 48% if PET
-CS - 70% if PET
-Placental abruption - Diagnosis of superimposed PET on chronic HTN
-SGA in those with chronic HTN not diagnostic of PET
-High suspicion if developing worse HTN
-Look for other fetal effects of PET - oligo, abnormal dopplers, raised Uterine artery dopplers
-If pre-existing proteinuria then other features must be present for diagnosis
Discuss HTN in pregnancy
-Definition of gHTN
-Risk of developing PET if gHTN (2)
-Definition of PET (7)
-Definition of early onset PET (1)
-Definition of severe PET (6)
- Definition of PIH/gHTN
New onset HTN >140/90 if >20/40 and resolves before 6/52 PP - Risk of developing PET
-If early onset gHTN (<30/40) risk = 40%
-If late onset gHTN (>38/40) risk = 7% chance - Definition of PET
New onset of HTN >20/40 + end organ dysfunction
End organ dysfunction:
-Renal - Proteinuria: uPCR >30 / >300mg/day, Cr >90 Oligouria <80mL/4hrs
(If underlying renal disease don’t use proteinuria)
-Haematological - Plts<100, Haemolysis (LDH, Bili, Haptoglobin)
-Liver -Epigastric pain, RUQ pain, Raised LFTs - >2x upper limit
-Neurological - eclampsia, hypereflexia, persistent headache
-Pulmonary oedema
-IUGR - Definition of early onset PET = <34/40
- Definition of severe PET
No clear definition
Difficulty controlling BP
HELLP, worsening thrombocytopenia, impending eclampsia, worsening growth restriction
Discuss eclampsia
-Definition
-Onset
-Risk factors (1)
- Definition
-Tonic clonic seizure
-Only 33% have dx of PET prior to seizure - Timing
-45% antinatal, 20% intrapartum, 35% postpartum - Risk factors
-3 x more common in teenagers
Discuss the pathogenesis of PET (7 points)
PET is multifactorial illness
1. Genetic role
-Increased risk if family Hx
2. Immune factors
3. Abnormal placentation with spiral arteries remaining under high resistance due to poor cytotrophoblastic invasion
4. Systemic endothelial dysfunction
-Placental release of antiangiogenic factors such as sFlt1 and sENG result in vascular permeability
5. Exaggerated systemic inflammatory response with endothelial dysfunction with increased vascular tone and capillary permeability
6. Vasoconstriction from increased thromboxane
7. Increased sensitivity to angiotensin II leading to increased BP
Discuss PET
-Risk factors (8)
-Protective factors (4)
- Risk factors
-BMI >30 RR 2
-Family Hx RR 3
-Age >40 RR 2
-Primip RR 2-3
-Multiple pregnancy RR 32
-Previous PET RR 7
-Pre-existing renal disease or HTN or APLS RR 10
-Low AFP
-Pre-existing diabetes RR 4 - Protective factors
-Previous miscarriage to same father as current pregnancy
-High fruit intake
-Smoking but not if have chronic HTN
-Taking >12 months to conceive
Discuss screening for women with new onset HTN >20/40
-What to screen for
-Other markers of PET but not recommended
- What to screen
-If onset HTN <20 weeks look for secondary causes
-Urinalysis - send PCR if +1 protein on dipstick
-FBC, U&E, Cr, LFT (Coags if platelets abnormal)
-If concern for haemolysis - LDH, haptoglobin, bili, blood film
-Regular GS LV and dopplers
-If early onset PET look for underlying renal disease, SLE, ALPS
-P1GF / sFlt1 ratio can be used for diagnosis. SOMANZ. Don’t use to time delivery. DOn’t use alone. - Other markers
-ADAM-12
-Low PAPP-A
-Uterine artery dopplers - high negative predictive value so useful in those at high risk
Discuss ongoing investigations for women with HTN in pregnancy
-Chronic HTN
-gHTN
-PET
- Chronic HTN - each visit:
-Assess BP, sx of PET, fetal wellbeing
-Proteinuria
-PET bloods if new proteinuria or sudden increase in BP - gHTN
-Assess BP, sx of PET, fetal wellbeing
-Proteinuria 1-2 x weekly
-PET bloods weekly - PET
-Assess BP, sx of PET, fetal wellbeing
-Assess proteinuria and if not proteinuria continue daily
-2 x weekly PET bloods or more frequently if unstable
Discuss treatment of HTN (6 general points)
-Treatment of HTN is the same regardless of underlying pathology
-Treatment allows prolongation of pregnancy but doesn’t treat underlying pathology
-MAP >150 is associated with loss of cerebral autoregulation and increased risk of stroke
-If BP is >160/110 treatment is mandatory
-Aim 135/80 for BP control. CHIPS and CHAPS study. No neonatal difference but better maternal outcmes with better control
-Definitive treatment is delivery
Discuss treatment meds for HTN
-First line treatments (3), second line (2) third line (1)
-Max dose
-Mechanism of action
-Contra-indications
- First line treatments
Labetalol
-Max dose 2.4g/24hrs 400mg Q4H
-MOA: Alpha and beta adrenergic blocker
-Caution with asthma, COPD
Nifedipine
-40mg PO BD
-MOA: Calcium channel blocker
-Caution with cardiac disease, aortic stenosis
Methyldopa
-Max dose 1g TDS
-MOA: Unclear but acts centrally
-Caution: depression, liver disease, OK in cardiac and renal conditions - Second line
Hydralazine
-Max dose 75mg QID
-MOA: Peripheral vasodilator through smooth muscle relaxation
-Avoid in SLE
Prazosin
Max dose 5mg TDS
MOA: Alpha adrenergic blocker - Third line
Metoprolol
-Max dose 95mg BD
-MOA: Beta adrenergic blocker
-Caution in asthma, safety for fetus not established
Discuss USS frequency and timing in women with HTN in pregnancy
-Chronic HTN
-GHTN
-PET
-PET with FGR
- Chronic HTN
-Early dating USS
-GS + LV and doppler from third trimester with frequency as indicated - gHTN
-GS + LV and doppler 3-4 weekly from time of diagnosis - PET
-GS + LV and doppler 2-3 weekly from time of diagnosis
-CTG twice weekly or more if indicated - PET with FGR
-CTG 2 x weekly
-GS every 2 weeks
-LV and doppler weekly or more frequently depending on dopplers and LV
Discuss timing of delivery
-Early onset < 24weeks
-If 24-34
-If >34
-If >37
-If HTN but no PET
- If <24/40
-Discuss TOP. Maternal morbidity 70%, perinatal mortality 80% - If <34
-Give steroids +/- MgSO4 and aim to deliver 48 hrs after this
-Transfer to tertiary institution
-Aim to prolong pregnancy. Leads to increased maternal morbidity - Increased risk severe morbidity = 25-41% - > 34
-Aim to prolong pregnancy
-Steroids if <35/40 - If >37
-Deliver - If HTN but no PET can deliver between 37-39 weeks
What are the indications for immediate delivery (within 48hrs) (11)
-Gestational age >37/40
-Inability to control HTN
-Deteriorating plt count
-Deteriorating LFTs
-Deteriorating renal function BUT not worsening proteinuria
-Placental abruption
-Eclampsia
-Persistent epigastric pain with N&V and abnormal LFTs
-Acute pulmonary oedema
-Severe fetal growth restriction
-Non-reassuring trace
-HELLP - 6% mortality with expectant management
Discuss management of severe PET
-Where to manage
-Who to involve
-Control of BP (3)
-Control of fluid (3)
-Fetal considerations (3)
-Other considerations (5)
- Manage in HDU or DS
- Involve anaesthetics, paeds, senior obstetrics
- Control BP
-Labetalol 20mg IV over 2 mins repeat in 10 mins continue until BP < 160/110. Max dose 80mg
-Hydralazine 10mg IV over 3-10mins repeat every 20 mins if BP >160/110 max dose 30mg. Give 250mL fluid bolus first
-Nifedipine 5-10mg FA with 10-20mg LA simultaneously. Repeat in 45mins if BP > 160/110. Max dose 40mg - Manage fluid
-Maintenance - 80mL/hr
-Fluid balance
-If oligouric 300mL fluid challenge - Fetal considerations
-Monitor with CTG
-Consider steriods
-Consider MgSO4 - Other considerations
-Consider MgSO4 - 50% reduction in eclampsia
-Consider VTE / SCD or TEDS if CS imminent and LMWH postnatal
-Continuous saturation monitoring
-Plan delivery
-Bloods - check plts twice daily if <100 + coags
Discuss management of eclampsia
-Immediate response (6)
-Medications (5)
-Other considerations (6)
- Immediate response
-Position safely
-Monitor fetus
-Oxygen + support airway
-IV access
-Call for help
-Sats probe - Medications
-4g MgSO4 over 20mins then 1g/hr infusion
-If further seizure give another 2g
-If prolonged seizure and can’t give MgSO4 can give IV diazepam 2mg/min for max of 10mg or clonazepam 1-2mg over 2-5 mins
-Monitor Mg levels - therapeutic dose 2-4 - if renal impairment
-Give half maintenance dose if AKI
-Continue for24hrs after last seizure - Other considerations
-Control BP to reduce risk of further seizures
-Monitor urine output, sats, BP, tendon reflexes, resp rate
-If for delivery consider mode
-If anaesthesia - regional better than GA as increased BP
-If PPH avoid ergo
-Postnatal meds - avoid tramadol, NSAIDS, Ketamine
