Introduction: Bacteremia is recognized as a critical condition that influences the outcome of sepsis. Although large-scale surveillance studies of bacterial species causing bacteremia have been published, the pathophysiological differences in bacteremias with different causative bacterial species remain unclear. The objective of the present study is to investigate the differences in pathophysiology and the clinical course of bacteremia caused by different bacterial species. Methods: We reviewed the medical records of all consecutive patients admitted to the general intensive care unit (ICU) of a university teaching hospital during the eight-year period since introduction of a rapid assay for interleukin (IL)-6 blood level to routine ICU practice in May 2000. White blood cell count, C-reactive protein (CRP), IL-6 blood level, and clinical course were compared among different pathogenic bacterial species. Results: The 259 eligible patients, as well as 515 eligible culture-positive blood samples collected from them, were included in this study. CRP, IL-6 blood level, and mortality were significantly higher in the septic shock group (n = 57) than in the sepsis group (n = 127) (P < 0.001). The 515 eligible culture-positive blood samples harbored a total of 593 isolates of microorganisms (Gram-positive, 407; Gram-negative, 176; fungi, 10). The incidence of Gram-negative bacteremia was significantly higher in the septic shock group than in the sepsis group (P < 0.001) and in the severe sepsis group (n = 75, P < 0.01). CRP and IL-6 blood level were significantly higher in Gram-negative bacteremia (n = 176) than in Gram-positive bacteremia (n = 407) (P < 0.001, <0.0005, respectively). Conclusions: The incidence of Gram-negative bacteremia was significantly higher in bacteremic ICU patients with septic shock than in those with sepsis or severe sepsis. Furthermore, CRP and IL-6 levels were significantly higher in Gram-negative bacteremia than in Gram-positive bacteremia. These findings suggest that differences in host responses and virulence mechanisms of different pathogenic microorganisms should be considered in treatment of bacteremic patients, and that new countermeasures beyond conventional antimicrobial medications are urgently needed.

Introduction: Neurological prognostic factors after cardiopulmonary resuscitation (CPR) in patients with cardiac arrest (CA) as early and accurately as possible are urgently needed to determine therapeutic strategies after successful CPR. In particular, serum levels of protein neuron-specific enolase (NSE) and S-100B are considered promising candidates for neurological predictors, and many investigations on the clinical usefulness of these markers have been published. However, the design adopted varied from study to study, making a systematic literature review extremely difficult. The present review focuses on the following three respects for the study design: definitions of outcome, value of specificity and time points of blood sampling. Methods: A Medline search of literature published before August 2008 was performed using the following search terms: "NSE vs CA or CPR", "S100 vs CA or CPR". Publications examining the clinical usefulness of NSE or S-100B as a prognostic predictor in two outcome groups were reviewed. All publications met with inclusion criteria were classified into three groups with respect to the definitions of outcome; "dead or alive", "regained consciousness or remained comatose", and "return to independent daily life or not". The significance of differences between two outcome groups, cutoff values and predictive accuracy on each time points of blood sampling were investigated. Results: A total of 54 papers were retrieved by the initial text search, and 24 were finally selected. In the three classified groups, most of the studies showed the significance of differences and concluded these biomarkers were useful for neurological predictor. However, in view of blood sampling points, the significance was not always detected. Nevertheless, only five studies involved uniform application of a blood sampling schedule with sampling intervals specified based on a set starting point. Specificity was not always set to 100%, therefore it is difficult to indiscriminately assess the cut-off values and its predictive accuracy of these biomarkers in this meta analysis. Conclusions: In such circumstances, the findings of the present study should aid future investigators in examining the clinical usefulness of these markers and determination of cut-off values.

Measures of peripheral perfusion can be used to assess the hemodynamic status of critically ill patients. By monitoring peripheral perfusion status, clinicians can promptly initiate life-saving therapy and reduce the likelihood of shock-associated death. Historically, abnormal perfusion has been indicated by the observation of pale, cold, and clammy skin with increased capillary refill time. The utility of these assessments has been debated given that clinicians may vary in their clinical interpretation of body temperature and refill time. Considering these constraints, current sepsis bundles suggest the need to revise resuscitation guidelines. New technologies have been developed to calculate capillary refill time in the hopes of identifying a new gold standard for clinical care. These devices measure either light reflected at the surface of the fingertip (reflected light), or light transmitted through the inside of the fingertip (transmitted light). These new technologies may enable clinicians to monitor peripheral perfusion status more accurately and may increase the potential for ubiquitous hemodynamic monitoring across different clinical settings. This review will summarize the different methods available for peripheral perfusion monitoring and will discuss the advantages and disadvantages of each approach.

Background: The concept that resuscitation from cardiac arrest ( CA ) results in a metabolic injury is broadly accepted, yet patients never receive this diagnosis. We sought to find evidence of metabolic injuries after CA by measuring O ₂ consumption and CO ₂ production ( VCO ₂ ) in a rodent model. In addition, we tested the effect of inspired 100% O ₂ on the metabolism. Methods and Results: Rats were anesthetized and randomized into 3 groups: resuscitation from 10‐minute asphyxia with inhaled 100% O ₂ (CA–fraction of inspired O ₂ [FIO ₂ ] 1.0), with 30% O ₂ ( CA ‐ FIO ₂ 0.3), and sham with 30% O ₂ (sham‐ FIO ₂ 0.3). Animals were resuscitated with manual cardiopulmonary resuscitation. The volume of extracted O ₂ ( VO ₂ ) and VCO ₂ were measured for a 2‐hour period after resuscitation. The respiratory quotient ( RQ ) was RQ = VCO ₂ / VO ₂ . VCO ₂ was elevated in CA ‐ FIO ₂ 1.0 and CA ‐ FIO ₂ 0.3 when compared with sham‐ FIO ₂ 0.3 in minutes 5 to 40 after resuscitation ( CA ‐ FIO ₂ 1.0: 16.7±2.2, P <0.01; CA ‐ FIO ₂ 0.3: 17.4±1.4, P <0.01; versus sham‐ FIO ₂ 0.3: 13.6±1.1 mL/kg per minute), and then returned to normal. VO ₂ in CA ‐ FIO ₂ 1.0 and CA ‐ FIO ₂ 0.3 increased gradually and was significantly higher than sham‐ FIO ₂ 0.3 2 hours after resuscitation ( CA ‐ FIO ₂ 1.0: 28.7±6.7, P <0.01; CA ‐ FIO ₂ 0.3: 24.4±2.3, P <0.01; versus sham‐ FIO ₂ 0.3: 15.8±2.4 mL/kg per minute). The RQ of CA animals persistently decreased ( CA ‐ FIO ₂ 1.0: 0.54±0.12 versus CA ‐ FIO ₂ 0.3: 0.68±0.05 versus sham‐ FIO ₂ 0.3: 0.93±0.11, P <0.01 overall). Conclusions: CA altered cellular metabolism resulting in increased VO ₂ with normal VCO ₂ . Normal VCO ₂ suggests that the postresuscitation Krebs cycle is operating at a presumably healthy rate. Increased VO ₂ in the face of normal VCO ₂ suggests a significant alteration in O ₂ utilization in postresuscitation. Several RQ values fell well outside the normally cited range of 0.7 to 1.0. Higher FIO ₂ may increase VO ₂ , leading to even lower RQ values.