Necrotizing Fasciitis (LRINEC) Calculator

Necrotizing Fasciitis (LRINEC) Calculator for Orthopedics. The result names the below-six, six-to-seven or eight-to-thirteen interval without assigning a personalized probability. Prospective emergency-department validation found important false negatives; even a zero score cannot rule out necrotizing infection.

For shared guidance on choosing a tool and documenting results, read the clinical calculator workflow.

How this calculator works

The category route sums the six published LRINEC point contributions, from zero to 13. CRP at 150 scores four; WBC at 15 or 25 remains in the one-point category. Hemoglobin at 11 or 13.5 scores one, not two or zero.

When to use this calculator

Use only as an adjunct while assessing possible necrotizing soft-tissue infection. A missing CRP or other laboratory value cannot be assigned zero. Do not delay urgent surgical assessment to obtain a complete panel.

Inputs used

  • All six laboratory categories from one assessment: CRP mg/L, white cells 10^9/L, hemoglobin g/dL, sodium mmol/L, creatinine mg/dL and glucose mg/dL.

Clinical interpretation

The result names the below-six, six-to-seven or eight-to-thirteen interval without assigning a personalized probability. Prospective emergency-department validation found important false negatives; even a zero score cannot rule out necrotizing infection.

Worked example

CRP 150, WBC 15, hemoglobin 13.5, sodium 135, creatinine 1.6 and glucose 180 give 4 + 1 + 1 + 0 + 0 + 0 = 6. The endpoint comparisons are intentional; sodium must be below 135 to add two.

Limitations and safety notes

Clinical trajectory and examination take precedence. The US creatinine threshold here is above 1.6 mg/dL, which is not mathematically identical to a rounded SI threshold above 141 umol/L. The input-based route uses the same US convention.

References

  • https://pubmed.ncbi.nlm.nih.gov/15241098/
  • https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0227748

Editorial review and citation methodology

Maintained by the Quick Medical Calculator Editorial Team. Content record date: September 9, 2026. A content date is not evidence of independent clinical review. Individual clinical sign-off is not recorded on this page.

  • Prefer original validation studies for scoring systems and prediction tools.
  • Use current specialty society guidance, transplant allocation policy, public health guidance, or regulator resources when they govern clinical use.
  • Include limitations and safety notes when a calculator is population-specific, context-dependent, or unsuitable as a standalone decision tool.

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