Introduction: Biomarkers can be useful for identifying or ruling out sepsis, identifying patients who may benefit from specific therapies or assessing the response to therapy. Methods: We used an electronic search of the PubMed database using the key words "sepsis" and "biomarker" to identify clinical and experimental studies which evaluated a biomarker in sepsis. Results: The search retrieved 3370 references covering 178 different biomarkers. Conclusions: Many biomarkers have been evaluated for use in sepsis. Most of the biomarkers had been tested clinically, primarily as prognostic markers in sepsis; relatively few have been used for diagnosis. None has sufficient specificity or sensitivity to be routinely employed in clinical practice. PCT and CRP have been most widely used, but even these have limited ability to distinguish sepsis from other inflammatory conditions or to predict outcome.

Introduction: Pathophysiology of brain dysfunction due to sepsis remains poorly understood. Cerebral microcirculatory alterations may play a role; however, experimental data are scarce. This study sought to investigate whether the cerebral microcirculation is altered in a clinically relevant animal model of septic shock. Methods: Fifteen anesthetized, invasively monitored, and mechanically ventilated female sheep were allocated to a sham procedure (n = 5) or sepsis (n = 10), in which peritonitis was induced by intra-abdominal injection of autologous faeces. Animals were observed until spontaneous death or for a maximum of 20 hours. In addition to global hemodynamic assessment, the microcirculation of the cerebral cortex was evaluated using Sidestream Dark-Field (SDF) videomicroscopy at baseline, 6 hours, 12 hours and at shock onset. At least five images of 20 seconds each from separate areas were recorded at each time point and stored under a random number to be analyzed, using a semi-quantitative method, by an investigator blinded to time and condition. Results: All septic animals developed a hyperdynamic state associated with organ dysfunction and, ultimately, septic shock. In the septic animals, there was a progressive decrease in cerebral total perfused vessel density (from 5.9 ± 0.9 at baseline to 4.8 ± 0.7 n/mm at shock onset, P = 0.009), functional capillary density (from 2.8 ± 0.4 to 2.1 ± 0.7 n/mm, P = 0.049), the proportion of small perfused vessels (from 95 ± 3 to 85 ± 8%, P = 0.02), and the total number of perfused capillaries (from 22.7 ± 2.7 to 17.5 ± 5.2 n/mm, P = 0.04). There were no significant changes in microcirculatory flow index over time. In sham animals, the cerebral microcirculation was unaltered during the study period. Conclusions: In this model of peritonitis, the cerebral microcirculation was impaired during sepsis, with a significant reduction in perfused small vessels at the onset of septic shock. These alterations may play a role in the pathogenesis of septic encephalopathy.

Sepsis is a condition characterized by high morbidity and mortality which is commonly encountered in an emergency and critical care setting. Despite a substantial body of research, the ideal biomarker for the diagnosis and prognostic stratification of septic patients remains unknown. This review aimed to summarize the publications referring to the validity of the biomarker presepsin when used for the detection, monitoring and prognosis in patients suffering with sepsis. This work is a narrative review based on a PubMed/Medline search conducted in order to identify all relevant publications referring to the use of presepsin in sepsis. Search was not limited by year of publication so all articles archived in the database would be retrieved. No article from before 2010 was identified. A total of 57 publications of the last decade were included, all of which support the use of presepsin as a biomarker for the assessment of septic patients. It has been used alone or in combination with commonly used biomarkers in the evaluation of patients with sepsis in settings such as the emergency department and the intensive care unit. It is useful in the initial workup of patients with suspected sepsis in the emergency setting and may be a predictive factor of mortality and the most severe complication of sepsis. Presepsin seems to be a valuable tool for the laboratory workup of sepsis, especially when used in conjunction with other biomarkers and clinical rating scores with an established role in this population. Further research is needed to evaluate the clinical implications of utilizing presepsin measurements in the workup of sepsis.

Transcranial Doppler can detect cerebral perfusion alteration in septic patients. We correlate static Transcranial Doppler findings with clinical signs of sepsis-associated encephalopathy.

Hyponatremia occurring as a result of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) or cerebral salt wasting syndrome is a common complication in patients with subarachnoid hemorrhage (SAH). The efficacy and safety of urea as treatment for SIADH-induced hyponatremia has not been reported in this population.

The aim of this study is to evaluate the feasibility and efficacy of Transcranial Doppler (TCD) in assessing cerebral perfusion changes in septic patients.