Procalcitonin: a valuable indicator of infection in a medical ICU?

Clinical usefulness of a host signature based on TRAIL, IP10, and CRP (MeMed BV) as infection biomarkers in intensive care units' patients. A retrospective observational study

INTRODUCTION

Infection complications are common in intensive care unit patients, and early detection remains a diagnostic challenge. Procalcitonin (PCT) and C-reactive protein (CRP) are commonly used biomarkers. A novel diagnostic approach focuses on the host immune response. One of the approaches, the MMBV index, is based on measuring in a blood sample three parameters: (i) tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), (ii) interferon-γ-induced protein-10 (IP10), and (iii) CRP. This study aimed to evaluate the usefulness of MMBV as an infection biomarker in an ICU cohort.

PATIENTS AND METHODS

Forty-six patients treated in the University Clinical Center in Gdansk ICU were enrolled in the study, and their clinical data were retrospectively analyzed. In total, 91 MMBV results were analyzed.

RESULTS

Most of the patients had high MMBV values, suggesting bacterial etiology. A weak correlation between PCT and MMBV was observed, and no correlation between parameter changes was noted. There was a correlation between CRP/MMBV and between changes in CRP / changes in MMBV.

CONCLUSION

It seems that MMBV is not valuable for ICU patients neither in diagnosing nor monitoring infection. Higher MMBV values may predict unfavorable treatment outcomes.

The Role of Mannose-Binding Lectin and Inflammatory Markers in Establishing the Course and Prognosis of Community-Acquired Pneumonia in Children

BACKGROUND

Community-acquired pneumonia (CAP) is one of the most significant childhood diseases worldwide and a leading infectious cause of death in children. This study aimed to evaluate the prognostic value of the inflammatory markers-C-reactive protein (CRP) and procalcitonin (PCT)-and the polymorphic glycoprotein mannose-binding lectin (MBL), deficiency of which is associated with severe infections, in the determination of the optimal type and timing of therapeutic intervention for CAP in childhood.

METHODS

Retrospective evaluation was conducted on a cohort of 204 children aged 4 months-17 years hospitalized with CAP. Their levels of CRP, PCT, and MBL were assessed for their association with a variety of outcomes, including the incidence of local and systemic complications, admission to the ICU, duration of antibiotic treatment and hospital stay, and death.

RESULTS

CRP and PCT proved to be better predictors of complications of CAP than MBL. The area under the curve (AUC) value was highest for PCT as a predictor of systemic complications (AUC = 0.931, 95%CI 0.895-0.967), while CRP (AUC = 0.674, 95%CI 0.586-0.761) performed best as a predictor of local complications (AUC = 0.674, 95%CI 0.586-0.761). Regarding admission to the ICU, CRP was the weakest predictor (AUC = 0.741), while PCT performed the best (AUC = 0.833), followed by MBL (AUC = 0.797). Sensitivity and specificity were calculated for the optimal threshold generated by receiver operating characteristic (ROC) curves, rendering sensitivity of 90% and specificity of 87% for PCT in assessing the risk of systemic complications, compared to sensitivity of 83% and specificity of 90% for CRP. MBL showed relatively high sensitivity (96%) but low specificity (25%) for predicting the need for ICU admission.

CONCLUSIONS

Early measurement of CRP, PCT, and MBL provides clinicians with important information regarding the course and prognosis of children diagnosed with CAP, thus ensuring prompt, optimal therapeutic management.

Serum Inflammatory Markers and Amputations in Hand Osteomyelitis: A Retrospective Review of 146 Cases

BACKGROUND

The diagnosis of hand osteomyelitis requires correlation of clinical, radiological, and microbiological findings. The role of serum inflammatory markers in diagnosing and prognosticating hand osteomyelitis remains uncertain. We sought to determine the utility of inflammatory markers in the diagnosis and follow-up of hand osteomyelitis, and their ability to predict outcomes, particularly amputation.

METHODS

We retrospectively reviewed 146 patients diagnosed with hand osteomyelitis and with serum inflammatory marker levels measured after the onset of symptoms and within 14 days either side of diagnosis. Blood results at first presentation including white cell count (WCC), neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and C-reactive protein (CRP) were reviewed, and associations with amputations assessed. Follow-up markers taken at 15 to 60 days from diagnosis were analyzed where available.

RESULTS

Mean WCC and CRP at diagnosis were 9.2 (SD: 4.6) and 30.2 (SD: 42.4) respectively, compared with 8.2 (SD: 3.9) and 30.2 (SD: 42.4) at follow-up. At diagnosis, sensitivity of CRP was 74%, and WCC was 31%. Each marker had a low positive predictive value for amputation at diagnosis (<29%). A rise in CRP between diagnosis and follow-up was associated with an increased risk of amputation compared with a fall in CRP. The finding that WCC and CRP were both normal at diagnosis had a high negative predictive value against amputation (96%).

CONCLUSION

C-reactive protein has a higher sensitivity than WCC, NLR, and PLR when used as a diagnostic adjunct in hand osteomyelitis. White cell count and CRP both within reference ranges at diagnosis was highly negatively predictive against amputation.

Monocyte distribution width (MDW) as a new tool for the prediction of sepsis in critically ill patients: a preliminary investigation in an intensive care unit

Background

Monocyte Distribution Width (MDW), a simple proxy marker of innate monocyte activation, can be used for the early recognition of sepsis along with Procalcitonin. This study explored the added value of MDW as an early predictor of ensuing sepsis in patients hospitalised in an Intensive Care Unit.

Methods

We performed an observational prospective monocentric study to estimate the analytical performance of MDW in detecting ensuing sepsis in a sample of consecutive patients assisted in an Intensive Care Unit for > 48 h for any reason. Demographic and clinical characteristics, past medical history and other laboratory measurements were included as potential predictors of confirmed sepsis in multivariate logistic regression.

Results

A total of 211 patients were observed, 129 of whom were included in the final sample due to the suspect of ensuing sepsis; of these, 74 (57%) had a confirmed diagnosis of sepsis, which was best predicted with the combination of MDW > 23.0 and PCT > 0.5 ng/mL (Positive Predictive Value, PPV: 92.6, 95% CI: 82.1–97.9). The best MDW cut-off to rule out sepsis was ≤20.0 (Negative Predictive Value, NPV: 86.4, 95% CI: 65.1–97.1). Multivariate analyses using both MDW and PCT found a significant association for MDW > 23 only (OR:17.64, 95% CI: 5.53–67.91).

Conclusion

We found that values of MDW > 23 were associated with a high PPV for sepsis, whereas values of MDW ≤ 20 were associated with a high NPV. Our findings suggest that MDW may help clinicians to monitor ICU patients at risk of sepsis, with minimal additional efforts over standard of care.

Mining of a Clinical Database: The Interpretation of Intense Serial Procalcitonin in the Prediction for Bloodstream Infection

Background: Procalcitonin (PCT) is a promising biomarker for predicting infection. Bloodstream infection (BSI) is usually a deteriorating stage of sepsis. The purpose of this study was to explore the predictive value of intense serial PCT assays for BSI in the intensive care unit (ICU). Methods: This study was a retrospective study based on a clinical database. We analyzed the data of critically ill patients from February 2016 to May 2020. The patients who received PCT assays and blood cultures (BCs) were classified into four groups according to the BCs: (i) BC negative, (ii) bacteria positive, (iii) fungi-positive, and (iv) combined-positive, and the patients with bacteremia were further subdivided into Gram+ and Gram- bacteremia. Results: The database included 11,219 patients. There were 3,593 patients who met the criteria for the analysis. The PCT concentration differed significantly across BC groups (p < 0.0001). The fluctuation of PCT significantly increased in the BC positive groups (p < 0.0001). According to the receiver operating characteristic (ROC), the optimum cutoff of the fluctuation of PCT was around 8 ng/ml for predicting BSI. Conclusion: Our study indicated that the fluctuation of PCT could be an indicator for screening BSI, but less accurate for Gram-positive infections. With a fluctuation of PCT less than 8 ng/ml, BSI should not be a rational cause for sepsis exacerbating.

Jaundice in patients with COVID-19

BACKGROUND AND AIM

While many studies have reported on liver injury in patients with coronavirus disease 2019 (COVID-19), none have specifically addressed the significance of hepatic jaundice. We aimed to determine the clinical consequences and etiologies of jaundice in patients with COVID-19.

METHODS

We retrospectively analyzed clinical features, laboratory abnormalities, and rates of survival and intensive care unit admission in 551 patients with COVID-19, hospitalized between 1 March 2020, and 31 May 2020 at a tertiary care academic medical center. Hepatic jaundice was defined as a serum total bilirubin concentration >2.5 mg/dL and a direct bilirubin concentration >0.3 mg/dL that was >25% of the total. Liver injury was characterized as cholestatic, mixed, or hepatocellular at the time of peak serum total bilirubin concentration by calculating the R factor.

RESULTS

Hepatic jaundice was present in 49 (8.9%) patients and associated with a mortality rate of 40.8% and intensive care unit admission rate of 69.4%, both significantly higher than for patients without jaundice. Jaundiced patients had an increased frequency of fever, leukopenia, leukocytosis, thrombocytopenia, hypotension, hypoxemia, elevated serum creatinine concentration, elevated serum procalcitonin concentration, and sepsis. Nine jaundiced patients had isolated hyperbilirubinemia. Of the 40 patients with abnormally elevated serum alanine aminotransferase or alkaline phosphatase activities, 62.5% had a cholestatic, 20.0% mixed, and 17.5% hepatocellular pattern of liver injury.

CONCLUSION

Hepatic jaundice in patients with COVID-19 is associated with high mortality. The main etiologies of liver dysfunction leading to jaundice appear to be sepsis, severe systemic inflammation, and hypoxic/ischemic hepatitis.

Diagnostic value of neutrophil CD64, procalcitonin, and interleukin-6 in sepsis: a meta-analysis

Background

The aim of the study was to conduct a meta-analysis to evaluate the accuracy of neutrophil CD64, procalcitonin (PCT), and interleukin-6 (IL-6) as markers for the diagnosis of sepsis in adult patients.

Methods

Various databases were searched to collect published studies on the diagnosis of sepsis in adult patients using neutrophil CD64, PCT, and IL-6 levels. Utilizing the Stata SE 15.0 software, forest plots and the area under the summary receiver operating characteristic curves were drawn. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the curve (AUC) were calculated.

Results

Fifty-four articles were included in the study. The pooled sensitivity, specificity, and AUC of neutrophil CD64 for the diagnosis of sepsis were 0.88 (95% confidence interval [CI], 0.81–0.92), 0.88 (95% CI, 0.83–0.91), and 0.94 (95% CI, 0.91–0.96), respectively. The pooled sensitivity, specificity, and AUC of PCT for the diagnosis of sepsis were 0.82 (95% CI, 0.78–0.85), 0.78 (95% CI, 0.74–0.82), and 0.87 (95% CI, 0.83–0.89), respectively. Subgroup analysis showed that the AUC for PCT diagnosis of intensive care unit (ICU) sepsis was 0.86 (95% CI, 0.83–0.89) and the AUC for PCT diagnosis of non-ICU sepsis was 0.82 (95% CI, 0.78–0.85). The pooled sensitivity, specificity, and AUC of IL-6 for the diagnosis of sepsis were 0.72 (95% CI, 0.65–0.78), 0.70 (95% CI, 0.62–0.76), and 0.77 (95% CI, 0.73–0.80), respectively.

Conclusions

Of the three biomarkers studied, neutrophil CD64 showed the highest diagnostic value for sepsis, followed by PCT, and IL-6. On the other hand, PCT showed a better diagnostic potential for the diagnosis of sepsis in patients with severe conditions compared with that in patients with non-severe conditions.

Procalcitonin in clinical practice: from diagnosis of sepsis to antibiotic therapy

A diagnostic algorithm that allows for the rapid identification of sepsis and possibly guides the appropriate antimicrobial therapy application is the cornerstone to obtaining effective treatment and better results. The use of emerging surrogate markers could significantly improve clinical practice, but the validity and clinical utility have been proved only for very few of them, and their availability in clinical routine is limited. For this purpose, numerous scientific evidence has indicated procalcitonin as a marker linked to sepsis and its evolution. This review aims to retrace the main evidence relating to the use of procalcitonin in sepsis. We analyzed the primary studies in the literature and the existing meta-analysis evaluating the behavior of procalcitonin as a marker of bacterial sepsis, its prognostic power, and its ability to influence antibiotic therapy. Recent evidence has suggested that procalcitonin could be an efficient marker for diagnosing sepsis and its therapeutic management in many types of patients. The choice of the appropriate timing to initiate and suspend antibiotic therapy, with obvious clinical advantages, the favorable effects could also include reducing health costs, both avoiding the administration of inappropriate antibiotic therapies, and reducing the duration of hospitalization. Moreover, limited studies reported high procalcitonin levels in coronavirus disease 2019 patients with a worse prognosis. Despite the considerable evidence in favor of the potential of procalcitonin as an index for managing septic patients, there are conflicting data that deserve specific and detailed studies.

Serum procalcitonin as a biomarker for differentiating between infectious and non-infectious fever after pancreas transplantation

Laboratory biomarkers that can differentiate non-infectious fever from infectious fever after pancreas transplantation have yet to be discovered. Non-infectious fever was defined as the presence of fever (>38.3°C) in the absence of a documented clinical diagnosis of infection or a positive culture. Among 184 consecutive recipients, a total of 91 recipients developed fever within 1-month post-transplant, of whom 46 had infectious fever and 45 had non-infectious fever at our center between August 2014 and July 2019. The onset of fever was earlier in the non-infectious fever group (14.4 ± 3.7 post-transplant days) compared with the infectious fever group (16.5 ± 5.8 post-transplant days; p = .033). Multivariate analysis showed that serum procalcitonin at the peak of fever could significantly differentiate infectious fever from non-infectious fever (OR 53.378, 95% CI: 6.819-417.802, p < .001). The area under the curve for differentiating between the two groups was 0.853 (95% CI, 0.780-0.926) for procalcitonin and 0.667 (95% CI, 0.549-0.785) for CRP. The best cutoff values of serum procalcitonin and CRP were 0.405 ng/ml (sensitivity, 77.1%; specificity, 80.8%) and 7.355 mg/dl (sensitivity, 66.7%; specificity, 67.3%), respectively. Serum procalcitonin may be useful for differentiating non-infectious fever from infectious fever after pancreas transplantation.

A randomized trial to compare procalcitonin and C-reactive protein in assessing severity of sepsis and in guiding antibacterial therapy in Egyptian critically ill patients

BACKGROUND

Procalcitonin (PCT) and C-reactive protein (CRP) are the main used biomarkers for sepsis and in guiding antibiotic therapy, although PCT high cost limits its use in developing countries.

OBJECTIVE

Comparing between PCT and CRP in assessing severity of sepsis and in guiding antibacterial therapy in critically ill patients.

METHODS

In a prospective randomized study, 60 patients were included from an Egyptian Intensive Care Unit. Patients were divided into CRP and PCT groups. CRP and PCT were measured at baseline and on days 4 and 7. Validity, sensitivity, and specificity of both biomarkers and their correlation with sepsis scores (Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sepsis-related Organ Failure Assessment (SOFA)) were evaluated. Antibacterial continuation at days 4 and 7 was assessed.

RESULTS

The diagnostic accuracy, specificity, and sensitivity of PCT were higher than CRP (80.79% vs 69.45%, 36% vs 28.7%, 87.6% vs 72.4%, respectively). PCT levels were significantly correlated with APACHE II score (P ≤ 0.0001) and SOFA score (P = 0.005), while CRP levels were not correlated with APACHEII and SOFA scores,(P > 0.05). PCT was associated with less antibacterial exposure (33% stopped their antibiotics on day 4 versus 6% in CRP, P = 0.009). Only 33% continued their antibacterial regimen in PCT group after 7 days versus 83% in CRP group (*P ≤ 0.0001).

CONCLUSION

PCT is a more accurate diagnostic and prognostic biomarker than CRP in patients with sepsis. PCT significantly shortened patients' exposure to antibacterial therapy and hospital length of stay.

The Use of Serum Procalcitonin in the Setting of Infected Ureteral Stones: A Prospective Observational Study

Introduction: Infected ureteral stones are a urologic emergency and require urgent decompression. We set out to determine whether serum procalcitonin (PCT) could aid in the diagnosis of infected ureteral stones. Methods: All consecutive patients presenting to the emergency room from November 9, 2016, to November 10, 2018, with an obstructing ureteral stone were included. All patients had complete blood count, urinalysis (UA), PCT, and urine culture (UCx). Subgroup analysis was performed in a "clinically equivocal" cohort of afebrile patients defined as a leukocytosis >10⁴/μL and UA with <50 white blood cells (WBCs) per high powered field (hpf). Patients with positive and negative UCx were compared. Results: A total of 231 patients were included, of whom 56 had a positive UCx. Of all covariates, UA WBCs with a cutoff of 9 per hpf performed best at predicting positive UCx with an area under the curve (AUC) of 0.87. PCT did not perform as well with an ideal cutoff of 0.08 ng/mL, having an AUC of 0.77, sensitivity 70.6%, specificity 73.9%, positive predictive value (PPV) 34.3%, and negative predictive value (NPV) 92.9%. When looking at the clinically equivocal cohort, UA WBCs with a cutoff of 6 per hpf appeared to perform best at predicting a positive UCx with an AUC of 0.72. PCT was less predictive in this cohort with an ideal cutoff of 0.3 ng/mL, having an AUC of 0.32, sensitivity 47.1%, specificity 85.2%, PPV 38.1%, and NPV 89.3%. Conclusion: PCT does not appear to be a superior marker for diagnosing urinary tract infection in the setting of obstructing ureterolithiasis when compared with components of the standard work-up.

Diagnostic Accuracy of Immunologic Biomarkers for Accurate Diagnosis of Bloodstream Infection in Patients with Malignancy: Procalcitonin in Comparison with C-Reactive Protein

Purpose

To calculate the diagnostic value of C-reactive protein (CRP) and serum procalcitonin (PCT) levels for the pathologic presence of microbes in the bloodstream of patients with malignancy, in comparison with blood culture. Methodology. Blood culture (by reference method) and assay results of PCT and CRP of febrile patients, with clinical suspicion to blood infections, were collected. Statistical aspects of PCT  and CRP tests were evaluated.

Results

Data from 255 cases were gathered. The area under the curve for differentiating bacteremia from nonbacteremia for PCT (0.741) was superior to that of CRP (0.612). Amongst the different cutoffs of PCT and CRP, the cutoff of ≥1.17 ng/ml and >47 mg/l had the sensitivity of 75 and 58.3%, the best NPV of 91.5% and 81.3%, and the best specificity of 79.9% and 72.8%, respectively. Discussion. Despite statistically nonsignificant results, PCT seems to be a superior indicator to CRP for rejecting the presence of microorganism in bloodstream. For PCT, the cutoff value of 1.17 ng/ml (bacteremia from nonbacteremia) had the highest NPV value of 91.5% in malignant patients, suspicion of sepsis.

Specific Patterns of Postoperative Temperature Elevations Predict Blood Infection in Pediatric Burn Patients

Using readily available temperature data, we seek to propose a scoring criteria that can facilitate accurate and immediate prediction of blood infection. The standard in diagnosing blood infection is a positive blood culture result that may take up to 3 days to process, requiring providers to make a prediction about which febrile patient is actually bacteremic. This prediction is difficult in burned children as systemic inflammation can cause fever in the absence of infection. An ability to make this prediction more accurate using readily available information would be useful. A retrospective chart review was performed for 28 pediatric patients, with a burn size 20% or greater, admitted to the burn unit between 2010 and 2014. All children had blood cultures drawn. They were divided into either infection (positive blood cultures) or control (negative blood cultures) groups. Median temperature and mean number of temperature elevations were compared between the two groups. We evaluated the predictive accuracy of using temperature elevation, pattern, and timing to predict blood infection. A significant difference was seen in the mean number of temperature elevations above 39°C. This was significant for each time stage, especially in the 0- to 24-hour post-surgery period. We found the most predictive accuracy in the 0- to 12-, 12- to 38-, and 12- to 48-hour time periods. We found a strong association between mean number of fever spikes above 39°C and blood infection, especially 12 to 24 hours after surgery. This readily available data can be useful to clinicians as they access children with burns.

Bacterial sepsis : Diagnostics and calculated antibiotic therapy

The mortality of patients with sepsis and septic shock is still unacceptably high. An effective calculated antibiotic treatment within 1 h of recognition of sepsis is an important target of sepsis treatment. Delays lead to an increase in mortality; therefore, structured treatment concepts form a rational foundation, taking relevant diagnostic and treatment steps into consideration. In addition to the assumed infection and individual risks of each patient, local resistance patterns and specific problem pathogens must be taken into account during the selection of anti-infective treatment. Many pathophysiologic alterations influence the pharmacokinetics (PK) of antibiotics during sepsis. The principle of standard dosing should be abandoned and replaced by an individual treatment approach with stronger weighting of the pharmacokinetics/pharmacodynamics (PK/PD) index of the substance groups. Although this is not yet the clinical standard, prolonged (or continuous) infusion of β‑lactam antibiotics and therapeutic drug monitoring (TDM) can help to achieve defined PK targets. Prolonged infusion is sufficient without TDM, but for continuous infusion, TDM is generally necessary. A further argument for individual PK/PD-oriented antibiotic approaches is the increasing number of infections due to multidrug-resistant (MDR) pathogens in the intensive care unit. For effective treatment, antibiotic stewardship teams (ABS teams) are becoming more established. Interdisciplinary cooperation of the ABS team with infectious disease (ID) specialists, microbiologists, and clinical pharmacists leads not only to rational administration of antibiotics, but also has a positive influence on treatment outcome. The gold standards for pathogen identification are still culture-based detection and microbiologic resistance testing for the various antibiotic groups. Despite the rapid investigation time, novel polymerase chain reaction(PCR)-based procedures for pathogen identification and resistance determination are currently only an adjunct to routine sepsis diagnostics, due to the limited number of studies, high costs, and limited availability. In complicated septic courses with multiple anti-infective therapies or recurrent sepsis, PCR-based procedures can be used in addition to treatment monitoring and diagnostics. Novel antibiotics represent potent alternatives in the treatment of MDR infections. Due to the often defined spectrum of pathogens and the practically (still) absent resistance, they are suitable for targeted treatment of severe MDR infections (therapy escalation). (Contribution available free of charge by "Free Access" [ https://link.springer.com/article/10.1007/s00101-017-0396-z ].).

Procalcitonin: A Marker of Bacteraemia in SIRS

A number of European studies have documented the ability of procalcitonin (PCT), a novel inflammatory marker, to discriminate patients with sepsis from those with other causes of systemic inflammatory response syndrome (SIRS). The aim of this study was to assess procalcitonin's performance in an Australian intensive care unit (ICU) setting to examine whether it could discriminate between these two conditions.

One hundred and twenty-three consecutive adult ICU patients fulfilling criteria for SIRS were enlisted in the study. Over a period of five days, daily serum PCT and C-reactive protein (CRP) levels were measured. At least two sets of cultures were taken of blood, sputum/broncho-alveolar lavage (BAL) and urine. Other cultures were taken as clinically indicated. Questionnaires to ascertain clinical suspicion of sepsis were prospectively answered by the ICU senior registrars.

PCT values were ten times higher in patients with positive blood cultures; CRP values were also significantly higher in the bacteraemic patients. Both PCT and CRP had a good ability to discriminate bacteraemia from non-infectious SIRS, with the area under receiver operating characteristics (ROC) curves for PCT being 0.8 and for CRP being 0.82. However neither PCT or CRP was able to discriminate patients with localized sepsis from those without. Utilizing both tests resulted in a more sensitive screen than either one alone, while PCT was a more accurate diagnostic test for bacteraemia than CRP. The PCT value also differed between those who died in hospital and those who survived.

Measurement of PCT alone or in combination with CRP can aid discrimination of septicaemia/bacteraemia with associated SIRS from non-infectious SIRS in an Australian ICU setting.

[Bacterial sepsis : Diagnostics and calculated antibiotic therapy]

The mortality of patients with sepsis and septic shock is still unacceptably high. An effective antibiotic treatment within 1 h of recognition of sepsis is an important target of sepsis treatment. Delays lead to an increase in mortality; therefore, structured treatment concepts form a rational foundation, taking relevant diagnostic and treatment steps into consideration. In addition to the assumed focus and individual risks of each patient, local resistance patterns and specific problem pathogens must be taken into account for selection of anti-infection treatment. Many pathophysiological alterations influence the pharmacokinetics of antibiotics during sepsis. The principle of standard dosing should be abandoned and replaced by an individual treatment approach with stronger weighting of the pharmacokinetics/pharmacodynamics (PK/PD) index of the substance groups. Although this is not yet the clinical standard, prolonged (or continuous) infusion of beta-lactam antibiotics and therapeutic drug monitoring (TDM) can help to achieve defined PK targets. Prolonged infusion is sufficient without TDM but for continuous infusion TDM is basically necessary. A further argument for individual PK/PD-oriented antibiotic approaches is the increasing number of infections due to multidrug resistant pathogens (MDR) in the intensive care unit. For effective treatment antibiotic stewardship teams (ABS team) are becoming more established. Interdisciplinary cooperation of the ABS team with infectiologists, microbiologists and clinical pharmacists leads not only to a rational administration of antibiotics but also has a positive influence on the outcome. The gold standards for pathogen detection are still culture-based detection and microbiological resistance testing for the various antibiotic groups. Despite the rapid investigation time, novel polymerase chain reaction (PCR)-based procedures for pathogen identification and resistance determination, are currently only an adjunct to routine sepsis diagnostics due to the limited number of studies, high costs and limited availability. In complicated septic courses with multiple anti-infective treatment or recurrent sepsis, PCR-based procedures can be used in addition to therapy monitoring and diagnostics. Novel antibiotics represent potent alternatives in the treatment of MDR infections. Due to the often defined spectrum of pathogens and the practically absent resistance, they are suitable for targeted treatment of severe MDR infections (therapy escalation).

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.

Diagnostic accuracy of procalcitonin, neutrophil-lymphocyte count ratio, C-reactive protein, and lactate in patients with suspected bacterial sepsis

Background

Early recognition is a key factor to achieve improved outcomes for septic patients. Combinations of biomarkers, as opposed to single ones, may improve timely diagnosis and survival. We investigated the performance characteristics of sepsis biomarkers, alone and in combination, for diagnosis of verified bacterial sepsis using Sepsis-2 and Sepsis-3 criteria, respectively.

Methods

Procalcitonin (PCT), neutrophil-lymphocyte count ratio (NLCR), C-reactive protein (CRP), and lactate were determined in a total of 1,572 episodes of adult patients admitted to the emergency department on suspicion of sepsis. All sampling were performed prior to antibiotic administration. Discriminant analysis was used to construct two composite biomarkers consisting of linear combinations of the investigated biomarkers, one including three selected biomarkers (i.e., NLCR, CRP, and lactate), and another including all four (i.e., PCT, NLCR, CRP, and lactate). The diagnostic performances of the composite biomarkers as well as the individual biomarkers were compared using the area under the receiver operating characteristic curve (AUC).

Results

For diagnosis of bacterial sepsis based on Sepsis-3 criteria, the AUC for PCT (0.68; 95% CI 0.65–0.71) was comparable to the AUCs for the both composite biomarkers. Using the Sepsis-2 criteria for bacterial sepsis diagnosis, the AUC for the NLCR (0.68; 95% CI 0.65–0.71) but not for the other single biomarkers, was equal to the AUCs for the both composite biomarkers. For diagnosis of severe bacterial sepsis or septic shock based on the Sepsis-2 criteria, the AUCs for both composite biomarkers were significantly greater than those of the single biomarkers (0.85; 95% CI 0.82–0.88 for the composite three-biomarker, and 0.86; 95% CI 0.83–0.89 for the composite four-biomarker).

Conclusions

Combinations of biomarkers can improve the diagnosis of verified bacterial sepsis in the most critically ill patients, but in less severe septic conditions either the NLCR or PCT alone exhibit equivalent performance.

Procalcitonin determined at emergency department as na early indicator of progression to septic shock in patient with sepsis associated with ureteral calculi

Introduction:

To investigate the role of initial procalcitonin (PCT) level as an early predictor of septic shock for the patient with sepsis induced by acute pyelonephritis (APN) secondary to ureteral calculi.

Materials and Methods:

The data from 49 consecutive patients who met criteria of sepsis due to APN following ureteral stone were collected and divided into two groups: with (n=15) or without (n=34) septic shock. The clinical variables including PCT level for this outcome were retrospectively compared by univariate analysis, followed by multivariable logistic regression model.

Results:

All subjects had hydronephrosis, and were hospitalized with the mean of 11.8 days (3–42 days). The mean size of the ureteral stones was 7.5mm (3–30mm), and 57% were located in upper ureter. At univariate analysis, patients with septic shock were significantly older, a higher proportion had hypertension, lower platelet count and serum albumin level, higher CRP and PCT level, and higher positive blood culture rate. Multivariate models indicated that lower platelet count and higher PCT level are independent risk factors (p=0.043 and 0.046, respectively). In ROC curve, the AUC was significantly wider in PCT (0.929), compared with the platelet count (0.822, p=0.004). At the cut-off of 0.52ng/mL, the sensitivity and specificity were 86.7% and 85.3%.

Conclusion:

Our study demonstrated elevated initial PCT levels as an early independent predictor to progress into septic shock in patients with sepsis associated with ureteral calculi.

Biomarkers for diagnosis of sepsis in patients with systemic inflammatory response syndrome: a systematic review and meta-analysis

Background

Sepsis is one of the most common diseases that seriously threaten human health. Although a large number of markers related to sepsis have been reported in the last two decades, the diagnostic accuracy of these biomarkers remains unclear due to the lack of similar baselines among studies. Therefore, we conducted a large systematic review and meta-analysis to evaluate the diagnostic value of biomarkers from studies that included non-infectious systemic inflammatory response syndrome patients as a control group.

Methods

We searched Medline, Embase and the reference lists of identified studies beginning in April 2014. The last retrieval was updated in September 2016.

Results

Ultimately, 86 articles fulfilled the inclusion criteria. Sixty biomarkers and 10,438 subjects entered the final analysis. The areas under the receiver operating characteristic curves for the 7 most common biomarkers, including procalcitonin, C-reactive protein, interleukin 6, soluble triggering receptor expressed on myeloid cells-1, presepsin, lipopolysaccharide binding protein and CD64, were 0.85, 0.77, 0.79, 0.85, 0.88, 0.71 and 0.96, respectively. The remaining 53 biomarkers exhibited obvious variances in diagnostic value and methodological quality.

Conclusions

Although some biomarkers displayed moderate or above moderate diagnostic value for sepsis, the limitations of the methodological quality and sample size may weaken these findings. Currently, we still lack an ideal biomarker to aid in the diagnosis of sepsis. In the future, biomarkers with better diagnostic value as well as a combined diagnosis using multiple biomarkers are expected to solve the challenge of the diagnosis of sepsis.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-016-3591-5) contains supplementary material, which is available to authorized users.

The role of C-reactive protein as a diagnostic predictor of sepsis in a multidisciplinary Intensive Care Unit of a tertiary care center in Nepal

Aim:

C-reactive protein (CRP) is a commonly used biomarker of sepsis, the leading cause of mortality in Intensive Care Units (ICUs). However, sufficient data are still lacking to strongly recommend it in clinical practice. The present study is aimed to find out its reliability in diagnosing sepsis.

Materials and Methods:

CRP was measured in ICU-admitted patients with systemic inflammatory response syndrome and compared using a cutoff of 50 mg/L with the gold standard for diagnosing sepsis, taken as isolation of organism from a suspected source of infection or the Centers for Disease Control criteria for clinical sepsis.

Results:

CRP had a sensitivity and specificity of 84.3% and 46.15%, respectively. Area under the receiver operating characteristics curve was calculated to be 0.683 (±0.153, P < 0.05). The cutoff value with the best diagnostic accuracy was found to be 61 mg/L.

Conclusion:

CRP is a sensitive marker of sepsis, but it is not specific.

Heart rate time series characteristics for early detection of infections in critically ill patients

It is difficult to make a distinction between inflammation and infection. Therefore, new strategies are required to allow accurate detection of infection. Here, we hypothesize that we can distinguish infected from non-infected ICU patients based on dynamic features of serum cytokine concentrations and heart rate time series. Serum cytokine profiles and heart rate time series of 39 patients were available for this study. The serum concentration of ten cytokines were measured using blood sampled every 10 min between 2100 and 0600 hours. Heart rate was recorded every minute. Ten metrics were used to extract features from these time series to obtain an accurate classification of infected patients. The predictive power of the metrics derived from the heart rate time series was investigated using decision tree analysis. Finally, logistic regression methods were used to examine whether classification performance improved with inclusion of features derived from the cytokine time series. The AUC of a decision tree based on two heart rate features was 0.88. The model had good calibration with 0.09 Hosmer-Lemeshow p value. There was no significant additional value of adding static cytokine levels or cytokine time series information to the generated decision tree model. The results suggest that heart rate is a better marker for infection than information captured by cytokine time series when the exact stage of infection is not known. The predictive value of (expensive) biomarkers should always be weighed against the routinely monitored data, and such biomarkers have to demonstrate added value.

Procalcitonin-guided antibiotic therapy for septic patients in the surgical intensive care unit

In critically ill patients, elucidating those patients with the systemic inflammatory response syndrome (SIRS) from an infectious source (sepsis), versus those who have SIRS without infection, can be challenging since the clinical features are the same.

Even with strict monitoring and testing, 39–98 % of patients with SIRS will never have bacteriological confirmation of an infection, and 6–17 % of patients with a documented infection will not show signs of SIRS. Due to this overlap, an extensive amount of research has been performed to investigate ways of determining and separating SIRS from infection, compared to SIRS due to trauma, surgical stress, or other non-infectious causes. This review article will discuss the recommended and peer-approved use of procalcitonin in septic patients in the intensive care unit and its use as a guide to antibiotic initiation and termination. The article will focus on the prospective randomized trials (Level 1 evidence) that have been conducted, and lesser levels of evidence will be referenced as needed to substantiate a conclusion.

The literature documents multiple benefits of using procalcitonin as a guide to cost savings and appropriate termination of antibiotics by its use as a new objective marker of bacteremia that was previously not available. This article will show that antibiotics should be terminated when the procalcitonin level falls below 0.5 ng/mL.

Use of a Combination Biomarker Algorithm To Identify Medical Intensive Care Unit Patients with Suspected Sepsis at Very Low Likelihood of Bacterial Infection

Sepsis remains a diagnostic challenge in the intensive care unit (ICU), and the use of biomarkers may help in differentiating bacterial sepsis from other causes of systemic inflammatory syndrome (SIRS). The goal of this study was to assess test characteristics of a number of biomarkers for identifying ICU patients with a very low likelihood of bacterial sepsis. A prospective cohort study was conducted in a medical ICU of a university hospital. Immunocompetent patients with presumed bacterial sepsis were consecutively enrolled from January 2012 to May 2013. Concentrations of nine biomarkers (α-2 macroglobulin, C-reactive protein [CRP], ferritin, fibrinogen, haptoglobin, procalcitonin [PCT], serum amyloid A, serum amyloid P, and tissue plasminogen activator) were determined at baseline and at 24 h, 48 h, and 72 h after enrollment. Performance characteristics were calculated for various combinations of biomarkers for discrimination of bacterial sepsis from other causes of SIRS. Seventy patients were included during the study period; 31 (44%) had bacterial sepsis, and 39 (56%) had other causes of SIRS. PCT and CRP values were significantly higher at all measured time points in patients with bacterial sepsis. A number of combinations of PCT and CRP, using various cutoff values and measurement time points, demonstrated high negative predictive values (81.1% to 85.7%) and specificities (63.2% to 79.5%) for diagnosing bacterial sepsis. Combinations of PCT and CRP demonstrated a high ability to discriminate bacterial sepsis from other causes of SIRS in medical ICU patients. Future studies should focus on the use of these algorithms to improve antibiotic use in the ICU setting.

What was old is new again: using the host response to diagnose infectious disease

A century of advances in infectious disease diagnosis and treatment changed the face of medicine. However, challenges continue to develop including multi-drug resistance, globalization that increases pandemic risks and high mortality from severe infections. These challenges can be mitigated through improved diagnostics, focusing on both pathogen discovery and the host response. Here, we review how 'omics' technologies improve sepsis diagnosis, early pathogen identification and personalize therapy. Such host response diagnostics are possible due to the confluence of advanced laboratory techniques (e.g., transcriptomics, metabolomics, proteomics) along with advanced mathematical modeling such as machine learning techniques. The road ahead is promising, but obstacles remain before the impact of such advanced diagnostic modalities is felt at the bedside.

Efficacy of measuring procalcitonin levels in determination of prognosis and early diagnosis of bacterial resistance in sepsis

Background:

Rapid and proper diagnosis of sepsis is one of the daily challenges of emergency department (ED) and intensive care units. The general aim of the present study was to determine the efficacy of measuring procalcitonin levels in the early diagnosis of bacterial resistance to antibiotics administered empirically in patients with sepsis.

Materials and Methods:

The present cross-sectional study consisted of patients with clinical evidence of sepsis or systemic inflammatory response syndrome (SIRS), referring to the ED of a third-level hospital in Tehran, Iran in 2012. After collection of basic and clinical data of patients, venous blood samples were taken for routine laboratory tests and determination of procalcitonin serum levels at baseline and 6 and 24 hours after administration of the first dose of an empirical antibiotic. The subjects were divided into two groups of discharged and expired and then comparisons were made using t-test, Chi-squared test and Fisher's test. Specificity and sensitivity of procalcitonin were evaluated along with ROC curve.

Results:

In the present study, 170 patients with sepsis were included. Evaluation of serum levels of procalcitonin 24 hours after administration of antibiotics exhibited the best sensitivity and specificity for each patient's response to antibiotics. Use of the cutoff point of 6.5 mg/mL for procalcitonin can predict the disease outcome with sensitivity and specificity of 67% and 80%, respectively.

Conclusion:

It is suggested that procalcitonin be used for the diagnosis of sepsis or SIRS resulting from an infectious disease, for follow-up of treatment and for evaluation of response to treatment.

Procalcitonin versus C-reactive protein: Usefulness as biomarker of sepsis in ICU patient

Background:

Early diagnosis and appropriate therapy of sepsis is a daily challenge in intensive care units (ICUs) despite the advances in critical care medicine. Procalcitonin (PCT); an innovative laboratory marker, has been recently proven valuable worldwide in this regard.

Objectives:

This study was undertaken to evaluate the utility of PCT in a resource constrained country like ours when compared to the traditional inflammatory markers like C - reactive protein (CRP) to introduce PCT as a routine biochemical tool in regional hospitals.

Materials and Methods:

PCT and CRP were simultaneously measured and compared in 73 medico-surgical ICU patients according to the American College of Chest Physicians (ACCP) criteria based study groups.

Results:

The clinical presentation of 75% cases revealed a range of systemic inflammatory responses (SIRS). The diagnostic accuracy of PCT was higher (75%) with greater specificity (72%), sensitivity (76%), positive and negative predictive values (89% and 50%), positive likelihood ratio (2.75) as well as the smaller negative likelihood ratio (0.33). Both serum PCT and CRP values in cases with sepsis, severe sepsis and septic shock were significantly higher from that of the cases with SIRS and no SIRS (P < 0.01).

Conclusion:

PCT is found to be superior to CRP in terms of accuracy in identification and to assess the severity of sepsis even though both markers cannot be used in differentiating infectious from noninfectious clinical syndrome.

C-reactive protein and lung diseases

C-reactive protein (CRP), a member of the pentraxin family of plasma proteins, is one of the most distinctive acute phase reactants. In response to inflammation, cell damage or tissue injury, plasma level of CRP rapidly and dramatically increases up to 1000-fold, a phenomenon that has been used for years to monitor infections and many destructive/inflammatory conditions. The magnitude of CRP increase usually correlates with the severity of injury or inflammation and reflects an important physiological role of this interesting but still under-investigated protein. It is now generally accepted that CRP is involved in host defense and inflammation. However, the exact function of this protein in health and disease remains unclear. Many studies have demonstrated that in different pathophysiological conditions CRP might be involved in the regulation of lung function and may participate in the pathogenesis of various pulmonary disorders. The fluctuation of CRP concentrations in both alveolar fluid and serum associated with different pulmonary diseases suggests its important role in lung biology. Discussion of the still controversial functions of CRP in lung physiology and diseases is the main focus of this review.

Measuring both procalcitonin and C-reactive protein for a diagnosis of sepsis in critically ill patients

BACKGROUND

The usefulness of procalcitonin (PCT) and C-reactive protein (CRP) as individual biomarkers, and in combination, for the identification of infections in a critically ill patient cohort was evaluated retrospectively.

METHODS

Best cut-off values for PCT and CRP for a diagnosis of sepsis in critically ill patients were determined using receiver operator characteristic (ROC) curve analysis. Both combined tests and individual tests were performed for PCT and CRP, with positive and negative results recorded, and accuracy evaluated using odds ratios (OR).

RESULTS

In the 55 critically ill patients studied, the best cut-off value for PCT for a diagnosis of sepsis was 1.1 ng/ml (sensitivity, specificity and negative predictive values [NPV] were 82%, 68% and 71%, respectively). In addition, the best cut-off value for CRP was 50.7 mg/l ( sensitivity, specificity and NPV of 90%, 68% and 83%, respectively). Measuring PCT and CRP in combination provided a sensitivity of 79%, a specificity of 86%, and a positive predictive value (PPV) of 90%. Diagnostic OR for the combination of biomarkers versus CRP alone (19 and 18, respectively) were greater than that for PCT (9).

CONCLUSION

For critically ill patients, CRP and CRP in combination with PCT were found to be suitable biomarkers for diagnosing sepsis, based on their NPV and PPV.

Biomarkers of sepsis

Sepsis remains a leading cause of death in critically ill patients, despite efforts to improve patient outcome. Thus far, no magic drugs exist for severe sepsis and septic shock. Instead, early diagnosis and prompt initial management such as early goal-directed therapy are key to improve sepsis outcome. For early detection of sepsis, biological markers (biomarkers) can help clinicians to distinguish infection from host response to inflammation. Ideally, biomarkers can be used for risk stratification, diagnosis, monitoring of treatment responses, and outcome prediction. More than 170 biomarkers have been identified as useful for evaluating sepsis, including C-reactive protein, procalcitonin, various cytokines, and cell surface markers. Recently, studies have reported on the usefulness of biomarker-guided antibiotic stewardships. However, the other side of these numerous biomarkers is that no novel single laboratory marker can diagnose, predict, and track the treatment of sepsis. The purpose of this review is to summarize several key biomarkers from recent sepsis studies.

The efficacy of procalcitonin as a biomarker in the management of sepsis: slaying dragons or tilting at windmills?

BACKGROUND

Sepsis is defined as systemic inflammatory response syndrome (SIRS) in the context of an underlying infectious process, and is associated with high rates of morbidity and mortality, particularly when initial therapy is delayed. Numerous biomarkers, including but not limited to cytokines (interleukins-2 and -6 [IL-2, IL-6] and tumor necrosis factor-α [TNF-α]), leukotrienes, acute-phase proteins (C-reactive protein [CRP]), and adhesion molecules, have been evaluated and rejected as unsuitable for the diagnosis of sepsis, predicting its severity, and guiding its treatment. Most recently, procalcitonin (PCT) has been suggested as a novel biomarker that may be useful in guiding therapeutic decision making in the management of sepsis. This article assesses critically the published literature on the clinical utility of PCT concentrations for guiding the treatment of sepsis in adult patients.

METHODS

A comprehensive search of all published studies of the use of serum concentrations of PCT to guide the treatment of sepsis in adult patients (1996 to 2011) was conducted with PubMed and Google Scholar. The search focused on the value of PCT concentrations to guide the diagnosis, prognosis, monitoring, and escalation and de-escalation of antbiotic therapy in these patients. Keywords searched included "procalcitonin," "sepsis," "sepsis biomarker," "sepsis diagnosis," "sepsis prognosis," "sepsis mortality," "antibiotic escalation," "antibiotic de-escalation," "antibiotic duration," and "antimicrobial stewardship."

RESULTS

Forty-six trials evaluating the efficacy of PCT concentrations in diagnosing sepsis have been published, with 39 of these trials yielding positive results and 7 yielding negative results. Wanner et al. published the largest study (n=405) demonstrating that peak PCT concentrations occur early after injury in both patients with sepsis and those with multiple organ dysfunction syndrome (MODS). Among 17 trials assessing the prognostic value of PCT concentrations with regard to clinical outcome and morbidity, 12 trials yielded positive results and five showed negative or equivocal results. Reith et al. published the largest study of the prognostic use of PCT concentrations (n=246), demonstrating that median PCT values on post-operative days (POD) one, four, and 10 were predictive of mortality in patients with abdominal sepsis (p<0.01). Among 14 trials of the utility of PCT concentrations for establishing an infectious cause of sepsis, 13 yielded positive results and only one yielded negative results. The largest study of this use of PCT concentrations, conducted by Baykut et al. (n=400), evaluated these concentrations in post-operative patients with infection, and demonstrated that concentrations of PCT remained elevated until POD 4, with a second increase observed between POD 4 and POD 6. In uninfected patients, PCT concentrations began to decrease on POD 2. Only a single study has assessed the utility of PCT concentrations in guiding the escalation of antibiotic therapy, and its results were negative. Specifically, Jensen et al. (n=1,200) compared a PCT-guided antibiotic escalation strategy with the standard of care for sepsis and found no difference in outcomes. They also found that the PCT group had a longer average stay in the intensive care unit (ICU), greater rates of mechanical ventilation, and a decreased estimated glomerular filtration rate (eGFR). Among four trials focusing on PCT concentrations and antibiotic de-escalation, all showed positive results with the measurement of PCT concentrations. The largest such study, by Bouadma et al. (n=621), demonstrated a four-day decrease in antibiotic duration when PCT concentrations were used to guide therapy relative to the study arm given the standard of care, with no increase in mortality (p=0.003).

CONCLUSIONS

The diagnostic value of serum PCT concentrations for discriminating among SIRS, sepsis, severe sepsis, and septic shock remains to be established. Although higher PCT concentrations suggest a systemic bacterial infection as opposed to a viral, fungal, or inflammatory etiology of sepsis, serum PCT concentrations do not correlate with the severity of sepsis or with mortality. At present, PCT concentrations are solely investigational with regard to determining the timing and appropriateness of escalation of antimicrobial therapy in sepsis. Nevertheless, serum PCT concentrations have established utility in monitoring the clinical response to medical and surgical therapy for sepsis, and in surveillance for the development of sepsis in burn and ICU patients, and may have a role in guiding the de-escalation of antibiotic therapy.

Sepsis: multiple abnormalities, heterogeneous responses, and evolving understanding

Sepsis represents the host's systemic inflammatory response to a severe infection. It causes substantial human morbidity resulting in hundreds of thousands of deaths each year. Despite decades of intense research, the basic mechanisms still remain elusive. In either experimental animal models of sepsis or human patients, there are substantial physiological changes, many of which may result in subsequent organ injury. Variations in age, gender, and medical comorbidities including diabetes and renal failure create additional complexity that influence the outcomes in septic patients. Specific system-based alterations, such as the coagulopathy observed in sepsis, offer both potential insight and possible therapeutic targets. Intracellular stress induces changes in the endoplasmic reticulum yielding misfolded proteins that contribute to the underlying pathophysiological changes. With these multiple changes it is difficult to precisely classify an individual's response in sepsis as proinflammatory or immunosuppressed. This heterogeneity also may explain why most therapeutic interventions have not improved survival. Given the complexity of sepsis, biomarkers and mathematical models offer potential guidance once they have been carefully validated. This review discusses each of these important factors to provide a framework for understanding the complex and current challenges of managing the septic patient. Clinical trial failures and the therapeutic interventions that have proven successful are also discussed.

A composite score combining procalcitonin, C-reactive protein and temperature has a high positive predictive value for the diagnosis of intensive care-acquired infections

Background

Nosocomial infection diagnosis in the intensive care unit (ICU) remains a challenge. We compared routine measurements of procalcitonin (PCT), C-reactive protein (CRP), white blood cell count (WBC) and temperature in the detection of ICU-acquired infections.

Method

Prospective observational cohort study in a University hospital Medicosurgical ICU. All patients admitted to the ICU ≥ 5 days (n = 141) were included into two groups, either infected (documented infection, n = 25) or non-infected (discharged from the ICU without diagnosis of infection, n = 88).

Results

PCT, CRP, WBC and temperature progression from day −4 (D-4) to day 0 (D0) (day of infection diagnosis or ICU discharge) was analysed. Differences (Δ) were calculated as D0 levels minus the lowest preceding value. D0 PCT and CRP were significantly increased in infected compared to non-infected patients (median, 1^st and 3^rd quartiles): 3.6 ng/mL (0.92-25) for PCT, 173 mg/L (126–188) for CRP versus 0.02 ng/mL (0.1-0.9) and 57 mg/mL (31–105) respectively (p < 0.0001). In multivariate analysis, D0 temperature > 38.6°C, PCT > 1.86 ng/mL, and CRP > 88 mg/L, performed well (AUCs of 0.88, 0.84, and 0.88 respectively). The sensitivity/specificity profiles of each marker (76%/94% for temperature, 68%/91% for PCT, and 92%/70% for CRP) led to a composite score (0.068 × D0 PCT + 0.005 × D0 CRP + 0.7 × temperature) more highly specific than each component (AUC of 0.90 and sensitivity/specificity of 80%/97%).

Conclusion

Combining CRP, PCT and temperature is an approach which may increase of nosocomial infection detection in the ICU.

Carboxy-terminal provasopressin may predict prognosis in nursing home acquired pneumonia

BACKGROUND

This study compares biomarker (including procalcitonin, pro-ANP, and copeptin) levels to pneumonia severity scores to predict 30-day mortality in NHAP (nursing home acquired pneumonia) patients.

METHODS

Seventy three patients aged ≥ 65 y, admitted to general hospitals and who fulfilled the definition of NHAP were included in the study. Data collected at admission included age, gender, nursing home admission, coexisting illness, symptoms and clinical parameters (blood pressure, pulse rate, respiratory rate and status). Additional data collected included laboratory results, radiographic findings and outcome variables. Severity of pneumonia was evaluated using a prediction rule calculated by CURB-65 criteria (confusion, urea nitrogen, respiratory rate, blood pressure, age>65 y).

RESULTS

After adjustment for age, sex and CURB-65, copeptin (OR=5.60, 95% confidence interval (CI)=1.20-26.24) was associated with 30-day mortality in NHAP patients, while procalcitonin and pro-ANP were not. The areas under the receiver operating characteristic curves (AUCs) for CURB-65, in predicting mortality were 0.685 [95% CI 0.559-0.811], whereas copeptin showed slightly superior accuracy with an AUC of 0.698 (95% CI 0.568-0.827).

CONCLUSIONS

Among 3 biomakers, copeptin was the strongest predictor of 30-day mortality from NHAP. The pathophysiologic and clinical implications of this finding require further investigation.

Procalcitonin as a diagnostic marker and IL-6 as a prognostic marker for sepsis

The diagnosis and prognosis of sepsis after antimicrobial therapy among systemic inflammatory response syndrome (SIRS) patients were evaluated with the biomarkers procalcitonin (PCT), interleukin-6 (IL-6), C-reactive protein (CRP), erythrocyte sedimentation rate, and white blood cell counts. Among 177 consecutive SIRS patients, 78 exhibited sepsis, with Escherichia coli (23.1%) being the most common pathogen. PCT showed the best diagnostic performance, with 74.4% and 93.7% sensitivity and 86.7% and 75.2% specificity among sepsis and severe sepsis/septic shock patients, respectively. PCT, IL-6, and CRP levels were significantly increased in nonsurvivors compared to survivors. Serial measurements at 0, 12, 24, 48, 72, and 96 h showed that IL-6 showed better kinetics in the survivor group and was decreased in more than 86% of survivors by the second day. PCT can support the diagnosis of bacterial infection, especially in septic shock and severe sepsis patients. IL6 exhibited the better kinetics for monitoring the effectiveness of antibiotic treatment.

Procalcitonin as a diagnostic marker for sepsis: a systematic review and meta-analysis

BACKGROUND

Procalcitonin is a promising marker for identification of bacterial infections. We assessed the accuracy and clinical value of procalcitonin for diagnosis of sepsis in critically ill patients.

METHODS

We searched Medline, Embase, ISI Web of Knowledge, the Cochrane Library, Scopus, BioMed Central, and Science Direct, from inception to Feb 21, 2012, and reference lists of identified primary studies. We included articles written in English, German, or French that investigated procalcitonin for differentiation of septic patients--those with sepsis, severe sepsis, or septic shock--from those with a systemic inflammatory response syndrome of non-infectious origin. Studies of healthy people, patients without probable infection, and children younger than 28 days were excluded. Two independent investigators extracted patient and study characteristics; discrepancies were resolved by consensus. We calculated individual and pooled sensitivities and specificities. We used I(2) to test heterogeneity and investigated the source of heterogeneity by metaregression.

FINDINGS

Our search returned 3487 reports, of which 30 fulfilled the inclusion criteria, accounting for 3244 patients. Bivariate analysis yielded a mean sensitivity of 0 · 77 (95% CI 0 · 72-0 · 81) and specificity of 0 · 79 (95% CI 0 · 74-0 · 84). The area under the receiver operating characteristic curve was 0 · 85 (95% CI 0 · 81-0 · 88). The studies had substantial heterogeneity (I(2)=96%, 95% CI 94-99). None of the subgroups investigated--population, admission category, assay used, severity of disease, and description and masking of the reference standard--could account for the heterogeneity.

INTERPRETATION

Procalcitonin is a helpful biomarker for early diagnosis of sepsis in critically ill patients. Nevertheless, the results of the test must be interpreted carefully in the context of medical history, physical examination, and microbiological assessment.

FUNDING

Ministry of Education and Research, the Deutsche Forschungsgemeinschaft, Thuringian Ministry for Education, Science and Culture, the Thuringian Foundation for Technology, Innovation and Research, and the German Sepsis Society.

Does C-reactive protein independently predict mortality in adult community-acquired bacteremia patients with known sepsis severity?

We evaluated whether sepsis severity and C-reactive protein (CRP) level on admission prognostically corroborated or annulled each other in adult patients with incident community-acquired bacteremia (Funen, Denmark, 2000-2008). We used logistic regression and area under the receiver operating characteristic curve (AUC) to evaluate 30-day mortality in four models: (i) age, gender, comorbidity, bacteria, and ward. (ii) Model 1 and sepsis severity. (iii) Model 1 and CRP. (iv) Model 1, sepsis severity, and CRP. Altogether, 416 of 1999 patients died within 30 days. CRP independently predicted 30-day mortality [Model 4, odds ratio (95% CIs) for 100 mg/L: 1.16 (1.06-1.27)], but it did not contribute to the AUC (Model 2 vs Model 4: p = 0.31). In the 963 non-severe sepsis patients, CRP independently predicted 30-day mortality [Model 4: 1.42 (1.20-1.69)] and it increased the AUC (Model 2 vs Model 4: p = 0.06), thus CRP contributed as much as sepsis severity to prognosis.

Diagnostic utilities of procalcitonin and C-reactive protein for the prediction of bacteremia determined by blood culture

BACKGROUND

We compared the diagnostic utilities of procalcitonin (PCT) and C-reactive protein (CRP) for predicting bacteremia diagnosed by blood cultures. PCT was also evaluated as a parameter for differentiating true bacteremia from culture contamination.

METHODS

We analyzed a total of 3343 patients in which PCT, CRP, and blood cultures were concurrently requested for detecting bacteremia from January 2010 to December 2011. PCT concentrations were measured by the VIDAS® Brahms PCT assay, and CRP concentrations were determined by a turbidimetric assay using CA-400 analyzer.

RESULTS

The PCT concentrations of bacteremia cases (n=331) were significantly higher than those of non-bacteremia (n=2856) (median: 3.2 ng/ml vs. 0.4 ng/ml, P<0.0001). The correlation coefficient between the PCT and CRP concentrations was 0.51. The areas under the receiver operating characteristic curves (ROC-AUCs) of PCT and CRP for discriminating bacteremia from non-bacteremia were 0.76 and 0.64, respectively. The ROC-AUC of PCT for differentiating true bacteremia from contamination was 0.86, while that of CRP was 0.65.

CONCLUSIONS

PCT concentration by single testing was more useful for predicting bacteremia than CRP. PCT also exhibited diagnostic utility for ruling out blood culture contamination. Thus, PCT could be helpful in the accurate diagnosis of bacteremia.

C-reactive protein as a marker of postoperative septic complications

THE AIM OF THE STUDY

was to answer the question whether or not determination of C-reactive protein in patients after serious abdominal surgeries can be prognostic of septic complications.

MATERIAL AND METHODS

36 patients who underwent elective surgeries were included in the study. The patients were included either in the group where no postoperative SIRS developed or in the group where postoperative SIRS did occur. In the seven-day period after the surgery, in 26 patients SIRS was found, and in 10 - sepsis was suspected (according to the ACCP/SCCM definitions). In patients who underwent abdominal surgeries blood concentration of C-reactive protein was determined prior to the surgery (measurement '0'), and then on postoperative days 1, 2, 3, 5 and 7.

RESULTS

The test for two variables (C-reactive protein on postoperative days five and seven) showed statistically significant difference, and for one variable (C-reactive protein on day three) - difference at the limit of significance. Thus, it was found that in the postoperative SIRS group the level of C-reactive protein is higher than in the non-SIRS group.

CONCLUSIONS

Serial measurements of C-reactive protein are useful in the first week after surgery, as they can be prognostic of postoperative septic complications. Such complications can be anticipated if CRP on postoperative day 5 is higher than 1/2 of the maximum CRP concentration on day 2 or day 3, or CRP > 150 mg/L as of postoperative day 3. Unfortunately, the severity of the disease cannot be projected based on C-reactive protein level.

[Usefulness of procalcitonin upon admission to intensive care in the diagnosis and prognosis of sepsis]

OBJECTIVE

To assess the usefulness of procalcitonin (PCT) upon admission to the Intensive Care Unit (ICU) in the diagnosis and prognosis of sepsis

DESIGN

A 12-month prospective observational cohort study was carried out

SETTING

An 11-bed polyvalent ICU Belonging to a University hospital

PATIENTS

Fifty patients with systemic inflammatory response syndrome (SIRS) were included. The mean age of the patients was 51.66 years, and 68% of them were males

VARIABLES OF INTEREST

Upon admission, the concentration of PCT and C-reactive protein (CRP) was assessed. At discharge, the final diagnosis and outcome were reviewed

RESULTS

Thirty-six patients had sepsis. Mean PCT ± SD was higher in sepsis than in non-infectious SIRS (19.3 ± 4.9 vs. 0.65 ± 0.2) ng/ml) (P=.001). PCT had greater discriminating power than CRP (AUC 0.932 vs. 0.827). The cut-off value of PCT for the diagnosis of sepsis was 0.92 ng/dl, with a sensitivity of 80.56%, specificity 85.71%, positive predictive value 93.55% and negative predictive value 63.16%, LR+ 5.64 and LR- 0.23. Mortality was higher in patients with sepsis (52.78% vs. 21.43%) (P=.039). Mean PCT ± SD upon admission among survivors and deceased patients with sepsis was 18.7 ± 6.7 and 19.5 ± 7.5 ng/ml, respectively (P=.934).

CONCLUSIONS

PCT upon admission to the ICU is useful for the diagnosis of sepsis, and is more effective than PCR in this respect. However, it is of no help in estimating the short-term prognosis.

Serum procalcitonin has negative predictive value for bacterial infection in active systemic lupus erythematosus

Background: Previous studies in systemic lupus erythematosus (SLE) patients have produced conflicting results regarding the diagnostic utility of procalcitonin (PCT). The aim of this study was to determine predictive values of PCT and C-reactive protein (CRP) for bacterial infection in SLE patients. Materials and methods: This was a cross-sectional study of clinic and hospitalized SLE patients with and without bacterial infection recruited over 18 months. Bacterial infection was defined as positive culture results. SLE disease activity was measured using SLEDAI. PCT and CRP were measured by automated immunoassays. Results: Sixty-eight patients (57 females) were studied. Ten patients (15%) had infection. The areas under the receiver operating characteristic curves for PCT and CRP were not significantly different [0.797 (CI 0.614–0.979) versus 0.755 (CI 0.600–0.910)]. In lupus flare patients, PCT but not CRP was higher with infection ( p = 0.019 versus 0.195). A PCT of <0.17 ng/ml ruled out infection with 94% negative predictive value (NPV). In remission patients, CRP but not PCT was elevated with infection ( p = 0.036 versus 0.103). CRP < 0.57 mg/dl had 96% NPV. Conclusion: PCT may be a better marker to rule out bacterial infection in lupus flare but not in remission or general screening.

Serum decoy receptor 3, a potential new biomarker for sepsis

BACKGROUND

Sepsis, a common deadly systemic infection caused by a variety of pathogens, has some clinical symptoms similar to the systemic inflammatory response syndrome (SIRS), a whole-body non-infectious inflammatory reaction to severe insults, such as burn, trauma, hypotensive shock and so on. Treatment of sepsis depends mainly on anti-microbial, while remedy for SIRS might require steroids that could possibly enhance the spread of microbes. Unfortunately, it is very difficult to distinguish these two completely different serious conditions without blood culture, which takes days to grow and identify causative pathogens. We examined a biomarker, serum decoy receptor 3 (DcR3), was evaluated for its utility in the differential diagnosis between sepsis and SIRS.

METHODS

Serum DcR3 level in 118 healthy controls, 24 sepsis patients and 43 SIRS patients, was quantitatively measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The serum DcR3 was significantly increased in sepsis patients compared with SIRS patients and healthy controls (6.11±2.58 ng/ml vs 2.62±1.46 ng/ml, and 0.91±0.56 ng/ml, respectively, p<0.001). The areas under the receiver operating characteristic curve of DcR3 for the normal vs. SIRS, normal vs. sepsis and SIRS vs. sepsis were 0.910 (0.870-0.950), 0.992 (0.984-1.000) and 0.896 (0.820-0.973), respectively. In addition, the DcR3 exhibited a positive correlation coefficient with APACHE II score, a most commonly used index for the severity of sepsis (r=0.556, p=0.005).

CONCLUSION

The serum DcR3 has a potential to serve as a new biomarker for sepsis with its high specificity and sensitivity.

C-reactive protein level as a predictor of mortality in liver disease patients with bacteremia

BACKGROUND AND OBJECTIVE

C-reactive protein (CRP) is synthesized in the liver in response to inflammation, and CRP is a widely used marker of sepsis. In bacteremia the initial CRP level is an independent predictor of mortality. Since the CRP response in patients with chronic liver disease is lower than in patients without liver disease the objective was to assess whether CRP levels in chronic liver disease and bacteremia was associated with case fatality.

PATIENTS

The study enrolled 105 patients with chronic liver disease and bacteremia as well as 202 patients with bacteremia and no recorded liver disease from the same region and time period.

METHODS

Retrospective review of medical records with registration of demography, co-morbidity, bacteriological, biochemical and clinical findings, and Child-Turcotte-Pugh scores. The primary outcome was 30-day mortality.

RESULTS

Mortality was significantly higher in patients with chronic liver disease (mortality rate ratio 2.2; 95% confidence interval 1.2-3.9) and it was correlated to Child-Turcotte-Pugh scores. CRP levels were not different between the three Child-Turcotte-Pugh classes (p = 0.33), and no linear correlation with 30-day mortality was observed.

CONCLUSION

Mortality associated with bacteremia is increased in patients with chronic liver disease and it is correlated with Child-Turcotte-Pugh score. The prognostic information of initial CRP levels in patients with chronic liver disease is weak. The clinical management of patients with chronic liver disease and suspected infection should initiate antimicrobial therapy based on clinical, radiological and microbiological findings, whereas the measurement of CRP in bacteremia is less helpful as compared with patients without liver disease.