What is the role of plasmapheresis in patients with pregnancy-induced hypertension (PIH) complicated by anuria?

Role of Plasmapheresis in PIH Patients with Anuria

Plasmapheresis is not recommended as a standard treatment for pregnancy-induced hypertension (PIH) patients with anuria, as there is insufficient evidence supporting its use in current guidelines.

Understanding PIH and Renal Complications

Pregnancy-induced hypertension (PIH) encompasses several hypertensive disorders including:

• Pre-existing hypertension (before 20 weeks gestation)
• Gestational hypertension (after 20 weeks)
• Pre-eclampsia (hypertension with proteinuria)
• Superimposed pre-eclampsia on chronic hypertension 1

When PIH progresses to severe forms, particularly pre-eclampsia, multi-organ dysfunction can occur, including acute kidney injury that may manifest as oliguria or anuria 2. This represents a serious complication requiring urgent intervention.

Assessment of Anuria in PIH

When evaluating a PIH patient with anuria:

1. Confirm severity of hypertension: Severe hypertension is defined as ≥160/110 mmHg 1
2. Assess for other signs of end-organ damage:
   • Laboratory abnormalities (elevated liver enzymes, thrombocytopenia, hemolysis)
   • Neurological symptoms
   • Pulmonary edema
3. Evaluate renal function:
   • Serum creatinine and BUN
   • Electrolyte abnormalities
   • Urinalysis for proteinuria (>300 mg/24h indicates pre-eclampsia) 1

Management Algorithm for PIH with Anuria

First-Line Management:

1. Immediate delivery if ≥37 weeks gestation or if maternal/fetal complications are present 3
2. Blood pressure control:
   • IV labetalol or hydralazine for severe hypertension
   • Oral nifedipine if IV access unavailable 1
   • IV nitroglycerin if pulmonary edema is present 1
3. Magnesium sulfate for seizure prophylaxis in severe pre-eclampsia 3
4. Fluid management:
   • Cautious fluid administration
   • Close hemodynamic monitoring
   • Consider diuretics if fluid overloaded 2

Management of Renal Failure:

1. Supportive care:
   • Maintain adequate perfusion pressure
   • Avoid nephrotoxic medications
   • Monitor fluid balance closely
2. Dialysis may be required for:
   • Refractory hyperkalemia
   • Severe metabolic acidosis
   • Volume overload unresponsive to diuretics
   • Uremic symptoms 4

Role of Plasmapheresis

Current guidelines from the European Society of Cardiology 1, International Society of Hypertension 1, and other authoritative sources do not mention plasmapheresis as a standard treatment for PIH patients with anuria. The absence of this recommendation in major guidelines suggests insufficient evidence supporting its routine use.

Important Considerations

1. Delivery is definitive treatment: The ultimate treatment for severe PIH is delivery of the fetus and placenta 2

2. Multidisciplinary approach: Management requires collaboration between obstetrics, nephrology, and critical care 2

3. Monitoring for persistent renal dysfunction: About 2.5% of patients may develop persistent renal failure following PIH-associated AKI 4

4. Avoid ACE inhibitors/ARBs: These medications are contraindicated in pregnancy due to fetotoxicity 3, 5

Caution

Maternal and fetal outcomes in PIH with anuria are significantly worse than uncomplicated PIH. Prompt recognition and management of this condition is essential to reduce morbidity and mortality. The reported maternal mortality in severe PIH can be as high as 2.5%, primarily due to complications like sepsis 4.

While plasmapheresis is not a standard recommendation, individual cases may warrant consideration of this therapy in specialized centers, particularly if there are features of thrombotic microangiopathy or HELLP syndrome that are unresponsive to standard therapy.