Severe sepsis and septic shock in the emergency department

Increased attention has focused recently on the acute management of severe sepsis and septic shock, conditions that represent the end-stage systemic deterioration of overwhelming infection. Clinical trials have identified new therapies and management approaches that, when applied early, appear to reduce mortality. Practice guidelines have been advanced by critical care societies, and many of the proposed interventions involve therapies other than antimicrobials directed at hemodynamic resuscitation or addressing adverse effects of the inflammatory cascade. Although many emergency departments (EDs) are now adopting treatment protocols for sepsis that are based on published treatment guidelines, recent research calls many of the initial recommendations into question, and validation trials of some of these approaches are ongoing. This article reviews the initial evaluation and treatment considerations of sepsis in the ED setting.

Antimicrobial-induced endotoxin and cytokine activity in an in vitro model of septicemia in foals

OBJECTIVE

To determine which antimicrobials that are used to treat neonatal foals with septicemia attributable to Escherichia coli will minimize endotoxin release from bacteria and subsequent activity of inflammatory mediators while maintaining bactericidal efficacy.

SAMPLE POPULATION

Blood samples from 10 healthy foals.

PROCEDURE

Escherichia coli isolates A and B were isolated from 2 septicemic foals, and minimal inhibitory concentrations (MIC) were determined for 9 antimicrobials. Five of these antimicrobials were tested in vitro at 2 and 20 times their respective MIC. Whole blood or mononuclear cells grown in tissue-culture media were incubated with 105 colony-forming units of E. coli and each antimicrobial or saline (0.9% NaCl) solution. After 6 hours, number of viable bacteria remaining was determined, and supernatant was tested for endotoxin and tumor necrosis activity.

RESULTS

Testing in whole blood was compromised by bactericidal effects of the blood itself. In mononuclear cell suspensions, each antimicrobial significantly reduced the number of viable bacteria to low or undetectable amounts. Antimicrobials did not differ significantly in efficacy of bacterial killing. Amikacin used alone or in combination with ampicillin resulted in significantly less endotoxin activity than did ampicillin, imipenem, or ceftiofur alone. There was a correlation between TNF-alpha and endotoxin activity.

CONCLUSIONS AND CLINICAL RELEVANCE

Aminoglycosides appear less likely to induce endotoxemia and TNF-alpha synthesis during bactericidal treatment of E. coli septicemia, compared with beta-lactam antimicrobials. Use of ampicillin, imipenem, or ceftiofur in the treatment of septicemic neonatal foals should be accompanied by appropriate treatment for endotoxemia.

The benefit of appropriate empirical antibiotic treatment in patients with bloodstream infection

OBJECTIVES

To test whether empirical antibiotic treatment that matches the in vitro susceptibility of the pathogen (appropriate treatment) improves survival in patients with bloodstream infections; and to measure the improvement.

DESIGN

Observational, prospective cohort study.

SETTING

University hospital in Israel.

SUBJECTS

All patients with bloodstream infections detected during 1988-94.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

In-hospital fatality rate and length of hospitalization.

RESULTS

Out of 2158 patients given appropriate empirical antibiotic treatment, 436 (20%) died, compared with 432 of 1255 patients (34%) given inappropriate treatment (P = 0.0001). The median durations of hospital stay for patients who survived were 9 days for patients given appropriate treatment and 11 days for patients given inappropriate treatment. For patients who died, the median durations were 5 and 4 days, respectively (P < 0.05), for both comparisons. In a stratified analysis, fatality was higher in patients given inappropriate treatment than in those given appropriate treatment in all strata but two: patients with infections caused by streptococci other than Streptococcus gr. A and Streptoccocus pneumoniae (odds ratio (OR) of 1.0, 95% confidence interval (95% CI) 0.4-2.5); and hypothermic patients (OR = 0.9, 95% CI = 0.3-2.4). Even in patients with septic shock, inappropriate empirical treatment was associated with higher fatality rate (OR = 1.6, 95% CI = 1.0-2.7). The highest benefit associated with appropriate treatment was observed in paediatric patients (OR = 5.1, 95% CI = 2.4-10.7); intra-abdominal infections (OR = 3.8, 95% CI = 2.0-7.1); infections of the skin and soft tissues (OR = 3.1, 95% CI = 1.8-5.6); and infections caused by Klebsiella pneumoniae (OR = 3.0, 95% CI = 1.7-5.1) and S. pneumoniae (OR = 2.6, 95% C = 1.1-5.9). On a multivariable logistic regression analysis, the contribution of inappropriate empirical treatment to fatality was independent of other risk factors (multivariable adjusted OR = 1.6, 95% CI = 1.3-1.9).

CONCLUSION

Appropriate empirical antibiotic treatment was associated with a significant reduction in fatality in patients with bloodstream infection.