Abstract
Introduction:
We aim to review the clinical course of patients with necrotizing fasciitis (NF) presenting to the emergency department, hence determining the need for close monitoring for deterioration, and the need for urgent and rapid surgical intervention.
Methods:
A retrospective review of electronic medical records of patients with the main diagnosis of NF presenting to the Department of Emergency Medicine, Singapore General Hospital, from 2006 to 2012 was performed. Data was collected in standardized forms and used for analysis. Patients’ demographics, LRINEC scores, time to disposition, and clinical course and outcome were reviewed.
Results:
A total of 27 cases with the main diagnosis of NF were reviewed. The median age was 56 years (range 20–79). Twenty-four (88.9%) cases had significant underlying comorbidities. Only 18 (66.7%) cases had a LRINEC score of six or more, mandating careful evaluation for NF. Seven (25.9%) cases were managed in the resuscitation room, with median time taken from registration to resuscitation room being 14 min (range 0–231). Four (14.8%) cases were sent to the operation theater from the emergency department with a median time 321.5 min (range 286–436). Case fatality rate in this series was 14.8%.
Conclusions:
NF can result in gross morbidity and mortality if not treated in the early stages. The emergency physician needs to have a high index of suspicion to recognize the disease early and initiate prompt resuscitative efforts in septic patients, including urgent referral for surgical debridement.
Keywords
Introduction
Necrotizing fasciitis (NF) is a rapidly progressing infection involving fascia and subcutaneous tissue leading to necrosis. It is characterized by fulminant tissue destruction, systemic signs of toxicity and high mortality. Conditions associated with increased risk of infection include diabetes, recent drug use, obesity, immunosuppression, recent surgery, and traumatic wounds. 1 Less than 10% of patients with NF had more than one etiological factor. 2
As patients seek out alternative therapies, there have been case reports of NF resulting from the use of acupuncture and moxibustion, 3 the application of topical herbal products, 4 and the consumption of traditional medicine such as Jamu, 5 a traditional Indonesian herb.
‘Red flags’ for NF include pain out of proportion, surgery at site of infection in the preceding 90 days, hypotension, altered mental status, erythema progression beyond marked margins, skin fluctuance, hemorrhagic bullae and skin necrosis. 6 The cornerstone of treatment for NF is early and complete surgical debridement of the necrotic tissue, combined with broad spectrum antimicrobial therapy. 7 This should be initiated as soon as possible within the emergency department.
However, NF is a diagnostic dilemma, with a majority of the cases initially misdiagnosed. 8 With the delay in timely interventions, these patients can rapidly deteriorate, leading to increased length of stay in hospital, need for ICU admission, morbidity and mortality. 9
We reviewed the clinical presentation and progression of cases of NF that presented to the Department of Emergency Medicine, Singapore General Hospital, to elucidate unique characteristics in the management of this group of patients.
Patients and methods
Study population and study design
A retrospective observational study was carried out. All cases that presented to the Department of Emergency Medicine, Singapore General Hospital, from 2006 to 2012, with the admitting diagnosis of NF were included. After identifying patients who fulfilled the criteria, their electronic medical records were accessed for data collection and tabulated in a standardized form. Information including demographics (age, gender, race), pre-existing comorbidities, presenting complaint, vital signs (temperature, heart rate, blood pressure, respiratory rate and oxygen saturation), Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score, clinical course within the emergency department and hospital, microbiology and clinical outcome of amputation or death were collected and analyzed using SPSS version 16.
This study was approved by the ethics committee of the institution.
Results
Characteristics of the study population
A total of 27 records were reviewed. The population studied had the following characteristics (see Table 1): median age 56 (range 20–79) years old; 74.1% male and 25.9% female; 63.0% Chinese, 14.8% Malay and 22.2% Indian.
General characteristics of study population.
Eleven (40.7%) patients were transferred from other hospitals to Singapore General Hospital for further management. Six of these patients had undergone surgical treatment (including fasciotomy and debridement, or amputation) prior to transfer.
Pre-existing comorbidities
Twenty-four (88.9%) patients had pre-existing comorbidities, with 20 of them having more than one existing comorbidity. Eleven patients (40.7%) had diabetes mellitus, which is known to be associated with increased mortality. 10 The prevalence of other comorbidities among patients with NF is presented in Table 2. The presence of any comorbidity was associated with a higher probability for the clinical outcome of death or amputation (p=0.222) (see Table 3).
Pre-existing comorbidities.
Includes hepatocellular carcinoma, hepatitis C carrier, fatty liver; bIncludes peripheral vascular disease, arterial ulcer, history of amputation; cIncludes previous history of cancer (no current treatment); dIncludes leprosy and Charcot joint.
Comorbidity and clinical outcome of death or amputation.
Laboratory Risk Indicator for NF (LRINEC) score
LRINEC score, consisting of C-reactive protein, total white blood cell count, hemoglobin, sodium, creatinine and glucose, has been validated and can be utilized to risk stratify patients to determine the likelihood of NF. 11 A score more than or equal to 6 indicates that NF should be seriously considered. In our case series, 18 (66.7%) patients had a LRINEC score of more than or equal to 6 at presentation to our emergency department.
Eleven (40.7%) patients underwent amputation. The median initial LRINEC score was 10 (range 2–12) (see Table 4). Four (14.8%) patients died from NF, including two patients who had undergone amputation. The median initial LRINEC score was 6 (range 2–11) (see Table 5).
LRINEC score and clinical outcome of amputation.
LRINEC score and clinical outcome of death.
LRINEC score was not significant for the clinical outcome of death or amputation (p=0.696). Similarly, none of the components of LRINEC score was a significant variable (see Table 6).
LRINEC score and clinical outcome (death or amputation).
Clinical course
Eight (29.6%) patients were managed in the resuscitation room as high-priority emergent (P1) cases. The median time from registration to resuscitation room was 14 minutes (range 0–231 minutes). Two of these patients were initially triaged as urgent (P2) cases but subsequently up-triaged to the high-priority emergent (P1) category due to hypotensive episodes within the emergency department.
Nineteen (70.4%) patients were admitted to the general ward, four (14.8%) patients were admitted to the high-dependency unit and four (14.8%) patients were transferred directly to the operation theater with a median time of 321.5 minutes from registration to operation theater (range 286–436 minutes).
The case fatality rate in this case series was 14.8%. Two of these patients were offered comfort measures in view of pre-existing comorbidities and high risk of operative management, while the other two patients underwent surgical management but succumbed due to overwhelming sepsis.
Microbiology
Monomicrobial infection was more common in 13 (48.1%) patients, with either Staphyloccocus aureus or Streptococcus spp (Groups A, B, C) being the main causative organism. Other microbes isolated from blood and tissue cultures included Enterococcus spp, Enterobacter spp, Proteus mirabilis, Klebsiella spp, Pseudomonas aeruginosa and Vibrio vulnificus. Eight (29.6%) patients had negative intraoperative cultures; three (11.1%) patients were transferred cases with prior operation and antibiotics.
Discussion
Clinical course
In our series, patients did not do worse regardless of their level of triage within the emergency department. Our patients received treatment as per sepsis management with early administration of antibiotics and source control, with prompt referral for definitive surgery. Of the two patients who were up-triaged due to deterioration within the emergency department, one patient died from overwhelming sepsis with disseminated intravascular coagulopathy, despite surgical intervention.
For the four patients who were transferred to the operation theater from the emergency department, the median time taken from registration was 321.5 minutes. Source control remains the most definitive treatment for patients with NF. While early administration of antibiotics with supportive treatment is important, the most crucial intervention remains definitive surgery. Of these four patients, only the patient who took the longest (436 minutes) to reach the operating theater died. Emergency physicians can play a vital role in expediting the transfer of critically ill patients to the operation theater by involving the relevant specialists (orthopedics, surgical intensivists, and anesthetists) early in those who are identified as critically ill.
The rate of ICU admissions for NF has been reported ranging from 56% 12 to 63%, 13 indicating the critical state these patients were in and the need for close monitoring due to the potential for rapid deterioration. However, 70.4% of the patients in this study were admitted to the general ward. This can be explained by the fact that 11 patients were transferred from another medical facility. Treatment had been initiated leading to stabilization, and six of them had definitive surgery performed prior to transfer. These patients were transferred for continuity of care by our specialists.
LRINEC
Like many other clinical rules which have been established across various specialties to aid the physician in making clinical decisions, LRINEC should not take over the clinical decision-making process from the emergency physician. The components of the LRINEC score are a measure of biochemical and inflammatory changes during sepsis. The severity of the sepsis response is likely to translate into a higher LRINEC score. However, it is important to emphasize that a low LRINEC score (less than 6) does not rule out NF and cannot be applied in this fashion. In our study, 88.9% of patients had underlying comorbidities. The presence of any comorbidity was associated with a higher probability of clinical outcome of death or amputation. Therefore, we propose that patients with any underlying comorbidity should be treated as high risk and would benefit from admission for further investigation and management if in doubt of diagnosis.
Our study also suggested that a higher LRINEC score may be associated with a greater likelihood for limb amputation, as indicated by the higher median LRINEC score in those who underwent amputation. Amputation was required in 40.7% of patients in our study. This was significantly higher than the reported rate of 5.4% in a population-based study by Holena et al., 14 and also other similar cohorts which ranged from none 15 to 25.7%. 16 The higher amputation rates likely reflected the increased severity of illness among the patients in our series.
Increased incidence
There seemed to be an apparent rise of incidence in NF in our case series (Figure 1). This could be an actual increased incidence due to chronic comorbidities, especially diabetes mellitus and obesity, increasingly being present in the population. Changes in virulence and infectivity of infecting microbes, increased clinician awareness of the specific clinical condition, and over-diagnosis of less severe skin and soft tissue infections as NF are other contributing factors. This finding was in line with those by Kaul et al. 17 and Das et al. 18
Number of cases from 2006 to 2012.
Limitations
Our study had a number of important limitations inherent to its retrospective design. Incomplete chart documentation could lead to under-detection of variables, as we had to assume the absence of documentation corresponded to an absence of the variable. Also, ascertainment bias may be present if the clinicians were more concerned about the clinical course of a rapidly deteriorating patient with NF. A prospective cohort design is difficult due to low recruitment rate for this rare and severe condition. As a result, any reports on its epidemiology, clinical features, resource utilization, and outcomes are usually from relatively small case series and cohorts, limiting the generalization of reported findings.19,20 The small numbers in our case series, though reflective of the incidence of NF, did not have adequate power to elucidate the unique characteristics in the management of NF with statistical significance.
Conclusion
NF can result in gross morbidity and mortality if not treated aggressively in the early stages. The main challenge is in establishing the diagnosis. The emergency physician needs to have a high index of suspicion to recognize the disease and make use of available tools, such as LRINEC score. Once the diagnosis is established, resuscitative efforts and monitoring should be initiated early. These include urgent referral for surgical debridement and initiating broad spectrum antimicrobial therapy. Time wasted on unnecessary investigation and tests can cause delay, leading to significant morbidity and mortality.
Footnotes
Declaration of Conflicting Interest
The authors declare that there is no conflict of interest.
Funding
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.