How to Use Light氏胸膜积液诊断标准计算器
Enter paired serum and pleural fluid values: protein, LDH, and the serum LDH upper limit from the laboratory. The Light Criteria Calculator then computes the protein ratio, LDH ratio, and the two-thirds LDH threshold.
The result is exudate if any one of the three criteria is positive. If none are positive, the page labels the fluid as transudate by Light criteria.
Use values from the same diagnostic episode. Mixing a serum result from a different day with pleural fluid results can change the ratios and the classification.
Formula & Theory — Light氏胸膜积液诊断标准计算器
The Light氏胸膜积液诊断标准计算器 uses the following formula or scoring rule:
Exudate if any is true:
pleural protein / serum protein > 0.5
pleural LDH / serum LDH > 0.6
pleural LDH > 2/3 × serum LDH ULNLight criteria are designed to be sensitive for exudates. That is why a single positive criterion is enough to move the classification to exudative.
The protein ratio checks whether pleural protein is high relative to serum protein. The LDH ratio and absolute LDH threshold capture inflammatory or cellular activity reflected by LDH.
Clinical interpretation may still consider diuretic use, heart failure context, albumin gradient, infection, malignancy, pulmonary embolism, and other data.
Use Cases for Light氏胸膜积液诊断标准计算器
The Light氏胸膜积液诊断标准计算器 is useful in specific situations such as:
- reviewing thoracentesis lab results at the bedside
- teaching why Light criteria use three separate checks
- documenting which criterion made an effusion exudative
- comparing protein-driven versus LDH-driven classifications