Clinical prognostic markers in patients with severe sepsis: a prospective analysis of 139 consecutive cases

Hierarchical Capability in Distinguishing Severities of Sepsis via Serum Lactate: A Network Meta-Analysis

Background: Blood lactate is a potentially useful biomarker to predict the mortality and severity of sepsis. The purpose of this study is to systematically review the ability of lactate to predict hierarchical sepsis clinical outcomes and distinguish sepsis, severe sepsis and septic shock. Methods: We conducted an exhaustive search of the PubMed, Embase and Cochrane Library databases for studies published before 1 October 2022. Inclusion criteria mandated the presence of case-control, cohort studies and randomized controlled trials that established the association between before-treatment blood lactate levels and the mortality of individuals with sepsis, severe sepsis or septic shock. Data was analyzed using STATA Version 16.0. Results: A total of 127 studies, encompassing 107,445 patients, were ultimately incorporated into our analysis. Meta-analysis of blood lactate levels at varying thresholds revealed a statistically significant elevation in blood lactate levels predicting mortality (OR = 1.57, 95% CI 1.48-1.65, I2 = 92.8%, p < 0.00001). Blood lactate levels were significantly higher in non-survivors compared to survivors in sepsis patients (SMD = 0.77, 95% CI 0.74-0.79, I2 = 83.7%, p = 0.000). The prognostic utility of blood lactate in sepsis mortality was validated through hierarchical summary receiver operating characteristic curve (HSROC) analysis, yielding an area under the curve (AUC) of 0.72 (95% CI 0.68-0.76), accompanied by a summary sensitivity of 0.65 (95% CI 0.59-0.7) and a summary specificity of 0.7 (95% CI 0.64-0.75). Unfortunately, the network meta-analysis could not identify any significant differences in average blood lactate values' assessments among sepsis, severe sepsis and septic shock patients. Conclusions: This meta-analysis demonstrated that high-level blood lactate was associated with a higher risk of sepsis mortality. Lactate has a relatively accurate predictive ability for the mortality risk of sepsis. However, the network analysis found that the levels of blood lactate were not effective in distinguishing between patients with sepsis, severe sepsis and septic shock.

Activation of thousands of genes in the lungs and kidneys by sepsis is countered by the selective nuclear blockade

The steady rise of sepsis globally has reached almost 49 million cases in 2017, and 11 million sepsis-related deaths. The genomic response to sepsis comprising multi-system stage of raging microbial inflammation has been reported in the whole blood, while effective treatment is lacking besides anti-microbial therapy and supportive measures. Here we show that, astoundingly, 6,237 significantly expressed genes in sepsis are increased or decreased in the lungs, the site of acute respiratory distress syndrome (ARDS). Moreover, 5,483 significantly expressed genes in sepsis are increased or decreased in the kidneys, the site of acute injury (AKI). This massive genomic response to polymicrobial sepsis is countered by the selective nuclear blockade with the cell-penetrating Nuclear Transport Checkpoint Inhibitor (NTCI). It controlled 3,735 sepsis-induced genes in the lungs and 1,951 sepsis-induced genes in the kidneys. The NTCI also reduced without antimicrobial therapy the bacterial dissemination: 18-fold in the blood, 11-fold in the lungs, and 9-fold in the spleen. This enhancement of bacterial clearance was not significant in the kidneys. Cumulatively, identification of the sepsis-responsive host's genes and their control by the selective nuclear blockade advances a better understanding of the multi-system mechanism of sepsis. Moreover, it spurs much-needed new diagnostic, therapeutic, and preventive approaches.

Understanding the complexity of sepsis mortality prediction via rule discovery and analysis: a pilot study

BACKGROUND

Sepsis, defined as life-threatening organ dysfunction caused by a dysregulated host response to infection, has become one of the major causes of death in Intensive Care Units (ICUs). The heterogeneity and complexity of this syndrome lead to the absence of golden standards for its diagnosis, treatment, and prognosis. The early prediction of in-hospital mortality for sepsis patients is not only meaningful to medical decision making, but more importantly, relates to the well-being of patients.

METHODS

In this paper, a rule discovery and analysis (rule-based) method is used to predict the in-hospital death events of 2021 ICU patients diagnosed with sepsis using the MIMIC-III database. The method mainly includes two phases: rule discovery phase and rule analysis phase. In the rule discovery phase, the RuleFit method is employed to mine multiple hidden rules which are capable to predict individual in-hospital death events. In the rule analysis phase, survival analysis and decomposition analysis are carried out to test and justify the risk prediction ability of these rules. Then by leveraging a subset of these rules, we establish a prediction model that is both more accurate at the in-hospital death prediction task and more interpretable than most comparable methods.

RESULTS

In our experiment, RuleFit generates 77 risk prediction rules, and the average area under the curve (AUC) of the prediction model based on 62 of these rules reaches 0.781 ([Formula: see text]) which is comparable to or even better than the AUC of existing methods (i.e., commonly used medical scoring system and benchmark machine learning models). External validation of the prediction power of these 62 rules on another 1468 sepsis patients not included in MIMIC-III in ICU provides further supporting evidence for the superiority of the rule-based method. In addition, we discuss and explain in detail the rules with better risk prediction ability. Glasgow Coma Scale (GCS), serum potassium, and serum bilirubin are found to be the most important risk factors for predicting patient death.

CONCLUSION

Our study demonstrates that, with the rule-based method, we could not only make accurate prediction on in-hospital death events of sepsis patients, but also reveal the complex relationship between sepsis-related risk factors through the rules themselves, so as to improve our understanding of the complexity of sepsis as well as its population.

The effect of activated protein C in the experimental disseminated intravascular coagulation model formed by lipopolysaccharide infusion

Purpose:

In this experimental study, activated protein C (APC), which has anticoagulant, antithrombotic, profibrinolytic, anti-inflammatory and antiapoptotic properties, was used to prevent coagulopathy in a disseminated intravascular coagulation (DIC) model formatted with lipopolysaccharide (LPS) infusion.

Methods:

Twenty-five Wistar albino rats weighting 280 – 320 g each were used. They were randomly divided into three groups: sham, control and study groups. To sham group (n = 5), only normal saline was infused. To control (n = 10) and study groups (n = 10), 30 mg/kg LPS was infused for 4 h from femoral vein. After LPS infusion, 100 µg/kg recombinant APC was given during 4 h in study group. Eight hours later, blood samples were taken from abdominal aorta and the animals sacrificed. From these samples, platelet, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen and D-dimer levels were studied.

Results:

Platelet counts and fibrinogen levels were significantly lower in control and study groups than sham group (p < 0.05). The PT, aPTT and D-dimer levels were significantly higher in control and study groups than in sham group (p < 0.05). When comparing control and study groups, platelet counts were not statistically different (p = 0.36). However, the difference of the fibrinogen levels was significant between these groups (p = 0.0001). While PT and aPTT were longer in the study group compared to the control group (p < 0.05), D-dimer levels were lower in the study group than in control (p = 0.0001).

Conclusion:

Use of APC can prevent hypercoagulation and consumption coagulopathy in the DIC as a result of correcting hematological parameters other than prolongation of coagulation time.

Pharmacodynamic evaluation of intermittent versus extended and continuous infusions of piperacillin/tazobactam in a hollow-fibre infection model against Klebsiella pneumoniae

OBJECTIVES

To compare bacterial killing and the emergence of resistance to piperacillin/tazobactam, administered by intermittent versus prolonged infusion (i.e. extended or continuous), for ceftriaxone-resistant Klebsiella pneumoniae clinical isolates in an in vitro dynamic hollow-fibre infection model (HFIM).

METHODS

K. pneumoniae 68 (Kp68; MIC = 8 mg/L, producing SHV-106 and DHA-1) and K. pneumoniae 69 (Kp69; MIC = 1 mg/L, producing CTX-M-14) were studied in the HFIM over 7 days (initial inoculum ~107 cfu/mL). Six piperacillin/tazobactam dosing regimens for Kp68 (4/0.5 g 8 hourly as 0.5 and 4 h infusions, 12/1.5 g/24 h continuous infusion, 4/0.5 g 6 hourly as 0.5 and 3 h infusions and 16/2 g/24 h continuous infusion) and three piperacillin/tazobactam dosing regimens for Kp69 (4/0.5 g 8 hourly as 0.5 and 4 h infusions and 12/1.5 g/24 h continuous infusion) were simulated (piperacillin clearance = 14 L/h, creatinine clearance = 100 mL/min). Total and resistant populations and MICs were quantified/determined.

RESULTS

For Kp68, all simulated dosing regimens exhibited approximately 4 log10 of bacterial killing at 8 h followed by regrowth to approximately 1011 cfu/mL within 24 h. The MICs for resistant subpopulations exceeded 256 mg/L at 72 h. Similarly, for Kp69, all simulated dosing regimens exhibited approximately 4 log10 of bacterial killing over 8 h; however, only the continuous infusion prevented bacterial regrowth.

CONCLUSIONS

Compared with intermittent infusion, prolonged infusion did not increase initial bacterial killing and suppression of regrowth of plasmid-mediated AmpC- and ESBL-producing K. pneumoniae. However, continuous infusion may suppress regrowth of some ESBL-producing susceptible K. pneumoniae, although more data are warranted to confirm this observation.

The Effects of Abnormal Body Temperature on the Prognosis of Patients with Septic Shock

We aimed to use temperature and the area under temperature curve to represent the severity of abnormal body temperature of patients with septic shock and to observe their impact on the prognosis. Five hundred twenty-eight adult patients with septic shock admitted to intensive care unit (ICU) were analyzed. Within the first 24 hours and throughout the period in ICU, the maximum temperature (24hT_max, T_max), lowest temperature (24hT_min, T_min), and the temperature range (24hT_max-min, T_max-min) were aggregated. Patients were divided into the survival group and the death group. Binary logistic regression was used to assess the relationship between body temperature aberrations and survival. The following risk factors of death in 21 days were identified: T_max (odds ratio [OR] 2.967, 95% confidence interval [CI] 1.626-5.414, p < 0.001), T_min (OR 0.337, 95% CI 0.143-0.794, p = 0.013), and T_max-min (OR 3.259, 95% CI 1.847-5.749, p < 0.001). This is an observational study, so one can infer association but not causation. Therefore, we infer that abnormal body temperature is associated with an adverse prognosis in patients with septic shock.

Clinical characteristics associated with mortality of patients with anaerobic bacteremia

The presence of anaerobes in the blood stream is known to be associated with a higher rate of mortality. However, few prognostic risk factor analyses examining whether a patient's background characteristics are associated with the prognosis have been reported. We performed a retrospective case-controlled study to assess the prognostic factors associated with death from anaerobic bacteremia. Seventy-four patients with anaerobic bacteremia were treated between January 2005 and December 2014 at Aichi Medical University Hospital. The clinical information included drug susceptibility was used for analysis of prognostic factors for 30-day mortality. Multivariate logistic analyses revealed an association between the 30-day mortality rate and malignancy (OR: 3.64, 95% CI: 1.08-12.31) and clindamycin resistance (OR: 7.93, 95% CI: 2.33-27.94). The result of Kaplan-Meier analysis of mortality showed that the 30-day survival rate was 83% in clindamycin susceptible and 38.1% in clindamycin resistant anaerobes causing bacteremia. The result of log-rank test also showed that susceptibility to clindamycin affected mortality (P < 0.001). Our results indicated that malignancy and clindamycin susceptibility could be used to identify subgroups of patients with anaerobic bacteremia with a higher risk of 30-day mortality. The results of this study are important for the early and appropriate management of patients with anaerobic bacteremia.

Host response biomarkers in the diagnosis of sepsis: a general overview

Critically ill patients who display a systemic inflammatory response syndrome (SIRS) are prone to develop nosocomial infections. The challenge remains to distinguish as early as possible among SIRS patients those who are developing sepsis. Following a sterile insult, damage-associated molecular patterns (DAMPs) released by damaged tissues and necrotic cells initiate an inflammatory response close to that observed during sepsis. During sepsis, pathogen-associated molecular patterns (PAMPs) trigger the release of host mediators involved in innate immunity and inflammation through identical receptors as DAMPs. In both clinical settings, a compensatory anti-inflammatory response syndrome (CARS) is concomitantly initiated. The exacerbated production of pro- or anti-inflammatory mediators allows their detection in biological fluids and particularly within the bloodstream. Some of these mediators can be used as biomarkers to decipher among the patients those who developed sepsis, and eventually they can be used as prognosis markers. In addition to plasma biomarkers, the analysis of some surface markers on circulating leukocytes or the study of mRNA and miRNA can be helpful. While there is no magic marker, a combination of few biomarkers might offer a high accuracy for diagnosis.

Recent Change in Treatment of Disseminated Intravascular Coagulation in Japan: An Epidemiological Study Based on a National Administrative Database

This study investigated the time trends and hospital factors affecting the use of drugs for infectious disease-associated disseminated intravascular coagulation (DIC) based on a national administrative database. A total of 14 324 patients with infectious disease-associated DIC were referred to 1041 hospitals from 2010 to 2012 in Japan. Patients' data were collected from the administrative database to determine time trends and hospital factors affecting the use of drugs for DIC. Three study periods were established, namely, the fiscal years 2010 (n = 3308), 2011 (n = 5403), and 2012 (n = 5613). The use of antithrombin, heparin, protease inhibitors, and recombinant human soluble thrombomodulin (rhs-TM) for DIC was evaluated. The frequency of use of antithrombin, heparin, and protease inhibitors decreased while that of rhs-TM significantly increased from 2010 to 2012 in Japan (25.1% in 2010, 43.1% in 2011, and 56.8% in 2012; P < .001, respectively). Logistic regression showed that the study period was associated with the use of rhs-TM in patients with DIC. The odds ratio (OR) for 2011 was 2.34 (95% confidence interval [CI], 2.12-2.58; P < .001) whereas that for 2012 was 4.34 (95% CI, 3.94-4.79; P < .001). A large hospital size was the most significant factor associated with the use of rhs-TM in patients with DIC (OR, 3.14; 95% CI, 2.68-3.66; P < .001). The use of rhs-TM has dramatically increased. A large hospital size was significantly associated with the increased use of rhs-TM in patients with DIC from 2010 to 2012 in Japan.

Observational study to compare antithrombin and thrombomodulin for disseminated intravascular coagulation

BACKGROUND

There have been no studies comparing the effects of antithrombin (AT-III) and recombinant human soluble thrombomodulin (rhs-TM) on outcomes in patients with disseminated intravascular coagulation (DIC) associated with infectious diseases.

OBJECTIVE

The aim of this observational study is to compare AT-III and rhs-TM in terms of outcomes such as mortality, length of hospitalization, and medical costs in patients with DIC associated with infectious diseases based on a Japanese administrative database.

SETTING

A total of 7,535 patients with DIC associated with infectious diseases in 886 hospitals from 2010 to 2012 in Japan. Methods We collected patients' data from the administrative database to compare clinical and medical economic outcomes of patients with DIC. Patients were divided into two groups according to treatment of DIC: AT-III (n = 3,601) and rhs-TM (n = 3,934).

MAIN OUTCOMES MEASURE

In-hospital mortality (within 14 days, within 28 days, and overall mortality), length of stay (LOS), and medical costs during hospitalization.

RESULTS

Multilevel logistic regression analysis showed that there were no significant differences with regard to in-hospital mortality between AT-III and rhs-TM within 14 days (odds ratio (OR) of rhs-TM 0.97, 95 % confidence interval (CI) 0.85-1.11, p = 0.744), within 28 days (OR 1.00, 95 % CI 0.89-1.13, p = 0.919), and overall (OR 0.95, 95 % CI 0.85-1.07, p = 0.470). However, multilevel linear regression analysis revealed that use of rhs-TM significantly decreased LOS and medical costs during hospitalization. The coefficient for LOS was -2.92 days (95 % CI -4.79 to -1.04 days; p = 0.002) whereas that for medical costs during hospitalization was -798.3 Euro (95 % CI -1,515.7 to -81.0 Euro; p = 0.029).

CONCLUSION

This study demonstrated no significant difference in in-hospital mortality between AT-III and rhs-TM. However, use of rhs-TM was significantly associated with decreased LOS and medical costs during hospitalization in patients with DIC associated with infectious diseases.

Delta neutrophil index as a prognostic marker of early mortality in gram negative bacteremia

Background

Sepsis is a syndrome that results in high morbidity and mortality. We investigated the delta neutrophil index (DN) as a predictive marker of early mortality in patients with gram-negative bacteremia.

Materials and Methods

We conducted a retrospective study at a tertiary referral hospital in South Korea from November 2010 to March 2011. The DN was measured at onset of bacteremia and 24 hours and 72 hours later. The DN was calculated using an automatic hematology analyzer. Factors associated with 10-day mortality were assessed using logistic regression.

Results

A total of 172 patients with gram-negative bacteremia were included in the analysis; of these, 17 patients died within 10 days of bacteremia onset. In multivariate analysis, Sequental organ failure assessment scores (odds ratio [OR]: 2.24, 95% confidence interval [CI]: 1.31 to 3.84; P = 0.003), DN-day 1 ≥ 7.6% (OR: 305.18, 95% CI: 1.73 to 53983.52; P = 0.030) and DN-day 3 ≥ DN-day 1 (OR: 77.77, 95% CI: 1.90 to 3188.05; P = 0.022) were independent factors associated with early mortality in gram-negative bacteremia. Of four multivariate models developed and tested using various factors, the model using both DN-day 1 ≥ 7.6% and DN-day 3 ≥ DN-day 1 was most predictive early mortality.

Conclusions

DN may be a useful marker of early mortality in patients with gram-negative bacteremia. We found both DN-day 1 and DN trend to be significantly associated with early mortality.

Prediction of outcome from community-acquired severe sepsis and septic shock in tertiary-care university hospital in a developing country

Our aim was to determine the risk factors on mortality in adult patients with community-acquired severe sepsis and septic shock. The main outcome measure was hospital mortality. This prospective single centre study was conducted from January 1, 2008 to December 31, 2010, and included 184 patients, of whom 135 (73.4%) were with severe sepsis and 49 (26.6%) had septic shock. Overall, ninety-five (51.6%) patients have died, 60 (44.4%) in severe sepsis and 35 (71.4%) patients with septic shock. The lung was the most common site of infection 121 (65.8%), and chronic heart failure was the most frequent comorbidity 65 (35.3%). Logistic multivariate analysis identified three independent risk factors for mortality in patients with severe sepsis: positive blood culture (odds ratio, 2.39; 95% confidence interval, 1.13-5.06; P = 0.02), three or more organ dysfunctions (odds ratio, 3.93; 95% confidence interval, 1.62-9.53; P = 0.002), and Simplified Acute Physiology Score (SAPS) II (odds ratio, 1.02; 95% confidence interval, 1.00-1.04; P = 0.01). In addition to SAPS II, positive blood culture, and three or more organ dysfunctions are important independent risk factors for mortality in patients with severe sepsis and septic shock.

Blood lactate levels differ significantly between surviving and nonsurviving patients within the same risk-adjusted Classification for Congenital Heart Surgery (RACHS-1) group after pediatric cardiac surgery

This study aimed to examine the association between lactate levels in the first hours after surgery for congenital heart defects and the results of Risk-Adjusted Classification for Congenital Heart Surgery (RACHS-1) scoring and to evaluate serial lactate levels over time to determine whether they can serve as a supplementary tool for postoperative assessment within the same RACHS-1 group of patients. A retrospective cohort study was performed using data retrieved from a clinical database of 255 children who had surgery for congenital heart defects between 1999 and 2001 at Sheba Medical Center. Lactate levels were measured postoperatively four times (mg/dL units). The last sample was taken at the end of the surgical procedure, and lactate levels were measured at admission to the pediatrics critical care unit, then 6 and 12 h after admission. The lactate level was measured via arterial blood gases. A total of 27 deaths occurred, yielding a mortality rate of 7.4% when Norwood operations were excluded and 10.16% when they were included. The mean initial postoperative lactate level was significantly lower for survivors (42.2 ± 32.0 mg/dL) than for nonsurvivors (85.4 ± 54.1 mg/dL) (p < 0.01). The serial mean lactate levels decreased progressively for all surviving patients (r (2) = 0.96) compared with nonsurvivors (r (2) = 0.02). The lactate levels correlated with the RACHS-1 subgroups at each time point (r (2) > 0.96 for all). The Pearson correlations between postoperative lactate levels (last lactate measurement taken in the operating room) and cardiopulmonary bypass (CPB) duration (r = 0.549), clamp duration (r = 0.586), and the inotropic score (r = 0.466) (p < 0.001 for all) were significantly positive. The correlations between the maximum lactate levels (during the first 12 postoperative hours) and CPB duration (r = 0.496), clamp duration (r = 0.509), and the inotropic score (r = 0.633) (p < 0.001 for all) were extremely positive. The early elevation of lactate levels in RACHS-1 subgroups 1 to 3 were highly correlated with poor prognosis and death (p < 0.03). In addition, the lactate levels differed significantly between survivors and nonsurvivors within the same RACHS-1 subgroup. The survivors in RACHS-1 subgroups 1 to 3 had lower mean lactate levels than the nonsurvivors in this group (P = 0.011), and this also held true for the survivors and nonsurvivors in RACHS-1 subgroups 4 to 6 (P = 0.026). Lactate levels differed significantly between survivors and nonsurvivors within the same RACHS-1 subgroup. This combination allows the targeting of appropriately intensive interventions and therapies toward the sickest patients.

Treatment of lactic acidosis: appropriate confusion

BACKGROUND

Lactic acidosis (LA) is common in hospitalized patients and is associated with poor clinical outcomes. There have been major recent advances in our understanding of lactate generation and physiology. However, treatment of LA is an area of controversy and uncertainty, and the use of agents to raise pH is not clearly beneficial.

AIM AND METHODS

We reviewed animal and human studies on the pathogenesis, impact, and treatment of LA, published in the English language and available through the PubMed/MEDLINE database. Our aim was to clarify the physiology of the generation of LA, its impact on outcomes, and the different treatment modalities available. We also examined relevant data regarding LA induced by medications commonly prescribed by hospitalists: biguanides, nucleoside analog reverse-transcriptase inhibitors (NRTIs), linezolid, and lorazepam.

RESULTS/CONCLUSIONS

Lactic acid is a marker of tissue ischemia but it also may accumulate without tissue hypoperfusion. In the latter circumstance, lactic acid accumulation may be an adaptive mechanism-a novel possibility quite in contrast to the traditional view of lactic acid as only a marker of tissue ischemia. Studies on the treatment of LA with sodium bicarbonate or other buffers fail to show consistent clinical benefit. Severe acidemia in the setting of LA is a particularly poorly studied area. In the settings of medication-induced LA, optimal treatment, apart from prompt cessation of the offending agent, is still unclear.

Predictive factors for septic shock in patients with ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is one of the most frequent infections in intensive care units (ICUs), and nearly 50% of patients with VAP develop septic shock. Septic shock is an independent predictor for mortality in these patients.

OBJECTIVE

To investigate the predictors for septic shock in VAP patients receiving appropriate antibiotic therapy.

METHODS

Eighty-nine patients with microbiologically confirmed VAP who were receiving appropriate antibiotic therapy were included in the study. They were divided into two groups according to the existence of septic shock. Clinical, hematological, biochemical and microbiological characteristics were compared.

RESULTS

Thirty-seven percent of the patients developed septic shock. Advanced age (OR 1.07, 95% CI 1.02-1.13, P = 0.009), lymphocytopenia (<1000/mm3) (OR 7.48, 95% CI 1.91-29, P = 0.004), high blood glucose levels >120 mg/dL (OR 4.75, 95% CI 1.38-16, P = 0.014), and increased clinical pulmonary infection scores (CPIS) (OR 1.64, 95% CI 1.16-2.33, P = 0.006) were identified as independent predictors for the development of septic shock.

CONCLUSION

Some clinical parameters such as lymphocytopenia, blood glucose >120 mg/dL, increasing age, and CPIS can predict septic shock during VAP, but large randomized controlled studies are needed to confirm these results.

An overview of sepsis

The purpose of this paper was to briefly define sepsis, severe sepsis, and septic shock and discuss evidence-based guidelines for implementing a sepsis protocol in the critical care setting. In addition, this article will further educate critical care nurses about sepsis and strategies to improve outcomes in this group of patients.

Simple coagulation tests improve survival prediction in patients with septic shock

BACKGROUND

Classic mortality prediction models in intensive care units (ICUs) are based on clinical scores, which do not contain any coagulation test (SAPS-II or SOFA scores).

OBJECTIVES

To determine whether coagulation tests can improve mortality prediction in patients with septic shock.

PATIENTS AND METHODS

One hundred fifty-eight consecutive patients with septic shock entering our institution's ICU were investigated on the first day of admission, and deaths were registered during the first month.

RESULTS

Among all the coagulation tests performed, only the fibrinogen (Fg) plasma level, together with the SAPS-II score and the age, were included in our simplified mortality score [area under the receiver operating curve (AUC) 0.927, standard deviation (SD) 0.030], which was more efficient than SAPS-II and SOFA scores themselves in predicting first-week mortality, its optimized cut-off having a very high negative predictive value (NPV) [0.989; 95% confidence interval (CI) 0.967-1.000)]. A simplified score predicting first-month mortality, containing the prothrombin ratio and the antithrombin activity values in addition to the age, the hemoglobin concentration, and the SAPS-II and SOFA scores (AUC 0.889, SD 0.026), was found to be superior to the SAPS-II and SOFA scores, the optimized cut-off value having a high NPV (0.952; 95% CI 0.888-1.000).

CONCLUSIONS

In patients admitted to an ICU with septic shock, some initial coagulation test values can help identify those who will survive in the first week and then in the first month.

Elevated S100B levels do not correlate with the severity of encephalopathy during sepsis

BACKGROUND

Sepsis-associated encephalopathy (SAE) is defined as a diffuse cerebral dysfunction induced by the systemic response to infection without any clinical or laboratory evidence of direct infectious involvement of the central nervous system. The astroglial protein S100B has been used as a marker of severity of brain injury and as a prognostic index in trauma patients and cardiac arrest survivors. We measured S100B serum levels in patients with severe sepsis to investigate if the severity of SAE correlated with an increase in S100B levels.

METHODS

Twenty-one patients, with a diagnosis of severe sepsis, were included in this study. S100B levels were measured at intensive care unit (ICU) admission, 72 h and 7 days after admission. Their association with markers of brain dysfunction such as Glasgow coma scale (GCS), and EEG, and with sepsis-related organ failure assessment score (SOFA) and ICU mortality was investigated.

RESULTS

Fourteen patients had elevated S100B levels. The levels did not correlate with GCS at admission, EEG pattern, or SOFA scores. Also, S100B levels did not differ between patients who recovered neurologically and those who did not (P = 0.62).

CONCLUSIONS

In severe sepsis, an increase in S100B does not allow the physicians to distinguish patients with severe impairment of consciousness from those with milder derangements or to prognosticate neurological recovery.

Accelerated in vitro differentiation of blood monocytes into dendritic cells in human sepsis

Summary Sepsis-induced immune depression is characterized by infection susceptibility and monocyte early deactivation. Because monocytes are precursors for dendritic cells (DC), alterations in their differentiation into DC may contribute to defective immune responses in septic patients. We therefore investigated the ability of monocytes to differentiate into functional DC in vitro in patients undergoing surgery for peritonitis. Monocytes from 20 patients collected immediately after surgery (D0), at week 1 and at weeks 3-4 and from 11 control donors were differentiated into immature DC. We determined the phenotype of monocytes and derived DC, and analysed the ability of DC to respond to microbial products and to elicit T cell responses in a mixed leucocyte reaction (MLR). We show that, although monocytes from septic patients were deactivated with decreased responses to lipopolysaccharide (LPS) and peptidoglycan and low human leucocyte antigen D-related (HLA-DR) expression, they expressed the co-stimulatory molecule CD80, CD40 and CCR7. Monocytes collected from patients at D0 and week 1 differentiated faster into DC with early loss of CD14 expression. Expression of HLA-DR increased dramatically in culture to reach control levels, as did responses of DC to LPS and peptidoglycan. However, although patient and control immature DC had similar abilities to induce T cell proliferation in MLR, maturation of DC derived from patients did not increase T cell responses. These results show that circulating monocytes from septic patients express markers of activation and/or differentiation despite functional deactivation, and differentiate rapidly into phenotypically normal DC. These DC fail, however, to increase their T cell activation abilities upon maturation.

Global fibrinolytic capacity in pediatric patients with sepsis and disseminated intravascular coagulation

There are many complex pathophysiologic changes of the coagulation system in sepsis. The fibrinolytic system was evaluated in septic children using the global fibrinolytic capacity (GFC), a new technique reflecting the overall fibrinolytic activity. The study consisted of 24 children with sepsis, 36 children with sepsis plus disseminated intravascular coagulation (DIC), and 20 healthy age-matched control individuals. Compared with controls, 86% of sepsis patients and 87% of sepsis plus DIC patients had decreased GFC levels. Between the sepsis plus DIC and sepsis groups there was no significant difference in terms of GFC levels. While 19 patients (52.7%) died in the sepsis plus DIC group, only three patients (12.5%) died in the sepsis group. When survivors and nonsurvivors were compared in terms of coagulation tests, there were significant differences for protein C, antithrombin, platelet, fibrinogen, aspartate aminotransferase, alanine aminotransferase, prothrombin time, and white blood cell values. In conclusion, the level of GFC reduced in most of the pediatric sepsis patients but no difference was observed between patients with sepsis and patients with sepsis plus DIC. While inhibition of fibrinolysis is an important finding in sepsis, the mortality is mainly associated with the presence of end-organ damage and the status of coagulation parameters.

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.

Epidemiology and outcome of sepsis in a tertiary-care hospital in a developing country

Sepsis continues to have a substantial mortality and morbidity despite advances in the diagnosis and management of this condition. We retrospectively analysed hospital charts of patients diagnosed to have sepsis between January 2002 and June 2003. Demographic characteristics of patients, microbiological findings and predictors of survival were evaluated. Sixty-nine sepsis episodes that occurred in 63 patients were analysed. The most common underlying diseases were hypertension, malignancies and diabetes mellitus. Renal insufficiency, respiratory distress and disseminated intravascular coagulation developed in 52.2, 30.4 and 30.4% of the episodes respectively; 47.7% of the blood cultures yielded an organism. Gram-negative bacteria were the predominant microorganisms (65.9%). Fifty-five patients (87.3%) died. Mechanical ventilation and underlying renal disease were significant determinants of mortality. In conclusion, Gram-negative bacteria remain the major pathogens in sepsis. The mortality remains very high, and a change in the clinical approach to the septic patient should be employed to improve the outcome.

Prognostic indexes of septic syndrome in the emergency department

OBJECTIVE

Sepsis is a frequent and often lethal condition. Rapid identification and aggressive therapy in the emergency department (ED) are essential for outcome. Several indexes were found to be significantly related to short-term clinical outcome, but only bedside, rapidly available tests are thought to be useful in the ED. To define the prevalence and mortality of patients with severe sepsis presenting to the ED of a tertiary care hospital in Italy, we furthermore investigated the ability of bedside, non-invasive prognostic indexes to identify patients with adverse short-term clinical outcome.

METHODS

All patients admitted to the ED with a diagnosis of severe sepsis or septic shock were included. Retrospective data were collected by a dedicated software program using predefined searching criteria including clinical data, vital sign parameters, sepsis-related organ failure assessment (SOFA) score, and blood tests. The relationship between prognostic indexes and 24-h or 28-day mortality was evaluated by multivariate logistic regression analysis.

RESULTS

Ninety patients were enrolled from June 2004 to June 2005 (0.2% of all incoming patients to ED and 0.7% of all critical patients). Mean age was 77 +/- 15 years, 54.4% were women. During follow-up (28 days) 46 patients died (51.1%), 21 patients (23.3%) within 24 h. At multivariate analyses, age >80 (odds ratio [OR] 4.10; 95% confidence intervals [CI] 1.39-11.90, p = 0.01), serum lactate >5 mmol/l (OR 3.40; 95% CI 1.21-9.60, p = 0.02) and acute renal failure (OR 18.90; 95% CI 1.80-200, p = 0.02) were independent predictors of 28-day mortality.

CONCLUSIONS

Among critical patients admitted to an Italian ED, those with severe sepsis/septic shock represent about 1%, with a very high mortality rate. Bedside non-invasive prognostic indexes are able to identify with high accuracy patients with adverse short-term clinical outcome.

Time course of endothelial damage in septic shock: prediction of outcome

Introduction

Endothelial damage accounts greatly for the high mortality in septic shock. Higher expression of mediators (IL-6, IL-8, soluble intercellular adhesion molecule 1 [sICAM-1], soluble endothelial-linked adhesion molecule 1 [sELAM-1]) have been described for non-survivors in comparison with survivors. We investigated the predictive value of the mediators IL-6, IL-8, sELAM-1 and sICAM-1 and their time course in intensive care unit patients who developed septic shock with respect to outcome.

Materials and methods

We measured serum levels of IL-6, IL-8, sELAM-1 and sICAM-1 in 40 intensive care unit patients who developed septic shock. Measurements were performed until death or until resolution of septic shock. Clinical and laboratory data were also recorded.

Results

After 48 hours the levels of sELAM-1 and sICAM-1 increased in non-survivors and decreased in survivors. sELAM-1 was predictive for outcome on the third day (P = 0.02) and the fourth day (P = 0.02) after diagnosis of septic shock. This difference in the time course between survivors and non-survivors occurred 7 days before death of the patients (median, 10 days). sICAM-1 levels increased significantly in non-survivors over the study period (P < 0.001). sELAM-1 (P = 0.04), IL-6 (P = 0.04) and IL-8 (P = 0.008) were significantly higher in non-survivors over the whole study period. The age and norepinephrine dose >0.5 μg/kg/min were significantly different between the groups.

Conclusion

sELAM-1 showed a markedly opposing course after 48 hours of septic shock. This adhesion molecule may be a useful early predictor of disease severity in the course of septic shock after early initial treatment of the patients, and might suggest considering endothelial-restoring therapy.

Screening of LPS-specific peptides from a phage display library using epoxy beads

The selection of identical or highly homologous peptides from phage display combinatorial peptide libraries has been unsuccessful in biopanning experiments using microtiter plates. In the present study, by biopanning on LPS-conjugated epoxy beads, we repeatedly enriched clones encoding AWLPWAK and NLQEFLF. These peptides were found to interact with the polysaccharide moiety of LPS, which is highly variable among gram negative bacterial species. In addition, phages encoding these peptides preferentially bound to the LPS of Salmonella family. AWLPWAK-conjugated beads absorbed Salmonella enteritidis from solution and showed a preference for S. enteritidis over Escherichia coli. In summary, this study shows for the first time that a peptide screened from phage displays of combinatorial peptide libraries can be synthesized on beads and be used practically to concentrate bacterial cells from solution.

Insights into severe sepsis in older patients: from epidemiology to evidence-based management

Up to 60% of patients who develop severe sepsis in the United States are > or =65 years of age, and the incidence of sepsis in this population is steadily increasing. Elderly individuals have an increased risk of developing sepsis, compared with younger patients, because of frequent comorbidities, institutionalization, declining performance status, and altered immune function. The clinical presentation of older patients with sepsis is often atypical, leading to a difficult and delayed diagnosis. Although increasing age appears to confer a high risk of death due to severe sepsis, recent evidence shows that many older patients respond well to selected interventions when the interventions are initiated in a timely fashion. Newly published clinical practice guidelines outline key recommendations regarding the treatment of patients with severe sepsis. Clinicians must be aware of the level of evidence in support of various interventions and must keenly screen older survivors for ongoing deficits that will limit their functional recovery.

Prevention and treatment of malaria in young African children

Malaria remains a major challenge to global public health, with morbidity and mortality rates being highest in African children infected with Plasmodium falciparum . All four species of human malaria may initially present as a nonspecific flu-like illness, whereas P. falciparum infection in nonimmune young children has a tendency to progress rapidly to life-threatening illness. These factors, together with the increasing emergence of multi-drug resistance, pose substantial challenges to current efforts to provide prompt and accurate diagnosis and effective treatment, particularly to the rural poor who are most affected by malaria. Acute episodes of severe malaria, repeated malaria infections leading to severe anemia, and infection during pregnancy which predisposes to low birth weight, a major risk factor for neonatal death, account for the majority of malaria-related deaths in young African children. Improved prevention and control strategies targeted at each of these clinical syndromes have been developed and are reviewed in this article. Coverage of protective measures of known safety and efficacy (insecticide-treated nets, Intermittent Preventive Treatment) remains alarmingly low in most high-burden areas. The growing global commitment to rapidly increase and sustain coverage among the most vulnerable populations, along with renewed investment in research to hasten the development of effective vaccines, antimalarial drugs, and insecticides, provides a unique opportunity to markedly reduce the burden of disease during the current decade.

Disseminated intravascular coagulation and coagulation disorders

PURPOSE OF REVIEW

An update on recent developments in diagnosis and treatment of disseminated intravascular coagulation.

RECENT FINDINGS

Disseminated intravascular coagulation is defined as a typical disease condition with laboratory findings indicating massive coagulation activation and reduction in procoagulant capacity. Clinical syndromes associated with the condition are consumption coagulopathy, sepsis-induced purpura fulminans, and viral hemorrhagic fevers. Consumption coagulopathy is observed in patients with sepsis, aortic aneurysms, acute promyelocytic leukemia, and other disseminated malignancies. Sepsis-induced purpura fulminans is characterized by microvascular occlusion causing hemorrhagic necrosis of the skin and organ failure. Viral hemorrhagic fevers result in massively increased tissue factor production in monocytes and macrophages, inducing microvascular thrombosis and consumption of platelets and coagulation factors. Current scoring systems do not distinguish between patients with asymptomatic disseminated intravascular coagulation, consumption coagulopathy and thrombotic syndromes. Patients with sepsis may be identified by activated partial thromboplastin time waveform analysis performed as part of routine coagulation testing. Drotrecogin alpha (activated) reduces mortality in patients with severe sepsis with and without disseminated intravascular coagulation and has been used in patients with sepsis-induced purpura fulminans. Tifacogin does not reduce mortality in severe sepsis associated with impaired coagulation. Patients with heterozygous factor V Leiden mutation and severe sepsis showed a lower 28-day mortality than patients without this mutation, supporting the assumption that an enhanced level of coagulation activation may be beneficial in patients with severe sepsis.

SUMMARY

Whereas antithrombin and tifacogin failed to improve clinical outcome in severe sepsis, drotrecogin alpha (activated) increased the chances of survival of patients with severe sepsis with and without disseminated intravascular coagulation.