right-hand column like this one does at the top
FIGURES 1A, 1B. Fournier gangrene of the scrotum.
are more specific than sensitive, being present in <40% of cases, so their absence does not preclude the presence of disease.8,11,16 During the final stages of FG, patients may develop multiorgan failure, including acute respiratory distress syndrome and disseminated intravascular coagulopathy.11 Therefore, it is incumbent upon clinicians to consider FG in all patients with risk factors even in the absence of notable physical examination findings, in particular those that are refractory to conservative outpatient treatment.2,10 Diagnostics
No laboratory markers specific for FG exist, although some serum studies assist in determining the extent of systemic involvement and provide biomarkers for prognosis, including: a comprehensive metabolic panel (which may reveal hyponatremia) and elevations of white blood cells, C-reactive protein, erythrocyte sedimentation rate, and lactate.4,7,8,13 Some studies have discussed that a white blood cell count >15,400 cells/µL and serum sodium <135 mEq/L significantly increase the likelihood of necrotizing infections, with the recognition that these laboratory studies have greater negative predictive value than positive predictive yield.8 Some providers therefore advocate the use of various scoring instruments, of which
laboratory analysis is of great significance. One such instrument is the laboratory risk indicator for necrotizing fasciitis (LRINEC), which is used to distinguish between necrotizing and non-necrotizing soft tissue infections by assigning points to laboratory findings in patients with suspected severe soft tissue infections to create a score that stratifies risk (Table 2). The utility of the score is dependent on a clinician’s high index of suspicion.8 When FG is suspected, blood and wound cultures should be obtained early so that appropriate antibiotics may be selected according to the susceptibility of the causative organism(s). Computed tomography (CT) with IV contrast is the preferred modality to confirm diagnosis across specialties, owing in large part to its availability and reliability in guiding surgical management.11,17,18 CT with IV contrast is able to reveal the path of disease, extent of inflammation, fascial thickening, formation of emphysema, fluid collection, and fat stranding.11,17,18 While magnetic resonance imaging with IV contrast offers benefits similar to CT, many clinicians regard this imaging modality as impractical in the emergent setting given resource limitations and challenges in obtaining reliably. It has been proposed that diagnosis of FG may be confirmed with bedside ultrasound, which can reveal the presence of subcutaneous gas. However, this is neither specific nor sensitive, as the absence of subcutaneous emphysema does not rule out FG and has the added limitation of being examiner dependent when used at the bedside.11 Treatment
FG historically has been a urologic emergency, with early surgical intervention being the cornerstone of mortality reduction.7,9,10 Conventional practice has allowed an interdisciplinary approach that includes both plastic and general surgery. Considering multiple provider consultations in the management of FG is essential to success and may include supportive inpatient medical management by a hospitalist and an infectious disease specialist.2,3,11 A number of antibiotic regimens that can halt disease progression may be administered preoperatively, although they are not meant to substitute for or delay surgical intervention.7,10 Generally, the regimen should cover polymicrobial sources including grampositive, gram-negative, aerobic, and anaerobic organisms, with consideration for emerging multidrug-resistant strains.2,10,15 Suitable regimens might include a combination of some or all of the following: an aminoglycoside, metronidazole, piperacillin/tazobactam, clindamycin, vancomycin, and/or a third-generation cephalosporin (Table 3).2,10 Clindamycin remains one of the preferred first-line agents, due in large part to its role in reduction of mortality through coverage against toxin-producing organisms including streptococcal
22 THE CLINICAL ADVISOR • JUNE 2019 • www.ClinicalAdvisor.com