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1. Introduction
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Hypertensive disorders of pregnancy affect approximately (5-8%) of women. They are a leading direct cause of maternal death and have a significant association with maternal morbidity, stillbirths, neonatal morbidity and mortality.
The aim of this document is to provide a standardised approach to the management of pre-eclampsia and eclampsia in the antenatal, intrapartum and postnatal period.
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2. Definitions
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Pre-eclampsia: a multi-system disorder, unique to pregnancy, which is usually associated with raised blood pressure and significant proteinuria. It rarely presents before 20 weeks gestation.
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Eclampsia: one or more generalised seizures in association with the syndrome of pre-eclampsia.
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Gestational hypertension: a new onset of raised blood pressure without maternal or fetal signs of pre-eclampsia, after 20 weeks gestation.
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Existing (essential) hypertension: known hypertension before pregnancy or raised blood pressure before 20 weeks gestation.
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Clinical practice note: taking of maternal blood pressure
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The woman should be resting and sitting at an angle of greater than 45 degrees with her feet supported.
The blood pressure cuff should be of the appropriate size and should be placed at the level of the heart.
Standard cuff for arms <33cm circumference. Large cuff (15x 33cm bladder) for larger arms.
Inflate cuff to 20-30mmHg above palpated systolic pressure. Deflate slowly.
Read and record blood pressure to nearest 2mmHg.
Systolic blood pressure is the first sound heard (Korotkoff phase 1)
Korotkoff phase 5 sound (sound disappearance) is the appropriate measurement of diastolic blood pressure. Where this does not occur, Korotkoff sound 4 (muffling) is acceptable
Multiple readings should be taken over several hours to confirm the diagnosis of hypertension/pre-eclampsia due to natural variation.
| Blood pressure readings must be manually recorded during the titration (of antihypertensive medicines) phase.
Automated blood pressure readings may be considered once the maintenance dose has been achieved and the blood pressure is stable.
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3. Complications associated with pre-eclampsia
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3.1 Maternal complications:
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- placental abruption
- disseminated intravascular coagulation (DIC)
- HELLP Syndrome (Haemolysis, Elevated Liver enzymes, Low Platelets)
- pulmonary oedema
- acute renal failure
- acute fatty liver of pregnancy
- liver rupture
- intracerebral haemorrhage
- eclampsia (incidence 1:200-300 women with pre-eclampsia in Australia1
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3.2 Fetal complications:
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- fetal growth restriction
- fetal death in utero.
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3.3 Neonatal complications
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Neonatal complications are those associated with preterm birth plus:
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- hypoxic and neurological injury
- perinatal death.
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4. Diagnosis of pre-eclampsia
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4.1 Pre-eclampsia classification
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Mild to moderate: Defined as systolic blood pressure of 140mmHg and/or diastolic blood pressure of 90mmHg or higher measured on at least two occasions over several hours, combined with proteinuria >300 mg total protein in a 24-hour urine collection, or ratio of protein to creatinine >30 mg/mmol.
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Severe pre-eclampsia: Defined as systolic blood pressure 160-170 and/or diastolic blood pressure of 110mmHg or higher measured on at least two occasions over several hours, combined with proteinuria >300mg total protein in a 24-hour urine collection, or ratio of protein to creatinine >30mg/mmol. All usually accompanied by other haematological, neurological, hepatic or renal derangement.1
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NOTE: A systolic blood pressure of 160mmHg or greater on two consecutive occasions, although not diagnostic of pre-eclampsia is significant and requires treatment.
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4.1.1 Additional symptoms of pre-eclampsia:
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- onset of oedema of face, hands or feet
- headache, or visual disturbance, or both
- epigastric pain or vomiting, or both
- reduced fetal movements.
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4.1.2 Signs of severe pre-eclampsia:
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- increased signs of clonus
- pitting oedema
- papilloedema
- liver tenderness.
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4.2 Associations
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- intrauterine growth restricted fetus (IUGR)
- placental abruption
- fetal death in utero.
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5. Biochemical changes
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- serum creatinine >0.09 units and/or oliguria
- raised transaminases (ALT or AST rising to above 70iu/L)
- platelets <100x109/L (DIC, haemolysis)
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6. Categorisation of care
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6.1 Inpatient care should be provided for women with severe hypertension and pre-eclampsia.
Women presenting with neurological symptoms should be initially assessed in the Birth Suite.
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6.2 Women with moderate pre-eclampsia should be admitted to the antenatal ward.
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6.3 For women with mild pre-eclampsia, pre-existing or pregnancy induced (gestational) hypertension, monitoring may be undertaken on an outpatient basis.
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7. Acute management of pre-eclampsia in the birth suite
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The management of pre-eclampsia in birth suite is multi-disciplinary and may involve the obstetrician, midwife, anaesthetist, physician, haematologist and paediatrician (as required).
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7.1. Full physical examination with respect to potential complications of pre-eclampsia must be undertaken on admission and thereafter at regular intervals.
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7.2. Investigations:
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 | - group and hold
- pre-eclampsia screen (FBE, U&E, Uric Acid, LFTs)
- coagulation profile (APTT, PT, fibrinogen- if platelets <100x109).
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7.3 Blood pressure control
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Patient may continue taking oral antenatal medicine unless BP <120/70 mmHg.
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Note: BP ≥170/110 mmHg requires prompt treatment.
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7.3.1 Use of magnesium sulphate
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Prophylaxis with magnesium sulphate should be implemented where there are premonitory signs of eclampsia (increased reflexes associated with clonus and/or severe headache, visual changes) or following diagnosis of severe pre-eclampsia (diastolic B/P >110 mmHg, proteinuria >300mg/24 hours, abnormal LFTs, thrombocytopenia4.
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| - magnesium sulphate commenced (as per CPG) and continued as a maintenance infusion
- serum magnesium concentrations should be checked every 6 hours in the antepartum and intrapartum phase (therapeutic level of magnesium sulphate: 1.7- 3.5 mmol/L)
- reflexes and signs of clonus should be assessed at 2 hourly intervals by medical staff
| - NOTE: wait for blood pressure to stabilise following administration of magnesium sulphate before considering other anti-hypertensive agents
| - maintain diastolic B/P ≈ 90-100mmHg.
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7.3.2 Acute control of severe hypertension
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Intravenous labetalol is considered to be the primary drug of choice for the urgent control of severe hypertension in pregnancy. It is associated with a lower incidence of adverse side effects and supplants the use of hydralazine. Usage will depend on availability and the clinicians experience and familiarity with the drug.
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Note: Hydralazine remains the drug of choice for women with asthma or congestive heart failure.
For details of administration and monitoring of IV labetalol and IV hydralazine, refer to CPG: Hypertension: Acute Control of Severe Hypertension in Pregnancy.
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7.4. Fluid balance
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Accurate assessment of fluid input/output is essential: iatrogenic fluid overload is a main cause of maternal death in the pre-eclampsia/eclampsia sequelae.
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Maintain a strict fluid balance chart: record on electronic fluid balance chart.
On admission to the Birth Suite it is recommended that a main line of sodium chloride 0.9% (Normal Saline) x 1L be commenced via a multiflow adapter into the IV site. Intravenous fluids should be administered via a controlled infusion pump at no greater than 84mL/hr.
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7.5. Renal function:
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- protein excretion should be monitored by a full ward test of urine four hourly
- a random urinary protein/creatinine ratio (UPRCR) may be considered.
- indwelling urinary catheter (+ urometer)
- urine output measured hourly.
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Note: Urine output <30mL/hour is considered inadequate during magnesium sulphate administration.
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Note: Management of oliguria (during magnesium sulphate administration) should be multidisciplinary:
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- Consider giving Hartmann’s 250mL stat. If no improvement in output, consider repeating bolus infusion
- If no response in urine output consider administering 6% Voluven® in aliquots of 100mL up to a maximum total of 500mL. BEWARE OF PULMONARY OEDEMA
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- Continuing oliguria requires obstetric and anaesthetic consultation. The insertion of a CVC may be considered.
- Persistent oliguria may be an indication for diuretic use following obstetric/ anaesthetic consultation
- Persisting oliguria may require transfer to a high dependency unit.
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7.6. Ongoing monitoring/observations
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- ½ hourly blood pressure, pulse, respiratory rate in acute phase
- 1 hourly patellar reflexes
- 1 hourly urine output measurement + 4 hourly testing of urinary protein (full ward test)
- 2 hourly temperature
- Continuous electronic fetal monitoring (antepartum and intrapartum) of fetus from 26 weeks gestation until clinical review/discussion by medical staff. Between 24- 26 weeks gestation individualised management in regard to fetal monitoring will be considered.
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7.7 Pain Management
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An epidural may be considered for pain management as it has the additional benefit of lowering the women’s blood pressure, in the absence of contra-indications and platelets must be >100 x 109/L.
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7.8 Fetal monitoring
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- continuous electronic fetal monitoring in labour (Birth Suite)
- remember the IUGR fetus will have less tolerance of labour than a well-grown healthy fetus.
- continuous electronic fetal monitoring during administration of magnesium sulphate (Birth Suite).
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7.9 Birth/delivery
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Deliver if any of the following:
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- severe pre-eclampsia/ eclampsia (once stable)
- BP uncontrolled despite treatment
- deterioration in LFT and/or RFT
- progressive decrease in platelets
- neurological symptoms / eclampsia
- abruption
- non-reassuring fetal status.
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Delivery is generally indicated in severe pre-eclampsia or in a fetus of greater than 37 weeks gestation.
An attempt may be made to defer delivery at very early gestations around the limits of viability.
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7.9.1 Mode of birth/delivery:
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- will depend on maternal and fetal factors (gestation, presentation)
- will require multidisciplinary consultation
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- If the fetus is <34 weeks gestation, and maternal condition warrants delay, consider deferring delivery to allow time for steroids to be administered.
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- If induction of labour is undertaken with oxytocin (Syntocinon®)/ ARM, an oxytocin (Syntocinon®) infusion must be delivered in a concentrated dose via a syringe driver pump.
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7.9.2 Second stage management
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- Operative birth is not routinely required for the second stage but may be necessary if the BP is poorly controlled, woman has symptoms of severe cerebral irritability, or progress is inadequate.
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7.9.3 Third stage management
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- should be actively managed: oxytocin 10 IU (ten international units) bolus IV for third stage
- refer to CPG: Labour: Third Stage Management.
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Note: Do not give ERGOMETRINE OR OXYTOCIN-ERGOMETRINE (SYNTOMETRINE®) as routine oxytocic management at birth.
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7.10 Postpartum
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7.10.1 Immediate management
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Most women will show signs of recovery within the first 24 hours of birth/delivery, however a minority will remain unstable or deteriorate after birth/delivery. As the majority of eclamptic seizures occur after the birth, close monitoring should therefore continue until:
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- BP is stable
- diuresis has occurred and urine output has normalised
- blood investigations (FBE, LFTs, RFTs, serum uric acid) are stable/improving.
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7.10.2 Management of magnesium sulphate
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- magnesium sulphate can usually 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
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- continue to check hourly patellar reflexes until infusion is ceased.
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8. Antenatal ward management
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8.1 Indication for in-patient admission:
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- BP ≥ 150/100mmHg on 2 occasions
- maternal symptoms
- concern for fetal well-being.
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8.2 Antenatal ward admission
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- admission
- 4/24 BP
- daily ward urinalysis
- FBE, U&Es, Uric Acid, LFTs (alternate days)
- MSU (MC&S), 24 hour urine (creatinine clearance and protein) - weekly
- fetal assessment:
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| - growth: 2nd weekly
- AFI, doppler: initially on admission and repeat as indicated by fetal condition
- CTG: 2 to 3 times per week
- biophysical profile as required weekly
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- antihypertensive therapy if BP >160/100mmHg (maintain BP at 130-140/80-90mmHg ). Usually the first line drug of choice is oral labetalol (caution with use in asthmatics).
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The use of antihypertensive therapy in cases of mild preeclampsia is equivocal and its use may compromise placental perfusion. It should only be used in the presence of other disease markers or existing co-morbidities, such as Type One diabetes, chronic hypertension, renal or vascular disease. When blood pressures begin to exceed 140/90mmHg, closer surveillance is required and consultation with senior colleagues is recommended before commencing antihypertensive therapy.
There is insufficient evidence to recommended one oral antihypertensive over another. The medications of choice are labetalol, methyldopa and nifedipine. The drug of choice should depend on the clinician’s experience and familiarity with a particular drug and on what is known about its adverse effects for both the woman and her baby1.
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| | | Labetalol
(avoid in women with asthma)
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Reference: 3Centres Collaboration Consensus Guideline – Hypertension in Pregnancy, Preeclampsia and Eclampsia. March 2010. p6
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- steroids if <34 weeks: 11.4mg IM Betamethasone (Celestone Chronodose®), daily for two (2) days.
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If patient’s condition deteriorates (i.e. BP becomes uncontrollable, or she shows signs of increased reflexes) seek a medical review of the woman PRIOR to transfer to Birth Suite.
For a patient with moderate pre-eclampsia consider induction of labour from 37 weeks gestation.
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9. Postnatal follow-up
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Women who have experienced pre-eclampsia may require discharge on antihypertensive medication and arrangements should be made for ongoing outpatient monitoring of blood pressure.
Women with severe or early onset pre-eclampsia should have physician review routinely at six weeks, although in some cases earlier and/or later follow up may be required. This process applies to women discharged on antihypertensive medication.
Hypertension that has not resolved after three months requires further review by a physician and investigation [consider renal disease, systemic disease (SLE, diabetes) endocrine disease (phaeochromocytoma, primary aldosteronism)] coarctation of the aorta, renal artery stenosis, essential hypertension.
Early onset (≤32 weeks) severe PE, particularly if associated with IUGR, requires further investigation (inherited or acquired thrombophilia, antiphospholipid syndrome, autoantibody screen, renal disease).These women should be offered an obstetric review appointment as well as review by a physician.
Timely communication with the woman’s primary health care provider at discharge is important.
The woman’s medical and obstetric history, current status and plan for ongoing care should be communicated to the women’s community health care providers (e.g. GP and Maternal and Child Health Nurse).
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10. Consumer information
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Consumer fact sheet (under review).
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11. Resources
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Clinical Practice Guidelines
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12. Performance indicators/audit tools (for consideration)
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- Rate of documented involvement of obstetric consultant and anaesthetist in acute management.
- Proportion of women who have received full complement of appropriate investigations.
- Proportion of women in whom fluid intake/management has been restricted to appropriate levels (80mL/hr).
- Proportion of women receiving appropriate management with magnesium sulphate prophylaxis.
- Proportion of women with eclampsia treated with magnesium sulphate.
- Proportion of women returning for postnatal review (obstetric/physician) and/or pre-conceptional counselling.
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References
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References
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Pre-eclampsia: Management:References
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Revised and updated: 17 June 2010
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Royal Women's Hospital Clinical Practice Guidelines (CPGs) are intended to provide guidance to health care professionals, based on a thorough evaluation of research evidence, on the practical assessment and management of specific clinical issues or situations. The guidelines allow some flexibility on the part of the health care professional based on the needs of the specific patient for whom they are caring.
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