What is the treatment for hyperkalemia in pregnancy?

Treatment of Hyperkalemia in Pregnancy

For hyperkalemia during pregnancy, treatment should follow a stepwise approach beginning with calcium gluconate for cardiac membrane stabilization, followed by insulin with glucose for intracellular potassium shifting, and beta-agonists as needed, while avoiding sodium polystyrene sulfonate due to risks of intestinal complications. 1

Initial Assessment and Severity Classification

Hyperkalemia during pregnancy requires prompt recognition and treatment based on severity:

• Mild: K+ 5.5-6.0 mmol/L
• Moderate: K+ 6.1-6.5 mmol/L
• Severe: K+ >6.5 mmol/L or with ECG changes

ECG changes to monitor for:

• Peaked T waves (earliest sign)
• Flattened or absent P waves
• Prolonged PR interval
• Widened QRS complex
• Sine-wave pattern (pre-arrest)

Treatment Algorithm for Hyperkalemia in Pregnancy

Step 1: Cardiac Membrane Stabilization (for severe hyperkalemia or ECG changes)

• Calcium gluconate 10%: 15-30 mL IV over 2-5 minutes 1
  • Preferred over calcium chloride in pregnancy
  • Onset: 1-3 minutes; Duration: 30-60 minutes
  • Note: Does not lower potassium levels but protects the heart

Step 2: Shift Potassium into Cells

• Insulin with glucose: 10 units regular insulin with 25g glucose (50 mL of D50W) IV over 15-30 minutes 1
  • Onset: 15-30 minutes; Duration: 2-4 hours
  • Monitor for maternal hypoglycemia
• Nebulized albuterol: 10-20 mg nebulized over 15 minutes 1
  • Can be used as adjunct therapy
  • May cause maternal tachycardia
• Sodium bicarbonate: 50 mEq IV over 5 minutes 1
  • Less effective as monotherapy
  • Consider primarily if metabolic acidosis is present

Step 3: Enhance Potassium Elimination

• Loop diuretics: Furosemide 40-80 mg IV 1
  • Only effective if renal function is preserved
  • Monitor for volume depletion
• Hemodialysis 1
  • Most effective for severe, refractory hyperkalemia
  • Consider when other measures fail or in renal failure

Special Considerations in Pregnancy

• Target potassium level during pregnancy is not well-established, but a level of 3.0 mmol/L has been suggested as a minimum 1
• Normal pregnancy causes a physiologic decrease in serum potassium by 0.2-0.5 mmol/L around midgestation 1
• Avoid sodium polystyrene sulfonate (Kayexalate) due to risk of intestinal necrosis, especially concerning in pregnancy 2
• Use caution with labetalol for blood pressure control in pre-eclamptic patients with hyperkalemia, as it may potentially worsen hyperkalemia 3

Monitoring and Follow-up

• Continuous cardiac monitoring during treatment
• Check serum potassium levels 1-2 hours after initiating treatment
• Monitor glucose levels when using insulin therapy
• Repeat ECG after treatment to assess resolution of changes
• Investigate underlying cause of hyperkalemia:
  • Medication review (ACE inhibitors, ARBs, NSAIDs, potassium-sparing diuretics)
  • Renal function assessment
  • Adrenal function evaluation if indicated

Cautions and Pitfalls

1. Temporary measures (insulin/glucose, albuterol) only shift potassium and do not eliminate it; rebound hyperkalemia can occur after 2-4 hours 1
2. Avoid magnesium sulfate with calcium channel blockers due to risk of hypotension 1
3. Recognize that normal potassium levels are physiologically lower during pregnancy
4. Hyperemesis gravidarum can worsen electrolyte disturbances in pregnant women with underlying disorders 1
5. Exchange transfusion may be necessary in severe cases unresponsive to conventional therapy, particularly in neonatal hyperkalemia 4

For pregnant women with recurrent hyperkalemia, a multidisciplinary approach involving nephrology and obstetrics is essential to develop an appropriate management plan 1.