Sodium Correction Rate Calculator

Calculate safe infusion rates for sodium correction using the Adrogue-Madias formula

Calculate Sodium Correction Rate

Normal: 135-145 mEq/L

Goal sodium level

Recommended: 24-48 hours

Example Calculation

Hyponatremia Patient

Patient: 70 kg adult male

Current Sodium: 120 mEq/L (severe hyponatremia)

Target Sodium: 130 mEq/L (conservative correction)

Fluid: 3% Saline (513 mEq/L sodium)

Timeframe: 24 hours

Step-by-Step Calculation

Step 1: TBW = 70 kg × 0.6 = 42 L

Step 2: Change per liter = (513 - 120) / (42 + 1) = 9.14 mEq/L per liter

Step 3: Volume needed = 10 mEq/L ÷ 9.14 mEq/L per liter = 1.09 L

Step 4: Infusion rate = 1090 mL ÷ 24 h = 45.4 mL/h

Result: 45.4 mL/h of 3% saline for safe correction

Total Body Water (TBW)

Child (≤18 years)

60% of body weight

Adult Male (19-65)

60% of body weight

Adult Female (19-65)

50% of body weight

Elderly Male (>65)

50% of body weight

Elderly Female (>65)

45% of body weight

Fluid Sodium Content

Hypotonic Solutions

  • • D5W: 0 mEq/L
  • • 0.225% NaCl: 39 mEq/L
  • • 0.45% NaCl: 77 mEq/L

Isotonic Solutions

  • • Lactated Ringer's: 130 mEq/L
  • • Plasmalyte: 140 mEq/L
  • • Normal Saline: 154 mEq/L

Hypertonic Solutions

  • • 3% Saline: 513 mEq/L
  • • 5% Saline: 855 mEq/L

Understanding Sodium Correction Rate

Adrogue-Madias Formula

The Adrogue-Madias formula is the most widely used method for predicting serum sodium changes during fluid therapy. It accounts for the patient's total body water and the sodium content of the infused fluid.

Safety Considerations

  • Maximum correction: 8 mEq/L per day
  • Severe symptoms: Initial rate 1-2 mEq/L/h
  • Monitor sodium every 4-6 hours
  • Risk of osmotic demyelination with rapid correction

Clinical Applications

Hyponatremia

Use hypertonic saline (3%) for severe symptomatic hyponatremia. Start with 1-2 mEq/L/h correction rate for immediate symptom relief.

Hypernatremia

Use hypotonic fluids (0.45% saline or D5W) for gradual correction. Slower correction rates (0.5-1 mEq/L/h) prevent cerebral edema.

Remember: This calculator provides estimates. Clinical judgment, continuous monitoring, and adjustment based on patient response are essential.