How to Calculate Meld Score

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MELD Score Calculator

function calculateMELD() { var bilirubin = parseFloat(document.getElementById('bilirubin').value); var inr = parseFloat(document.getElementById('inr').value); var creatinine = parseFloat(document.getElementById('creatinine').value); var sodium = parseFloat(document.getElementById('sodium').value); var dialysis = document.getElementById('dialysis').checked; var resultDiv = document.getElementById('meldResult'); // Input validation if (isNaN(bilirubin) || isNaN(inr) || isNaN(creatinine) || isNaN(sodium) || bilirubin <= 0 || inr <= 0 || creatinine <= 0 || sodium <= 0) { resultDiv.style.backgroundColor = '#f8d7da'; resultDiv.style.borderColor = '#f5c6cb'; resultDiv.style.color = '#721c24'; resultDiv.innerHTML = 'Please enter valid positive numbers for all fields.'; return; } // Apply caps and floors for MELD calculation var bilirubin_calc = Math.max(1.0, Math.min(50.0, bilirubin)); var inr_calc = Math.max(1.0, Math.min(6.0, inr)); var creatinine_calc; if (dialysis) { creatinine_calc = 4.0; } else { creatinine_calc = Math.max(1.0, Math.min(4.0, creatinine)); } // Calculate base MELD score var meld_base = (3.78 * Math.log(bilirubin_calc)) + (11.2 * Math.log(inr_calc)) + (9.57 * Math.log(creatinine_calc)) + 6.43; // Apply caps and floors for Sodium adjustment var sodium_calc = Math.max(125, Math.min(137, sodium)); // Calculate MELD-Na adjustment var meld_na_adjusted = meld_base + (1.32 * (137 – sodium_calc)) – (0.033 * meld_base * (137 – sodium_calc)); // Final MELD-Na score is rounded to the nearest whole number and capped between 6 and 40 var final_meld_score = Math.round(Math.min(40, Math.max(6, meld_na_adjusted))); resultDiv.style.backgroundColor = '#e9f7ef'; resultDiv.style.borderColor = '#d4edda'; resultDiv.style.color = '#28a745'; resultDiv.innerHTML = 'Your MELD Score is: ' + final_meld_score + ''; }

Understanding the MELD Score

The MELD (Model for End-Stage Liver Disease) score is a numerical scale used to assess the severity of chronic liver disease. It predicts the three-month survival rate for patients with advanced liver disease and is a critical tool in prioritizing patients for liver transplantation. A higher MELD score indicates more severe liver disease and a greater urgency for transplant.

How is the MELD Score Calculated?

The MELD score is calculated using a specific mathematical formula that incorporates several routine laboratory values. The most commonly used version, MELD-Na, also includes serum sodium levels, as hyponatremia (low sodium) is a common complication of advanced liver disease and is associated with increased mortality.

The key lab values used in the MELD-Na calculation are:

  1. Total Bilirubin (mg/dL): A measure of how well the liver is clearing bile. High levels indicate impaired liver function.
  2. INR (International Normalized Ratio): A measure of how quickly blood clots. The liver produces clotting factors, so a high INR suggests severe liver dysfunction.
  3. Creatinine (mg/dL): A measure of kidney function. Liver disease can affect kidney function, and elevated creatinine levels indicate renal impairment. If a patient has undergone two or more dialysis treatments within the last seven days, their creatinine value is automatically set to 4.0 mg/dL for the calculation, reflecting severe kidney dysfunction.
  4. Sodium (mEq/L): Serum sodium levels are incorporated to refine the MELD score, as low sodium (hyponatremia) is an independent predictor of mortality in liver disease.

The calculator above uses the MELD-Na formula, which involves a base MELD calculation and then an adjustment based on sodium levels. Specific caps and floors are applied to each lab value to ensure the score remains within a clinically relevant range. The final MELD score typically ranges from 6 (least severe) to 40 (most severe).

Interpreting Your MELD Score

The MELD score is a dynamic tool, and its interpretation should always be done by a healthcare professional. Generally, a higher score indicates a greater risk of mortality within three months without a liver transplant. Here's a general guide:

  • 6-9: Relatively low risk of mortality.
  • 10-19: Moderate risk.
  • 20-29: High risk, often indicating a strong need for transplant evaluation.
  • 30-40: Very high risk, indicating urgent need for transplant.

It's important to remember that the MELD score is just one factor in a comprehensive medical evaluation. Other clinical factors, such as the presence of hepatocellular carcinoma (liver cancer) or specific metabolic diseases, can also influence transplant priority.

Examples of MELD Score Calculation

Let's look at a few examples to illustrate how different lab values impact the MELD score:

Example 1: Moderate Liver Disease

  • Total Bilirubin: 2.5 mg/dL
  • INR: 1.8
  • Creatinine: 1.2 mg/dL
  • Sodium: 135 mEq/L
  • Dialysis in last 7 days: No

Calculated MELD Score: 20
This score suggests moderate liver dysfunction, warranting close monitoring and potentially transplant evaluation.

Example 2: Severe Liver Disease with Renal Impairment

  • Total Bilirubin: 15.0 mg/dL
  • INR: 3.0
  • Creatinine: 3.5 mg/dL
  • Sodium: 128 mEq/L
  • Dialysis in last 7 days: Yes

Calculated MELD Score: 40
In this case, the high bilirubin, INR, and the fact that the patient is on dialysis (which sets creatinine to 4.0 for the calculation) result in a very high MELD score, indicating severe, life-threatening liver disease and urgent need for transplant.

Example 3: Early Liver Disease or Healthy Liver

  • Total Bilirubin: 0.8 mg/dL (capped at 1.0 for calculation)
  • INR: 0.9 (capped at 1.0 for calculation)
  • Creatinine: 0.7 mg/dL (capped at 1.0 for calculation)
  • Sodium: 140 mEq/L (capped at 137 for calculation)
  • Dialysis in last 7 days: No

Calculated MELD Score: 6
This score represents the lowest possible MELD score, indicating minimal or no significant liver dysfunction.

The MELD score is a powerful tool in hepatology, but it is crucial to consult with a medical professional for accurate diagnosis, prognosis, and treatment planning for liver disease.

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