Original Articles
 

By Dr. Alvin Mathew , Dr. Mridula M , Dr. Shashidhar Vishwanath , Dr. Chiranjay Mukhopadhyay , Prof. Gabriel Rodrigues
Corresponding Author Prof. Gabriel Rodrigues
Kasturba Medical College, Manipal University, - India 576104
Submitting Author Prof. Gabriel Rodrigues
Other Authors Dr. Alvin Mathew
Kasturba Medical College, Manipal University, - India

Dr. Mridula M
Department of Microbiology, Kasturba Medical College, Manipal University, - India

Dr. Shashidhar Vishwanath
Department of Microbiology, Kasturba Medical College, Manipal University, - India

Dr. Chiranjay Mukhopadhyay
Department of Microbiology, Kasturba Medical College, Manipal University, - India

GENERAL SURGERY

Necrosis, fasciitis, debridement, antibiotics, mortality, morbidity

Mathew A, M M, Vishwanath S, Mukhopadhyay C, Rodrigues G. Clinico-microbiological Profile Of Necrotizing Fasciitis Secondary To Diabetes Mellitus In A Tertiary Care Hospital. WebmedCentral GENERAL SURGERY 2010;1(12):WMC001399
doi: 10.9754/journal.wmc.2010.001399
No
Submitted on: 22 Dec 2010 04:26:59 AM GMT
Published on: 22 Dec 2010 04:04:48 PM GMT

Abstract


Objectives: Necrotizing fasciitis is a life-threatening soft-tissue infection primarily involving the superficial fascia. The present study describes the clinical presentation and microbiological characteristics of this condition as well as risk factors, management and outcome of the patients.
Materials and Methods: In this prospective study, tissue and/or wound swabs and blood for culture from 50 clinically suspected cases were cultured aerobically and anaerobically and the isolates tested for sensitivity. Clinical correlation and follow-up was done.
Results: The age range was 17-87 years (mean=54 yrs) with a male predominance. The most common site of infection was the calf region (59.5%) and diabetes mellitus was the most common associated comorbidity (44.7%). Majority of the patients presented with symptoms of sepsis, systemic toxicity, or evidence of skin inflammation. Hyperacute cases presented with sepsis and quickly progressed to multiorgan failure (40%). 23 patients (57.5%) had microbiological isolates and in 16% of the cases, there was an anaerobic growth. Staphylococcus aureus and Klebsiella pneumonia were the most common isolates, whereas Pseudomonas aeruginosa was the most common environmental strains, suggestive to be colonizer. Antibiotics were instituted in all patients and all required debridement. Amputation had to be done in 2 patients. 21.3% of the patients were admitted in the ICU. Most of the patients recovered on treatment.
Conclusions: Necrotizing fasciitis is a common condition that results in gross morbidity and mortality if not treated at early stages. A high index of suspicion is important in view of the paucity of the specific cutaneous findings early in the course of the disease.


Introduction


Necrotizing fasciitis (NF) is a progressive, rapidly spreading, inflammatory infection of the deep fascia, with secondary necrosis of the subcutaneous tissues usually associated with trauma and immunodeficiency. [1] A variety of terms are used to describe this condition like Fournier’s gangrene, phagedena, phagedena gangrene, hospital gangrene, progressive bacterial synergistic gangrene (Meleney’s gangrene) and haemolytic streptococcal gangrene and depend on the site of infection. The term NF was first coined by Wilson in 1952, is perhaps most accurate to describe the key features of infectious process. [2] In South East Asian countries it is associated with 30-70% mortality despite advancement in therapy. [3-5] According to the microbiological characteristics, NF is classified as: Type 1 (polymicrobial) and Type 2 (monomicrobial), the former being more common. [6, 7] Type 1 NF commonly occurs in immunocompromised individuals, such as patients with diabetes mellitus or chronic renal failure. The etiologic isolates consist of Gram positive organisms such as Staphylococcus aureus, Staphylococcus pyogenes and Eenterococci species. Gram negative aerobes such as Escherichia coli and Pseudomonas species and anaerobic organisms such as Bacteroides and Clostridum species.[8, 9]
Classical clinical signs include edema, woody hard texture to subcutaneous tissue, disappropriate pain in relation to affected area with skin vesicles and soft tissue crepitus. The progression of the disease is often fulminant and the prognosis hinges on accurate diagnosis and immediate restitution of appropriate antibiotic treatment. While differentiation from common soft tissue infection such as cellulitis and abscess is critically important due to the paucity of cutaneous findings early in the course of the disease makes the diagnosis challenging. [3]Complications of the disease depend on the causative agent, like Clostridium which can give rise to subcutaneous gas and toxin producing bacteria which lead to toxic shock syndrome. [6] NF is most common in patients with uncontrolled DM, around 25%. [10] Higher blood sugar and low oxygen tension favours microbial growth

Methods


Objectives
The purpose of study was (1) to analyze the clinical presentation, type of infection and various risk factors, especially association with DM; (2) to determine the bacteriological profile of Type 1 and 2 NF; and (3) to see the resistance pattern of the bacteria isolated.
Materials and Methodology
Medical records of all patients who were diagnosed to have NF at a tertiary care University Hospital were prospectively reviewed for 3 months during the period of May 2010 to July 2010. Fifty patient records were studied and tissue/wound swab was collected after taking informed consent. All patients meeting the clinical and/or histopathology criteria for NF were included. The following criteria were used for establishing the diagnosis.
a) Inclusion Criteria
1. Patient has organisms cultured from tissue or discharge from affected site
2. Patient has purulent drainage at affected site
3. Patient has an abscess or other evidence of infection seen during surgical debridement or histopathological examination.
4. Patient has at least 2 of these signs or symptoms at the affected site with no other recognized cause: localized pain or tenderness, redness, swelling or heat.
b) Collection and processing
Wound swab from all patients diagnosed to have NF was collected after surgical debridement. Blood culture (2 sets preferably) were done if there was any sign of bacteremia. The tissue was homogenized under sterile conditions and was cultured on blood and McConkey agar. The culture plates were incubated overnight at 370C for aerobic growth. Bacterial growth was identified by the biochemical test and the resistance pattern by disc diffusion method according to CLSI (Clinical and Laboratory Standards Institute) guidelines. The tissue sample or the wound swab was inoculated immediately after collection in RCM (Robertson’s Cooked Meat) media for further anaerobic culture and identification. Variables that were examined included age, sex, mode of presentation, site/location of infection, co-morbid illness, etiological factors, admitting diagnosis, investigations, microbiological characteristics, antibiotic sensitivity and the treatment outcome. Statistical Analysis was performed using SPSS statistical software (version16.0).


Results


The minimum age of appearance of NF was 17 years and the maximum being 87 years (mean age=54). There were 46 males (93.6%) and only 4 females (6.4%). 46.8% of the people were agriculturists by profession. Majority of the patients had calf region involvement (59.5%). The various sites involved is outlined in Table 1.
Among the risk factors Type 2 DM was present in 21 (44.7%) cases. 12 (25.5%) had hypertension, 3 (6.4%) had liver cirrhosis, 4 (8.5%) had renal failure, 3 (6.4%) had COPD and 2 (4%) had IHD. Hepatitis B, jaundice, seizure disorder, HIV positive status, ear infection and CVA was present in one patient each. In 15 (31.9%) patients, no risk factor could be identified and 12 (25.5%) were aged more than 60 years (Figure 1).
Figure 1. Bar diagram showing various risk factors.
Clinical diagnosis at admission was NF in 23 (48.9%) of the cases, cellulitis in 16 (34%), diabetic ulcer in 4 (8.5%), abscess and others in 2 patients (Figure 2).
Figure 2. Pie chart showing admitting diagnosis.
Etiological factors were soft tissue infection in 20 (42.6%), trauma in 17 (36.2%), thorn prick in 3 (6.4%), snake bite in 2 (4.3%), abscess in 2 (4.3%), RTA, postoperative status, burns in 1 patient each (Figure 3).
Figure 3. Pie chart showing various etiological factors.
Physical findings were varied. Tenderness was the commonest and was seen in 46 patients (97.9%) followed by edema in 43 (91.5%). Erythema, skin vescicles/bullae, soft tissue crepitus, woody hard texture, hypotension, fever, tachycardia, altered mental status, tachpnoea were others and have been summarized in Table 2. All patients responded well to treatment, which was recorded as after 7-10 days and 10-15 days. Investigations were done on admission and repeated as after 7-10 days and 10-15 days and are summarized in Table 3.
Outcome
Mean number of surgical debridements were 1.44. Amputation was done in 3 patients (2 below knee and 1 above knee) and were diabetic. 21.3% underwent ICU care. 2 (4%) patients died, 3 (6%) patients were lost to follow up and 45 (90%) recovered. 40% of the patients had multiple organ failure.
Microbiological characterestics
After culture 20 (42.5%) showed no growth and 27 (57.5%) showed growth (55.6% monomircrobial and 44.4% polymicrobial). Of all the organisms 81.5% were aerobic, 7.4% anaerobic and 11.1% mixed. Out of the 21 diabetic patients, 47% had positive cultures of which 50% were monomicrobial and 50% polymicrobial (Figure 4). Amoxi-clav was the most preferred first line antibiotic for treatment (40.5%) to which 39.5% of the isolates showed resistance and 11.6% were sensitive.
Figure 4. Frequency of organisms isolated

Discussion


NF is a surgical emergency with a high degree of morbidity and mortality which requires early recognition and aggressive debridement to avoid sepsis. Most of the studies have reported a mortality rate of 30-70%. [10, 11-14] However in our study only two patients died since it may be due to the early diagnosis and debridement of most of the cases or can be attributed to reduced virulence of the microorganism. Although only 2 patients died serious complications like septic shock, renal failure, hypotension, tachypnoea, altered mental status were seen in our patients.
These patients usually have a preexisting disease which increases the susceptibility to infection. Most common ones are DM, age >60 years, hypertension and chronic renal failure. [10] In our study the most common risk factor was DM, which is consistent with other studies. [15, 16]High blood sugar in these patients predispose to an environment of low oxygen tension and a rich substrate for bacterial growth. The most common site of infection was lower limb and this can be explained by the fact that most of our patients were diabetics, who are more prone for lower limb infections. Often it is difficult to make a diagnosis of NF due to paucity of cutaneous findings early in the course of the disease. In our study close to 50% of the cases were diagnosed as NF. However in a study conducted by Wong et al [3] only 14.8% of the cases were diagnosed as NF. Though broad spectrum antibiotics (BSA) were started in these misdiagnosed cases the progression of the disease was not altered which emphasizes the need for accurate diagnosis and emergency surgical debridement. The most common etiological factor was soft tissue infection since most of them merely presented as superficial infection of skin which later on progressed to involve the deeper structures. This would explain the number of cases diagnosed as cellulitis (34%).In our study, edema and tenderness were seen in most of the cases compared to erythema (60%), which may suggest that these to be one of the early signs of the disease. Following debridement and administration of BSA, edema and erythema subsided in majority of the patients. An intermediate stage characterized by the formation of bullae was noted in 50% of the patients. According to Wong it is an important diagnostic clue and should raise the suspicion of NF. [3] Soft tissue crepitus and woody hard texture were inconsistent findings in our patients. Fever and leucocytosis may be considered systemic manifestations of the disease process.
Out of 21 patients who were diabetic 47% had positive cultures, of which 50% were poly microbial and 50% monomicrobial. On the other hand out of 27 cultures which yielded bacterial growth, 55.6% were monomicrobial and 44.4% polymicrobial. Most common organism isolated was Pseudomonas aeruginosa (23%) followed by Klebsiella pneumoniae (16%) and Staphylococcus aureus (16%). Escherichia coli andbeta hemolytic Streptococcus is also reported to be an important cause of monomicrobial infection (45.6%) in necrotizing fasciitis. [12] In this study it accounted only for 9% of total growth positive cultures.Bacteriology of NF can be polymicrobial involving combinations of anaerobes and facultative anaerobes. Mixed flora accounts for around 68% of cultures. [12] Anaerobes alone can also be significant pathogens (22%). [14] In this study 7.4% of growth positive cultures had anaerobic organisms and 11.1% had mixed aerobic and anaerobic bacteria.

References


1.Surjushe A, Vasani R, Thakre M, Saple DG. Necrotizing fasciitis in a HIV infected patient. Indian J Dermatol Venereol Leprol 2008;74:268-70.
2.Puvanendran R, Huey MC, Pasupathy S. Necrotizing fasciitis. Clinical review. Can Fam Physician 2009;55:981-987.            3.Wong CH, Chang HC, Pasupathy S, Khin LW, Tan JC, Low CO. Necrotizing fasciitis: Clinical presentation, microbiology and determinants of mortality. Am J Bone Joint Surg 2003;85:1454-1460.
4.Singh G, Sinha SK, Adhikary S, Babu KS, Ray P, Khanna SK. Necrotizing infections of soft tissue a clinical profile. Eur J Surg 2002;168:366-371.
5.Rangaswamy M. Necrotizing fasciitis: a 10 year retrospective study of cases in a single university hospital in Oman. Acta Trop 2001;80:169-175.
6.Anuradha DE, Biswas J, Saraswathi K, Gogate A. Microbiological features of necrotizing fasciitis. Indian Journal of Medical Microbiology 1999;17:18-21.
7.Sudarsky LA, Laschinger JC, Coppa GF, Spencer FC. Improved results from a standardized approach in treating patients with necrotizing fasciitis. Ann Surg 1987;206:661-665.
8.Miller LC, Perdreau-Remington F, Rieg G, Mehdi S, Perlroth J, Bayer AS, et al. Necrotizing fasciitis caused by community associated methicillin-resistant Staphyococcus aureus in Los Angeles. N Eng J Med 2005;352:1445-1453.
9.Ananya DA, Dellinger EP. Necrotizing soft tissue infection: diagnosis and management Clin infect Dis 2007;44:705-710.
10.Sentochnik DE. Deep and soft tissue infections in diabetic patients. Infect Dis Clin North Am 1995;9:53-64.
11.Elliott D, Kufera JA, Myers RA. The microbiology of necrotizing soft tissue infections. Am J Surg 2000;179:361-366.
12.Demirag B, Tirelioglu AO, Sarisozen B, Durak K. Necrotizing fasciitis in the lower extremity secondary to the diabetic wounds. Acta Orthop Traumatol Turc 2004;38(3):195-199.
13.Anaya DA, McMahon K, Nathens AB, SullivanSR, Foy H, Bulger E. Predictors of Mortality and Limb Loss in Necrotizing Soft Tissue Infections. Arch Surg 2005;140:151-157. 
14.Shaikh N. Necrotizing fasciitis and diabetes mellitus. Int J Diab Dev Ctries 2007;27:14-17.
15.Shaikh N, Ummunissa F, Hanssen Y, Makki YA, Shok HM. Hospital epidemiology of emergent cervical necrotizing fasciitis. J Emerg Trauma Shock 2010;2:123–125.
16.Salvador VB, San Juan MD, Salisi JA, Consunji RJ. Clinical and microbiological spectrum of necrotizing fasciitis in surgical patients at a Philippine University Medical Centre. Asian J Surg 2010;33:51-8.

Source(s) of Funding


ICMR funded this project

Competing Interests


Nil

Disclaimer


This article has been downloaded from WebmedCentral. With our unique author driven post publication peer review, contents posted on this web portal do not undergo any prepublication peer or editorial review. It is completely the responsibility of the authors to ensure not only scientific and ethical standards of the manuscript but also its grammatical accuracy. Authors must ensure that they obtain all the necessary permissions before submitting any information that requires obtaining a consent or approval from a third party. Authors should also ensure not to submit any information which they do not have the copyright of or of which they have transferred the copyrights to a third party.
Contents on WebmedCentral are purely for biomedical researchers and scientists. They are not meant to cater to the needs of an individual patient. The web portal or any content(s) therein is neither designed to support, nor replace, the relationship that exists between a patient/site visitor and his/her physician. Your use of the WebmedCentral site and its contents is entirely at your own risk. We do not take any responsibility for any harm that you may suffer or inflict on a third person by following the contents of this website.

Comments
0 comments posted so far

Please use this functionality to flag objectionable, inappropriate, inaccurate, and offensive content to WebmedCentral Team and the authors.

 

Author Comments
0 comments posted so far

 

What is article Popularity?

Article popularity is calculated by considering the scores: age of the article
Popularity = (P - 1) / (T + 2)^1.5
Where
P : points is the sum of individual scores, which includes article Views, Downloads, Reviews, Comments and their weightage

Scores   Weightage
Views Points X 1
Download Points X 2
Comment Points X 5
Review Points X 10
Points= sum(Views Points + Download Points + Comment Points + Review Points)
T : time since submission in hours.
P is subtracted by 1 to negate submitter's vote.
Age factor is (time since submission in hours plus two) to the power of 1.5.factor.

How Article Quality Works?

For each article Authors/Readers, Reviewers and WMC Editors can review/rate the articles. These ratings are used to determine Feedback Scores.

In most cases, article receive ratings in the range of 0 to 10. We calculate average of all the ratings and consider it as article quality.

Quality=Average(Authors/Readers Ratings + Reviewers Ratings + WMC Editor Ratings)