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Complicated intraabdominal infections (i.e., those requiring both operative drainage and antimicrobial therapy) are among the most common infections in general surgery. Antimicrobial therapy is an important element in the management of these infections; there are convincing data that absent or inadequate empiric antibiotic therapy results in both increased failure rates and increased mortality. 1–4 The infecting flora seen with community-acquired intraabdominal infections is well known and consists of aerobic, facultative, and anaerobic gram-negative bacilli, various streptococci and enterococci, and a plethora of gram-positive anaerobes. 5–7 The synergistic interactions between endotoxin-bearing gram-negative organisms and Bacteroides fragilis define both groups as important targets for antimicrobial therapy. 8 Ertapenem (formerly MK-0826, Merck & Co., Inc.) is being investigated as a once-a-day parenteral β-lactam antimicrobial agent with the potential for use as monotherapy for the treatment of community-acquired mixed flora infections. This approach is based on its spectrum of activity, previously reported clinical studies that used once-a-day dosing, pharmacodynamic studies in animals, and pharmacokinetic studies in both humans and animals. 9,10 Ertapenem is highly active in vitro against gram-positive and gram-negative aerobic, facultative, and anaerobic bacteria, including the predominant pathogens responsible for intraabdominal infections. 11–13 However, it provides limited coverage against Pseudomonas aeruginosa, Acinetobacter spp, and enterococci, organisms generally associated with nosocomial infections. The primary objectives of this study were to determine the clinical and microbiologic efficacy and safety of ertapenem for patients with complicated intraabdominal infections. The comparative agent was piperacillin/tazobactam, a β-lactam/β-lactamase inhibitor combination agent that has been well studied and is approved in the treatment of intraabdominal infection. 14 This agent is typically administered at 3.375 g every 6 hours in the United States. This study also provided an opportunity to analyze an additional element of clinical trial design, the adequacy of surgical source control. Inadequate control of infection, through either incomplete drainage or incomplete management of enteric perforations, is an independent risk factor for treatment failure. 15,16 An expert panel review process was conducted to examine, under blinded conditions, the adequacy of surgical source control as a component of evaluability in a prospectively generated and well-documented group of patients.

Background Catheter hub contamination is being increasingly recognized as a source of catheter-related sepsis. The authors have investigated the efficacy of a new hub design in preventing endoluminal catheter contamination and catheter-related sepsis arising at the hub. Methods Adult surgical and intensive care patients requiring a subclavian catheter for at least 1 week were randomly assigned to receive catheters with standard connectors (control group, n = 73) or equipped with a new hub model (new hub group, n = 78). Skin, catheter tip, and hub cultures were performed at the time the catheter was withdrawn because therapy was terminated or because of suspicion of sepsis, in which case peripheral blood cultures were taken. Results Of the 151 patients included, 15 (10%) developed catheter-related sepsis. Catheters were more often withdrawn because suspicion of infection in the control group (42 vs. 19%, p < 0.005). Catheter sepsis rate was higher in the control group (16 vs. 4%, p < 0.01) because of the low rate of catheter sepsis arising at the hub observed in the new hub group (1 vs. 11%, p < 0.01). The prevalence of culture-positive catheter hubs without associated bacteremia (colonization) was higher in the control group (18 vs. 5%, p < 0.03). Conclusions A new catheter hub has proved to be useful in preventing endoluminal bacterial colonization and catheter-related sepsis in subclavian lines inserted for a mean of 2 weeks.

The role of the Nae/Ke ratio (the ratio of exchangeable sodium to exchangeable potassium) was examined as a nutritional marker in surgical patients in relation to anthropometrical and biochemical indexes by its ability to identify patients at risk for mortality after hospitalization. In 73 patients with sepsis and malnutrition (Training Group, Madrid) the following were determined: percentage of recent weight loss, triceps skin fold, midarm muscle circumference, serum albumin, serum transferrin, delayed hypersensitivity skin test response, total lymphocytes, and Nae/Ke ratio by multiple isotope dilution. The predictive power of Nae/Ke ratio was so strong (F = 105.1; p less than 0.00001) that it displaced anthropometric, biochemical, and immunologic variables from the linear equation derived from stepwise discriminant analysis using hospital mortality as the dependent variable. A theoretical curve of expected deaths was developed, based on an equation obtained by logistic regression analysis: Pr/death/ = 1/(1 + e[11.8-5.2 Nae/Ke]). Pre- and post-test probabilities on that curve allowed us to determine two cut-off values, Nae/Ke ratios of 1.5 and 2.5, which were markers for nonrisk and mortality, respectively. The model was tested in a heterogeneous data base of surgical patients (n = 417) in another hospital (Validation Group, Montreal). For patients exhibiting an abnormal Nae/Ke ratio (greater than 1.2) and a greater than 10% of probability of death, 54 deaths were expected and 53 observed (X2 = 1.8 NS). Two tests confirmed the basic agreement between the model and its performance, a G statistic of -0.704 and the area beneath the "receiver-operating-characteristic" (ROC) curve (Az = 0.904 + 0.0516 for the Madrid group vs. Az = 0.915 + 0.0349 for the Montreal group, NS). It was concluded from this analysis that, compared with the usual anthropometric measurements, the Nae/Ke ratio, if available, is the best method for identifying malnourished patients at risk of dying.