Laboratory Risk Indicator for Necrotizing Fasciitis of the Oro-Cervical Region (LRINEC-OC): A Possible Diagnostic Tool for Emergencies of the Oro-Cervical Region

C-reactive protein and neutrophil-to-lymphocyte ratio as key inflammatory indicators in the diagnosis of cervical necrotizing fasciitis

BACKGROUND

Cervical necrotizing fasciitis (CNF) is a life-threatening bacterial infection with a diagnostic challenge. Currently, there is insufficient evidence on the diagnostic accuracy of inflammatory indicators in CNF.

OBJECTIVE

This study aims to identify key inflammatory indicators and assess their diagnostic accuracy for CNF.

METHODS

A diagnostic case-control study was conducted at a tertiary healthcare facility from January 2020 to December 2023. Laboratory data from patients with CNF and non-CNF at admission were evaluated. Key inflammatory indicators were identified through consistent outcomes from multivariable logistic regression and receiver operating characteristic curves analyses. The diagnostic accuracy of these indicators, with the results of combined tests, were calculated.

RESULTS

CNF was confirmed in 21 of the 67 patients investigated. C-reactive protein (CRP) and neutrophil-to-lymphocyte ratio (NLR) were identified as key inflammatory indicators, with sensitivities of 0.905 and 0.810, and specificities of 0.870 and 0.913, respectively, at CRP threshold of 165.0 mg/L and NLR of 15.8. Combining CRP and NLR in parallel and serial tests increased sensitivity to 0.952 and specificity to 1.0, respectively.

CONCLUSIONS AND SIGNIFICANCE

CRP and NLR have been verified as key inflammatory indicators with satisfactory diagnostic abilities for CNF diagnosis, providing a strong foundation for future studies.

Application of the laboratory risk indicator for necrotizing fasciitis score to the head and neck: a systematic review and meta-analysis

BACKGROUND

Recent studies have attempted to verify the predictive capability of the Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) for cervical necrotizing fasciitis (CNF).

METHODS

The two authors independently reviewed six databases (PubMed, Cochrane, Embase, Web of Science, SCOPUS and Google Scholar databases were searched). Seven cohort studies were included in the analysis. Sensitivity and specificity were determined by extracting items from binary classification from each paper. The diagnostic accuracy of the included studies was evaluated using QUADAS ver. 2.

RESULTS

The diagnostic odds ratio (OR) of LRINEC for CNF with the cutoff value of 6 was 13.9952 (95% CI, 3.8537; 50.8255, I²  = 76.7%). The area under the SROC curve was 0.842, suggesting acceptable diagnostic accuracy. The correlation between sensitivity and false positive rate was 0.055, indicating that it was not heterogeneous. The sensitivity, specificity, and negative predictive values were 0.7503 ([0.4637; 0.9126], I²  = 79.1%), 0.8455 ([0.7084; 0.9250], I²  = 96.0%) and 0.9829 ([0.9089; 0.9970], I²  = 93.7%), respectively. In the comparison of subgroups according to a LRINEC score (6-8, and), the cutoff value of 6 showed moderate sensitivity (75%) and high specificity (85%) and greater diagnostic power than other cutoff values.

CONCLUSIONS

LRINEC is a useful adjunctive tool for predicting CNF in patients with a soft tissue infection. In addition, a more accurate diagnosis is possible by using the LRINEC score with a cutoff value of 6.

Early diagnosis of craniofacial necrotising fasciitis: Analysis of clinical risk factors

Necrotising fasciitis (NF) is a rapidly progressing fatal disease. Craniofacial necrotising fasciitis (CNF) is limited to the region above the mandibular margin, and early diagnosis is particularly difficult in the absence of related studies. Ten-year data of patients with craniofacial infection were collected from four separate hospitals. Based on the diagnostic criteria, patients were classified into abscess and CNF. The risk factors for early diagnosis were analysed by comparing the two groups. Simple abscess was found in 176 patients, and CNF was detected in 25 patients. The risk factors associated with CNF include old age, presence of odontogenic infection, elevated white blood cell count (WBC), increased C-reactive protein (CRP), high levels of creatinine (Cr) and glucose (Glu) and low levels of haemoglobin (Hb) and albumin (Alb). In addition, fever above 38°C and sinusitis at the time of admission and progressive sepsis after admission were also risk factors. Among the statistically significant risk factors, low Alb level showed the greatest association with CNF progression. Appropriate management of CNF via early diagnosis and extensive surgical intervention based on identified risk factors can reduce the mortality rate, complications and unnecessary medical expenses. Clinical question/level of evidence: Diagnostic, III.

Modified Laboratory Risk Indicator for Necrotizing Fasciitis (m-LRINEC) Score System in Diagnosing Necrotizing Fasciitis: A Nested Case-Control Study

Aim

This study aims to present a modified Laboratory Risk Indicator for Necrotizing Fasciitis (m-LRINEC) scoring system and to evaluate its ability in discriminating necrotizing fasciitis (NF) from other severe soft-tissue infections.

Methods

Patients with NF diagnosed by surgical findings in our institution between January 2014 and December 2020 were included as the case group, matched by controls with severe soft-tissue infections other than NF in a ratio of 2:1, based on demographics, calendar time and immunosuppressant status. Patients’ demographics, comorbidities and laboratory test results were extracted from medical records. Logistic regression analyses were used to determine the association with NF after adjustment for confounders, whereby m-LRINEC was developed. Receiver operating characteristics (ROC) curves and the area under the curve (AUC) were used to evaluate its discriminating ability.

Results

There were 177 patients included, 59 in the NF group and 118 in the non-NF group. We added comorbid diabetes and kidney disease to the original LRINEC scoring system, used high-sensitivity C-reactive protein (HCRP) to replace the CRP and redefined the cut-off values for the other four variables, to develop the m-LRINEC system. The cut-off value for m-LRINEC was 17 points, with corresponding sensitivity of 93.2% and specificity of 86.9%, and the AUC was 0.935 (95% CI 0.892 to 0.977; p<0.001).

Conclusion

The m-LRINEC scoring system shows a high sensitivity and specificity in discriminating NF from other severe soft-tissue infections. Patients with an m-LRINEC score of >17 points should have a high index of suspicion for the presence of NF. The validity of the m-LRINEC needs to be confirmed in studies with larger samples and better design.

Utility of modified Laboratory Risk Indicator for Necrotizing Fasciitis (MLRINEC) score in distinguishing necrotizing from non-necrotizing soft tissue infections

Background

We conducted this study to promote a modified Laboratory Risk Indicator for Necrotizing Fasciitis (MLRINEC) score and evaluate the utility in distinguishing necrotizing fasciitis (NF) from other soft-tissue infections.

Method

A retrospective cohort study of hospitalized patients with NF diagnosed by surgical finding was conducted in two tertiary hospital in southern Taiwan between January 2015 and January 2020. Another group was matched by controls with non-necrotizing soft tissue infections based on time, demographics, and immune status. Data such as infectious location, comorbidities, and laboratory findings were recorded and compared. Logistics regression were used to determine the association with NF after adjustment for confounders and MLRINEC score was developed by then. Receiver operating curve (ROC) and the area under the curve (AUC) were used to evaluate its discriminating ability.

Result

A total of 303 patients were included; 101 in NF group and 202 in non-NF group. We added serum lactate and comorbid liver disease to the original LRINEC score and re-defined the cut-off values for 3 variables to develop the MLRINEC score. The cut-off value for MLRINEC score was 12 points with corresponding sensitivity of 91.8% and a specificity of 88.4%, and the area under ROC (AUC) was 0.893 (95% CI, 0.723 to 0.948; p < 0.01).

Conclusion

MLRINEC score shows a high sensitivity and specificity in distinguishing NF from non-necrotizing soft-tissue infections. Patients with a MLRINEC score > 12 points should be highly suspected of presence of necrotizing fasciitis.

Early detecting cervical necrotizing fasciitis from deep neck infections: a study of 550 patients

PURPOSE

The aim of this retrospective review study is to evaluate Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score as an indicative parameter in early detecting cervical necrotizing fasciitis (CNF) from deep neck infections (DNI).

METHODS

We reviewed 12 cases of CNF and 538 cases of non-necrotizing deep neck infection hospitalized in our hospital over the last decade. Cervical necrotizing fasciitis was histologically confirmed.

RESULTS

Using an LRINEC score of 6 as a cutoff sensitivity was calculated at 100% (95% CI 99.9-100) and specificity 72.5% (95% CI 72.4-72.6). Negative predicted value (NPV) was 100% and positive predicted value (PPV) was 7.5%. C-reactive protein (CRP), white blood count (WBC), and glucose (Glu) levels have a higher correlation. Haemoglobin (Hb), sodium (Na), and creatinine (Cr) do not seem to have a big impact in our study.

CONCLUSION

LRINEC score proves to be a useful "rule-out" tool that works on the safe side with high sensitivity and poor specificity. WBC, CRP, and Glu seem to be the most significant variables of the LRINEC score. Hb, Na, and Cr make the score safer. Decision for surgery must be based on medical history, clinical symptoms and signs, imaging findings, and laboratory tests and not according to the LRINEC score itself.