Comparison of WBC, ESR, CRP and PCT serum levels in septic and non-septic burn cases

Dynamic changes and diagnostic and prognostic significance of serum PCT, hs-CRP and s-100 protein in central nervous system infection

The aim of the study was to analyze the dynamic changes and diagnostic and prognostic significance of serum procalcitonin (PCT), high-sensitivity C-reactive protein (hs-CRP) and s-100 protein in central nervous system infection. A total of 110 patients diagnosed with central nervous system infection in Department of Neurology in the People's Hospital of Rizhao from January 2014 to January 2016 were selected and retrospectively analyzed; they were divided into the bacterium (n=70) and virus (n=40) groups. Another 45 normal subjects were selected as the control group. PCT, hs-CRP and s-100 protein values in serum and cerebrospinal fluid were measured. The serum PCT, hs-CRP and s-100 protein levels in the bacterium group were significantly higher than those in the virus and control groups (p<0.05). The serum PCT, hs-CRP and s-100 protein levels in the bacterium and virus groups after treatment were obviously decreased compared with those before treatment (p<0.05). PCT, hs-CRP and s-100 protein levels in serum and cerebrospinal fluid in the bacterium and virus groups had no statistically significant differences after treatment (p>0.05). PCT, hs-CRP and s-100 protein levels in deaths in bacterium group were significantly higher than those in survivors (p<0.05). The serum PCT, hs-CRP and s-100 protein levels, can serve as important indexes for the diagnosis of central nervous system infection and their dynamic changes can be used to monitor the changes in disease condition, severity of bacterial infection and prognosis, providing help for the clinical treatment thereof.

Procalcitonin kinetics after burn injury and burn surgery in septic and non-septic patients - a retrospective observational study

BACKGROUND

Early sepsis diagnosis is crucial for the correct management of burn patients, and it clearly influences outcomes. The systemic inflammatory response triggered by burns mimics sepsis presentation and complicates early sepsis diagnosis. Biomarkers were advocated to aid the diagnosis of early sepsis. Serum procalcitonin (PCT) exhibits fair accuracy and good correlation with sepsis severity, being used in diverse clinical settings. However, few studies have evaluated perioperative changes in PCT levels in burn patients. The present study evaluated PCT kinetics during the first days after burn injury and subsequent surgical interventions to assess PCT utility in distinguishing septic from non-septic inflammatory responses.

METHODS

This study was a retrospective observational study of all burn patients admitted to the Coimbra Burns Unit (Portugal) between January 2011 and December 2014 who presented with a total burn surface area ≥ 15% and who underwent subsequent surgery. PCT kinetics were investigated a) during the first five days after burn injury and b) preoperatively during the five days after surgery in three subsets of patients, including those with no preoperative and no postoperative sepsis (NN), no preoperative but postoperative sepsis (NS), and preoperative and postoperative sepsis (SS). A total of 145 patients met the selection criteria and were included in the analysis.

RESULTS

PCT levels in the first five days after burn injury were significantly higher in patients who developed at least one sepsis episode (n = 85) compared with patients who did not develop sepsis (n = 60). PCT values > 1.00 ng/mL were clearly associated with sepsis. Study participants (n = 145) underwent a total of 283 surgical interventions. Their distribution by preoperative/postoperative sepsis status was 142 (50.2%) in NN; 62 (21.9%) in NS; and 79 (27.9%) in SS. PCT values exhibited a parallel course in the three groups that peaked on the second postoperative day and returned to preoperative levels on the third day or later. The lowest PCT values were found in NN, and the highest values were observed in SS; the NS values were intermediate.

CONCLUSIONS

PCT kinetics coupled with a clinical examination may be helpful for sepsis diagnosis during the first days after burn injury and burn surgery.

C-reactive protein may be useful to differentiate idiopathic orbital inflammation and orbital cellulitis in cases with acute eyelid erythema and edema

Purpose

Idiopathic orbital inflammation (IOI) and orbital cellulitis can present similar clinical features, and the diagnoses of these two disorders are sometimes confused. The purpose of the present study was to determine whether or not inflammatory markers in the blood can be useful to differentiate between IOI and orbital cellulitis in cases with acute eyelid erythema and edema.

Subjects and methods

In this retrospective single-institute study, we reviewed the medical records spanning the past 10 years at the Department of Ophthalmology, Osaka Medical College Hospital, Takatsuki, Osaka, Japan, and found 45 cases, with patients >15 years of age, with presumed IOI. Their blood samples were obtained within 5 days after the onset of IOI. Of those cases, 15 patients (10 males, 5 females, mean age of 56.9 years; range 38–76 years) presented acute eyelid erythema and edema, and were initially misdiagnosed as orbital cellulitis. Thus, inflammatory markers in the blood (ie, white blood cells [WBCs] and C-reactive protein [CRP]) of those 15 patients were analyzed with 17 patients (10 males, 7 females) having orbital cellulitis. The receiver operating characteristic curve analysis was performed to determine the optimal cut-off values.

Results

The mean ± standard error (SE) levels of the WBC were 6.80±0.70×10³/μL in the IOI patients, and 8.54±0.91×10³/μL in the orbital cellulitis patients, and no significant differences were observed (P=0.15, Student’s t-test). However, the mean ± SE levels of CRP were 1.04±0.43 mg/dL in the IOI patients, yet were significantly increased to 4.65±1.21 mg/dL in the orbital cellulitis patients (P=0.01, Student’s t-test). The area under the curve value was 0.80 and the optimal cut-off value was 0.43 for orbital cellulitis, with sensitivity and specificity being 82% and 73%, respectively.

Conclusion

The findings of this study indicate that CRP may be useful in distinguishing patients with idiopathic orbital inflammation from those with orbital cellulitis.

MR-proADM: A New Biomarker for Early Diagnosis of Sepsis in Burned Patients

Mid regional pro-adrenomedullin (MR-proADM) has been used as a marker of sepsis, but its dynamics and role in a burn injury setting has not been tested. In a prospective observational study, we included 42 consecutive patients with >15% TBSA. Daily blood specimens collected over the initial 20 days of treatment were submitted for laboratory analysis of MR-proADM and procalcitonin (PCT) via immunoluminometric sandwich assay (Kryptor, BRAHMS, Berlin, Germany). In patients with an absence of sepsis, an initial increase in MR-proADM and PCT levels was noted post-burn injury, peaking on the second day postadmission and thereafter demonstrated a continued decline in MR-proADM and PCT levels. In those patients who went on to develop sepsis (n = 27, 64.3%), the levels of MR-proADM and PCT were significantly higher (P < .001) on days categorized as septic, than on days categorized as nonseptic. The increase in PCT levels was noted on the first day to be categorized as septic. In contrast, the MR-proADM levels demonstrated an increase one day earlier. The optimal relationship between the specificity and sensitivity of MR-proADM and PCT for the detection of sepsis was an increase of 31% and at least 0.015 nmol/L (area under curve 0.76) or of >39% and at least 0.15 µg/L (area under the curve 0.83), respectively. Burn injury is associated with increased levels of MR-proADM. Subsequent increases may be considered as diagnostic of sepsis onset. In this context, PCT displayed higher specificity and sensitivity, while MR-proADM may be more suitable for the early recognition of sepsis (ClinicalTrials.gov number, NCT01055587).

Pentraxin-3 as a marker of sepsis severity and predictor of mortality outcomes: A systematic review and meta-analysis

OBJECTIVES

Pentraxin-3 (PTX-3) is a multi-functional pattern recognition molecule produced by various cell types of peripheral tissues in different infections. It is raised in sepsis, but its values in predicting disease severity or mortality outcomes have been controversial. Therefore, we conducted a systematic review and meta-analysis of these associations.

METHODS

PubMed and Embase were searched until July 18, 2017 for studies that evaluated the relationship between PTX-3 levels and disease severity or mortality in sepsis.

RESULTS

A total of 23 and 10 entries were retrieved from both databases, respectively, of which 16 studies were included in the final meta-analysis. A total of 3001 patients (56% male, mean age 63 ± 15 years; mean follow-up duration of 207 days) were analysed. PTX-3 was significantly higher in patients with more severe sepsis compared to those with less severe sepsis (standard mean difference = 18.5 ng/mL, standard error: 4.5 ng/mL, P < 0.0001) and higher in non-survivors compared to survivors (standard mean difference = 40.3 ng/mL, standard error: 6.8 ng/mL, P < 0.0001). Elevated PTX-3 levels significantly increased the risk of all-cause mortality (hazard ratio: 1.91, 95% CI: 1.53 to 2.46, P < 0.0001).

CONCLUSIONS

PTX-3 significantly predicts disease severity and mortality in sepsis.

Independent impacts of aging on mitochondrial DNA quantity and quality in humans

BACKGROUND

The accumulation of mitochondrial DNA (mtDNA) mutations, and the reduction of mtDNA copy number, both disrupt mitochondrial energetics, and may contribute to aging and age-associated phenotypes. However, there are few genetic and epidemiological studies on the spectra of blood mtDNA heteroplasmies, and the distribution of mtDNA copy numbers in different age groups and their impact on age-related phenotypes. In this work, we used whole-genome sequencing data of isolated peripheral blood mononuclear cells (PBMCs) from the UK10K project to investigate in parallel mtDNA heteroplasmy and copy number in 1511 women, between 17 and 85 years old, recruited in the TwinsUK cohorts.

RESULTS

We report a high prevalence of pathogenic mtDNA heteroplasmies in this population. We also find an increase in mtDNA heteroplasmies with age (β = 0.011, P = 5.77e-6), and showed that, on average, individuals aged 70-years or older had 58.5% more mtDNA heteroplasmies than those under 40-years old. Conversely, mtDNA copy number decreased by an average of 0.4 copies per year (β = -0.395, P = 0.0097). Multiple regression analyses also showed that age had independent effects on mtDNA copy number decrease and heteroplasmy accumulation. Finally, mtDNA copy number was positively associated with serum bicarbonate level (P = 4.46e-5), and inversely correlated with white blood cell count (P = 0.0006). Moreover, the aggregated heteroplasmy load was associated with blood apolipoprotein B level (P = 1.33e-5), linking the accumulation of mtDNA mutations to age-related physiological markers.

CONCLUSIONS

Our population-based study indicates that both mtDNA quality and quantity are influenced by age. An open question for the future is whether interventions that would contribute to maintain optimal mtDNA copy number and prevent the expansion of heteroplasmy could promote healthy aging.

Parameters of the Endocannabinoid System as Novel Biomarkers in Sepsis and Septic Shock

Sepsis represents a dysregulated immune response to infection, with a continuum of severity progressing to septic shock. This dysregulated response generally follows a pattern by which an initial hyperinflammatory phase is followed by a state of sepsis-associated immunosuppression. Major challenges in improving sepsis care include developing strategies to ensure early and accurate identification and diagnosis of the disease process, improving our ability to predict outcomes and stratify patients, and the need for novel sepsis-specific treatments such as immunomodulation. Biomarkers offer promise with all three of these challenges and are likely also to be the solution to determining a patient’s immune status; something that is critical in guiding effective and safe immunomodulatory therapy. Currently available biomarkers used in sepsis lack sensitivity and specificity, among other significant shortcomings. The endocannabinoid system (ECS) is an emerging topic of research with evidence suggesting a ubiquitous presence on both central and peripheral tissues, including an intrinsic link with immune function. This review will first discuss the state of sepsis biomarkers and lack of available treatments, followed by an introduction to the ECS and a discussion of its potential to provide novel biomarkers and treatments.

Non-coding RNA: a potential biomarker and therapeutic target for sepsis

Sepsis, a syndrome of physiologic, pathologic, and biochemical abnormalities caused by an altered systemic host response to infection, has become the main cause of death among patients admitted to the intensive care units. Recently, genome-wide expression analysis revealed that over 80% of the essential genetic elements were altered in critically ill patients. Notably, non-coding RNAs, including microRNAs, long non-coding RNAs and circular RNAs, have been proven to play essential roles in innate immunity, mitochondrial dysfunction and organ dysfunction. In this review, we introduced the biogenesis of non-coding RNAs briefly and summed up different kinds of non-coding RNAs in regulation of sepsis, which could provide a more comprehensive understanding about pathogenesis of the disease. Additionally, we summarized the limitations of current biomarkers and then recommended some non-coding RNAs as novel potential biomarkers for sepsis and sepsis-induced organ dysfunction. Besides, we also introduced some problems and challenges that need to be overcome during the clinical application of non-coding RNAs. Future research should focus on elucidating their molecular mechanisms, particularly long non-coding RNAs as well as circular RNAs and sepsis, to further understanding of the disease process. With the in-depth understanding of the mechanism of sepsis, non-coding RNAs provide a new insight into sepsis and could become the novel therapeutic targets in the future.

Predicting and managing sepsis in burn patients: current perspectives

Modern burn care has led to unprecedented survival rates in burn patients whose injuries were fatal a few decades ago. Along with improved survival, new challenges have emerged in the management of burn patients. Infections top the list of the most common complication after burns, and sepsis is the leading cause of death in both adult and pediatric burn patients. The diagnosis and management of sepsis in burns is complex as a tremendous hypermetabolic response secondary to burn injury can be superimposed on systemic infection, leading to organ dysfunction. The management of a septic burn patient represents a challenging scenario that is commonly encountered by providers caring for burn patients despite preventive efforts. Here, we discuss the current perspectives in the diagnosis and treatment of sepsis and septic shock in burn patients.

The Use of Procalcitonin (PCT) for Diagnosis of Sepsis in Burn Patients: A Meta-Analysis

The continuous development of resuscitation techniques and intensive care reduced the mortality rate induced by the initial shock in burn patients and, currently, infections (especially sepsis) are the main causes of mortality of these patients. The misuse of antimicrobial agents is strongly related to antimicrobial and adverse patient outcomes, development of microbial resistance and increased healthcare-related costs. To overcome these risks, antimicrobial stewardship is mandatory and biomarkers are useful to avoid unnecessary medical prescription, to monitor antimicrobial therapy and to support the decision of its stop. Among a large array of laboratory tests, procalcitonin (PCT) emerged as the leading biomarker to accurately and time-effectively indicate the presence of systemic infection. In the presence of systemic infection, PCT blood levels undergo a sudden and dramatic increase, following the course of the infection, and quickly subside after the control of the septic process. This work is a meta-analysis on PCT performance as a biomarker for sepsis. This meta–analysis showed that overall pooled area under the curve (AUC) is 0.83 (95% CI = 0.76 to 0.90); the estimated cut-off is 1.47 ng/mL. The overall sepsis effect in PCT levels is significant and strong (Cohen's d is 2.1 and 95% CI = 1.1 to 3.2). This meta–analysis showed PCT may be considered as a biomarker with a strong diagnostic ability to discriminate between the septic from the non-septic burn patients. Thus, this work encourages the determination of PCT levels in clinical practice for the management of these patients, in order to timely identify the susceptibility to sepsis and to initiate the antimicrobial therapy, improving the patients’ outcomes.

Diagnostic accuracy of presepsin (sCD14-ST) and procalcitonin for prediction of bacteraemia and bacterial DNAaemia in patients with suspected sepsis

Early diagnosis and prompt targeted therapy are essential for septic patients' outcome. Procalcitonin (PCT) has been shown to predict bacteraemia and bacterial DNAaemia. Presepsin, the circulating soluble form of CD14 subtype, increases in response to bacterial infections, and is considered a new, emerging, early marker for sepsis. We evaluated the diagnostic accuracy of presepsin in predicting bacteraemia and bacterial DNAaemia in 92 patients with suspected sepsis, and we compared it with that of PCT and C-reactive protein (CRP). Presepsin median values were significantly higher in bacteraemic vs non-bacteraemic patients [1290 pg ml-1, interquartile range (IQR) 1005-2041 vs 659 pg ml-1, IQR 381-979; P<0.001] and in patients with vs patients without bacterial DNAaemia (1297 pg ml-1, IQR 1001-2046 vs 665 pg ml-1, IQR 381-940; P<0.001). Receiver operating characteristics analysis showed an area under the curve (AUC) for presepsin of 0.788 [95 % confidence interval (CI): 0.687-0.889; P<0.001] in predicting bacteraemia and of 0.777 (95 % CI: 0.676-0.878; P<0.001) in predicting bacterial DNAaemia, lower, but not significantly different, than those of PCT (0.876, P=0.12 and 0.880, P=0.07, respectively). Both biomarkers performed significantly better than CRP, which had an AUC for bacteraemia of 0.602 and for DNAaemia of 0.632 (all P values <0.05). In conclusion, in patients with suspected sepsis, presepsin and PCT showed a good diagnostic accuracy in predicting both bacteraemia and bacterial DNAaemia, superior to CRP.

Circulating MicroRNAs as Biomarkers for Sepsis

Sepsis represents a major cause of lethality during intensive care unit (ICU) treatment. Pharmacological treatment strategies for sepsis are still limited and mainly based on the early initiation of antibiotic and supportive treatment. In this context, numerous clinical and serum based markers have been evaluated for the diagnosis, the severity, and the etiology of sepsis. However until now, few of these factors could be translated into clinical use. MicroRNAs (miRNAs) do not encode for proteins but regulate gene expression by inhibiting the translation or transcription of their target mRNAs. Recently it was demonstrated that miRNAs are released into the circulation and that the spectrum of circulating miRNAs might be altered during various pathologic conditions, such as inflammation, infection, and sepsis. By using array- and single PCR-based methods, a variety of deregulated miRNAs, including miR-25, miR-133a, miR-146, miR-150, and miR-223, were described in the context of sepsis. Some of the miRNAs correlated with the disease stage, as well as patients' short and long term prognosis. Here, we summarize the current findings on the role of circulating miRNAs in the diagnosis and staging of sepsis in critically ill patients. We compare data from patients with findings from animal models and, finally, highlight the challenges and drawbacks that currently prevent the use of circulating miRNAs as biomarkers in clinical routine.

A comprehensive bioinformatics method to screen key genes for severe burn

Severe burn is a kind of traumatic injury, which can lead to serious financial burden, high morbidity and mortality following inflammatory response and complications. Microarray analysis has emerged as a popular tool for generating gene expression data and revealing the complex gene expression patterns. The Gene Expression Omnibus (GEO) repository at the National Center for Biotechnology Information has become the leading public repository of microarray data. This study aimed to study the mechanisms of severe burn. Microarray of GSE37069 was downloaded from GEO including blood samples from 244 severe burn patients and blood samples from 35 healthy controls. The differentially expressed genes (DEGs) between blood samples from healthy controls and patients were identified by t-test in the LIMMA package of R. Their interaction relationships were searched using STRING online software and then protein-protein interaction (PPI) network was constructed by Cytoscape. Using DAVID online tool, underlying functions of the DEGs involved in the PPI network were analyzed by functional and pathway enrichment analyses. We screened 541 DEGs in blood samples from severe burns patients compared with blood samples from healthy controls. Meanwhile, DEGs including MMP9, TIMP1, GZMK, GZMA, and GZMB showed higher degrees in the PPI networks. Moreover, they may function in severe burn through interacting with others. According to functional enrichment analysis, these DEGs were mainly involved in BP categories associated with inflammatory responses. MMP9, TIMP1, HGF, GZMA, GZMB, and GZMK might play important roles in severe burns.

The utility of C-reactive protein and procalcitonin for sepsis diagnosis in critically burned patients: A preliminary study

Objective

To assess the utility of C-reactive protein (CRP) and procalcitonin (PCT) as biomarkers of infection in patients with severe burn injury.

Methods

The present study included severe burn injury patients consecutively admitted to the Virgen del Rocío University Hospital (Andalucia, Spain) intensive care unit during a 12-month period. The variables of interest were: age, sex, mechanism of injury, percentage of burned body surface area, the Abbreviated Burn Severity Index (ABSI) and the absence/presence of sepsis. The authors analyzed serum levels of CRP and PCT at admission and every 48 h thereafter until intensive care unit discharge or death. Each determination was considered to be a sample or unit of analysis.

Results

A total of 157 determinations were analyzed from 17 severe burn injury patients. Fifty-four samples were considered to be septic, 25 of which corresponded to the first day of a new onset of sepsis. The mean duration of these symptoms was four days (interquartile range two to five days). Significant differences were found in the distributions of CRP and PCT values between sepsis and no-sepsis samples. Analysis of the changes in these biomarkers over time showed that PCT increase (ΔPCT) differentiated these diagnoses, whereas CRP increase (ΔCRP) did not. ROC curve analysis revealed that ΔPCT could predict positive sepsis samples (area under the curve 0.75 [95% CI 0.58 to 0.90]; P=0.003).

Conclusion

These preliminary results showed that PCT had a better discriminatory capacity than CRP for identifying infectious processes in patients with severe burn injury. A larger sample size would be needed to confirm these results.

Peritoneal wash contents used to predict mortality in a murine sepsis model

BACKGROUND

Cecal ligation and puncture (CLP) is considered the gold standard for inducing abdominal sepsis in mice. However, the model lacks source control, a component of sepsis management in humans. Using a CLP-excision model, we characterized peritoneal cytokines and cells and hypothesized these analyses would allow us to predict survival.

METHODS

Fifty-eight mice were first subjected to CLP. Twenty hours later, the necrotic cecums were debrided, abdominal cavity lavaged, and intraperitoneal antibiotics administered. Peritoneal cytokines and leukocytes collected from the peritoneal lavage were analyzed. These immune parameters were used to generate receiver operator characteristic curves. In separate experiments, the accuracy of the model was verified with a survival cohort. Finally, we collected the peritoneal lavage and analyzed both serum and peritoneal cytokines, bacterial load, and leukocyte functionality.

RESULTS

Peritoneal interleukin (IL)-6 levels and neutrophil CD11b intensity were observed to be significantly different in mice that lived versus those who died. In separate experiments, mice predicted to live (P-LIVE) had decreased bacterial loads, systemic IL-10, and neutrophil oxidative burst and increased peritoneal inflammatory monocyte numbers and phagocytosis.

CONCLUSIONS

This study couples a clinically relevant sepsis model with methodology to limit pathogen spread. Using surgical waste, stratification of the mice into groups P-LIVE and predicted to die was possible with a high degree of accuracy and specificity. In mice P-LIVE, increased inflammatory monocyte recruitment and phagocytosis were associated with decreased systemic IL-10 and bacterial loads.

Prognostic value of natriuretic peptides in severe trauma patients with multiple organ dysfunction syndrome

The aim of the present study was to evaluate the prognostic values of the N-terminal peptide of pro-atrial natriuretic peptide (NT-proANP) and the N-terminal fragment of B-type natriuretic peptide (NT-proBNP) in severe trauma patients developing multiple organ dysfunction syndrome (MODS). Out of the 126 severe trauma patients that were admitted to the Emergency Intensive Care Unit of the General Hospital of Shenyang Military Region between January 2009 and December 2011, 26 patients with multiple injuries and an injury severity score (ISS) of >16 points were included in the study. The MODS score was calculated on admission as well as 24, 48 and 72 h after the injury. Patients were divided into two groups: Group A consisted of patients with minor signs of organ dysfunction (MODS score, ≤4 points) and group B of patients with major organ dysfunction (MODS score, >4 points). Venous blood (5 ml) was extracted from the patients on admission and 6, 12, 24, 48 and 72 h after the injury. The Elecsys proBNP® and proANP® assays were used to determine the NT-proBNP and NT-proANP levels, respectively. The changes in the levels of C-reactive protein, white blood cells and neutrophils were detected and analyzed on admission. Acute physiology and chronic health evaluation II scores and ISSs were collected 72 h after the injury. The hemodynamic monitoring of cardiac index (CI) was performed using The Pulse index Continuous Cardiac Output system. The serum NT-proANP and NT-proBNP concentrations were elevated in all 26 patients. Upon admission, the serum NT-proANP and NT-proBNP values were 637.3±8.9 and 137.3±8.9 pmol/l, respectively, in group A and 1,185.0±7.2 and 185.0±7.2 pmol/l, respectively, in group B. The NT-proANP and NT-proBNP levels in group A were significantly lower than those in group B at all subsequent time-points (P<0.001). By contrast, the CI in group A was significantly higher than that in group B at all time-points (P<0.001). An inverse correlation was observed between the NT-proANP or NT-proBNP concentration and CI at 24, 48 and 72 h after the injury (r=-0.679 and -0.772, respectively; P<0.001). In conclusion, the serum NT-proANP and NT-proBNP concentrations following multiple injuries have been found to be significantly correlated with the clinical signs of MODS, and a distinct correlation has been observed between the levels of serums NT-proANP and NT-proBNP and decreased CI. The data of this pilot study suggest that NT-proANP and NT-proBNP levels may be of value in the diagnosis of post-traumatic cardiac impairment.

Assessing the immune status of critically ill trauma patients by flow cytometry

BACKGROUND

Unintentional injury or trauma remains the leading cause of death among young adults. About one fifth of these trauma patients require care in an intensive care unit (ICU) because of severity of injuries and comorbidities. Patients hospitalized in an ICU are at increased risk for nosocomial infections, such as urinary tract infections, pneumonia, bacteremia, and wound infections. Many of these patients will develop sepsis or septic shock, and some will progress to multiple organ failure and death. The balance between the proinflammatory and counterinflammatory immune response appears to be a driving factor in this progression. At present, there is no proposed method for the timely detection of the immune status in trauma patients, making rational decisions to use immune-altering therapies difficult.

OBJECTIVE

We demonstrate that flow cytometry, with its capabilities to characterize and/or enumerate (a) leukocyte subtypes, (b) leukocyte activation markers, (c) leukocyte-derived cytokines and microvesicles, and (d) leukocyte function is well suited to monitor the immune status of critically ill trauma patients.

METHODS

Information for the review was obtained from the extant literature.

DISCUSSION

We suggest that flow cytometry is a research method that might aid nurse scientists in investigating the immune status of critically ill patients, the recovery status of conditions such as hemorrhagic shock and tissue injury and the relationship between cancer disease progression and symptoms. Therefore, flow cytometry has the potential to broaden nursing research priority areas so that a comprehensive approach to understanding the cellular response is attained.

A new marker of sepsis post burn injury?*

OBJECTIVES

Accurate diagnosis of sepsis is difficult in patients post burn due to the large inflammatory response produced by the major insult. We aimed to estimate the values of serum N-terminal pro-B-type natriuretic peptide and procalcitonin and the changes in hemodynamic variables as markers of sepsis in critically ill burn patients.

DESIGN

Prospective, observational study.

SETTING

A quaternary-level university-affiliated ICU.

PATIENTS

Fifty-four patients with burns to total body surface area of greater than or equal to 15%, intubated with no previous cardiovascular comorbidities, were enrolled.

INTERVENTIONS

At admission, a FloTrac/Vigileo system was attached and daily blood samples taken from the arterial catheter. Infection surveillance was carried out daily with patients classified as septic/nonseptic according to American Burns Consensus criteria.

MEASUREMENTS AND MAIN RESULTS

N-terminal pro-B-type natriuretic peptide, procalcitonin, and waveform analysis of changes in stroke volume index and systemic vascular resistance index were measured within the first 24 hours after burn and daily thereafter for the length of the ICU stay or until their first episode of sepsis. Prevalences of stroke volume variation less than 12% (normovolemia) with hypotension (systolic blood pressure < 90 mm Hg) were recorded. Patients with sepsis differed significantly from "no sepsis" for N-terminal pro-B-type natriuretic peptide, systemic vascular resistance index, and stroke volume index on days 3-7. Procalcitonin did not differ between sepsis and "no sepsis" except for day 3. Area under the receiver operating characteristic curves showed excellent discriminative power for B-type natriuretic peptide (p = 0.001; 95% CI, 0.99-1.00), systemic vascular resistance index (p < 0.001; 95% CI, 0.97-0.99), and stroke volume index (p < 0.01; 95% CI, 0.96-0.99) in predicting sepsis but not for procalcitonin (not significant; 95% CI, 0.29-0.46). A chi-square crosstab found that there was no relationship between hypotension with normovolemia (stroke volume variation < 12%) and sepsis.

CONCLUSIONS

Serum N-terminal pro-B-type natriuretic peptide levels and certain hemodynamic changes can be used as an early indicator of sepsis in patients with burn injury. Procalcitonin did not assist in the early diagnosis of sepsis.

Procalcitonin better than C-reactive protein, erythrocyte sedimentation rate, and white blood cell count in predicting DNAemia in patients with sepsis

BACKGROUND

Procalcitonin (PCT) levels can be used to predict bacteremia and DNAemia in patients with sepsis. In this study, the diagnostic accuracy of PCT in predicting blood culture (BC) results and DNAemia, as detected by real-time PCR (RT-PCR), was compared with that of other markers of inflammation commonly evaluated in patients with suspected sepsis, such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and white blood cell (WBC) count.

METHODS

A total of 571 patients for whom BC, blood RT-PCR, PCT, CRP, ESR, and WBC count were requested for laboratory diagnosis of sepsis were included in the study. Receiver operating characteristic curve analysis was performed to compare the ability of the above biomarkers to predict BC and blood RT-PCR results.

RESULTS

A total of 108 pathogens were identified by BC (79 pathogens, 14.5% positive rate) and/or RT-PCR (90 pathogens, 16.5% positive rate), after exclusion of 26 contaminated samples. The PCT areas under the curve (AUCs) in predicting BC (0.843; 95% CI 0.796-0.890; p < 0.0001) and RT-PCR (0.916; 95% CI 0.888-0.945; p < 0.0001) results were significantly greater than AUCs found for CRP, ESR, and WBC count.

CONCLUSIONS

PCT showed a better diagnostic accuracy than CRP, ESR, and WBC count in predicting DNAemia and bacteremia in patients with suspected sepsis.

Biphasic changes (overreduction and overoxidation) of plasma redox status and clinical implications in early stage of severe burns

PURPOSE

Although the changes of redox status in the early stage of severe burns are considered to be associated with the disease progression, whereas antioxidant therapy cannot improve the prognosis, the characteristics and mechanisms of dynamic change of redox status related with the disease progression deserve further study.

METHODS

Blood redox potential (ORP) values (ΔORP value was adopted), plasma uric acid (UA) levels, and the inflammation-related indicators of 67 burn patients were dynamically monitored in the early stage.

RESULTS

Compared with healthy persons, the results revealed the biphasic changes of redox status in the early stage after burns, and both of them were closely related to the prognosis of severe burns. Overreduction status and overoxidation status were related to the dynamic changes of plasma UA level and the inflammation-related indicators of severe burns. In addition, the change of ΔORP value was found to associate with the traditional prognostic markers.

CONCLUSIONS

This study firstly revealed the excessive, biphasic changes of redox status and clinical implications in the early stage of severe burns, providing a new viewpoint for early pathological changes of severe burns and will be helpful for corresponding early treatment. ΔORP value also appears to be a potential early prognostic marker.

Evaluation of soluble CD14 subtype (presepsin) in burn sepsis

BACKGROUND

Diagnosing sepsis is difficult in burn patients because of the inflammatory mediators that alter postburn metabolic profile. Here, we compare a new marker presepsin with procalcitonin (PCT), c-reactive protein (CRP) and white blood cell (WBC) in diagnosis and follow up of sepsis in burn patients.

METHODS

Patients admitted to burn center of our institute were prospectively investigated. Presepsin, PCT, CRP and WBC levels were measured at admission and every 6h for first day and daily thereafter. At all timing samples, patients were classified as sepsis or non-sepsis according to the current American Burn Association Consensus Criteria (ABA) 2007.

RESULT

37 adult patients were evaluated. A total data of 611 time points were supplied. Sepsis time points differ significantly from non-sepsis in presepsin (p < 0.0001), PCT (p = 0.0012) and CRP (p < 0.0001) levels. Non-surviving patient results differ significantly from survivors in presepsin (p < 0.0001), PCT (p = 0.0210) and CRP (p = 0.0008). AUC-ROC % values for diagnosing sepsis were 83.4% for presepsin, 84.7% for PCT, 81.9% for CRP and 50.8% for WBC. Sepsis patients had significantly different presepsin, CRP and WBC but not PCT levels on their first day of sepsis compared to previous days.

CONCLUSION

Plasma presepsin levels have comparable performance in burn sepsis.

Biomarkers for sepsis: a review with special attention to India

Sepsis is a serious infection and still a common cause of morbidity and mortality in resource-limited settings such as India. Even when microbiologic diagnostics are available, bacteremia is only identified in a proportion of patients who present with sepsis and bloodstream infections. Biomarkers have been used in a variety of disease processes and can help aid in diagnosing bacterial infections. There have been numerous biomarkers investigated to aid with diagnosis and prognostication in sepsis with the majority suffering from lack of sensitivity or specificity. Procalcitonin has been heralded as the biomarker that holds the most promise for bloodstream infections. Data are emerging in India, and in this review, we focus on the current data of biomarkers in sepsis with particular attention to how biomarkers could be used to augment diagnosis and treatment in India.

Role of biomarkers in sepsis care

Sepsis is one of the leading causes of mortality and morbidity, even with the current availability of extended-spectrum antibiotics and advanced medical care. Biomarkers offer a tool in facilitating early diagnosis, in identifying patient populations at high risk of complications, and in monitoring progression of the disease, which are critical assessments for appropriate therapy and improvement in patient outcomes. Several biomarkers are already available for clinical use in sepsis; however, their effectiveness in many instances is limited by the lack of specificity and sensitivity to characterize the presence of an infection and the complexity of the inflammatory and immune processes and to stratify patients into homogenous groups for specific treatments. Current advances in molecular techniques have provided new tools facilitating the discovery of novel biomarkers, which can vary from metabolites and chemical products present in body fluids to genes and proteins in circulating blood cells. The purpose of this review was to examine the current status of sepsis biomarkers, with special emphasis on emerging markers, which are undergoing validation and may transition into clinical practice for their informative value in diagnosis, prognosis, or response to therapy. We will also discuss the new concept of combination biomarkers and biomarker risk models, their existing challenges, and their potential use in the daily management of patients with sepsis.

Clinical review: the critical care management of the burn patient

Between 4 and 22% of burn patients presenting to the emergency department are admitted to critical care. Burn injury is characterised by a hypermetabolic response with physiologic, catabolic and immune effects. Burn care has seen renewed interest in colloid resuscitation, a change in transfusion practice and the development of anti-catabolic therapies. A literature search was conducted with priority given to review articles, meta-analyses and well-designed large trials; paediatric studies were included where adult studies were lacking with the aim to review the advances in adult intensive care burn management and place them in the general context of day-to-day practical burn management.

C-reactive protein and erythrocyte sedimentation rate discordance: frequency and causes in adults

C-reactive protein (CRP) levels and the erythrocyte sedimentation rate (ESR) are widely used tests of inflammation that sometimes show opposite results. We performed a retrospective cohort study to clarify the frequency and causes of CRP/ESR discordance in adults. Between January and December of 2011, the laboratories of Texas Health Presbyterian Hospital performed 2150 paired CRP/ESR measurements in 1753 patients, 1731 of whom were nonpregnant adults aged ≥ 18 years. Initial CRP and ESR results for each patient were divided into quartiles. CRP/ESR discordance, predefined as results differing by 2 or 3 quartiles, occurred in 212 patients (12%), 105 of whom had high CRP/low ESR discordance (6%) and 107 of whom had high ESR/low CRP discordance (6%). The 212 patients in the CRP/ESR-discordant group (128 women and 84 men) were subdivided into 1 of 6 diagnostic categories, and the causes of discordances were compared. The high CRP/low ESR-discordant group had more patients with infections than the high ESR/low CRP-discordant group (P = 0.001), particularly infections in the urinary tract (P = 0.03), gastrointestinal tract (P = 0.001), lungs (P = 0.005), and bloodstream (P = 0.03). However, they had fewer bone and joint infections than the high ESR/low CRP-discordant group (P = 0.001). Connective tissue diseases, such as systemic lupus erythematosus, were less common in the high CRP/low ESR-discordant group than in the high ESR/low CRP-discordant group (P = 0.001). Ischemic strokes or transient ischemic attacks almost invariably occurred in the high ESR/low CRP-discordant group (P = 0.001), whereas myocardial infarction or venous thromboembolism was limited to the high CRP/low ESR-discordant group (P = 0.001). Our findings provide information to physicians who order these 2 tests together and receive discordant results, which occurs in approximately 1 in 8 patients.

Correlation of American Burn Association sepsis criteria with the presence of bacteremia in burned patients admitted to the intensive care unit

Severe burn injury is accompanied by a systemic inflammatory response, making traditional indicators of sepsis both insensitive and nonspecific. To address this, the American Burn Association (ABA) published diagnostic criteria in 2007 to standardize the definition of sepsis in these patients. These criteria include temperature (>39°C or <36°C), progressive tachycardia (>110 beats per minute), progressive tachypnea (>25 breaths per minute not ventilated or minute ventilation >12 L/minute ventilated), thrombocytopenia (<100,000/μl; not applied until 3 days after initial resuscitation), hyperglycemia (untreated plasma glucose >200 mg/dl, >7 units of insulin/hr intravenous drip, or >25% increase in insulin requirements over 24 hours), and feed intolerance >24 hours (abdominal distension, residuals two times the feeding rate, or diarrhea >2500 ml/day). Meeting >3 of these criteria should "trigger" concern for infection. In this initial assessment of the ABA sepsis criteria correlation with infection, the authors evaluated the ABA sepsis criteria's correlation with bacteremia because bacteremia is not associated with inherent issues of diagnosis as occurs with pneumonia or soft tissue infections, and blood cultures are typically obtained due to concern for ongoing infections falling within the definition of "septic." A retrospective electronic records review was performed to evaluate episodes of bacteremia in the United States Army Institute of Research from 2006 through 2007. A total of 196 patients were admitted during the study period who met inclusion criteria. The first positive and negative cultures, if present, from each patient were evaluated. This totaled 101 positive and 181 negative cultures. Temperature, heart rate, insulin resistance, and feed intolerance criteria were significant on univariate analysis. Only heart rate and temperature were found to significantly correlate with bacteremia on multivariate analysis. The receiver operating characteristic curve area for meeting >3 ABA sepsis criteria is 0.638 (95% confidence interval 0.573-0.704; P < .001). Among severe burn patients, the ABA trigger for sepsis did not correlate strongly with bacteremia in this retrospective chart review.

Procalcitonin in early onset ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is a significant problem in intensive care and there exists great demand for a suitable biomarker. Procalcitonin (PCT) has been proposed as a candidate marker.

AIM

To assess the clinical usefulness of monitoring PCT concentrations in non-surgical patients with early onset VAP.

METHODS

Thirty-four patients were enrolled with early onset VAP defined as VAP diagnosed between 48 h and 6 days of the onset of mechanical ventilation. Serum PCT was measured on days 1, 2, 3, 5, 6 and 7.

FINDINGS

The mortality rate was 21%. Non-survivors had significantly elevated PCT levels on days 3 and 7. For non-survival, the areas under the receiver operator curve (AUC) for PCT were 0.762 [95% confidence interval (CI): 0.6-0.923] on day 3 and 0.754 (95% CI: 0.586-0.922) on day 7. Among septic patients, PCT was significantly higher on days 1, 2, 3, 5, and 7, with the highest AUC on day 1 (0.783; 95% CI: 0.626-0.94): a cut-off of 1 ng/mL on day 1 had a positive predictive value of 0.813 for the development of septic shock.

CONCLUSION

No association was found between PCT concentration and the adequacy of antibiotic therapy or the aetiology of VAP. In logistic regression analysis, PCT was not significantly correlated with poor outcome. Although PCT levels were higher in non-survivors and those who developed septic shock, PCT is not a strong predictor of these outcomes.

Immune regulation of procalcitonin: a biomarker and mediator of infection

Procalcitonin (PCT) has recently emerged as a powerful biomarker for an early and accurate diagnosis of bacterial infection. Here we summarize our current understanding of the expression pathways of PCT, its potential cellular sources including immune cells, and factors inducing its secretion. Also addressed is the significance of increased blood PCT concentration, which may allow this molecule not only to act as a clinical biomarker but also as an active participant in the development and progression of infectious processes. Experimental approaches to delineate a better understanding of PCT functions, molecular pathways that modulate its expression and therapeutic opportunities to curtail its biological actions are discussed, as well.

Update on the critical care management of severe burns

Care of the severely injured patient with burn requires correct diagnosis, appropriately tailored resuscitation, and definitive surgical management to reduce morbidity and mortality. Currently, mortality rates related to severe burn injuries continue to steadily decline due to the standardization of a multidisciplinary approach instituted at tertiary health care centers. Prompt and accurate diagnoses of burn wounds utilizing Lund-Browder diagrams allow for appropriate operative and nonoperative management. Coupled with diagnostic improvements, advances in resuscitation strategies involving rates, volumes, and fluid types have yielded demonstrable benefits related to all aspects of burn care. More recently, identification of comorbid conditions such as inhalation injury and malnutrition have produced appropriate protocols that aid the healing process in severely injured patients with burn. As more patients survive larger burn injuries, the early diagnosis and successful treatment of secondary and tertiary complications are becoming commonplace. While advances in this area are exciting, much work to elucidate immune pathways, diagnostic tests, and effective treatment regimens still remain. This review will provide an update on the critical care management of severe burns, touching on accurate diagnosis, resuscitation, and acute management of this difficult patient population.

PCT as a diagnostic and prognostic tool in burn patients. Whether time course has a role in monitoring sepsis treatment

OBJECTIVE

To evaluate the diagnostic and prognostic performance of inflammatory markers for septic and non septic (localized) bacterial infections in patients with severe burn.

METHODS AND RESULTS

Data of 145 patients were prospectively included in this study. Serum procalcitonin and other inflammatory markers were measured within 24 h after burn and daily thereafter. Maximum procalcitonin (p=0.004) was independent predictors of outcome in logistic regression analysis. PCT thresholds of 1.5 ng/ml, 0.52 ng/ml and 0.56 ng/ml had adequate sensitivity and specificity to diagnose sepsis, respiratory tract and wound infections respectively. A threshold value of 7.8 ng/ml in PCT concentration on day 3 was associated with the effectiveness of the sepsis treatment with an AUC of 0.86 (95% CI 0.69-1.03, p=0.002). C-reactive protein levels and WBCs showed no significant change over the first 3 days in the patients with successfully treated sepsis (p=0.93).

CONCLUSION

The maximum procalcitonin level has prognostic value in burn patients. PCT can be used as a diagnostic tool in patients with infectious complications with or without bacteremia during ICU stay. Daily consecutive PCT measurements may be a valuable tool in monitoring the effectiveness of antibiotic therapy in burn ICU patients.

Sepsis in burns: a review of current practice and future therapies

Sepsis is a major cause of death worldwide and remains the subject of much research and debate within the critical care community. Despite advances in burn prevention, treatment, and rehabilitation, sepsis remains a common cause of death in patients who have sustained a severe burn injury. The unique physical, metabolic, and physiologic changes seen after major thermal injury mean that the management of sepsis in burns poses a particular challenge and differs in many respects to the management of sepsis in the general critical care population. This article describes current issues in the prevention, diagnosis, and treatment of sepsis in burns with a review of the associated literature. In addition, we discuss possible future therapies for managing this condition.