What is the nephrology management for pre-eclampsia?

Nephrology Management for Pre-eclampsia

The nephrology management of pre-eclampsia requires careful fluid management with 60-80 mL/h IV fluids to avoid pulmonary edema while preventing acute kidney injury, along with close monitoring of renal function through twice-weekly assessment of creatinine, uric acid, and proteinuria. 1

Diagnosis and Assessment

• Pre-eclampsia is defined as new-onset hypertension and proteinuria at ≥20 weeks of gestation, or hypertension with evidence of systemic disease in the absence of proteinuria 2
• Proteinuria is optimally assessed by screening with automated dipstick urinalysis and then quantifying with a urine protein/creatinine ratio; a ratio ≥30 mg/mmol (0.3 mg/mg) is abnormal 1
• When neither 24-hour urine collection nor protein/creatinine ratio is available, dipstick testing provides reasonable assessment, particularly when values are >1 g/L (2+) 1

Renal Monitoring

• Maternal monitoring should include repeated assessments for proteinuria if not already present 1
• Blood tests for renal function (creatinine and uric acid) should be performed at least twice weekly in women with pre-eclampsia 1
• Additional testing should be performed in response to any change in clinical status 1
• Urinary output should be closely monitored, with oliguria being a concerning sign requiring prompt intervention 1

Fluid Management

• Women with pre-eclampsia should not be "run dry" as they are already at risk of acute kidney injury (AKI) 1
• Intravenous fluid replacement should be at a rate of 60-80 mL/h to avoid risks of pulmonary edema while maintaining adequate renal perfusion 1
• Fluid management should account for anticipated urinary losses (0.5-1 mL/kg per hour) 1

Medication Management

• NSAIDs should be avoided in women with pre-eclampsia, especially in the setting of AKI, and alternative pain relief should be used 1
• Magnesium sulfate should be administered for convulsion prophylaxis in women with pre-eclampsia who have proteinuria and severe hypertension, or hypertension with neurological signs or symptoms 1
• Caution should be used with magnesium sulfate in women with renal insufficiency as it may lead to magnesium toxicity 3
• Diuretics are generally contraindicated as uteroplacental circulation perfusion is already reduced in pre-eclampsia with fetal growth restriction 1
• If diuretics are needed (e.g., in pulmonary edema or cardiac failure), thiazides should be chosen; furosemide has been used safely in pregnancy complicated by renal or cardiac failure 1

Antihypertensive Management

• Blood pressure requires urgent treatment in a monitored setting when severe (>160/110 mm Hg); acceptable agents include oral nifedipine or intravenous labetalol or hydralazine 1
• For less severe hypertension (≥140/90 mm Hg), treatment should aim for a target diastolic BP of 85 mm Hg (and systolic BP of 110-140 mm Hg) 1
• Antihypertensive drugs should be reduced or ceased if diastolic BP falls <80 mm Hg 1
• Acceptable agents include oral methyldopa, labetalol, oxprenolol, and nifedipine; second or third line agents include hydralazine and prazosin 1

Delivery Considerations

• Women with pre-eclampsia should be delivered if they develop progressively abnormal renal function tests 1
• The only definitive treatment for pre-eclampsia is delivery of the placenta and baby 1

Postpartum Management

• Monitor blood pressure at least 4 to 6 hourly during the day for at least 3 days postpartum 1
• Repeat hemoglobin, platelets, creatinine, and liver transaminases the day after delivery and then second daily until stable if any of these were abnormal before delivery 1
• Antihypertensives should be restarted after delivery and tapered slowly only after days 3 to 6 postpartum unless BP becomes low (<110/70 mm Hg) 1

Long-term Follow-up

• All women with pre-eclampsia should be reviewed 3 months postpartum, by which time BP, urinalysis, and all laboratory tests should have normalized 1
• Further investigation is required for persistent abnormalities, including a work-up for secondary causes of persistent severe hypertension or underlying renal disease with persistent proteinuria 1
• Women with pre-eclampsia have increased risks of cardiovascular disease, stroke, diabetes mellitus, venous thromboembolic disease, and chronic kidney disease compared with women who have had normotensive pregnancies 1
• Regular follow-up with a general practitioner is recommended to monitor BP and periodic measurement of fasting lipids and blood sugar 1