Wong et al developed the Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score in order to help distinguish necrotizing from non-necrotizing soft tissue infections. This can help select patients for early surgical debridement based on laboratory values that are widely available. The authors are from Singapore General Hospital.
Patient selection: significant soft tissue infection
Parameters:
(1) C-reactive protein (CRP)
(2) white blood cell (WBC) count
(3) hemoglobin
(4) serum sodium
(5) serum creatinine
(6) glucose
|
Parameter |
Finding |
Points |
|
C-reactive protein (CRP) |
< 150 mg/L |
0 |
|
|
>= 150 mg/L |
4 |
|
WBC count |
< 15,000 per µL |
0 |
|
|
15,000 - 25,000 per µL |
1 |
|
|
> 25,000 per µL |
2 |
|
hemoglobin |
> 13.5 g/dL |
0 |
|
|
11.0 - 13.5 g/dL |
1 |
|
|
< 11 g/dL |
2 |
|
serum sodium |
>= 135 mmol/L |
0 |
|
|
< 135 mmol/L |
2 |
|
serum creatinine |
<= 1.6 mg/dL |
0 |
|
|
> 1.6 mg/dL |
2 |
|
glucose |
<= 180 mg/dL |
0 |
|
|
> 180 mg/dL |
1 |
where:
• I am assuming the use of serum or plasma glucose as opposed to whole blood glucose.
• A CRP >= 150 mg/L is significantly elevated.
total score =
= SUM(points for all 6 parameters)
Interpretation:
• minimum score: 0
• maximum score: 13
• A score < 6 can be seen with non-necrotizing soft tissue infections.
• A score >= 6 favors the diagnosis necrotizing fasciitis.
|
LRINEC Score |
Risk of Necrotizing Fasciitis |
Probability of Necrotizing Infection |
|
0 to 5 |
low |
< 50% |
|
6 or 7 |
intermediate |
50 - 75% |
|
8 to 13 |
high |
> 75% |
Performance:
• In the initial report the positive predictive value was 92% and the negative predictive value was 96%. The area under the ROC curve was 0.98.
• The score is intended for patients who have a significant soft tissue infection (high pre-test probability).
Specialty: Infectious Diseases, Surgery, general
ICD-10: ,
