Evaluation of Antibiotic Duration after Surgical Debridement of Necrotizing Soft Tissue Infection

Necrotizing Soft Tissue Infections: A Review

Importance

Necrotizing soft tissue infections (NSTIs) are severe life- and limb-threatening infections with high rates of morbidity and mortality. Unfortunately, there has been minimal improvement in outcomes over time.

Observations

NSTIs are characterized by their heterogeneity in microbiology, risk factors, and anatomical involvement. They often present with nonspecific symptoms, leading to a high rate of delayed diagnosis. Laboratory values and imaging help increase suspicion for NSTI, though ultimately, the diagnosis is clinical. Surgical exploration is warranted when there is high suspicion for NSTI, even if the diagnosis is uncertain. Thus, it is acceptable to have a certain rate of negative exploration. Immediate empirical broad-spectrum antibiotics, further tailored based on tissue culture results, are essential and should be continued at least until surgical debridement is complete and the patient shows signs of clinical improvement. Additional research is needed to determine optimal antibiotic duration. Early surgical debridement is crucial for improved outcomes and should be performed as soon as possible, ideally within 6 hours of presentation. Subsequent debridements should be performed every 12 to 24 hours until the patient is showing signs of clinical improvement and there is no additional necrotic tissue within the wound. There are insufficient data to support the routine use of adjunct treatments such as hyperbaric oxygen therapy and intravenous immunoglobulin. However, clinicians should be aware of multiple ongoing efforts to develop more robust diagnostic and treatment strategies.

Conclusions and Relevance

Given the poor outcomes associated with NSTIs, a review of clinically relevant evidence and guidelines is warranted. This review discusses diagnostic and treatment approaches to NSTI while highlighting future directions and promising developments in NSTI management.

Fever and infections in surgical intensive care: an American Association for the Surgery of Trauma Critical Care Committee clinical consensus document

The evaluation and workup of fever and the use of antibiotics to treat infections is part of daily practice in the surgical intensive care unit (ICU). Fever can be infectious or non-infectious; it is important to distinguish between the two entities wherever possible. The evidence is growing for shortening the duration of antibiotic treatment of common infections. The purpose of this clinical consensus document, created by the American Association for the Surgery of Trauma Critical Care Committee, is to synthesize the available evidence, and to provide practical recommendations. We discuss the evaluation of fever, the indications to obtain cultures including urine, blood, and respiratory specimens for diagnosis of infections, the use of procalcitonin, and the decision to initiate empiric antibiotics. We then describe the treatment of common infections, specifically ventilator-associated pneumonia, catheter-associated urinary infection, catheter-related bloodstream infection, bacteremia, surgical site infection, intra-abdominal infection, ventriculitis, and necrotizing soft tissue infection.

Current challenges in acute bacterial skin infection management

PURPOSE OF REVIEW

There are aspects of skin and soft tissue infections (SSTIs) that remain unresolved, such as current numbers, classification criteria, how best to define severity and predict the outcome, what diagnostic tests to perform, what new treatment options are available, or what the duration of antibiotic treatment should be. We have reviewed the literature over the last 18 months to clarify these issues and provide our opinion.

RECENT FINDINGS

SSTIs are common and among the top 10 most frequent infections worldwide. They represent a burden on the healthcare system and have a major impact on the quality of life of patients. Regarding classification, the Infectious Diseases Society of America (IDSA) provides a practical guide that distinguishes between uncomplicated and complicated infections, acute and chronic wound infections, and necrotising and nonnecrotizing infections based on skin extension and tissue necrosis. With new microbiological and imaging diagnostic techniques, SSTIs can now be better diagnosed. New PCR techniques are available, and mass spectrometry can be applied to samples collected in liquid transport media. Moreover, new treatment methods such as photodynamic therapy, reactive oxygen, and phages are emerging. SSTI patients can be treated with shorter antibiotic courses if they receive an active drug with good tissue penetration. Antibiotic treatment in necrotizing infections can be shortened to 48 h after the last debridement.

SUMMARY

SSTIs remain a challenge regarding rapid and accurate diagnosis and clinical management.

Toxic Shock Syndrome: A Literature Review

Toxic shock syndrome (TSS) is a rare, life-threatening, toxin-mediated infectious process linked, in the vast majority of cases, to toxin-producing strains of Staphylococcus aureus or Streptococcus pyogenes. The pathophysiology, epidemiology, clinical presentation, microbiological features, management and outcome of TSS are described in this review. Bacterial superantigenic exotoxins induces unconventional polyclonal lymphocyte activation, which leads to rapid shock, multiple organ failure syndrome, and death. The main described superantigenic exotoxins are toxic shock syndrome toxin-1 (TSST-1) and enterotoxins for Staphylococcus aureus and Streptococcal pyrogenic exotoxins (SpE) A, B, and C and streptococcal superantigen A (SsA) for Streptococcus pyogenes. Staphylococcal TSS can be menstrual or nonmenstrual. Streptococcal TSS is linked to a severe group A streptococcal infection and, most frequently, to a necrotizing soft tissue infection. Management of TSS is a medical emergency and relies on early detection, immediate resuscitation, source control and eradication of toxin production, bactericidal antibiotic treatment, and protein synthesis inhibiting antibiotic administration. The interest of polyclonal intravenous immunoglobulin G administration as an adjunctive treatment for TSS requires further evaluation. Scientific literature on TSS mainly consists of observational studies, clinical cases, and in vitro data; although more data on TSS are required, additional studies will be difficult to conduct due to the low incidence of the disease.

Defining the Optimal Antibiotic Duration in Necrotizing Skin and Soft Tissue Infections: Clinical Experience from a Quaternary Referral Center

Background: Early initiation of broad-spectrum antibiotic agents is a cornerstone of the care of necrotizing skin and soft tissue infections (NSTI). However, the optimal duration of antibiotic agents is unclear. We sought to characterize antibiotic prescribing patterns for patients with NSTI, as well as associated complications. Patients and Methods: Using an NSTI registry, we characterized antibiotic use at a quaternary referral center. Kaplan-Meier analyses were used to describe overall antibiotic duration and relative to operative source control, stratified by presence of other infections that independently influenced antibiotic duration. Factors associated with successful antibiotic discontinuation were identified using logistic regression. Results: Between 2015 and 2018, 441 patients received antibiotic agents for NSTI with 18% experiencing a complicating secondary infection. Among those without a complicating infection, the median duration of antibiotic administration was 9.8 days (95% confidence interval [CI], 9.2-10.5) overall, and 7.0 days after the final debridement. Perineal NSTI received fewer days of antibiotic agents (8.3 vs. 10.6) compared with NSTI without perineal involvement. White blood cell (WBC) count and fever were not associated with failure of antibiotic discontinuation, however, a chronic wound as the underlying infection etiology was associated with greater odds of antibiotic discontinuation failure (odds ratio [OR], 4.33; 95% CI, 1.24-15.1). Conclusions: A seven-day course of antibiotic agents after final operative debridement may be sufficient for NSTI without any secondary complicating infections, because clinical characteristics do not appear to be associated with differences in successful antibiotic discontinuation.