LRINEC Score Calculator
Laboratory Risk Indicator for Necrotizing Fasciitis
What is the LRINEC Score?
The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis) score is a clinical tool developed to help clinicians distinguish necrotizing fasciitis from other severe soft tissue infections, such as cellulitis or abscesses. Since necrotizing fasciitis is a surgical emergency with a high mortality rate, early identification is critical.
Scoring Criteria and Logic
The score is calculated based on six routine laboratory parameters available in most emergency settings:
- C-Reactive Protein (CRP): Values ≥150 mg/L indicate significant inflammation (4 points).
- White Blood Cell (WBC) Count: Elevated levels correlate with infection severity (1-2 points).
- Hemoglobin: Lower levels suggest systemic illness (1-2 points).
- Sodium: Hyponatremia (<135 mmol/L) is a common finding in necrotizing infections (2 points).
- Creatinine: Elevated levels (>1.6 mg/dL) indicate potential renal impairment (2 points).
- Glucose: Hyperglycemia (>180 mg/dL) is often seen in diabetic patients or as a stress response (1 point).
Interpreting the Results
The maximum possible score is 13. Generally, the risk categories are defined as follows:
| Total Score | Risk Level | Probability of Necrotizing Fasciitis |
|---|---|---|
| ≤ 5 | Low Risk | < 50% |
| 6 – 7 | Intermediate Risk | 50% – 75% |
| ≥ 8 | High Risk | > 75% |
Clinical Example
Imagine a patient presenting with extreme pain in the lower leg and a high fever. Their labs show: CRP 160 (4 pts), WBC 22 (1 pt), Hb 10.5 (2 pts), Sodium 132 (2 pts), Creatinine 1.2 (0 pts), and Glucose 110 (0 pts). The total LRINEC score is 9, placing the patient in the high-risk category, necessitating immediate surgical consultation.
Disclaimer: This calculator is for educational purposes and should not be used as the sole basis for clinical decisions. A low LRINEC score does not rule out necrotizing fasciitis if clinical suspicion remains high.