Prognostic values of B-type natriuretic peptide in severe sepsis and septic shock

OBJECTIVE: To investigate the changes in B-type natriuretic peptide concentrations in patients with severe sepsis and septic shock and to investigate the value of B-type natriuretic peptide in predicting intensive care unit outcomes. DESIGN: Prospective observational study. SETTING: General intensive care unit. PATIENTS: Forty patients with severe sepsis or septic shock. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: B-type natriuretic peptide measurements and echocardiography were carried out daily for 10 consecutive days. In-hospital mortality and length of stay were recorded. The admission B-type natriuretic peptide concentrations were generally increased (747 +/- 860 pg/mL). B-type natriuretic peptide levels were elevated in patients with normal left ventricular systolic function (568 +/- 811 pg/mL), with sepsis-related reversible cardiac dysfunction (630 +/- 726 pg/mL), and with chronic cardiac dysfunction (1311 +/- 1097 pg/mL). There were no significance changes in B-type natriuretic peptide levels over the 10-day period. The daily B-type natriuretic peptide concentrations for the first 3 days neither predicted in-hospital mortality nor correlated with length of intensive care unit or hospital stay. CONCLUSION: B-type natriuretic peptide concentrations were increased in patients with severe sepsis or septic shock regardless of the presence or absence of cardiac dysfunction. Neither the B-type natriuretic peptide levels for the first 3 days nor the daily changes in B-type natriuretic peptide provided prognostic value for in-hospital mortality and length of stay in this mixed group of patients, which included patients with chronic cardiac dysfunction.     

Clinical utility of B-type natriuretic peptide in early severe sepsis and septic shock

B-type natriuretic peptide (BNP) has diagnostic, therapeutic, and prognostic utility in critically ill patients. For severe sepsis and septic shock patients in particular, similar clinical utility from the most proximal aspects of hospital presentation to the intensive care unit has not been examined. BNP levels were measured at 0, 3, 6, 12, 24, 36, 48, 60, and 72 hours in 252 patients presenting to the emergency department with severe sepsis and septic shock. The clinicians were blinded to the BNP levels. Elevated BNP levels (>100 pg/mL) were seen in 42% and 69% of patients on presentation and at 24 hours, respectively. Elevated BNP ranges (>230 pg/mL) were significantly associated with myocardial dysfunction and severity of global tissue hypoxia. When adjusted for age, gender, history of heart failure, renal function, organ dysfunction, and mean arterial pressure, a BNP greater than 210 pg/mL at 24 hours was the most significant independent indicator of increased mortality: odds ratio 1.061 (1.026-1.097), P < .001, 95% confidence interval. Patients with severe sepsis and septic shock often have elevated BNP levels, which are significantly associated with organ and myocardial dysfunction, global tissue hypoxia, and mortality. Serial BNP levels may be a useful adjunct in the early detection, stratification, treatment, and prognostication of high-risk patients.     

Comparable increase of B-type natriuretic peptide and amino-terminal pro-B-type natriuretic peptide levels in patients with severe sepsis, septic shock, and acute heart failure

OBJECTIVE: B-type natriuretic peptide (BNP) and N-terminal pro-BNP measurements are used for the diagnosis of congestive heart failure (HF). However, the diagnostic value of these tests is unknown under septic conditions. We compared patients with severe sepsis or septic shock and patients with acute HF to unravel the influence of the underlying diagnosis on BNP and N-terminal pro-BNP levels. DESIGN: Prospective, clinical study. SETTING: Academic medical intensive care unit (ICU). PATIENTS: A total of 249 consecutive patients were screened for the diagnosis of sepsis or HF. Sepsis was defined according to published guidelines. HF was diagnosed in the presence of an underlying heart disease and congestive HF, pulmonary edema, or cardiogenic shock. INTERVENTIONS: BNP and N-terminal pro-BNP were measured from blood samples that were drawn daily for routine analysis. MEASUREMENTS AND MAIN RESULTS: We identified 24 patients with severe sepsis or septic shock and 51 patients with acute HF. At admission, the median (range) BNP and N-terminal pro-BNP levels were 572 (13-1,300) and 6,526 (198-70,000) ng/L in patients with sepsis and 581 (6-1,300) and 4,300 (126-70,000) ng/L in patients with HF. The natriuretic peptide levels increased during the ICU stay, but the differences between the groups were not significant. Nine patients with sepsis and eight patients with HF were monitored with a pulmonary artery catheter. Mean (sd) pulmonary artery occlusion pressure were 16 (4.2) and 22 (5.3) mm Hg (p = .02), and cardiac indexes were 4.6 (2.8) and 2.2 (0.6) L/min/m (p = .03) in patients with sepsis and HF, respectively. Despite these clear hemodynamic differences BNP and N-terminal pro-BNP levels were not statistically different between the two groups. CONCLUSION: In patients with severe sepsis or septic shock, BNP and N-terminal pro-BNP values are highly elevated and, despite significant hemodynamic differences, comparable with those found in acute HF patients. It remains to be determined how elevations of natriuretic peptide levels are linked to inflammation and sepsis-associated myocardial dysfunction.     

Clinical spectrum, frequency, and significance of myocardial dysfunction in severe sepsis and septic shock

ObjectiveTo determine the frequency and spectrum of myocardial dysfunction in patients with severe sepsis and septic shock using transthoracic echocardiography and to evaluate the impact of the myocardial dysfunction types on mortality.Patients and MethodsA prospective study of 106 patients with severe sepsis or septic shock was conducted from August 1, 2007, to January 31, 2009. All patients underwent transthoracic echocardiography within 24 hours of admission to the intensive care unit. Myocardial dysfunction was classified as left ventricular (LV) diastolic, LV systolic, and right ventricular (RV) dysfunction. Frequency of myocardial dysfunction was calculated, and demographic, hemodynamic, and physiologic variables and mortality were compared between the myocardial dysfunction types and patients without cardiac dysfunction.ResultsThe frequency of myocardial dysfunction in patients with severe sepsis or septic shock was 64% (n=68). Left ventricular diastolic dysfunction was present in 39 patients (37%), LV systolic dysfunction in 29 (27%), and RV dysfunction in 33 (31%). There was significant overlap. The 30-day and 1-year mortality rates were 36% and 57%, respectively. There was no difference in mortality between patients with normal myocardial function and those with left, right, or any ventricular dysfunction.ConclusionMyocardial dysfunction is frequent in patients with severe sepsis or septic shock and has a wide spectrum including LV diastolic, LV systolic, and RV dysfunction types. Although evaluation for the presence and type of myocardial dysfunction is important for tailoring specific therapy, its presence in patients with severe sepsis and septic shock was not associated with increased 30-day or 1-year mortality.     

The applications of B-type natriuretic peptide measurement in the intensive care unit

PURPOSE OF REVIEW: Plasma B-type natriuretic peptide levels are used to screen for cardiac dysfunction in the emergency department and outpatient population. However, in the critically ill patient elevated plasma B-type natriuretic peptide levels do not necessarily reflect just ventricular dysfunction, as there are important confounding factors to consider. This review summarizes the recent advances in the application of B-type natriuretic peptide measurement in the intensive care unit. RECENT FINDINGS: B-Type natriuretic peptide levels are very useful in identifying cardiac dysfunction but not the specific pathology, whether it is right or left ventricular failure, diastolic or systolic dysfunction. Elevated serum B-type natriuretic peptide levels also occur in severe sepsis or septic shock. It also predicts cardiac dysfunction in sepsis. The lack of correlation of B-type natriuretic peptide concentrations with filling pressures in the intensive care unit precludes its use for monitoring cardiac therapy. Some studies involving patients with sepsis or septic shock demonstrate a positive correlation with mortality, while others failed to establish such a relation. The prognostic value of B-type natriuretic peptide in predicting mortality and morbidity remains controversial, partly due to different study designs. SUMMARY: B-Type natriuretic peptide is potentially a very useful diagnostic tool in the intensive care unit. To date there have been few studies and the results are often contradictory, mainly due to the special setting of the intensive care unit, which is constantly exposed to hemodynamically unstable patients, different case mixes as well as vigorous treatments. All of these are potential confounders to B-type natriuretic peptide levels and make interpretations of B-type natriuretic peptide difficult. We need more research on these confounding factors to accentuate the positive value of B-type natriuretic peptide in the intensive care unit.     

Prognostic value of increased plasma levels of brain natriuretic peptide in patients with septic shock

Our objective was to investigate the plasma levels of brain and atrial natriuretic peptides (BNP and ANP, respectively) in patients with septic shock/severe sepsis and to study the association of BNP and ANP levels with hemodynamic parameters, severity of the disease, and prognosis of those patients. This is a prospective case series study of 22 patients with septic shock, 11 patients with severe sepsis, and 20 healthy volunteers at the Department of Emergency and Critical Care Medicine, Nara Medical University Hospital, Japan. Blood collection was performed on admission and on days 1, 2, and 4. Plasma BNP and ANP levels were measured by radioimmunoassay. Right atrial pressure, mean pulmonary arterial pressure, pulmonary arterial wedge pressure, and left ventricular stroke work index were determined using a thermodilution catheter. Acute Physiological and Chronic Health Evaluation II scores were calculated. Plasma levels of BNP and ANP were markedly elevated in patients with septic shock/severe sepsis compared with controls (BNP, 7 +/- 0.3 pg mL; ANP, 13 +/- 1 pg mL). In patients with septic shock, both BNP and ANP peaked on day 2 (BNP, 987 +/- 160 pg mL; ANP, 103 +/- 17 pg mL). Plasma levels of BNP on day 2 in patients with septic shock significantly correlated with right atrial pressure (r = 0.744, P < 0.01), mean pulmonary arterial pressure (r = 0.670, P < 0.01), pulmonary arterial wedge pressure (r = 0.709, P < 0.01), left ventricular stroke work index (r = -0.552, P < 0.05), Acute Physiological and Chronic Health Evaluation II score (r = 0.581, P < 0.01), and poor prognosis (P < 0.05). The optimal cutoff point for predicting mortality in patients with septic shock was a BNP level of 650 pg mL on day 2, in which sensitivity and specificity were 92% and 80%, respectively. Increased plasma levels of BNP may reflect not only the severity of myocardial depression but also the disease severity and could be of prognostic value in patients with septic shock.     

Increased plasma levels of NT-proANP and NT-proBNP as markers of cardiac dysfunction in septic patients

The family of natriuretic peptides comprises several structurally related 22-53-amino acid peptides, such as atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), which are vasoactive peptides with vasodilator and diuretic properties and play an important role in cardiovascular homeostasis. The salutary cardiovascular effects of natriuretic peptides suggest that ANP and BNP may have a pathophysiological significance in the cardiac dysfunction of septic patients. We determined plasma levels of the stable N-terminal prohormone forms of ANP (NT-proANP) and BNP (NT-proBNP) as well as troponin I (TNI) as a marker of myocardial cell injury by ELISA methods in 19 septic patients and 19 healthy controls at day one of severe sepsis. Left ventricular ejection fraction (LVEF) was determined on day 1 of severe sepsis by echocardiography. Significantly higher concentrations of NT-proANP were measured in non-survivors (mean = 13415 pmol/l +/- SEM = 4295) and survivors (mean = 7386 pmol/l +/- SEM = 1807) as compared to controls (mean = 1404 pmol/l +/- SEM = 181; p<0.001). Levels of NT-proBNP were also significantly higher in non-survivors (mean = 3439 pmol/l +/- SEM = 1246; p<0.05) and survivors (mean = 1009 pmol/l +/- SEM = 263; p<0.001) as compared to controls (mean = 200 pmol/l +/- SEM = 24) and correlated well with an increase in TNI-levels (r = 0.71; p<0.001). NT-proANP and NT-proBNP may serve as useful laboratory markers to indicate myocardial dysfunction and may help to differentiate between survivors and non-survivors of severe sepsis.     

Elevated nucleosome levels in systemic inflammation and sepsis

OBJECTIVE: Multiple organ dysfunction syndrome is a frequent complication of severe sepsis and septic shock and has a high mortality. We hypothesized that extensive apoptosis of cells might constitute the cellular basis for this complication. DESIGN: Retrospective study. SETTING: Medical and surgical wards or intensive care units of two university hospitals. PATIENTS: Fourteen patients with fever, 15 with systemic inflammatory response syndrome, 32 with severe sepsis, and eight with septic shock. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We assessed circulating levels of nucleosomes, specific markers released by cells during the later stages of apoptosis, with a previously described enzyme-linked immunosorbent assay in these 69 patients with fever, systemic inflammatory response syndrome, severe sepsis, or septic shock. Severity of multiple organ dysfunction syndrome was assessed with sepsis scores, and clinical and laboratory variables. Elevated nucleosome levels were found in 64%, 60%, 94%, and 100% of patients with fever, systemic inflammatory response syndrome, severe sepsis, or septic shock, respectively. These levels were significantly higher in patients with septic shock as compared with patients with severe sepsis, systemic inflammatory response syndrome, or fever, and in nonsurvivors as compared with survivors. In patients with advanced multiple organ dysfunction syndrome, nucleosome levels correlated with cytokine plasma levels as well as with variables predictive for outcome. CONCLUSIONS: Patients with severe sepsis and septic shock have elevated plasma levels of nucleosomes. We suggest that apoptosis, probably resulting from exposure of cells to excessive amounts of inflammatory mediators, might by involved in the pathogenesis of multiple organ dysfunction syndrome.     

What does high NT-proBNP mean in septic shock patients? A part of the puzzle

B-type natriuretic peptide (BNP) and amino-terminal pro-BNP (NT-proBNP) plasma levels are commonly high at the early phase of septic shock and have been suggested to be prognostic markers for this condition. It is uncertain, however, whether this increase reflects sepsis related cardiac dysfunction. In a recent issue of Critical Care, Mokart and coworkers showed the accuracy of NT-proBNP in predicting intensive care unit mortality in cancer patients with septic shock, which could help in identifying high risk cancer patients. Results from repeated transthoracic echocardiographs show that NT-proBNP on day 2 after admission was higher in patients presenting with cardiac dysfunction, whereas NT-proBNP on day 1 did not predict cardiac dysfunction. These data suggest that after an initial overexpression of NT-proBNP in all septic patients, patients with cardiac dysfunction will present persistent high levels of NT-proBNP.     

qSOFA Has Poor Sensitivity for Prehospital Identification of Severe Sepsis and Septic Shock

Objectives: Sepsis is a common and deadly disease process for which early recognition and intervention can significantly improve clinical outcomes. Despite this, sepsis remains underrecognized and therefore undertreated in the prehospital setting. Recent recommendations by the Society of Critical Care and European Society of Intensive Care Medicine advocate use of the qSOFA (quick Sequential [Sepsis-related] Organ Failure Assessment) score in non-ICU settings to screen for septic patients at greater risk for poor outcomes. Methods: We retrospectively evaluated the sensitivity and specificity of a prehospital qSOFA score ≥ 2 for prehospital identification of patients with severe sepsis or septic shock. Emergency Department (ED) patients with confirmed or suspected infection were classified as having infection without sepsis (n = 71), sepsis (n = 38), or severe sepsis/septic shock (n = 43), where designation of severe sepsis/septic shock required evidence of end-organ dysfunction, hypoperfusion (lactate > 2), or vasopressor requirement. Results: We found that a prehospital qSOFA score ≥ 2 was 16.3% sensitive (95% CI 6.8–30.7%) and 97.3% specific (95% CI 92.1–99.4%) for patients ultimately confirmed to have severe sepsis/septic shock in the ED. Adding an additional point to the prehospital qSOFA score for a pulse > 100, nursing home residence, age > 50, or reported fever increased the sensitivity to 58.1% (95% CI 42.1–73.0%) and decreased the specificity to 78.0% (95% CI 69.0–85.4%). During their ED stay, approximately two-thirds of patients meeting severe sepsis/septic shock criteria eventually met qSOFA criteria with a sensitivity of 67.4% (95% CI 51.5–80.9) and specificity of 86.2% (95% CI 78.3–92). Failure to meet qSOFA criteria prehospital was predominantly due to a systolic blood pressure and respiratory rate that did not yet meet predetermined thresholds. Conclusions: These findings suggest that the dynamic nature of sepsis can make sensitive detection difficult in the prehospital setting, although combining qSOFA with other clinical information (age, nursing home status, fever, and tachycardia) can identify more patients with sepsis who may benefit from time critical interventions.     

The epidemiology of the systemic inflammatory response

Objective: To examine the incidence, risk factors, aetiologies and outcome of the various forms of the septic syndromes (the systemic inflammatory response syndrome [SIRS] sepsis, severe sepsis, and septic shock) and their relationships with infection.¶Design: Review of published cohort studies examining the epidemiology of the septic syndromes, with emphasis on intensive care unit (ICU) patients.¶Results: The prevalence of SIRS is very high, affecting one-third of all in-hospital patients, and > 50 % of all ICU patients; in surgical ICU patients, SIRS occurs in > 80 % patients. Trauma patients are at particularly high risk of SIRS, and most these patients do not have infection documented. The prevalence of infection and bacteraemia increases with the number of SIRS criteria met, and with increasing severity of the septic syndromes. About one-third of patients with SIRS have or evolve to sepsis. Sepsis may occur in approximately 25 % of ICU patients, and bacteraemic sepsis in 10 %. In such patients, sepsis evolves to severe sepsis in > 50 % of cases, whereas evolution to severe sepsis in non-ICU patients is about 25 %. Severe sepsis and septic shock occur in 2 %–3 % of ward patients and 10 %–15 % or more ICU patients, depending on the case-mix; 25 % of patients with severe sepsis have shock. There is a graded severity from SIRS to sepsis, severe sepsis and septic shock, with an associated 28-d mortality of approximately 10 %, 20 %, 20 %–40 %, and 40 %–60 %, respectively. Mortality rates are similar within each stage, whether infection is documented or not, and microbiological characteristics of infection do not substantially influence outcome, although the source of infection does. While about three of four deaths occur during the first months after sepsis, the septic syndromes significantly impact on long-term outcome, with an estimated 50 % reduction of life expectancy over the following five years. The major determinants of outcome, both short-term and long-term, of patients with sepsis are the severity of underlying diseases and comorbidities, the presence of shock and organ failures at onset of sepsis or evolving thereafter. It has been estimated that two-thirds of the overall mortality can be attributed to sepsis.¶Conclusions: The prevalence of sepsis in ICU patients is very high, and most patients have clinically or microbiologically documented infection, except in specific subset of patients. The prognosis of septic syndromes is related to underlying diseases and the severity of the inflammatory response and its sequelae, reflected in shock and organ dysfunction/failures.     

New insights into the mechanisms involved in B-type natriuretic peptide elevation and its prognostic value in septic patients

Introduction

Elevated plasma B-type natriuretic peptide (BNP) levels in patients with critical sepsis (severe sepsis and septic shock) may indicate septic cardiomyopathy. However, multiple heterogeneous conditions may also be involved in increased BNP level. In addition, the prognostic value of BNP in sepsis remains debatable. In this study, we sought to discover potential independent determinants of BNP elevation in critical sepsis. The prognostic value of BNP was also evaluated.

Methods

In this observational study, we enrolled mechanically ventilated, critically septic patients requiring hemodynamic monitoring through a pulmonary artery catheter. All clinical, laboratory and survival data were prospectively collected. Plasma BNP concentrations were measured daily for five consecutive days. Septic cardiomyopathy was assessed on day 1 on the basis of left and right ventricular ejection fractions (EF) derived from echocardiography and thermodilution, respectively. Mortality was recorded at day 28.

Results

A total of 42 patients with severe sepsis (N = 12) and septic shock (N = 30) were ultimately enrolled. Daily BNP levels were significantly elevated in septic shock patients compared with those with severe sepsis (P ≤0.002). Critical illness severity (assessed by Acute Physiology and Chronic Health Evaluation II and maximum Sequential Organ Failure Assessment scores), and peak noradrenaline dose on day 1 were independent determinants of BNP elevation (P <0.05). Biventricular EFs were inversely correlated with longitudinal BNP measurements (P <0.05), but not independently. Pulmonary capillary wedge pressures (PCWP) and volume expansion showed no correlation with BNP. In septic shock, increased central venous pressure (CVP) and CVP/PCWP ratio were independently associated with early BNP values (P <0.05).Twenty-eight-day mortality was 47.6% (20 of 42 patients). Daily BNP values poorly predicted outcome; BNP on day 1 > 800 pg/ml (the best cutoff point) fairly predicted mortality, with a sensitivity%, specificity% and area under the curve values of 65, 64 and 0.70, respectively (95% confidence interval = 0.54 to 0.86; P = 0.03). Plasma BNP levels declined faster in survivors than in nonsurvivors in both critical sepsis and septic shock (P ≤0.002). In septic shock, a BNP/CVP ratio >126 pg/mmHg/ml on day 2 and inability to reduce BNP <500 pg/ml implied increased mortality (P ≤0.036).

Conclusions

The severity of critical illness, rather than septic cardiomyopathy, is probably the major determinant of BNP elevation in patients with critical sepsis. Daily BNP values are of limited prognostic value in predicting 28-day mortality; however, fast BNP decline over time and a decrease in BNP <500 pg/ml may imply a favorable outcome.     

ADAMTS-13, von Willebrand factor and related parameters in severe sepsis and septic shock

BACKGROUND: Insufficient control of von Willebrand factor (VWF) multimer size as a result of severely deficient ADAMTS-13 activity results in thrombotic thrombocytopenic purpura associated with microvascluar thrombosis and platelet consumption, features not seldom seen in severe sepsis and septic shock. METHODS: ADAMTS-13 activity and VWF parameters of 40 patients with severe sepsis or septic shock were compared with those of 40 healthy controls of the same age and gender and correlated with clinical findings and sepsis outcome. RESULTS: ADAMTS-13 activity was significantly lower in patients than in healthy controls [median 60% (range 27-160%) vs. 110% (range 63-200%); P < 0.001]. VWF parameters behaved reciprocally and both VWF ristocetin cofactor activity (RCo) and VWF antigen (VWF:Ag) were significantly (P < 0.001) higher in patients compared with controls. Neither ADAMTS-13 activity nor VWF parameters correlated with disease severity, organ dysfunction or outcome. However, a contribution of acute endothelial dysfunction to renal impairment in sepsis is suggested by the significantly higher VWF propeptide and soluble thrombomodulin levels in patients with increased creatinine values as well as by their strong positive correlations (creatinine and VWF propeptide r(s) = 0.484, P < 0.001; creatinine and soluble thrombomodulin r(s) = 0.596, P < 0.001). CONCLUSIONS: VWF parameters are reciprocally correlated with ADAMTS-13 activity in severe sepsis and septic shock but have no prognostic value regarding outcome.     

Levosimendan in septic shock in patients with biochemical evidence of cardiac dysfunction: a subgroup analysis of the LeoPARDS randomised trial

Myocardial dysfunction is common in sepsis but optimal treatment strategies are unclear. The inodilator, levosimendan was suggested as a possible therapy; however, the levosimendan to prevent acute organ dysfunction in Sepsis (LeoPARDS) trial found it to have no benefit in reducing organ dysfunction in septic shock. In this study we evaluated the effects of levosimendan in patients with and without biochemical cardiac dysfunction and examined its non-inotropic effects. Two cardiac biomarkers, troponin I (cTnI) and N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and five inflammatory mediators were measured in plasma from patients recruited to the LeoPARDS trial at baseline and over the first 6 days. Mean total Sequential Organ Failure Assessment (SOFA) score and 28-day mortality were compared between patients with normal and raised cTnI and NT-proBNP values, and between patients above and below median values. Levosimendan produced no benefit in SOFA score or 28-day mortality in patients with cardiac dysfunction. There was a statistically significant treatment by subgroup interaction (p = 0.04) in patients with NT-proBNP above or below the median value. Those with NT-proBNP values above the median receiving levosimendan had higher SOFA scores than those receiving placebo (mean daily total SOFA score 7.64 (4.41) vs 6.09 (3.88), mean difference 1.55, 95% CI 0.43–2.68). Levosimendan had no effect on the rate of decline of inflammatory biomarkers. Adding levosimendan to standard care in septic shock was not associated with less severe organ dysfunction nor lower mortality in patients with biochemical evidence of cardiac dysfunction.     

Elevated serum levels of S-100beta protein and neuron-specific enolase are associated with brain injury in patients with severe sepsis and septic shock

OBJECTIVE: We investigated whether serum levels of neuron-specific enolase (NSE) and S-100beta protein could be used to evaluate cerebral injury and to predict outcome in severe sepsis and severe septic shock. DESIGN: Prospective study. SETTING: University hospital. PATIENTS AND MEASUREMENTS: In 170 consecutively enrolled patients with severe sepsis and septic shock, serum S-100beta and NSE were measured daily during four consecutive days after intensive care unit admission. Admission Glasgow Coma Scale before sedation and daily Sequential Organ Failure Assessment scores were recorded in all patients. Acute encephalopathy was defined as either a state of agitation, confusion, irritability, and convulsions (type A) or characterized by somnolence, stupor, and coma (type B) and persistently observed during 72 hrs after withdrawing sedation. When clinically indicated, contrast computed tomography or magnetic resonance imaging were performed to evaluate brain injury. MAIN RESULTS: S-100beta and NSE increased in, respectively, 72 (42%) and 90 (53%) patients. High biomarker levels were associated with the maximum Sequential Organ Failure Assessment scores (p = .001), and the highest values were found in patients who died early, within 4 days of inclusion (p = .005). Low consciousness encephalopathy type B was more frequently observed in patients with elevated S-100beta (p = .004). S-100beta levels of >or=4 microg/L were associated with severe brain ischemia or hemorrhage, and values of <2 microg/L were found in patients with diffuse cerebral embolic infarction lesions. High S-100beta levels were associated with higher intensive care unit mortality (p = .04) and represented the strongest independent predictor of intensive care unit survival, whereas NSE and the Glasgow Coma Scale failed to predict fatal outcome. CONCLUSIONS: S-100beta and NSE are frequently increased and associated with brain injury in patients with severe sepsis and septic shock. S-100beta levels more closely reflected severe encephalopathy and type of brain lesions than NSE and the Glasgow Coma Scale.     

Clinical review: Myocardial depression in sepsis and septic shock

Myocardial dysfunction frequently accompanies severe sepsis and septic shock. Whereas myocardial depression was previously considered a preterminal event, it is now clear that cardiac dysfunction as evidenced by biventricular dilatation and reduced ejection fraction is present in most patients with severe sepsis and septic shock. Myocardial depression exists despite a fluid resuscitation-dependent hyperdynamic state that typically persists in septic shock patients until death or recovery. Cardiac function usually recovers within 7-10 days in survivors. Myocardial dysfunction does not appear to be due to myocardial hypoperfusion but due to circulating depressant factors, including the cytokines tumor necrosis factor alpha and IL-1beta. At a cellular level, reduced myocardial contractility seems to be induced by both nitric oxide-dependent and nitric oxide-independent mechanisms. The present paper reviews both the clinical manifestations and the molecular/cellular mechanisms of sepsis-induced myocardial depression.     

Urinary liver-type fatty acid-binding protein in septic shock: effect of polymyxin B-immobilized fiber hemoperfusion

We aimed to determine retrospectively whether urinary liver-type fatty acid-binding protein (L-FABP) levels are altered in patients with septic shock or severe sepsis without shock and whether polymyxin B-immobilized fiber (PMX-F) hemoperfusion affects these levels. Forty patients with septic shock, 20 patients with severe sepsis without shock, 20 acute renal failure (ARF) patients without septic shock (mean serum creatinine, 2.8 mg/dL), and 30 healthy volunteers were included in this study. Polymyxin B-immobilized fiber hemoperfusion was performed twice in 40 patients. In addition, 10 patients with septic shock without PMX-F treatment (conventional treatment) were also enrolled in this study. Their families did not choose PMX-F treatment. Thus, their informed consents to perform PMX-F treatment were not obtained. Septic shock or severe sepsis was defined by the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference Committee. Patients with septic shock were eligible for inclusion in the study if they had a definable source of infection and/or positive blood cultures. Patients with cardiogenic or hemorrhagic shock were excluded from the study. The patients were not randomly allocated to receive PMX-F treatment. Urinary and serum L-FABP levels were measured by enzyme-linked immunosorbent assay method. Plasma endotoxin levels in patients with septic shock were significantly higher than those in patients with severe sepsis (P < 0.05), patients with ARF (P < 0.001), and healthy subjects (P < 0.001). Urinary L-FABP levels in patients with septic shock were significantly higher than those in patients with severe sepsis without shock (P < 0.001), patients with ARF (P < 0.001), and healthy subjects (P < 0.001), whereas serum L-FABP levels showed no significant differences between patients with septic shock, patients with severe sepsis, patients with ARF, and healthy subjects. Urinary L-FABP was not correlated with serum L-FABP. Twenty-eight patients with septic shock survived, and 12 patients died. Polymyxin B-immobilized fiber treatment reduced plasma endotoxin levels (P < 0.01) and urinary L-FABP levels (P < 0.01). In 10 patients with septic shock without PMX-F treatment, L-FABP levels remained high 7 days after initiation of conventional treatment (P = 0.12). These results suggest that urinary L-FABP levels are significantly increased in patients with septic shock and that PMX-F treatment is effective in reducing these levels.     

The impact of the severity of sepsis on the risk of hypoglycaemia and glycaemic variability

Introduction

The purpose of this study was to assess the relation between glycaemic control and the severity of sepsis in a cohort of patients treated with intensive insulin therapy (IIT).

Methods

In a prospective, observational study, all patients in the intensive care unit (ICU) (n = 191) with sepsis, severe sepsis or septic shock were treated with IIT (target blood glucose (BG) level 80 to 140 mg/dl instead of strict normoglycaemia). BG values were analysed by calculating mean values, rate of BG values within different ranges, rate of patients experiencing BG values within different levels and standard deviation (SD) of BG values as an index of glycaemic variability.

Results

The number of patients with hypoglycaemia and hyperglycaemia was highly dependent on the severity of sepsis (critical hypoglycaemia ≤ 40 mg/dl: sepsis: 2.1%, severe sepsis: 6.0%, septic shock: 11.5%, p = 0.1497; hyperglycaemia: >140 mg/dl: sepsis: 76.6%, severe sepsis: 88.0%, septic shock: 100%, p = 0.0006; >179 mg/dl: sepsis: 55.3%, severe sepsis: 73.5%, septic shock: 88.5%, p = 0.0005; >240 mg/dl: sepsis: 17.0%, severe sepsis: 48.2%, septic shock: 45.9%, p = 0.0011). Multivariate analyses showed a significant association of SD levels with critical hypoglycaemia especially for patients in septic shock (p = 0.0197). In addition, SD levels above 20 mg/dl were associated with a significantly higher mortality rate relative to those with SD levels below 20 mg/dl (24% versus 2.5%, p = 0.0195).

Conclusions

Patients with severe sepsis and septic shock who were given IIT had a high risk of hypoglycaemia and hyperglycaemia. Among these patients even with a higher target BG level, IIT mandates an increased awareness of the occurrence of critical hypoglycaemia, which is related to the severity of the septic episode.     

Sepsis incidence and outcome: contrasting the intensive care unit with the hospital ward

OBJECTIVE: To describe the outcome of patients with sepsis according to location on a ward or in an intensive care unit. DESIGN: Prospective multicentered observational study. SETTING: Three academic hospitals in Madrid, Spain. PATIENTS: Consecutive patients with sepsis admitted to participating hospitals from March 1 to June 30, 2003. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: During the study period, 15,852 patients >18 yrs of age were admitted. Sepsis was identified in 702 patients, giving an estimated cumulative incidence rate of 367 cases per 100,000 adult area residents per year and a cumulative incidence rate among patients admitted to the hospital of 4.4%. Most septic patients had a community-acquired infection (71%). Severe sepsis developed in 199 patients (incidence rate, 104 cases per 100,000 adult area residents per year), and 59 patients developed septic shock (incidence rate, 31 cases per 100,000 adult area residents per year). Most of the patients met the criteria for severe sepsis or septic shock on the same day that they would have qualified for the septic status one step down the scale. In the other patients, the median time between sepsis and severe sepsis was 2 days (interquartile range, 2-5) and between severe sepsis and septic shock was 3 days (interquartile range, 1-4). Only 32% of severe sepsis patients received intensive care. The hospital mortality for all septic patients was 12.8%; for severe sepsis, 20.7%; and for septic shock, 45.7%. CONCLUSIONS: This study shows the high incidence of sepsis in a general population of patients admitted to hospital. A significant proportion of patients with severe sepsis are not transferred to the intensive care unit.     

血浆脑钠肽对重度脓毒症患者诊断及预后的影响

目的评价血浆脑钠肽（BNP）水平在预测重度脓毒症患者死亡及诊断中的价值。方法重度脓毒症患者41例,非脓毒组（对照组）20例,比较2组BNP水平的变化。根据脓毒症患者是否于28 d内存活将其分为存活组和死亡组,比较患者入院第1天反应蛋白、危重病评分（APACHEⅡ和SOFA）、血浆BNP水平和第3天血浆BNP水平差异。结果脓毒症组患者入院第1d和第3d血浆BNP水平明显高于对照组;死亡组重度脓毒症患者第1天和第3天血浆BNP水平与存活组相比均明显增高;logistic回归分析发现,在年龄、APACHEⅡ、SOFA、CRP及第1天和第3天BNP水平诸因素中,第3天的BNP水平和SOFA评分为预测ICU死亡的独立危险因素。结论绝大多数老年重度脓毒症患者的血浆BNP水平明显升高,BNP可成为预测老年重度脓毒症患者预后和诊断的实验室指标。