Clinical sepsis and septic shock—definition, diagnosis and management principles

Developing a shared sepsis data infrastructure: a systematic review and concept map to FHIR

The development of a shared data infrastructure across health systems could improve research, clinical care, and health policy across a spectrum of diseases, including sepsis. Awareness of the potential value of such infrastructure has been heightened by COVID-19, as the lack of a real-time, interoperable data network impaired disease identification, mitigation, and eradication. The Sepsis on FHIR collaboration establishes a dynamic, federated, and interoperable system of sepsis data from 55 hospitals using 2 distinct inpatient electronic health record systems. Here we report on phase 1, a systematic review to identify clinical variables required to define sepsis and its subtypes to produce a concept mapping of elements onto Fast Healthcare Interoperability Resources (FHIR). Relevant papers described consensus sepsis definitions, provided criteria for sepsis, severe sepsis, septic shock, or detailed sepsis subtypes. Studies not written in English, published prior to 1970, or “grey” literature were prospectively excluded. We analyzed 55 manuscripts yielding 151 unique clinical variables. We then mapped variables to their corresponding US Core FHIR resources and specific code values. This work establishes the framework to develop a flexible infrastructure for sharing sepsis data, highlighting how FHIR could enable the extension of this approach to other important conditions relevant to public health.

The Dipeptidyl Peptidase-4 Inhibitor Linagliptin Ameliorates Endothelial Inflammation and Microvascular Thrombosis in a Sepsis Mouse Model

The pathophysiology of sepsis involves inflammation and hypercoagulability, which lead to microvascular thrombosis and compromised organ perfusion. Dipeptidyl peptidase (DPP)-4 inhibitors, e.g., linagliptin, are commonly used anti-diabetic drugs known to exert anti-inflammatory effects. However, whether these drugs confer an anti-thrombotic effect that preserves organ perfusion in sepsis remains to be investigated. In the present study, human umbilical vein endothelial cells (HUVECs) were treated with linagliptin to examine its anti-inflammatory and anti-thrombotic effects under tumor necrosis factor (TNF)-α treatment. To validate findings from in vitro experiments and provide in vivo evidence for the identified mechanism, a mouse model of lipopolysaccharide (LPS)-induced systemic inflammatory response syndrome was used, and pulmonary microcirculatory thrombosis was measured. In TNF-α-treated HUVECs and LPS-injected mice, linagliptin suppressed expressions of interleukin-1β (IL-1β) and intercellular adhesion molecule 1 (ICAM-1) via a nuclear factor-κB (NF-κB)–dependent pathway. Linagliptin attenuated tissue factor expression via the Akt/endothelial nitric oxide synthase pathway. In LPS-injected mice, linagliptin pretreatment significantly reduced thrombosis in the pulmonary microcirculation. These anti-inflammatory and anti-thrombotic effects were independent of blood glucose level. Together the present results suggest that linagliptin exerts protective effects against endothelial inflammation and microvascular thrombosis in a mouse model of sepsis.

Let-7i-5p Mediates the Therapeutic Effects of Exosomes from Human Placenta Choriodecidual Membrane-Derived Mesenchymal Stem Cells on Mitigating Endotoxin-Induced Mortality and Liver Injury in High-Fat Diet-Induced Obese Mice

Obesity complicates sepsis and increases the mortality of sepsis. We examined the effects of exosomes (from human placenta choriodecidual membrane-derived mesenchymal stem cells, pcMSCs) on preventing sepsis in obesity and the mitigating role of hsa-let-7i-5p microRNA. Obese mice (adult male C57BL/6J mice fed a high-fat diet for 12 weeks) received normal saline (HFD), endotoxin (10 mg/kg, intraperitoneal (ip); HFDLPS), endotoxin with exosomes (1 × 10⁸ particles/mouse, ip; HLE), or endotoxin with let-7i-5p microRNA inhibitor-pretreated exosomes (1 × 10⁸ particles/mouse, ip; HLEi). Our data demonstrated that the 48-h survival rate in the HLE (100%) group was significantly higher than in the HFDLPS (50%) and HLEi (58.3%) groups (both p < 0.05). In the surviving mice, by contrast, levels of liver injury (injury score, plasma aspartate transaminase and alanine transaminase concentrations, tissue water content, and leukocyte infiltration in liver tissues; all p < 0.05), inflammation (nuclear factor-κB activation, hypoxia-inducible factor-1α activation, macrophage activation, and concentrations of tumor necrosis factor-α, interleukin-6, and leptin in liver tissues; all p < 0.05), and oxidation (malondialdehyde in liver tissues, with p < 0.001) in the HLE group were significantly lower than in the HFDLPS group. Levels of mitochondrial injury/dysfunction and apoptosis in liver tissues in the HLE group were also significantly lower than in the HFDLPS group (all p < 0.05). Inhibition of let-7i-5p microRNA offset the effects of the exosomes, with most of the aforementioned measurements in the HLEi group being significantly higher than in the HLE group (all p < 0.05). In conclusion, exosomes mitigated endotoxin-induced mortality and liver injury in obese mice, and these effects were mediated by let-7i-5p microRNA.

Differences between Risk Factors for Sepsis and Septic Shock in Obstructive Urolithiasis

BACKGROUND

Complicated acute pyelonephritis (APN) is a life-threatening condition that requires immediate intervention. This study examined the characteristics of APN occurring as a complication of ureteral stone.

METHODS

We retrospectively reviewed 85 patients diagnosed with APN complicated by ureteral stone between December 2006 and July 2017 at our institution. Patients with concomitant renal stone, multiple ureteral stones, ureteral strictures, ureteral cancer, and urogenital anomalies, including vesicoureteral reflux were excluded. Clinical characteristics including age, sex, underlying disease, medical history, stone characteristics, initial laboratory data, and the procedure used to correct urinary obstruction were summarized, and the risk factors associated with sepsis and septic shock were analyzed.

RESULTS

Sepsis was diagnosed at initial presentation in 62 patients, 17 of whom suffered from septic shock. Disease-related death did not occur in any patient. Previous history of stone (P = 0.015), leukocytosis (P < 0.001), elevated C-reactive protein levels (P = 0.006), and low albumin (P = 0.038) were significant risk factors for progression to sepsis. The absence of hypertension (P = 0.047), thrombocytopenia (P = 0.006), decreased erythrocyte sedimentation rate (ESR) (P = 0.003), elevated blood urea nitrogen (P = 0.016), and positive blood culture (P = 0.018) were significant predictors for progression to septic shock. Multivariate analysis revealed that previous history of stone (P = 0.015) was an independent risk factor for sepsis, while the absence of hypertension (P = 0.047), thrombocytopenia (P = 0.013), and decreased ESR (P = 0.009) were risk factors for shock.

CONCLUSION

The risk factors associated with the progression from APN to sepsis differed from those associated with the progression from sepsis to septic shock. Various factors should be considered while selecting treatment options based on the severity of APN associated with ureteral stone. It should be managed with aggressive treatment and close observation, especially in the presence of risk factors.

Evaluation of the clinical diagnostic value of traditional inflammatory markers and novel biomarkers in intracellular bacterial bloodstream infections

OBJECTIVES

The clinical symptoms of the patients with intracellular bacterial bloodstream infections (Intra-bac BSIs) are atypical, and no early and accurate diagnostic biomarkers exist, which can easily lead to misdiagnosis, inappropriate and delayed treatment. Therefore, it is imperative to find novel biomarkers to help clinical diagnosis of Intra-bac BSIs. The present study was initiated to evaluate the diagnostic values of traditional inflammatory biomarkers (PCT, WBC and NEU% in identifying the patients with Intra-bac BSIs, and to further explore into the possibility of using suPAR and sCD14-ST as novel biomarkers for Intra-bac BSIs.

METHODS

A multi-center retrospective study was conducted in three teaching hospitals in Chongqing. A total of 146 cases with BSIs, including 73 cases with Intra-bac BSIs and 73 cases with extracellular bacterial BSIs (Extra-bac BSIs) were enrolled in the retrospective study. We then prospectively enrolled 34 patients with Intra-bac BSIs, 34 patients with Extra-bac BSIs, 34 patients with viral infection and with normal medical examination results as a control group for further detection of sCD14-ST and suPAR by ELISA.

RESULTS

PCT levels, WBC counts and NEU% in patients with Intra-bac BSIs were not increased or minimally increased, they were significantly lower than that with Extra-bac BSIs (P < 0.05), especially those with the Brucella bacterial BSIs, demonstrated a respective negative rate of 84% and 92% for PCT and WBC counts. In the prospective study, the levels of suPAR and sCD14-ST in both the Intra-bac BSIs and the Extra-bac BSIs groups were significantly higher than those in the viral infection group and normal control group (P < 0.05). The areas under the curve (AUC) of Intra-bac BSIs were 0.830 for suPAR, and 0.855 for sCD14-ST. The sensitivity, specificity, Youden's index for suPAR and sCD14-ST were respectively 76.5%, 88.2%, 0.647 and 94.1%, 64.7%, 0.588.

CONCLUSIONS

Our multi-center study demonstrated that while the traditional inflammatory markers such as PCT, WBC counts, NEU% could not be served as promising diagnostic markers for Intra-bac BSIs; CRP can help guide the diagnosis of Intra-bac BSIs; Both suPAR and sCD14-ST could be considered as novel diagnostic biomarkers for Intra-bac BSIs as they showed good diagnostic accuracies in Intra-bac BSIs, especially suPAR.

Neutrophil-lymphocyte ratio and plasma lactate predict 28-day mortality in patients with sepsis

OBJECTIVE

The predictive potential of the neutrophil-to-lymphocyte ratio (NLR) and plasma lactate was investigated in regard to the prognosis of patients with sepsis.

METHODS

Sixty-three nonsurgical and nontrauma adult patients with sepsis admitted to the intensive care unit (ICU) from September 2016 to October 2018 were consecutively included in the study. In addition, healthy subjects were assigned to a control group. Neutrophil and lymphocyte counts were evaluated via a complete blood count. Plasma lactate, procalcitonin (PCT), and C-reactive protein (CRP) levels were measured. The main outcome was 28-day mortality.

RESULTS

Neutrophil-to-lymphocyte ratio and plasma lactate levels of the patients were significantly higher than those of control subjects: 19.44 (14.3-34.53) vs 14.09 (8.17-28.99), P = 0.049; and 3.7 (3-6.6) vs 2.72 (2.13-4.3) ng/mL, P = 0.008, respectively. There were no statistical differences in the concentrations of PCT and CRP between nonsurvivors and survivors: 6.1 (3.43-33.59) vs 9.43 (4.24-37.68) ng/mL, P = 0.44; and 108 (77.8-153) vs 114.5 (71.43-162) ng/mL, P = 0.672, respectively. With an optimal cutoff of 14.08, the sensitivity and specificity of NLR for prediction of 28-day mortality were 78.3% and 50%, respectively. And the sensitivity and specificity of plasma lactate level to predict 28-day mortality, at an optimal cutoff value of 2.99 mmol/L, were 82.6% and 55%, respectively.

CONCLUSIONS

Neutrophil-to-lymphocyte ratio and plasma lactate were associated with poor outcomes in patients with sepsis and predicted mortality.

Efficacy of Coupled Plasma Filtration Adsorption in Treating Patients with Severe Intra-Abdominal Infection: A Retrospective Study

Background: Coupled plasma filtration adsorption (CPFA) is an extracorporeal treatment based on plasma filtration associated with an adsorbent cartridge and hemofiltration. CPFA is able to remove inflammatory mediators and it has been used to treat severe sepsis and multiple organ dysfunction. Limited experience exists on the use of CPFA in treating intra-abdominal infection (IAI). Methods: In this study, the efficacy of CPFA in treating patients with severe IAI and liver failure was evaluated in a retrospective analysis of 76 cases. Results: The survival rate of patients treated with CPFA was 82.6%, with effective removal of endotoxin and inflammatory mediators. Conclusion: Our data suggest that CPFA can be safely and effectively used to lower morbidity and mortality rates of patients with severe IAI and liver failure.

The neutrophil-lymphocyte count ratio as a diagnostic marker for bacteraemia: A systematic review and meta-analysis

BACKGROUND

Bacteraemia is a common cause of increased morbidity and mortality in critically ill patients, but its early diagnosis and identification are complicated. The neutrophil-lymphocyte count ratio (NLCR) has been suggested as a useful indicator for the diagnosis of bacteraemia. We performed this meta-analysis to investigate the diagnostic accuracy of the NLCR for bacteraemia.

METHODS

We searched the PubMed, Embase, Web of Science, and Cochrane Library databases for this meta-analysis. We calculated individual and pooled sensitivities and specificities. I² statistics and Cochran's Q test were used to evaluate heterogeneity, and the cause of heterogeneity was explored with sensitivity analyses.

RESULTS

In total, 8 of 1086 eligible articles were included in the present meta-analysis. The pooled analyses revealed that the diagnostic accuracy of the NLCR in terms of its bacteraemia sensitivity was 0.723 [95% CI: 0.660, 0.777], and its specificity was 0.596 [95% CI: 0.556, 0.634]. The area under the summary receiver operating characteristic curve was 0.69 [95% CI 0.65-0.73].

CONCLUSION

The NLCR is an easy-to-collect marker for bacteraemia. However, the NLCR is inadequate, and only a combination of multiple biomarkers will improve its diagnostic accuracy for bacteraemia.

Laboratory automation reduces time to report of positive blood cultures and improves management of patients with bloodstream infection

The impact on time to results (TTR) and clinical decisions was evaluated for mono-microbial positive blood cultures (BC) processed using the BD Kiestra Work Cell Automation (WCA) system. Positive BC were processed by the WCA system by full-automatic subculture on solid media and digital imaging after 8 h of incubation (8-h method) followed by identification (ID) and antimicrobial susceptibility testing (AST). To evaluate the accuracy of the 8-h method, ID and AST from 8-h and overnight incubated colonies were compared for the same organisms. To evaluate its clinical impact, results from 102 BC processed by the 8-h method (cases) were compared with those from 100 BC processed by overnight incubation method (controls) in a comparable period. Identification after 8-h and overnight incubation gave concordant results in 101/102 (99.0%) isolates. Among a total of 1379 microorganism-antimicrobial combinations, categorical agreement was 99.4% (1371/1379); no very major error, 7 major errors, and one minor error were observed. TTR in cases (32.8 h ± 8.3 h) was significantly (p < 0.001) shorter than in controls (55.4 h ± 13.3 h). A significant reduction was observed for duration of empirical therapy (cases 54.8 h ± 23.3 h vs controls 86.9 h ± 34.1 h, p < 0.001) and 30-day crude mortality rate (cases 16.7% vs controls 29.0%, p < 0.037). Automation and 8-h digital reading of plates from positive BC, followed by ID and AST, greatly reduce TTR and shorten the duration of antimicrobial empiric therapy, possibly improving outcome in patients with mono-microbial bloodstream infections.

Superior accuracy of mid-regional proadrenomedullin for mortality prediction in sepsis with varying levels of illness severity

BACKGROUND

The use of novel sepsis biomarkers has increased in recent years. However, their prognostic value with respect to illness severity has not been explored. In this work, we examined the ability of mid-regional proadrenomedullin (MR-proADM) in predicting mortality in sepsis patients with different degrees of organ failure, compared to that of procalcitonin, C-reactive protein and lactate.

METHODS

This was a two-centre prospective observational cohort, enrolling severe sepsis or septic shock patients admitted to the ICU. Plasma biomarkers were measured during the first 12 h of admission. The association between biomarkers and 28-day mortality was assessed by Cox regression analysis and Kaplan-Meier curves. Patients were divided into three groups as evaluated by the Sequential Organ Failure Assessment (SOFA) score. The accuracy of the biomarkers for mortality was determined by area under the receiver operating characteristic curve (AUROC) analysis.

RESULTS

A total of 326 patients with severe sepsis (21.7%) or septic shock (79.3%) were enrolled with a 28-day mortality rate of 31.0%. Only MR-proADM and lactate were associated with mortality in the multivariate analysis: hazard ratio 8.5 versus 3.4 (p < 0.001). MR-proADM showed the best AUROC for mortality prediction at 28 days in the analysis over the entire cohort (AUROC [95% CI] 0.79 [0.74-0.84]) (p < 0.001). When patients were stratified by the degree of organ failure, MR-proADM was the only biomarker to predict mortality in all severity groups (SOFA ≤ 6, SOFA = 7-12, and SOFA ≥ 13), AUROC [95% CI] of 0.75 [0.61-0.88], 0.74 [0.66-0.83] and 0.73 [0.59-0.86], respectively (p < 0.05). All patients with MR-proADM concentrations ≤0.88 nmol/L survived up to 28 days. In patients with SOFA ≤ 6, the addition of MR-proADM to the SOFA score increased the ability of SOFA to identify non-survivors, AUROC [95% CI] 0.70 [0.58-0.82] and 0.77 [0.66-0.88], respectively (p < 0.05 for both).

CONCLUSIONS

The performance of prognostic biomarkers in sepsis is highly influenced by disease severity. MR-proADM accuracy to predict mortality is not affected by the degree of organ failure. Thus, it is a good candidate in the early identification of sepsis patients with moderate disease severity but at risk of mortality.

Comparison of Consent Models in a Randomized Trial of Corticosteroids in Pediatric Septic Shock

OBJECTIVES

To describe the use of deferred and prior informed consent models in the context of a low additional risk to standard of care, placebo-controlled randomized controlled trial of corticosteroids in pediatric septic shock.

DESIGN

An observational substudy of consent processes in a randomized controlled trial of hydrocortisone versus placebo.

SETTING

Seven tertiary level PICUs in Canada.

PATIENTS

Children newborn to 17 years inclusive admitted to PICU with suspected septic shock between July 2014 and March 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Information on the number of families approached, consent rates obtained, and spontaneously volunteered reasons for nonparticipation were collected for both deferred and informed consent. The research ethics board of five of seven centers approved a deferred consent model; however, implementation criteria for use of this model varied across sites. The consent rate using deferred versus prior informed consent was significantly higher (83%; 35/42 vs 58%; 15/26; p = 0.02). The mean times from meeting inclusion criteria to randomization (1.8 ± 1.8 vs 3.6 ± 2.1 hr; p = 0.007) and study drug administration (3.4 ± 2.7 hr vs 4.8 ± 2.1 hr; p = 0.05) were significantly shorter with the use of deferred consent versus prior informed consent. No family member or research ethics board expressed concern following use of deferred consent.

CONCLUSIONS

Deferred consent was acceptable in time-sensitive critical care research to most research ethics boards, families, and healthcare providers and resulted in higher consent rates and more efficient recruitment. Larger studies on deferred consent and consistency interpreting jurisdictional guidelines are needed to advance pediatric acute care.

Shock due to urosepsis: A multicentre study

INTRODUCTION

Urosepsis is a severe infection that can cause shock afterwards. The purpose of this study is to investigate the clinical and bacterial risk factors for shock in those cases with urosepsis caused by urinary tract infection in a multicentre study.

METHODS

Our study included 77 consecutive urosepsis cases from four hospitals. We examined factors such as patient characteristics, underlying disease, serum white blood cell (WBC) count, platelet count, C-reactive protein (CRP) level at the time of diagnosis of urosepsis, urinary tract occlusion, causative bacteria, and bacterial antibiotic susceptibilities. Statistical analyses were performed to assess the potential risk factors for shock during the clinical course of urosepsis by a multivariate analysis.

RESULTS

We had 38 male and 39 female patients aged 25-104 (median 73). Underlying diseases included cancers (n=22, 28.6 %) and diabetes mellitus (n=17, 22.1 %). Positive blood culture was seen in 74 cases; these involved 88 bacterial strains, of which Escherichia coli was the most common (34 strains, 38.6 %). There were 31 cases with shock (40.3 %) and multivariate analyses demonstrated that serum CRP was the only clinical risk factor for shock due to urosepsis.

CONCLUSIONS

Our study demonstrated that serum CRP was a risk factor for shock during urosepsis in a multicentre analysis. Further prospective studies with a greater number of patients are needed to draw more definitive conclusions.

Ascorbate inhibits platelet-endothelial adhesion in an in-vitro model of sepsis via reduced endothelial surface P-selectin expression

Plugging of the capillary bed can lead to organ failure and mortality in sepsis. We have reported that intravenous ascorbate injection reduces platelet adhesion to the capillary wall and capillary plugging in septic mice. Both platelet adhesion and capillary plugging require P-selectin, a key adhesion molecule. To elucidate the beneficial effect of ascorbate, we hypothesized that ascorbate reduces platelet-endothelial adhesion by reducing P-selectin surface expression in endothelial cells. We used mouse platelets, and monolayers of cultured microvascular endothelial cells (mouse skeletal muscle origin) stimulated with lipopolysaccharide, to examine platelet-endothelial adhesion. P-selectin mRNA expression in endothelial cells was determined by real-time PCR and P-selectin protein expression at the surface of these cells by immunofluorescence. Secretion of von Willebrand factor from cells into the supernatant (a measure of P-selectin-containing granule exocytosis) was determined by ELISA. Lipopolysaccharide (10 μg/ml, 1 h) increased platelet-endothelial adhesion. P-selectin-blocking antibody inhibited this adhesion. Lipopolysaccharide also increased P-selectin mRNA in endothelial cells, P-selectin expression at the endothelial surface, and von Willebrand factor secretion. Ascorbate pretreatment (100 μmol/l, 4 h) inhibited the increased platelet adhesion, surface expression of P-selectin, and von Willebrand factor secretion, but not the increase in P-selectin mRNA. The lipopolysaccharide-induced increase in platelet-endothelial adhesion requires P-selectin presence at the endothelial surface. Ascorbate's ability to reduce this presence could be important in reducing both platelet adhesion to the capillary wall and capillary plugging in sepsis.

Immature platelet fraction in septic patients: clinical relevance of immature platelet fraction is limited to the sensitive and accurate discrimination of septic patients from non-septic patients, not to the discrimination of sepsis severity

Background

The immature platelet fraction (IPF) reflects the degree of reticulated platelets. We evaluated performances of IPF as a biomarker for the discrimination of septic patients from non-septic patients and sepsis severity.

Methods

Total 312 patients admitted between March and July 2013 were enrolled and samples were obtained at admission. Lactate (LA), procalcitonin (PCT), C-reactive protein (CRP), immature granulocyte fraction (IG), immature reticulocyte fraction (IRF), and IPF were analyzed as sepsis biomarkers and their performances were compared.

Results

The performance of IPF (area under the curve [AUC]=0.868) in the discrimination of septic patients from non-septic patients was comparable to PCT/CRP/LA/IG (AUC=0.923/0.940/0.781/0.812, P=0.233/0.106/0.186/0.353, respectively), and was significantly better than the IRF (AUC=0.658, P=0.007). Sensitivity (89.8%, 95% confidence interval [CI] 84.9-99.8%) and accuracy (83.2%, 95% CI 78.8-90.0%) of IPF were the best among all biomarkers. The performance of IPF in discriminating septic patients from non-septic patients with local infection showed similar results. However, the IPF could not efficiently discriminate sepsis severity (AUC=0.599), similar to other biomarkers (AUC=0.519-0.752).

Conclusions

The IPF possessed high sensitivity/accuracy in discriminating septic patients from non-septic patients, regardless of local infection status. However, the IPF did not efficiently discriminate sepsis severity. The clinical relevance of IPF as a sepsis biomarker is, therefore, limited to sensitive and accurate discrimination of septic patients from non-septic patients, not discrimination of sepsis severity.

Procalcitonin levels in bloodstream infections caused by different sources and species of bacteria

OBJECTIVE

The aim of this study was to evaluate procalcitonin (PCT) diagnostic accuracy in discriminating gram-negative (GN) from gram-positive (GP) bloodstream infections and determining the relationship between PCT levels, infection sites, and pathogen types.

METHODS

Clinical and laboratory data were collected from patients with blood culture (BC)-positive sepsis between January 2014 and December 2015. PCT levels at different infection sites were compared, as was the presence of GN and GP bloodstream infection. A receiver operating characteristic (ROC) curve was generated to assess diagnostic accuracy.

RESULTS

Of the 486 monomicrobial BCs, 254 (52.26%) were positive for GN bacteria (GNB), and 202 (42.18%) for GP bacteria (GPB). Median PCT levels were higher in BCs positive for GN (2.42ng/ml, IQR: 0.38-15.52) than in those positive for GPB (0.49ng/ml, IQR: 0.13-5.89) (P<0.001). In the ROC analysis to differentiate between GNB and GPB, the area under the curve was 0.628 (95% CI: 0.576-0.679). When the cutoffs for PCT were 10.335 and 15.000ng/ml, the specificity of GNB infection was 80.2% and 84.2%, respectively. PCT levels caused by GNB differed between Escherichia coli and Acinetobacter baumanni/Burkholderia cepacia, Klebsiella pneumonia and Acinetobacter baumanni. PCT levels caused by GPB differed between Staphylococcus epidermidis/Staphylococcus aureus and Staphylococcus hominis/Staphylococcus haemolyticus, Enterococcus faecium and Enterococcus faecalis/S.hominis/S. haemolyticus. Among patients with known infection sites, there were statistical differences in PCT levels between abdominal infection and pneumonia/infective endocarditis, urinary tract infection and pneumonia/catheter-related infection/infective endocarditis.

CONCLUSION

PCT can distinguish between GNB and GPB infection, as well as between different bacterial species and infection sites.

Steroids in fluid and/or vasoactive infusion dependent pediatric shock: study protocol for a randomized controlled trial

Background

Physicians often administer corticosteroids for the treatment of fluid and vasoactive infusion dependent pediatric shock. This use of corticosteroids is controversial, however, and has never been studied in a pediatric randomized controlled trial (RCT). This pilot trial will determine the feasibility of a larger RCT on the role of corticosteroids in pediatric shock.

Methods/design

Steroids in Fluid and/or Vasoactive Infusion Dependent Pediatric Shock (STRIPES) is a pragmatic, seven-center, double-blind, pilot RCT. We aim to randomize 72 pediatric patients with fluid and vasoactive infusion dependent shock to receive either hydrocortisone or a saline placebo for 7 days or until clinical stability, whichever occurs first. The primary outcome of this pilot trial is the feasibility of recruitment, defined as the number of patients enrolled over a 1-year period. Secondary outcomes include the frequency of, and reasons for, open-label steroid use, protocol adherence, incidence of mortality and corticosteroid-associated adverse events, time to discontinuation of inotropes, and feasibility of blood sampling.

Discussion

Corticosteroids are used for the treatment of pediatric shock without sufficient evidence to support this practice. While there is a scientific rationale and limited data supporting their use in this setting, there is also evidence from other populations suggesting potential harm. The STRIPES pilot study will assess the feasibility of a larger, much needed trial powered for clinically important outcomes.

Trial registration

ClinicalTrials.gov: NCT02044159

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1365-6) contains supplementary material, which is available to authorized users.

Effect of acute kidney injury on mortality and hospital stay in patient with severe acute pancreatitis

AIM

Severe acute pancreatitis (SAP) is believed to be a major risk factor leading to acute kidney injury (AKI) among critically ill patients, but little is known about SAP-induced AKI. We study the incidence of AKI defined by the Acute Kidney Injury Network (AKIN) criteria and the risk factors associated with outcomes among SAP-induced AKI patients.

METHOD

We conducted a multicenter retrospective study of critically ill SAP-induced AKI patients during the period August 2009 to June 2013. Data on enrolled patients were retrieved from electronic records. Univariate and multiple regression analyses were performed.

RESULTS

Among a total of 414 SAP patients admitted to intensive care units(ICU), 287 (69.3%) developed AKI during their ICU stay, with 16.7%, 18.4%, and 34.3% classified as AKI stage I,II, and III, respectively. SAP-induced AKI patients experienced a significantly higher ICU mortality than those without AKI. The risk factors associated with ICU mortality among SAP-induced AKI patients included ACS (odds ratio (OR) 10.58), RRT (OR 3.31), sepsis (OR 2.46), CTSI (OR 3.01), APACHE II score (OR 1.82), AKI III (OR 1.38), ICU-length-of-stay (OR 1.04), and multi-organ failure.

CONCLUSIONS

The paper represents the first attempt to investigate the etiology and epidemiology of AKI following SAP under the AKIN criteria among critically ill patients. Several independent risk factors were found to be associated with ICU mortality for AKI patients. The findings may pinpoint crucial therapeutic measures for preventing AKI among a vulnerable population and for more effective management of SAP-induced AKI to improve the quality of intensive care.

Staphylococcus epidermidis as a cause of bacteremia

Staphylococcus epidermidis is a biofilm-producing commensal organism found ubiquitously on human skin and mucous membranes, as well as on animals and in the environment. Biofilm formation enables this organism to evade the host immune system. Colonization of percutaneous devices or implanted medical devices allows bacteria access to the bloodstream. Isolation of this organism from blood cultures may represent either contamination during the blood collection procedure or true bacteremia. S. epidermidis bloodstream infections may be indolent compared with other bacteria. Isolation of S. epidermidis from a blood culture may present a management quandary for clinicians. Over-treatment may lead to patient harm and increases in healthcare costs. There are numerous reports indicating the difficulty of predicting clinical infection in patients with positive blood cultures with this organism. No reliable phenotypic or genotypic algorithms currently exist to predict the pathogenicity of a S. epidermidis bloodstream infection. This review will discuss the latest advances in identification methods, global population structure, pathogenicity, biofilm formation, antimicrobial resistance and clinical significance of the detection of S. epidermidis in blood cultures. Previous studies that have attempted to discriminate between invasive and contaminating strains of S. epidermidis in blood cultures will be analyzed.

Thymoquinone modulates nitric oxide production and improves organ dysfunction of sepsis

AIMS

The present investigation was designed to evaluate the effect of thymoquinone in a septic animal model and to explore the role of nitric oxide (NO) in the process.

MAIN METHODS

To achieve this, mice (n=12 per group) were treated in parallel with thymoquinone (0.75mg/kg/day) and/or NG-nitro-l-arginine methyl ester (L-NAME; 400μg/g/day) prior to sepsis induction with live Escherichia coli.

KEY FINDINGS

Thymoquinone significantly improved renal and hepatic functions alone and in combination with L-NAME. This was associated with less NO production and lower oxidative stress in treated animals. Tumor necrosis factor-α concentration with thymoquinone and L-NAME were 36.27±3.41pg/ml and 56.55±5.85pg/ml, respectively, as opposed to 141.11±6.46pg/ml in septic controls. Similarly, Interleukin-1α, 2, 6 and 10 levels decreased significantly upon treatment with thymoquinone and L-NAME as compared with untreated septic animals. NF-κB and NF-κB-DNA binding activity in nuclear proteins were also significantly down-regulated. Vascular responsiveness studies in isolated mouse aortae demonstrated a reduced relaxation to acetylcholine exposure in septic mice treated with thymoquinone.

SIGNIFICANCE

These findings suggest that thymoquinone prevents sequels of the multiple organ failure syndrome of sepsis by modulating the production of NO and its inflammatory sequela, and adjusting vascular responsiveness.

Novel relationships between oxidative stress and angiogenesis-related factors in sepsis: New biomarkers and therapies

Sepsis is a systemic uncontrolled inflammatory response in the presence of an infection. It remains a major cause of morbidity and mortality in hospitalized patients. According to its severity, sepsis can progress to three different states: severe sepsis, septic shock, and multiple organ dysfunction syndrome, related to organ dysfunction and/or tissue hypoperfusion. Different processes underlie its pathophysiology; among them are oxidative stress, endothelial and mitochondrial dysfunction, and angiogenesis-related factors. However, no studies have integrated these elements in sepsis. The main difficulty in sepsis is its diagnosis. Currently, the potential of inflammatory biomarkers in septic patients remains weak. In this context, the research into new biomarkers is essential to aid with sepsis diagnosis and prognostication. Furthermore, even though the current management of severe forms of sepsis has been effective, morbimortality remains elevated. Therefore, it is essential to explore alternative approaches to therapy development. The aim of this review is to present an update of evidence supporting the role of oxidative stress and angiogenesis-related factors in the pathophysiology of the different forms of sepsis. It proposes a novel convergence between both elements in their role in the disease, and it will cover their utility as new diagnostic tools, predictors of outcome, and as novel therapeutic targets.

The OVLT initiates the fall in arterial pressure evoked by high dose lipopolysaccharide: evidence that dichotomous, dose-related mechanisms mediate endotoxic hypotension

This study tested the hypothesis that lipopolysaccharide (LPS) lowers arterial pressure through two different mechanisms depending on the dose. Previously, we found that a low hypotensive dose of LPS (1mg/kg) lowers arterial pressure by activating vagus nerve afferents. Here we report that hypotension evoked by high dose LPS (15mg/kg) can be prevented by injecting lidocaine into the OVLT but not by vagotomy or inactivation of the NTS. The hypotension produced by both LPS doses was correlated with elevated extracellular norepinephrine concentrations in the POA and prevented by blocking alpha-adrenergic receptors. Thus, initiation of endotoxic hypotension is dose-related, mechanistically.

Role of CD64 expression on neutrophils in the diagnosis of sepsis and the prediction of mortality in adult critically ill patients

Intensive care unit patients who developed systemic inflammatory response syndrome (SIRS) with proven microbial etiology were assigned to the infectious causes (n = 29), while patients with negative cultures and more probable other etiology were assigned to the noninfectious causes (n = 37). Flow cytometry was used to detect the presence of CD64 on neutrophils. The multivariate analysis revealed that KPC-producing Klebsiella pneumoniae rectal colonization and >1.39 mean fluorescence intensity (MFI) of CD64 expression on neutrophils upon day 1 of SIRS were significantly associated with an infectious SIRS. The overall mortality was 29% (19 patients) and was independently associated with Simplified Acute Physiology Score II >44 points and multiple-organ dysfunction syndrome, while appropriate antibiotic treatment was identified as predictor of good prognosis. MFI of CD64 expression on neutrophils showed high sensitivity, specificity, and accuracy in the diagnosis of sepsis but not for the prediction of survival.

The protective effect of atractylenolide I on systemic inflammation in the mouse model of sepsis created by cecal ligation and puncture

CONTEXT

Atractylenolide I (AT-I), an active compound isolated from Atractylodes macrocephala Koidz (Compositae), shows several pharmacological activities.

OBJECTIVE

Our present study is designed to investigate the protective effect of AT-I on systemic inflammation in the mouse model of sepsis created by cecal ligation and puncture (CLP), and explore the possible mechanism.

MATERIALS AND METHODS

Sepsis mouse model was established by CLP, and the tested dosages of AT-I were 10, 20, and 40 mg/kg (ip). Pro-inflammatory cytokines in serum (TNF-α, IL-1β and IL-6) were determined by the ELISA method; serum lipopolysaccharide (LPS) level was measured by the Limulus Amebocyte Lysate (LAL) test; white blood cells (WBC) were counted by Blood cell analyzer; contents of alanine transaminase (ALT), aspartate transarninase (AST), creatinine (Cre), and blood urea nitrogen (BUN) in serum were determined by automatic biochemistry analyzer. For survival rate tests, CLP mice were observed within 7 days, and body temperature was measured at 0, 4, 8, 12, 24, 48 and 72 h after surgery.

RESULTS

Our results indicated that AT-I significantly increased the survival rate of mice with sepsis (p < 0.05), whereas the WBCs and levels of LPS, pro-inflammatory cytokines (TNF-α, IL-1β and IL-6), ALT, AST, Cre, and BUN decreased significantly after treatment with AT-I (p < 0.05).

CONCLUSION

In conclusion, the AT-I ameliorates sepsis syndrome by reduction of pro-inflammatory cytokines and LPS, and provides an improvement in liver and kidney functions.

Arginine and citrulline and the immune response in sepsis

Arginine, a semi-essential amino acid is an important initiator of the immune response. Arginine serves as a precursor in several metabolic pathways in different organs. In the immune response, arginine metabolism and availability is determined by the nitric oxide synthases and the arginase enzymes, which convert arginine into nitric oxide (NO) and ornithine, respectively. Limitations in arginine availability during inflammatory conditions regulate macrophages and T-lymfocyte activation. Furthermore, over the past years more evidence has been gathered which showed that arginine and citrulline deficiencies may underlie the detrimental outcome of inflammatory conditions, such as sepsis and endotoxemia. Not only does the immune response contribute to the arginine deficiency, also the impaired arginine de novo synthesis in the kidney has a key role in the eventual observed arginine deficiency. The complex interplay between the immune response and the arginine-NO metabolism is further underscored by recent data of our group. In this review we give an overview of physiological arginine and citrulline metabolism and we address the experimental and clinical studies in which the arginine-citrulline NO pathway plays an essential role in the immune response, as initiator and therapeutic target.

Urinary netrin-1 and KIM-1 as early biomarkers for septic acute kidney injury

BACKGROUND

Acute kidney injury (AKI) during sepsis is associated with poor outcome. However, diagnosis of AKI with serum creatinine (SCr) level change is neither highly sensitive nor specific. Therefore, identification of novel biomarkers for early diagnosis of AKI is desirable.

AIMS

To evaluate the capacity of combining urinary netrin-1 and human kidney injury molecule type 1 (KIM-1) in the early diagnosis of septic AKI.

METHODS

We prospectively recruited 150 septic patients from Jun 2011 to Jun 2013 at Zhejiang Provincial People's Hospital, China. SCr, urinary netrin-1, and KIM-1 levels were recorded at 0, 1, 3, 6, 24, and 48 h of ICU admission and compared between AKI and non-AKI patients. In addition, we investigated the prognostic value of netrin-1 and KIM-1 between non-survivors and survivors in septic AKI patients.

RESULTS

SCr levels started to show elevation after 24 h of ICU admission. However, netrin-1 levels increased significantly as early as 1 h, peaked at 3-6 h and remained elevated up to 48 h of ICU admission in septic AKI patients. KIM-1 increased significantly by 6 h, peaked at 24 h and remained significantly elevated until 48 h of ICU admission. Furthermore, we observed significant higher urinary KIM-1 levels at 24 h and 48 h in non-survivors compared to survivors in AKI patients.

CONCLUSIONS

Our results suggest that both netrin-1 and KIM-1 are clinically useful as early biomarkers in the diagnosis of septic AKI. In addition, persistent elevation of urinary KIM-1 level may be associated with poor prognosis.

Validating a pragmatic definition of shock in adult patients presenting to the ED

OBJECTIVE

The importance of the early recognition of shock in patients presenting to emergency departments is well recognized, but at present, there is no agreed practical definition for undifferentiated shock. The main aim of this study was to validate an a priori clinical definition of shock against 28-day mortality.

DESIGN, SETTING AND SUBJECTS

This prospective, observational, cross-sectional, single-center study was conducted in Hong Kong, China. Data were collected between July 1, 2012, and January 31, 2013. An a priori definition of shock was designed, whereby patients admitted to the resuscitation room or high dependency area of the emergency department were divided into 1 of 3 groups-no shock, possible shock, and shock. The primary outcome was 28-day mortality. Secondary outcomes were in-hospital mortality or admission to the intensive or coronary care unit.

MEASUREMENTS AND MAIN RESULTS

A total of 111 patients (mean age, 67.2 ± 17.1 years; male = 69 [62%]) were recruited, of which 22 were classified as no shock, 54 as possible shock, and 35 as shock. Systolic blood pressure, mean arterial pressure, lactate, and base deficit correlated well with shock classifications (P < .05). Patients who had 3 or more positively defined shock variables had a 100% poor composite outcome rate (5 of 5). Patients with 2 shock variables had a 66.7% (4 of 6) poor composite outcome rate.

CONCLUSIONS

A simple, practical definition of undifferentiated shock has been proposed and validated in a group of patients presenting to an emergency department in Hong Kong. This definition needs further validation in a larger population and other settings.

Update on the management of neonatal sepsis in horses

Despite advances in neonatal intensive care sepsis, severe sepsis and septic shock remain the biggest killers of neonatal foals. Management of this severe syndrome remains difficult, requiring intensive intervention. Key aspects of management include infection control, hemodynamic support, immunomodulatory interventions, and metabolic/endocrine support. Infection control largely consists of early antimicrobial therapy, plasma transfusions, and local therapy for the infected focus. In cases with severe sepsis or septic shock, hemodynamic support with fluids, vasoactive agents, and respiratory support insuring oxygen delivery to vital organs is important. Nutritional support is important, but close monitoring is needed to avoid hyperglycemia and hypoglycemia.

Identification of microRNA as sepsis biomarker based on miRNAs regulatory network analysis

Sepsis is regarded as arising from an unusual systemic response to infection but the physiopathology of sepsis remains elusive. At present, sepsis is still a fatal condition with delayed diagnosis and a poor outcome. Many biomarkers have been reported in clinical application for patients with sepsis, and claimed to improve the diagnosis and treatment. Because of the difficulty in the interpreting of clinical features of sepsis, some biomarkers do not show high sensitivity and specificity. MicroRNAs (miRNAs) are small noncoding RNAs which pair the sites in mRNAs to regulate gene expression in eukaryotes. They play a key role in inflammatory response, and have been validated to be potential sepsis biomarker recently. In the present work, we apply a miRNA regulatory network based method to identify novel microRNA biomarkers associated with the early diagnosis of sepsis. By analyzing the miRNA expression profiles and the miRNA regulatory network, we obtained novel miRNAs associated with sepsis. Pathways analysis, disease ontology analysis, and protein-protein interaction network (PIN) analysis, as well as ROC curve, were exploited to testify the reliability of the predicted miRNAs. We finally identified 8 novel miRNAs which have the potential to be sepsis biomarkers.

Ascorbate reduces mouse platelet aggregation and surface P-selectin expression in an ex vivo model of sepsis

OBJECTIVE

Compromised perfusion of the capillary bed can lead to organ failure and mortality in sepsis. We have reported that intravenous injection of ascorbate inhibits platelet adhesion and plugging in septic capillaries. In this study, we hypothesized that ascorbate reduces aggregation of platelets and their surface expression of P-selectin (a key adhesion molecule) in mice.

METHODS

Platelets were isolated from control mice and subjected to agents known to be released into the bloodstream during sepsis (thrombin, ADP or U46619, thromboxane A2 analog). Platelet aggregation was analyzed by aggregometry and P-selectin expression by flow cytometry.

RESULTS

Platelet-activating agents increased aggregation and P-selectin expression. Ascorbate inhibited these increases. This inhibitory effect was NOS-independent (LNAME had no effect). In contrast to the platelet-activating agents, direct stimuli lipopolysaccharide, TNFα, or plasma from septic mice did not increase aggregation/expression, a finding consistent with the literature. The results suggest a complex mechanism of platelet aggregation and P-selectin expression in sepsis, where generation of platelet-activating stimuli is required first, before platelet aggregation and adhesion in capillaries occur.

CONCLUSION

The ability of ascorbate to reduce platelet aggregation and P-selectin expression could be an important mechanism by which ascorbate inhibits capillary plugging in sepsis.

Biomarkers and molecular analysis to improve bloodstream infection diagnostics in an emergency care unit

Molecular pathogen detection from blood is still expensive and the exact clinical value remains to be determined. The use of biomarkers may assist in preselecting patients for immediate molecular testing besides blood culture. In this study, 140 patients with ≥ 2 SIRS criteria and clinical signs of infection presenting at the emergency department of our hospital were included. C-reactive protein (CRP), neutrophil-lymphocyte count ratio (NLCR), procalcitonin (PCT) and soluble urokinase plasminogen activator receptor (suPAR) levels were determined. One ml EDTA blood was obtained and selective pathogen DNA isolation was performed with MolYsis (Molzym). DNA samples were analysed for the presence of pathogens, using both the MagicPlex Sepsis Test (Seegene) and SepsiTest (Molzym), and results were compared to blood cultures. Fifteen patients had to be excluded from the study, leaving 125 patients for further analysis. Of the 125 patient samples analysed, 27 presented with positive blood cultures of which 7 were considered to be contaminants. suPAR, PCT, and NLCR values were significantly higher in patients with positive blood cultures compared to patients without (p < 0.001). Receiver operating characteristic curves of the 4 biomarkers for differentiating bacteremia from non-bacteremia showed the highest area under the curve (AUC) for PCT (0.806 (95% confidence interval 0.699–0.913)). NLCR, suPAR and CRP resulted in an AUC of 0.770, 0.793, and 0.485, respectively. When compared to blood cultures, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for SepsiTest and MagicPlex Sepsis Test were 11%, 96%, 43%, 80%, and 37%, 77%, 30%, 82%, respectively. In conclusion, both molecular assays perform poorly when one ml whole blood is used from emergency care unit patients. NLCR is a cheap, fast, easy to determine, and rapidly available biomarker, and therefore seems most promising in differentiating BSI from non-BSI patients for subsequent pathogen identification using molecular diagnostics.

Identifying novel spatiotemporal regulators of innate immunity

The innate immune response plays a critical role in pathogen clearance. However, dysregulation of innate immunity contributes to acute inflammatory diseases such as sepsis and many chronic inflammatory diseases including asthma, arthritis, and Crohn's disease. Pathogen recognition receptors including the Toll-like family of receptors play a pivotal role in the initiation of inflammation and in the pathogenesis of many diseases with an inflammatory component. Studies over the last 15 years have identified complex innate immune signal transduction pathways involved in inflammation that have provided many new potential therapeutic targets to treat disease. We are investigating several novel genes that exert spatial and in some cases temporal regulation on innate immunity signaling pathways. These novel genes include Tbc1d23, a RAB-GAP that inhibits innate immunity. In this review, we will discuss inflammation, the role of inflammation in disease, innate immune signal transduction pathways, and the use of spatiotemporal regulators of innate immunity as potential targets for discovery and therapeutics.

Protective effect of curcumin against cardiac dysfunction in sepsis rats

CONTEXT

The heart is one of the target organs susceptible to attack by sepsis, and protection of the cardiac function in sepsis or alleviation dysfunction caused by sepsis appears a serious and urgent problem.

OBJECTIVE

This study was designed to explore the effect of curcumin on myocardial injury induced by sepsis and to explore the therapeutic effect of curcumin in managing sepsis induced cardiac dysfunction.

METHODS

Cecal ligation and puncture surgery were used to establish the sepsis model. Curcumin was administered by peritoneal injection (200 mg/kg/d, 3 days). The effects of curcumin on the cardiac functions [Ejection Fraction (EF), Fractional Shortening (FS), Cardiac Output (CO), Heart Rate (HR)], body temperature, cTn I and superoxide dismutase levels, malondialdehyde content (an index of lipid peroxidation), and myocardial histopathological and ultrastructural studies were carried out.

RESULTS

We demonstrated that treatment of rats with curcumin significantly decreased elevated levels of cTn I and MDA (p < 0.05) in plasma, and increase the levels of SOD (p < 0.05) after CLP. Moreover, curcumin markedly enhanced the myocardial contractility by increasing the decreased EF and FS in rats with sepsis induced by CLP (p < 0.05). In addition, curcumin could alleviate the myocardial inflammation and structure damage of myocardial cells in sepsis induced by CLP.

CONCLUSION

In conclusion, the results from the present study demonstrate that curcumin has the protective effects on cardiac function in rats with sepsis and curcumin could be considered as an effective and safe therapeutic agent for the management of sepsis induced cardiac dysfunction.

Procalcitonin predicts real-time PCR results in blood samples from patients with suspected sepsis

BACKGROUND

Early diagnosis and rapid bacterial identification are of primary importance for outcome of septic patients. SeptiFast® (SF) real-time PCR assay is of potential utility in the etiological diagnosis of sepsis, but it cannot replace blood culture (BC) for routine use in clinical laboratory. Procalcitonin (PCT) is a marker of sepsis and can predict bacteremia in septic patients. The aim of the present study was to investigate whether PCT serum levels could predict SF results, and could help screening febrile patients in which a SF assay can improve the etiological diagnosis of sepsis.

METHODS

From 1009 febrile patients with suspected sepsis, 1009 samples for BC, SF real-time PCR, and PCT determination were obtained simultaneously, and results were compared and statistically analysed. Receiver operating characteristic (ROC) curves were generated to determine the area under the curve and to identify which cut-off of PCT value produced the best sensitivity to detect SF results.

RESULTS

Mean PCT values of sera drawn simultaneously with samples SF positive (35.42 ± 61.03 ng/ml) or BC positive (23.14 ± 51.56 ng/ml) for a pathogen were statistically higher than those drawn simultaneously with SF negative (0.84 ± 1.67 ng/ml) or BC negative (2.79 ± 16.64 ng/ml) samples (p<0.0001). For SF, ROC analysis showed an area under the curve of 0.927 (95% confidence interval: 0.899-0.955, p<0.0001). The PCT cut-off value of 0.37 ng/ml showed a negative predictive value of 99%, reducing the number of SF assays of 53.9%, still identifying the 96.4% of the pathogens.

CONCLUSION

PCT can be used in febrile patients with suspected sepsis to predict SF positive or negative results. A cut-off value of 0.37 ng/ml can be considered for optimal sensitivity, so that, in the routine laboratory activity, SF assay should not be used for diagnosis of sepsis in an unselected patient population with a PCT value <0.37 ng/ml.

Is simultaneous splenectomy an additive risk factor in surgical treatment for active endocarditis?

PURPOSE

Splenic abscess formation is a serious complication in the setting of active endocarditis, and splenectomy is recommended. However, the optimal timing for splenectomy is yet undetermined. The purpose of this study was to evaluate the role of a one-stage splenectomy and valve surgery for active endocarditis.

METHODS

Among 202 consecutive endocarditis patients, 18 had splenic lesions on preoperative abdominal screening, who underwent cardiac surgery and splenectomy as a one-stage procedure (group A) and were compared to patients with unremarkable abdominal screening (group B, n = 184) undergoing sole cardiac surgery.

RESULTS

No difference was observed regarding preoperative characteristics (age, gender, New York Heart Association [NYHA] grade, diabetes, coronary artery disease, redo surgery, adiposity, smoking), intubation time, and prolonged ventilation. There were 23 early postoperative deaths in group B (12.5%) vs. none in group A. At 180 days, survival was significantly higher for patients in group A (94.4%) vs. group B (67.9%, p = 0.016), although this difference did not reach statistical significance (log-rank test, p = 0.073). Multivariate Cox proportional hazards regression revealed age above 50 years (hazard ratio [HR] 3.327, 95% confidence interval [CI] 1.279-8.650) and NYHA class above III (NYHA III or IV: HR 3.117, 95% CI 1.119-8.683, p = 0.030; NYHA IV: HR 3.678, 95% CI 1.984-6.817, p < 0.001) as independent risk factors for mortality at 180 days. A trend towards a protective factor was observed for simultaneous splenectomy (HR = 0.171, 95% CI 0.023-1.255).

CONCLUSION

Simultaneous valve surgery and splenectomy is an approach for active endocarditis complicated by splenic lesions with a low 180-day mortality. Despite the expected risk elevation by septic lesions and the additive trauma of a laparotomy, patients with simultaneous splenectomy had a favourable outcome regarding early mortality and mortality at 6 months.

Wirsungostomy as a salvage procedure after pancreaticoduodenectomy

BACKGROUND

  Mortality rates associated with postoperative peritonitis or haemorrhage secondary to pancreatic fistula (PF) after pancreaticoduodenectomy (PD) remain high. This study analysed the results of an alternative management strategy for these life-threatening complications.

METHODS

  All patients undergoing PD between January 2004 and April 2011 were identified. Patients who underwent further laparotomy for failure of the pancreatico-digestive anastomosis were identified. Since 2004, this problem has been managed by dismantling the pancreatico-digestive anastomosis and cannulating the pancreatic duct remnant with a thin polyethylene tube (Escat tube), which is then passed through the abdominal wall. Main outcome measures were mortality, morbidity and longterm outcome.

RESULTS

  From January 2004 to April 2011, 244 patients underwent a PD. Postoperatively, 21 (8.6%) patients required re-laparotomy to facilitate a wirsungostomy. Two patients were transferred from another hospital with life-threatening PF after PD. Causes of re-laparotomy were haemorrhage (n= 12), peritonitis (n= 4), septic shock (n= 4) and mesenteric ischaemia (n= 1). Of the 21 patients who underwent wirsungostomy, six patients subsequently died of liver failure (n= 3), refractory septic shock (n= 2) or mesenteric ischaemia (n= 1) and nine patients suffered complications. The median length of hospital stay was 42 days (range: 34-60 days). The polyethylene tube at the pancreatic duct was removed at a median of 4 months (range: 2-11 months). Three patients developed diabetes mellitus during follow-up.

CONCLUSIONS

  These data suggest that preservation of the pancreatic remnant with wirsungostomy has a role in the management of patients with uncontrolled haemorrhage or peritonitis after PF.

Sepsis: from pattern to mechanism and back

Sepsis is a clinical entity in which complex inflammatory and physiological processes are mobilized, not only across a range of cellular and molecular interactions, but also in clinically relevant physiological signals accessible at the bedside. There is a need for a mechanistic understanding that links the clinical phenomenon of physiologic variability with the underlying patterns of the biology of inflammation, and we assert that this can be facilitated through the use of dynamic mathematical and computational modeling. An iterative approach of laboratory experimentation and mathematical/computational modeling has the potential to integrate cellular biology, physiology, control theory, and systems engineering across biological scales, yielding insights into the control structures that govern mechanisms by which phenomena, detected as biological patterns, are produced. This approach can represent hypotheses in the formal language of mathematics and computation, and link behaviors that cross scales and domains, thereby offering the opportunity to better explain, diagnose, and intervene in the care of the septic patient.

PCR-based rapid sepsis diagnosis effectively guides clinical treatment in patients with new onset of SIRS

INTRODUCTION

Early detection of the causing microorganism and timely therapeutic intervention are crucial for improved outcome of patients with sepsis. Quite recently, we evaluated the technical and diagnostic feasibility of a commercial multiplex real-time polymerase chain reaction (PCR) (LightCycler SeptiFast® assay) for detection of blood stream infections in a cohort of intensive care unit (ICU) patients with the risk of abdominal sepsis.

RESULTS AND FINDINGS

The PCR positivity rate showed a high coincidence with systemic inflammatory response syndrome (SIRS; 75.8%). In this study, we focussed on patients from the same surgical ICU with upcoming SIRS and addressed the utility on therapeutic decision making following diagnostic application of PCR in addition and comparison to conventional microbiological and laboratory tests. In total, 104 patients on the ICU fulfilling the American College of Chest Physicians/Society of Critical Care Medicine SIRS criteria were enrolled. Blood samples were taken within 24 h of upcoming SIRS. Some 39.9% (n = 59) of the blood samples (n (Total) = 148) were positive using multiplex-PCR and 20.3% (n = 30) using conventional culture. In 11.4% of all samples, multiplex-PCR detected more than one microorganism. Among the 77 microorganisms identified by multiplex-PCR, only 25 (32.5%) could be confirmed by blood culture; an additional 17 could be confirmed by microbiological test results from other significant patient specimen. Positive blood samples independent of the detection method were characterised by significant elevated levels of procalcitonin (p < 0.05) but not C-reactive protein. In 25 cases (16.9%, n = 148), the rapid identification of involved pathogens by multiplex-PCR led to prompt adjustment of therapy.

CONCLUSIONS

Our study demonstrates improved detection of specific pathogens with a high intrinsic resistance and positive impact on therapeutic decision-making by additional multiplex-PCR-based analysis of blood samples for infectious agents in patients with new onset of SIRS. Thus, we showed for the first time that PCR test results guide clinical treatment successfully.

TREM-1 expression on neutrophils and monocytes of septic patients: relation to the underlying infection and the implicated pathogen

BACKGROUND

Current knowledge on the exact ligand causing expression of TREM-1 on neutrophils and monocytes is limited. The present study aimed at the role of underlying infection and of the causative pathogen in the expression of TREM-1 in sepsis.

METHODS

Peripheral venous blood was sampled from 125 patients with sepsis and 88 with severe sepsis/septic shock. The causative pathogen was isolated in 91 patients. Patients were suffering from acute pyelonephritis, community-acquired pneumonia (CAP), intra-abdominal infections (IAIs), primary bacteremia and ventilator-associated pneumonia or hospital-acquired pneumonia (VAP/HAP). Blood monocytes and neutrophils were isolated. Flow cytometry was used to estimate the TREM-1 expression from septic patients.

RESULTS

Within patients bearing intrabdominal infections, expression of TREM-1 was significantly lower on neutrophils and on monocytes at severe sepsis/shock than at sepsis. That was also the case for severe sepsis/shock developed in the field of VAP/HAP. Among patients who suffered infections by Gram-negative community-acquired pathogens or among patients who suffered polymicrobial infections, expression of TREM-1 on monocytes was significantly lower at the stage of severe sepsis/shock than at the stage of sepsis.

CONCLUSIONS

Decrease of the expression of TREM-1 on the membrane of monocytes and neutrophils upon transition from sepsis to severe sepsis/septic shock depends on the underlying type of infection and the causative pathogen.

Sepsis: Something old, something new, and a systems view

Sepsis is a clinical syndrome characterized by a multisystem response to a microbial pathogenic insult consisting of a mosaic of interconnected biochemical, cellular, and organ-organ interaction networks. A central thread that connects these responses is inflammation that, while attempting to defend the body and prevent further harm, causes further damage through the feed-forward, proinflammatory effects of damage-associated molecular pattern molecules. In this review, we address the epidemiology and current definitions of sepsis and focus specifically on the biologic cascades that comprise the inflammatory response to sepsis. We suggest that attempts to improve clinical outcomes by targeting specific components of this network have been unsuccessful due to the lack of an integrative, predictive, and individualized systems-based approach to define the time-varying, multidimensional state of the patient. We highlight the translational impact of computational modeling and other complex systems approaches as applied to sepsis, including in silico clinical trials, patient-specific models, and complexity-based assessments of physiology.

Sepsis and acute kidney injury

Sepsis is a severe and dysregulated inflammatory response to infection characterized by end-organ dysfunction distant from the primary site of infection. Development of acute kidney injury (AKI) during sepsis increases patient morbidity, predicts higher mortality, has a significant effect on multiple organ functions, is associated with an increased length of stay in the intensive care unit, and hence consumes considerable healthcare resources. When compared with AKI of nonseptic origin, septic AKI is characterized by a distinct pathophysiology and therefore requires a different approach. Despite impressive advances in several fields of medicine, the pathophysiology, diagnostic procedures, and appropriate therapeutic interventions in sepsis are still highly debatable. Numerous immunomodulatory agents showing promise in preclinical studies fail to reduce the overwhelmingly high mortality rate of sepsis and provoke AKI when compared with other critically ill patients. Major impediments to progress in understanding, early diagnosis, and application of appropriate therapeutic modalities in sepsis-induced AKI include limited histopathologic information, few animal models that closely mimic human sepsis, and a relative shortage of specific diagnostic tools. Here we discuss the most recent advances in understanding the fundamental mechanisms of sepsis-induced AKI, characteristics of relevant animal models available, and potential therapies.