Title of the Topic - Validation of Lrinec (Laboratory Risk

RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES

KARNATAKA, BANGALORE

ANNEXURE II

PERFORMA FOR REGISTRATION OF SUBJECT FOR DISSERTATION

(to be submitted in duplicate)

TITLE OF THE TOPIC - VALIDATION OF LRINEC (LABORATORY RISK

INDICATOR FOR NECROTIZING FASCIITIS) SCORING

SYSTEM FOR THE DIAGNOSIS OF NECROTIZING

FASCIITIS IN PATEINTS PRESENTING WITH SOFT

TISSUE INFECTIONS.

6. BRIEF RESUME OF INTENDED WORK:

6.1 NEED FOR WORK –

It has been shown by numerous studies in the past that early recognition and

surgical intervention at the earliest is the sole factor in preventing the morbidity and

mortality in patients with necrotising fasciitis. The paucity of specific cutaneous signs to

distinguish necrotising fasciitis from other soft tissue infections such as cellulitis makes the

diagnosis extremely difficult. So a scoring system which is easy to follow and cost effective

with high positive and negative predictive value is required. One such scoring system is the

LRINEC scoring system devised by Wong. etal in 2005 which claims to have a positive

predictive value of 92.0% and negative predictive value of 96.0%. Hence we would like to

validate this scoring system in our patients and if found to have similar comparable

predictive values, it would prove to be a boon to developing countries like India

where the mortality of the disease reported ranges from 7 to 76% and also where there is

also constraint for resources.

6.2 REVIEW OF LITERATURE:

Necrotizing fasciitis is perhaps the most severe form of soft tissue infection primarily

involving the superficial fascia. This disease has bewildered physicians for centuries.

Hippocrates in the fifth century BC gave the first description of this dreaded disease [1]. The

first report of this disease in the United States was by a Confederate Army surgeon, Joseph

Jones in 1871 and he named this entity ‘hospital gangrene’[2]. Meleney [3] in 1924 reported

an outbreak of hospital gangrene in Beijing and coined the term haemolytic streptococcal

gangrene. The term necrotizing fasciitis was first introduced by Wilson [4] in 1952 and is the

preferred term today describing the most consistent and key feature of this disease, fascia

necrosis. While the understanding of the pathophysiology of necrotizing fasciitis continues

to improve, but the mortality of this disease remains alarmingly high with reported

mortality rates ranging from 6 to 76% [5]. Delayed diagnosis and consequently delayed

operative debridement have been shown in multiple studies to increase mortality

.This is understandable: the greater the delay, the greater the tissue loss and sepsis with

consequent increased mortality. One of the main reasons for the continued high

mortality of patients afflicted by necrotizing fasciitis today is a failure to recognize and

diagnose the condition early because of the paucity of specific cutaneous signs early in its

evolution[5]. It is therefore imperative that the treating physician has a high index of

suspicion and is aware of the armamentarium of diagnostic adjuncts at his disposal when

confronted with such clinical uncertainties.

6.3 OBJECTIVES OF THE STUDY

To validate the LRINEC scoring system for the diagnosis of necrotizing fasciitis among

patients presenting with soft tissue infections to M S Ramaiah Hospitals.

7 MATERIALS AND METHODS

7.1 STUDY SUBJECTS:

All patients presenting to M S Ramaiah Hospital with symptoms suggestive of soft tissue

infections.

7.2 STUDY DURATION - 2 Years

7.3 METHODS OF COLLECTION OF DATA:

Patients presenting with symptoms suggestive of soft tissue infections will undergo clinical

examinations and the below mentioned investigations. Following which information

regarding the demographics & covariates of soft tissue infections will be collected using a

pretested semi- structured proforma cum observational checklist. LRINEC scoring system

will be applied to each of the study subjects. The confirmatory diagnosis for necrotising

fasciitis will be done vide histopathology for all patients, irrespective of the result of the

LRINEC scoring system.

The LRINEC (laboratory risk indicator for necrotizing fasciitis) score

LRINEC score of 6 or greater is considered positive for necrotizing fasciitis

7.4 INCLUSION CRITERIA

Patients presenting to M S Ramaiah Hospital with symptoms suggestive of soft tissue

infections during the study period.

7.5 EXCLUSION CRITERIA

1) Patients below 15 yrs or above 75 yrs of age.

2) Patients who have received antibiotic treatment in the last 48 hours or a minimum of 3

doses of antibiotic prior to presentation.

3) Patient who has undergone surgical debridement for present episode of soft tissue

infection.

4) Patients with boils or furuncles with no evidence of cellulitis.

7.6 Does the study require any investigation or intervention to be conducted on patients or

other humans or animals? If so, describe briefly.

·  Haemoglobin

·  Total white cell counts

·  Random blood sugar

·  Serum creatinine

·  Serum sodium

·  Serum C-reactive protein.

Special investigations:

·  Tissue for histopathology

·  Tissue for culture and sensitivity

·  Tissue fluid for gram staining.

STUDY DESIGN:

Hospital based observational study

STATISTICAL ANALYSIS:

Sample size estimation:

The sample size was estimated based on Positive predictive value of LRINEC as cited in

the below mentioned article, “Wong CH, Wang YS. The diagnosis of necrotizing fasciitis

Current Opinion in Infectious Diseases 2005, 18:101–106”. The study shows a Positive

Predictive Value of 92% of LRINEC system for diagnosis of NF.

Using a Positive predictive value of 92%, precision of 5% and confidence intervals of

95% the sample size was estimated to be a minimum of 113. Assuming an attrition and

non- response of 20%, a final sample size of 140 was estimated.

Descriptive statistics

-  All quantitive data like age ,vital signs and investigations will be presented as mean

and standard deviation.

-  All qualitative data like sex, symptoms ,examination findings and histopathology will

be presented as frequency and percentages.

Analytical statistics

-  Validation of LRINEC scoring system will be analysed vide sensitivity, specificity,

positive predictive value and negative predictive value. Analysis will be done using

SPSS software.

7.7 Has ethical clearance been obtained from your institution? YES

8. LIST OF REFERENCES

1.  Descamps V, Aitken J, Lee MG. Hippocrates on necrotizing fasciitis. Lancet

1994; 344:556.

2. Jones J. Investigation on the nature, causes and treatment of hospital

gangrene as it prevails in the confederate armies 1861–1865. In: Hasting

Hamilton F, editor. Surgical memoirs of the war of rebellion. New York:

Sanitary Commission; 1871.

3. Meleney FL. Hemolytic streptococcus gangrene. Arch Surg 1924; 9:317–

364.

4. Wilson B. Necrotizing fasciitis. Am Surg 1952; 18:416.

5. . Wong CH, Khin LW, Heng KS, Tan KC, Low CO. The LRINEC

(Laboratory Risk Indicator for Necrotizing Fasciitis) score: a tool for

distinguishing necrotizing fasciitis from other soft tissue infections.

Critical Care Med. 2004 Jul;32(7):1535-41