Principles of Antibiotic Therapy

Antimicrobial therapy of sepsis and septic shock--when are two drugs better than one?

In clinical practice, physicians frequently use combination therapy despite the conflicting evidence for its effectiveness. The results of recent studies have contributed to our understanding of this important issue. In this article, we examine the evidence for, or against, the use of combination drug therapy compared with monotherapy in the management of serious infections, sepsis, and septic shock.

Optimizing antimicrobial therapy in sepsis and septic shock

Every patient with sepsis and septic shock must be evaluated thoroughly at presentation before the initiation of antibiotic therapy. However, in most situations, an abridged initial assessment focusing on critical diagnostic and management planning elements is sufficient. Intravenous antibiotics should be administered as early as possible, and always within the first hour of recognizing severe sepsis and septic shock. Broad-spectrum antibiotics must be selected with one or more agents active against likely bacterial or fungal pathogens and with good penetration into the presumed source. Antimicrobial therapy should be reevaluated daily to optimize efficacy, prevent resistance, avoid toxicity, and minimize costs. Consider combination therapy in Pseudomonas infections, and combination empiric therapy in neutropenic patients. Combination therapy should be continued for no more than 3 to 5 days and de-escalation should occur following availability of susceptibilities. The duration of antibiotic therapy typically is limited to 7 to 10 days; longer duration is considered if response is slow, if there is inadequate surgical source control, or in the case of immunologic deficiencies. Antimicrobial therapy should be stopped if infection is not considered the etiologic factor for a shock state.

Optimizing antimicrobial therapy in sepsis and septic shock

This article reviews principles in the rational use of antibiotics in sepsis and septic shock and presents evidence-based recommendations for optimal antibiotic therapy. Every patient with sepsis and septic shock must be evaluated at presentation before the initiation of antibiotic therapy. However, in most situations, an abridged initial assessment focusing on critical diagnostic and management planning elements is sufficient. Intravenous antibiotics should be administered as early as possible, and always within the first hour of recognizing severe sepsis and septic shock. Broad-spectrum antibiotics must be selected with one or more agents active against likely bacterial or fungal pathogens and with good penetration into the presumed source. Antimicrobial therapy should be reevaluated daily to optimize efficacy, prevent resistance, avoid toxicity, and minimize costs. Consider combination therapy in Pseudomonas infections, and combination empiric therapy in neutropenic patients. Combination therapy should be continued for no more than 3 to 5 days and deescalation should occur following availability of susceptibilities. The duration of antibiotic therapy typically is limited to 7 to 10 days; longer duration is considered if response is slow, if there is inadequate surgical source control, or in the case of immunologic deficiencies. Antimicrobial therapy should be stopped if infection is not considered the etiologic factor for a shock state.

Antimicrobial management of sepsis and septic shock

Every patient who has sepsis and septic shock must be evaluated appropriately at presentation before the initiation of antibiotic therapy. However, in most situations, an abridged initial assessment focusing on critical diagnostic and management planning elements is sufficient. Intravenous antibiotics should be administered as early as possible, and always within the first hour of recognizing severe sepsis and septic shock. Broad-spectrum antibiotics must be selected with one or more agents active against likely bacterial or fungal pathogens and with good penetration into the presumed source. Antimicrobial therapy should be reevaluated daily to optimize efficacy, prevent resistance, avoid toxicity, and minimize costs. Consider combination therapy in septic shock Pseudomonas infections in neutropenic patients. Combination therapy should be continued for no more than 3 to 5 days and de-escalation should occur following availability of susceptibilities. The duration of antibiotic therapy typically is limited to 7 to 10 days. Longer duration is considered if response is slow, if there is inadequate surgical source control, or if immunologic deficiencies are evident. Antimicrobial therapy should be stopped if infection is not considered the etiologic factor for a shock state.

SuperToxic: a comprehensive database of toxic compounds

Within our everyday life, we are confronted with a variety of toxic substances of natural or artificial origin. Toxins are already used, e.g. in medicine, but there is still an increasing number of toxic compounds, representing a tremendous potential to extract new substances. Since predictive toxicology gains in importance, the careful and extensive investigation of known toxins is the basis to assess the properties of unknown substances. In order to achieve this aim, we have collected toxic compounds from literature and web sources in the database SuperToxic. The current version of this database compiles about 60,000 compounds and their structures. These molecules are classified according to their toxicity, based on more than 2 million measurements. The SuperToxic database provides a variety of search options like name, CASRN, molecular weight and measured values of toxicity. With the aid of implemented similarity searches, information about possible biological interactions can be gained. Furthermore, connections to the Protein Data Bank, UniProt and the KEGG database are available, to allow the identification of targets and those pathways, the searched compounds are involved in. This database is available online at: http://bioinformatics.charite.de/supertoxic.

Necrotizing soft tissue infections of the chest wall

BACKGROUND

Necrotizing soft tissue infections of the chest wall are uncommon, and they have received little discussion in the medical literature.

METHODS

We performed a collective review of the literature to summarize information on etiology, prevention, treatment, complications, and outcome of chest wall necrotizing soft tissue infections. Manual, Medline, and Current Contents searches of the English-language medical literature were done.

RESULTS

There were 9 reported cases of necrotizing soft tissue infection of the chest wall. Eight were complications of invasive procedures and operations. Tube thoracostomy for empyema (4 patients) was the most common antecedent procedure. Excessive soft tissue dissection during chest tube insertion was implicated in the genesis of these infections. Necrotizing infections complicated esophageal operations in 2 patients. Overall mortality was 89%. Only 3 of the 9 patients underwent early and adequate debridement. Chest wall stability and wound reconstruction were problematic in patients who survived the initial septic illness.

CONCLUSIONS

Necrotizing soft tissue infections of the chest wall are highly lethal infections that require urgent and aggressive debridement. Diagnostic delay and inadequate debridement are common reasons for treatment failure. Repetitive surgical debridement is often needed to control sepsis. Wound closure is challenging in patients who survive the initial septic phase of their illness.

Risk factors leading to clinical failure in the treatment of intra-abdominal or skin/soft tissue infections

A study of determinants of outcome in adult patients with intra-abdominal or skin/soft tissue infections treated with cefotetan, cefoxitin, or ampicillin/sulbactam monotherapy was undertaken. Patients were matched for principal infectious process, surgery performed for the management of the infection, year of hospital admission, age, and sex. The criteria for inclusion, exclusion, and matching of patients and assignment of clinical and microbiological outcome were based on the 1992 Infectious Diseases Society of America/Federal Drug Administration guidelines for the evaluation of anti-infective drug products. One hundred and thirty-seven cases of intra-abdominal or skin and soft tissue infections treated with cefotetan (n = 47), cefoxitin (n = 43), or ampicillin/sulbactam (n = 47) monotherapy were selected without knowledge of outcome and analyzed using a single blinded analysis. The baseline characteristics did not differ between the treatment groups, nor did the rates of clinical or microbiological failure. A multivariate analysis showed that isolation of an organism resistant to the treatment regimen, including Pseudomonas spp., [odds ratio (OR) = 14.9, p = 0.001], being on antibiotic therapy at the time of admission (OR = 4.5, p = 0.007), and diagnosis of a complicated intra-abdominal infection (OR = 3.5, p = 0.014) were independently associated with clinical failure. These data support the assertion that antibiotic resistant organisms in mixed anaerobic/aerobic infections are associated with clinical failure and suggest that the antibiotic regimen should be modified to include Pseudomonas spp. in its spectrum when this organism is isolated from patients with such infections.