Accuracy of oxygen tissue saturation values in assessing severity in patients with sepsis admitted to emergency departments.

INTRODUCTION: Near-infrared spectrometry assesses hemoglobin saturation of oxygen in tissues (StO2). Although it may provide additional information on local microcirculation function, the usefulness of near-infrared spectrometry in septic patients is debated. This study evaluated whether baseline StO2 value is useful in septic patients admitted to the emergency department with a diagnosis of severe sepsis. MATERIALS AND METHODS: We carried out a prospective multicenter study in three emergency departments in Paris, France. Triage nurses were to record StO2, the results were blinding to the emergency physicians. Patients were eligible when presenting with at least two of the following parameters: temperature higher than 38°C or less than 36°C, respiratory rate greater than 30/min, heart rate greater than 120/min, and systolic arterial blood pressure less than 110 mmHg. Patients with a final diagnosis of sepsis and severe sepsis were analyzed. RESULTS: We analyzed 98 patients (70 with sepsis and 28 with severe sepsis). Thirty-day mortality was 2.9 versus 14.3% (P=0.048) in the sepsis and the severe sepsis group, respectively. No significant difference in the median StO2 was observed in patients with sepsis and severe sepsis [79% (74-85%) vs. 77% (72-83%), respectively; P=0.66]. The area under the curve of the receiver operating characteristic curve for StO2 to predict severe sepsis was 0.53 (0.39-0.66; P=0.5) and the cutoff value was 77%. Median StO2 did not differ in patients admitted to the ICU [80% (60-88%) vs. 79% (74-84%); P=0.78] and in nonsurvivors compared with that of survivors [79% (74-85%) vs. 76% (73-83%); P=0.64]. CONCLUSION: This study fails to show any value of StO2 baseline at triage for early detection of severe sepsis in emergency patients.

Role of biomarkers in the management of antibiotic therapy: an expert panel review II: clinical use of biomarkers for initiation or discontinuation of antibiotic therapy.

Biomarker-guided initiation of antibiotic therapy has been studied in four conditions: acute pancreatitis, lower respiratory tract infection (LRTI), meningitis, and sepsis in the ICU. In pancreatitis with suspected infected necrosis, initiating antibiotics best relies on fine-needle aspiration and demonstration of infected material. We suggest that PCT be measured to help predict infection; however, available data are insufficient to decide on initiating antibiotics based on PCT levels. In adult patients suspected of community-acquired LRTI, we suggest withholding antibiotic therapy when the serum PCT level is low (<0.25 ng/mL); in patients having nosocomial LRTI, data are insufficient to recommend initiating therapy based on a single PCT level or even repeated measurements. For children with suspected bacterial meningitis, we recommend using a decision rule as an aid to therapeutic decisions, such as the Bacterial Meningitis Score or the Meningitest®; a single PCT level ≥0.5 ng/mL also may be used, but false-negatives may occur. In adults with suspected bacterial meningitis, we suggest integrating serum PCT measurements in a clinical decision rule to help distinguish between viral and bacterial meningitis, using a 0.5 ng/mL threshold. For ICU patients suspected of community-acquired infection, we do not recommend using a threshold serum PCT value to help the decision to initiate antibiotic therapy; data are insufficient to recommend using PCT serum kinetics for the decision to initiate antibiotic therapy in patients suspected of ICU-acquired infection. In children, CRP can probably be used to help discontinue therapy, although the evidence is limited. In adults, antibiotic discontinuation can be based on an algorithm using repeated PCT measurements. In non-immunocompromised out- or in- patients treated for RTI, antibiotics can be discontinued if the PCT level at day 3 is < 0.25 ng/mL or has decreased by >80-90%, whether or not microbiological documentation has been obtained. For ICU patients who have nonbacteremic sepsis from a known site of infection, antibiotics can be stopped if the PCT level at day 3 is < 0.5 ng/mL or has decreased by >80% relative to the highest level recorded, irrespective of the severity of the infectious episode; in bacteremic patients, a minimal duration of therapy of 5 days is recommended.

Role of biomarkers in the management of antibiotic therapy: an expert panel review: I - currently available biomarkers for clinical use in acute infections.

In the context of worldwide increasing antimicrobial resistance, good antimicrobial prescribing in more needed than ever; unfortunately, information available to clinicians often are insufficient to rely on. Biomarkers might provide help for decision-making and improve antibiotic management. The purpose of this expert panel review was to examine currently available literature on the potential role of biomarkers to improve antimicrobial prescribing, by answering three questions: 1) Which are the biomarkers available for this purpose?; 2) What is their potential role in the initiation of antibiotic therapy?; and 3) What is their role in the decision to stop antibiotic therapy? To answer these questions, studies reviewed were limited to recent clinical studies (<15 years), involving a substantial number of patients (>50) and restricted to controlled trials and meta-analyses for answering questions 2 and 3. With regard to the first question concerning routinely available biomarkers, which might be useful for antibiotic management of acute infections, these are currently limited to C-reactive protein (CRP) and procalcitonin (PCT). Other promising biomarkers that may prove useful in the near future but need to undergo more extensive clinical testing include sTREM-1, suPAR, ProADM, and Presepsin. New approaches to biomarkers of infections include point-of-care testing and genomics.