The Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC) score was developed in 2004 to risk-stratify patients with soft tissue infections using common blood tests when the clinical picture is equivocal. A score ≥ 6 conferred a positive predictive value (PPV) of 92% and negative predictive value of 96% for necrotising fasciitis.

We retrospectively calculated LRINEC scores for Orthopaedic patients admitted to ITU in our hospital with limb soft-tissue infection and confirmed Group-A Streptococcus or Staphylococcus in fluid, blood, tissue or swab culture between 2010–2017 (n=10). Mean age = 57.4 and 60% were female. Half of all patients died during admission. Mean LRINEC score of all patients was 5.3±3.1 (median = 6). Mean score in deceased patients was 4.8±2.8 (scores: 0,5,6,6,7; median = 6); in discharged patients mean = 5.8±3.7 (scores: 0,5,7,7,10; median = 7). 6 patients had a score ≥6, making our PPV 60%. 4 patients had necrotising fasciitis confirmed on histology (LRINEC scores = 0,5,7,10).

Our PPV of 60% is less than the figure obtained in the original paper. 2 patients with a LRINEC score <6 died during admission, including a patient with a score of 0. Furthermore, a patient with necrotising fasciitis confirmed on histology also had a LRINEC score of 0. We conclude that LRINEC scores should not delay surgery when clinical suspicion is high, and should be used as an adjunct to clinical decision-making, rather than a replacement, as patients with low LRINEC scores can also have confirmed necrotising fasciitis and poor outcomes.