Procalcitonin: A Marker of Bacteraemia in SIRS

Experience with Tissue Bank Services in 2014 and 2020 in Turku, Finland

BACKGROUND

The objective of a musculoskeletal tissue bank is to collect, test, store, and provide musculoskeletal tissue allografts required in orthopedic procedures. Strict exclusion criteria are followed when selecting suitable cadaver musculoskeletal tissue donors, and the allografts are procured under sterile conditions to avoid bacterial contamination. Tissue banking in Turku, Finland, began in 1972, and tissue bank services were last reviewed in 2003. This study aimed to review the operation of the musculoskeletal tissue bank in Turku, Finland, between 2014 and 2020 and to analyze the number, types, and contamination rate of the allografts procured from the cadaver donors. Potential donor-related factors causing bacterial contamination of the allografts and whether potential musculoskeletal tissue donors were overlooked among multiorgan donors were also studied.

METHODS

A retrospective review of all cadaver musculoskeletal tissue donors used in the Hospital District of Southwest Finland Tyks Orto Musculoskeletal Tissue Bank during the study period was conducted, and data on the procured allograft was collected and presented. The donors were selected among patients treated in the intensive care unit (ICU) of Turku University Hospital (TYKS).

RESULTS

A total of 28 cadaver donors were used, and 636 allografts were procured between 2014 and 2020. The bacterial contamination rate was 2.5%, which was lower than that in the previous international literature. The median treatment time in the ICU was significantly longer, and the median value of the highest C-reactive protein level was significantly higher in the group of donors with positive allograft bacterial cultures.

CONCLUSIONS

The bacterial contamination rate in the tissue bank was low on an international scale. Some suitable musculoskeletal tissue donors were overlooked among multiorgan donors.

Comparative Characterization of Procalcitonin (Sensitivity, Specificity, Predictability, and Cut-Off Reference Values) as a Marker of Inflammation in Odontogenic Abscesses of the Head and Neck in the Female Population

Introduction Odontogenic abscesses of the head and neck can lead to serious complications and even end in death. This requires healthcare professionals to have a good knowledge of all the markers of inflammation that can be used in their diagnosis and treatment. Such markers that we use in our daily medical practice are leukocytes (WBC), neutrophils (Neu), and C-reactive protein (CRP). Somehow, in the background is procalcitonin (PCT), which has not been studied in detail in this type of purulent infection. The aim of the present study is to investigate and analyze PCT in odontogenic purulent infections of the head and neck in the female population and to compare it with already proven markers of inflammation such as CRP, WBC, and Neu. For the first time in the literature, as per our knowledge, the sensitivity, specificity, and predictability of PCT were determined when using it as an independent indicator of inflammation, and its cut-off reference values were determined in women with odontogenic abscesses of the head and neck. Materials and methods This is a prospective study, in which the CRP, WBC, Neu, and PCT of 30 women with odontogenic abscesses of the head and neck with a mean age of 47 (18-81) years were examined and analyzed. As a control group, we included 30 healthy women with a mean age of 48 (18-80) years, in whom there was no anamnestic and physical evidence of the presence of any infection in the last three months. The four markers were measured for the control group too. Results In the clinical group of women with odontogenic abscesses of the head and neck, the average values of CRP, WBC, Neu, and PCT were significantly higher (p<0.0001) compared to the same in the control group of healthy women; CRP: 95.46±76.41 mg/l vs. 0.63±0.37 mg/l, WBC: 10.44±2.97x103/L vs. 6.5±1.49x103/L, Neu: 7.92±2.93x103/L vs. 4.03±1.07x103/L, PCT: 0.74±0.69 ng/ml vs. 0.14±0.08 ng/ml. Discussion PCT, as well as CRP, WBC, and Neu, increases its plasma concentration in women with odontogenic abscesses of the head and neck and is extremely well positively correlated with them, with a high correlation with CRP and a significant correlation with WBC and Neu. In addition, PCT has a number of advantages over the other markers; it begins to increase its plasma concentration faster, reaches its maximum plasma concentration faster, normalizes its concentration faster after the infection subsides, and increases its blood level only in bacterial infection genesis. Conclusions PCT as a marker of inflammation not only positively correlates well with CRP, WBC, and Neu but also, with its advantages over them, it appears to be the most accurate indicator in the diagnosis, treatment, and follow-up of odontogenic head and neck abscesses in the near future; not only in women but also in the male and children's population. Its sensitivity, specificity, and predictability as an independent indicator of inflammation are 80%, 76.7%, and 83%, respectively, and its cut-off value of 0.225 ng/ml is lower than the generally accepted 0.5 ng/ml.

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.

Score performance of SAPS 2 and SAPS 3 in combination with biomarkers IL-6, PCT or CRP

OBJECTIVE

We aimed to evaluate the effects of combining the Simplified-Acute-Physiology-Score (SAPS) 2 or the SAPS 3 with Interleukin-6 (IL-6) or Procalcitonin (PCT) or C-Reactive Protein (CRP) concentrations for predicting in-hospital mortality.

MATERIAL AND METHODS

This retrospective study was conducted in an interdisciplinary 22-bed intensive care unit (ICU) at a German university hospital. Within an 18-month period, SAPS 2 and SAPS 3 were calculated for 514 critically ill patients that were admitted to the internal medicine department. To evaluate discrimination performance, the area under the receiver operating characteristic curves (AUROCs) and the 95% confidence intervals (95% CIs) were calculated for each score, exclusively or in combination with IL-6 or PCT or CRP. DeLong test was used to compare different AUROCs.

RESULTS

The SAPS 2 exhibited a better discrimination performance than SAPS 3 with AUROCs of 0.81 (95% CI, 0.76-0.86) and 0.72 (95% CI, 0.66-0.78), respectively. Overall, combination of the SAPS 2 with IL-6 showed the best discrimination performance (AUROC 0.82; 95% CI, 0.77-0.87), albeit not significantly different from SAPS2. IL-6 performed better than PCT and CRP with AUROCs of 0.75 (95% CI, 0.69-0.81), 0.72 (95% CI, 0.66-0.77) and 0.65 (95% CI, 0.59-0.72), respectively. Performance of the SAPS 3 improved significantly when combined with IL-6 (AUROC 0.76; 95% CI, 0.69-0.81) or PCT (AUROC 0.73; 95% CI, 0.67-0.78).

CONCLUSIONS

Our analysis provided evidence that the risk stratification performance of the SAPS 3 and, to a lesser degree, also of the SAPS 2 can increase when combined with IL-6. A more accurate detection of aberrant or dysregulated systemic immunological responses (by IL-6) may explain the higher performance achieved by SAPS 3 + IL-6 vs. SAPS 3. Thus, implementation of IL-6 in critical care scores can improve prediction outcomes, especially in patients experiencing acute inflammatory conditions; however, statistical results may vary across hospital types and/or patient populations with different case mix.

Diagnostic value of plasma and peritoneal fluid procalcitonin concentrations in horses with strangulating intestinal lesions

OBJECTIVE

To assess the diagnostic value of plasma and peritoneal fluid procalcitonin concentrations for identification of horses with strangulating intestinal lesions.

ANIMALS

65 horses with signs of colic of intestinal origin and 10 healthy (control) horses.

PROCEDURES

For each horse, plasma and peritoneal fluid samples were obtained for a CBC and determination of total protein, procalcitonin, and lactate concentrations. Signalment and clinicopathologic findings were compared among control horses and horses with strangulating and nonstrangulating intestinal lesions.

RESULTS

Mean ± SD plasma (274.9 ± 150.8 pg/mL) and peritoneal fluid (277 ± 50.6 pg/mL) procalcitonin concentrations for horses with colic were significantly greater than the mean ± SD plasma (175.5 ± 46.0 pg/mL) and peritoneal fluid (218.8 ± 48.7 pg/mL) procalcitonin concentrations for control horses. Mean procalcitonin concentration in peritoneal fluid, but not plasma, differed significantly between horses with strangulating lesions and those with nonstrangulating lesions. A peritoneal fluid procalcitonin concentration ≥ 281.7 pg/mL had a sensitivity of 81%, specificity of 69%, positive predictive value of 56.7%, and negative predictive value of 87.9% for detection of strangulating lesions.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that peritoneal fluid procalcitonin concentration, when evaluated in conjunction with other clinicopathologic results, might be a sensitive indicator of intestinal ischemia and facilitate early identification of horses that require surgery to address a strangulating lesion.

Procalcitonin levels among patients with fever secondary to severe intracerebral infection. A cross-sectional study

BACKGROUND

Making the differential diagnosis between central fever and infectious fever is critically important among intracerebral hemorrhage patients followed up in intensive care units (ICUs). Serum procalcitonin (PCT) has been found to be a promising biomarker for the initial diagnosis of infection, even before culturing results.

OBJECTIVES

To investigate the relationship between PCT and both fever etiologies and C-reactive protein (CRP) levels among critically ill patients with suspected intracerebral hemorrhage.

DESIGN AND SETTING

Cross-sectional study in a public university hospital in Elazig, Turkey.

METHODS

ICU patients diagnosed with intracerebral hemorrhage and normal procalcitonin levels were included in this study. From clinical assessments and cultures, they were classified as presenting either infectious or central fever. The sensitivity and specificity of PCT and CRP for predicting infection were calculated using a receiver operating characteristic (ROC) curve.

RESULTS

There were 98 ICU patients with diagnoses of intracerebral hemorrhage. The median (interquartile range) PCT levels of patients with infectious and central fever were 4 (0.9-11) and 0.1 (0.1-0.4) ng/ml, respectively, with a statistically significant intergroup difference (P < 0.001). The areas under the ROC curve for predicting infectious or central fever PCT and CRP were 0.958 (P < 0.001) and 0.816 (P < 0.001), respectively. A statistically significant positive correlation was detected between PCT and CRP levels in patients with infectious fever (rho: 0.461; P = 0.003), but not in patients with central fever.

CONCLUSIONS

PCT can possibly be used as a biomarker to differentiate between infectious and central fever among ICU patients.

Is Procalcitonin Useful in Pediatric Critical Care Patients?

This review examines the use of procalcitonin in different clinical situations in the pediatric patient, with special emphasis on those requiring intensive care. We review the latest articles on its potency as a biomarker in both infectious processes at diagnosis and on the response to treatment.

Inflammatory cytokine and C-reactive protein concentrations in dogs with systemic inflammatory response syndrome

OBJECTIVE

To evaluate C-reactive protein (CRP), interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α) kinetics in dogs with a systemic inflammatory response syndrome (SIRS) presented to an emergency service. We hypothesized serum CRP concentrations would increase and vary during hospitalization, and would correlate with plasma IL-6 and TNF-α concentrations, vary in magnitude according to the underlying disease, and predict survival.

DESIGN

Prospective, observational, clinical study.

SETTING

University emergency department.

ANIMALS

Sixty-nine dogs with SIRS weighing over 5 kg who could tolerate the blood sampling.

INTERVENTIONS

Serum and plasma were collected (and stored at -80°C) at presentation (T0), after 6 (T6), 12 (T12), 24 (T24), and 72 (T72) hours, and at a follow-up visit at least 1 month after discharge (T1m). Underlying diseases were categorized as infection (I), neoplasia (N), trauma (T), gastric-dilation and volvulus (GDV), other gastrointestinal (GI), renal (R), and miscellaneous (M) disease.

MEASUREMENTS AND MAIN RESULTS

Serum CRP concentration was measured using a canine-specific immunoturbidimetric assay. Biologically active plasma IL-6 and TNF-α concentrations were assessed using bioassays. Forty-four dogs survived, 8 died, and 17 were euthanized. Nineteen dogs had follow-up visits. At T0, serum CRP concentration was above the reference interval in 73.1% (49/67), and was within the reference interval (0-141.9 nmol/L) throughout hospitalization in only 6% (4/67). Serum CRP concentrations were significantly higher (P < 0.0001) at T0 (882.9 ± 1082.9 nmol/L) and at all time points during hospitalization (P < 0.0001) compared to T1m, with highest concentrations observed at T24 (906. 7 ± 859.0 nmol/L). At T1m, serum CRP concentrations were within the reference interval (22.9 ± 42.9 nmol/L) in 95% (18/19) of dogs. Logarithmic concentrations of serum CRP and plasma IL-6 were significantly correlated (P < 0.001, r = 0.479). None of the measured cytokines were associated with disease category or outcome.

CONCLUSIONS

Serum CRP concentration is increased in dogs with SIRS, and decreases during treatment and hospitalization. Serum CRP, plasma IL-6, and plasma TNF-α concentrations cannot predict outcome in dogs with SIRS.

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.

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.

Systemic inflammatory response syndrome is more associated with bacteremia in elderly patients with suspected sepsis in emergency departments

Early diagnosis of bacteremia for patients with suspected sepsis is 1 way to improve prognosis of sepsis. Systemic inflammatory response syndrome (SIRS) has long been utilized as a screening tool to detect bacteremia by front-line healthcare providers. The value of SIRS to predict bacteremia in elderly patients (≥65 years) with suspected sepsis has not yet been examined in emergency departments (EDs).We aimed to evaluate the performance of SIRS components in predicting bacteremia among elderly patients in EDs.We retrospectively evaluated patients with suspected sepsis and 2 sets of blood culture collected within 4 hours after admitting to ED in a tertiary teaching hospital between 2010 and 2012. Patients were categorized into 3-year age groups: young (18-64 years), young-old (65-74 years), and old patients (≥75 years). Vital signs and Glasgow Coma Scale with verbal response obtained at the triage, comorbidities, sites of infection, blood cultures, and laboratory results were retrieved via the electronic medical records.A total of 20,192 patients were included in our study. Among them, 9862 (48.9%) were the elderly patients (young-old and old patients), 2656 (13.2%) developed bacteremia. Among patients with bacteremia, we found the elderly patients had higher SIRS performance (adjusted odds ratio [aOR]: 2.40, 95% confidence interval [CI]: 1.90-3.03 in the young-old and aOR: 2.66, 95% CI: 2.19-3.23 in the old). Fever at the triage was most predictive of bacteremia, especially in the elderly patients (aOR: 2.19, 95% CI: 1.81-2.65 in the young-old and aOR: 2.27, 95% CI: 1.95-2.63 in the old), and tachypnea was not predictive of bacteremia among the elderly patients (all P > 0.2).The performance of SIRS to predict bacteremia was more suitable for elderly patients in EDs observed in this study. The elderly patients presented with more fever and less tachypnea when they had bacteremia.

Procalcitonin to guide taking blood cultures in the intensive care unit; a cluster-randomized controlled trial

OBJECTIVES

We aimed to study the safety and efficacy of procalcitonin in guiding blood cultures taking in critically ill patients with suspected infection.

METHODS

We performed a cluster-randomized, multi-centre, single-blinded, cross-over trial. Patients suspected of infection in whom taking blood for culture was indicated were included. The participating intensive care units were stratified and randomized by treatment regimen into a control group and a procalcitonin-guided group. All patients included in this trial followed the regimen that was allocated to the intensive care unit for that period. In both groups, blood was drawn at the same moment for a procalcitonin measurement and blood cultures. In the procalcitonin-guided group, blood cultures were sent to the department of medical microbiology when the procalcitonin was >0.25 ng/mL. The main outcome was safety, expressed as mortality at day 28 and day 90.

RESULTS

The control group included 288 patients and the procalcitonin-guided group included 276 patients. The 28- and 90-day mortality rates in the procalcitonin-guided group were 29% (80/276) and 38% (105/276), respectively. The mortality rates in the control group were 32% (92/288) at day 28 and 40% (115/288) at day 90. The intention-to-treat analysis showed hazard ratios of 0.85 (95% CI 0.62-1.17) and 0.89 (95% CI 0.67-1.17) for 28-day and 90-day mortality, respectively. The results were deemed non-inferior because the upper limit of the 95% CI was below the margin of 1.20.

CONCLUSION

Applying procalcitonin to guide blood cultures in critically ill patients with suspected infection seems to be safe, but the benefits may be limited.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: ID NCT01847079. Registered on 24 April 2013, retrospectively registered.

The diagnostic ability of procalcitonin and interleukin-6 to differentiate infectious from noninfectious systemic inflammatory response syndrome and to predict mortality

PURPOSE

The purpose of the study was to quantify the ability of procalcitonin (PCT) and interleukin-6 (IL-6) to differentiate noninfectious systemic inflammatory response syndrome (SIRS) and sepsis and to predict hospital mortality.

MATERIALS

We recruited consecutively adult patients with SIRS admitted to an intensive care unit. They were divided into sepsis and noninfectious SIRS based on clinical assessment with or without positive cultures. Concentrations of PCT and IL-6 were measured daily over the first 3 days.

RESULTS

A total of 239 patients were recruited, 164 (68.6%) had sepsis, and 68 (28.5%) died in hospital. The PCT levels were higher in sepsis compared with noninfectious SIRS throughout the 3-day period (P < .0001). On admission, PCT concentration was diagnostic of sepsis (area under the curve of 0.63 [0.55-0.71]), and IL-6 was predictive of mortality, (area under the curve of 0.70 [0.62-0.78]). Peak IL-6 concentration improved the risk assessment of Sequential Organ Failure Assessment (SOFA) score for prediction of mortality among those who went on to die by an average of 5% and who did not die by 2%

CONCLUSIONS

Procalcitonin measured on intensive care unit admission was diagnostic of sepsis, and IL-6 was predictive of mortality. Addition of IL-6 concentration to SOFA score improved risk assessment for prediction of mortality. Future studies should include clinical indices, for example, SOFA score, for prognostic evaluation of biomarkers.

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.

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.

Early detection of severe sepsis in the emergency room: diagnostic value of plasma C-reactive protein, procalcitonin, and interleukin-6

OBJECTIVES

To determine the diagnostic values of plasma C-reactive protein (CRP), procalcitonin (PCT), and interleukin-6 (IL-6) using an electrochemiluminescence immunoassay (ECLIA) method (Roche Diagnostics GmbH, Mannheim, Germany) to identify severe sepsis in an emergency room (ER) setting.

METHODS

This was a single-centre prospective follow-up study of 539 consecutive adult patients admitted to the ER with suspected infection. Blood samples were taken concurrently with blood cultures at admission. Patients were divided into 5 groups on the basis of systemic inflammatory response syndrome (SIRS) criteria, documentation of bacterial infection, and organ dysfunction. Fifty-nine patients with no SIRS or bacterial infection, 68 patients with bacterial infection but no SIRS, 54 patients with SIRS but no bacterial infection, 309 patients with sepsis (SIRS and bacterial infection), and 49 patients with severe sepsis (sepsis and organ failure) were evaluated.

RESULTS

In a logistic regression model, the odds ratio (OR) for PCT was 1.58 (95% confidence interval (CI) 1.37-1.82, p < 0.0001), for IL-6 was 1.54 (95% CI 1.32-1.80, p < 0.0001), and for CRP was 1.33 (95% CI 1.01-1.75, p = 0.045). The area under the curve (AUC) was 0.77 (95% CI 0.71-0.84) for PCT, 0.72 (95% CI 0.64-0.80) for IL-6, and 0.60 (95% CI 0.51-0.69) for CRP. PCT emerged as the best marker for severe sepsis, but the difference in AUC was not significant between PCT and IL-6. In multivariate logistic regression analysis, after adjusting for confounders, PCT and IL-6 remained significant independent predictors of severe sepsis.

CONCLUSIONS

PCT and IL-6 proved superior to CRP in detecting patients with severe sepsis. The findings thus support the use of either PCT or IL-6 as an early tool to diagnose severe sepsis. The automatic ECLIA method allows even night-shift measurements.

Biomarkers in the critically ill patient: procalcitonin

Infection and/or sepsis biomarkers should help to make the diagnosis and thus initiate therapy earlier, help to differentiate between infectious and sterile inflammation, allow the use of more-specific antimicrobials, shorten the time of antimicrobial use, and ideally identify distinct phenotypes that may benefit from specific adjunctive sepsis therapies. Procalcitonin (PCT) was proposed as a sepsis and infection marker more than 15 years ago. Meanwhile, PCT has been evaluated in various clinical settings. In this review the present use of PCT on the ICU and in critically ill patients is summarized, included it's role for diagnosis of severe sepsis and septic shock and antibiotic stewardship with PCT.

Procalcitonin and C-reactive protein as markers of bacterial infection in critically ill children at onset of systemic inflammatory response syndrome

OBJECTIVE

To compare the accuracy of procalcitonin and C-reactive protein as diagnostic markers of bacterial infection in critically ill children at the onset of systemic inflammatory response syndrome (SIRS).

DESIGN

Prospective cohort study.

SETTING

Tertiary care, university-affiliated pediatric intensive care unit (PICU).

PATIENTS

Consecutive patients with SIRS.

INTERVENTIONS

From June to December 2002, all PICU patients were screened daily to include cases of SIRS. At inclusion (onset of SIRS), procalcitonin and C-reactive protein levels as well as an array of cultures were obtained. Diagnosis of bacterial infection was made a posteriori by an adjudicating process (consensus of experts unaware of the results of procalcitonin and C-reactive protein). Baseline and daily data on severity of illness, organ dysfunction, and outcome were collected.

MEASUREMENTS AND MAIN RESULTS

Sixty-four patients were included in the study and were a posteriori divided into the following groups: bacterial SIRS (n = 25) and nonbacterial SIRS (n = 39). Procalcitonin levels were significantly higher in patients with bacterial infection compared with patients without bacterial infection (p = .01). The area under the receiver operating characteristic curve for procalcitonin was greater than that for C-reactive protein (0.71 vs. 0.65, respectively). A positive procalcitonin level (>or=2.5 ng/mL), when added to bedside clinical judgment, increased the likelihood of bacterial infection from 39% to 92%, while a negative C-reactive protein level (<40 mg/L) decreased the probability of bacterial infection from 39% to 2%.

CONCLUSIONS

Procalcitonin is better than C-reactive protein for differentiating bacterial from nonbacterial SIRS in critically ill children, although the accuracy of both tests is moderate. Diagnostic accuracy could be enhanced by combining these tests with bedside clinical judgment.

Procalcitonin assay in systemic inflammation, infection, and sepsis: clinical utility and limitations

OBJECTIVE

The use of procalcitonin (ProCT) as a marker of several clinical conditions, in particular, systemic inflammation, infection, and sepsis, will be clarified, and its current limitations will be delineated. In particular, the need for a more sensitive assay will be emphasized. For these purposes, the medical literature comprising clinical studies pertaining to the measurement of serum ProCT in various clinical settings was examined.

DATA SOURCE AND SELECTION

A PubMed search (1965 through November 2007) was conducted, including manual cross-referencing. Pertinent complete publications were obtained using the MeSH terms procalcitonin, C-reactive protein, sepsis, and biological markers. Textbook chapters were also read and extracted.

DATA EXTRACTION AND SYNTHESIS

Available clinical and other patient data from these sources were reviewed, including any data relating to precipitating factors, clinical findings, associated illnesses, and patient outcome. Published data concerning sensitivity, specificity, and reproducibility of ProCT assays were reviewed.

CONCLUSIONS

Based on available data, the measurement of serum ProCT has definite utility as a marker of severe systemic inflammation, infection, and sepsis. However, publications concerning its diagnostic and prognostic utility are contradictory. In addition, patient characteristics and clinical settings vary markedly, and the data have been difficult to interpret and often extrapolated inappropriately to clinical usage. Furthermore, attempts at meta-analyses are greatly compromised by the divergent circumstances of reported studies and by the sparsity and different timing of the ProCT assays. Although a high ProCT commonly occurs in infection, it is also elevated in some noninfectious conditions. Thus, the test is not a specific indicator of either infection or sepsis. Moreover, in any individual patient, the precipitating cause of an illness, the clinical milieu, and complicating conditions may render tenuous any reliable estimations of severity or prognosis. It also is apparent that even a febrile septic patient with documented bacteremia may not necessarily have a serum ProCT that is elevated above the limit of functional sensitivity of the assay. In this regard, the most commonly applied assay (i.e., LUMItest) is insufficiently sensitive to detect potentially important mild elevations or trends. Clinical studies with a more sensitive ProCT assay that is capable of rapid and practicable day-to-day monitoring are needed and shortly may be available. In addition, investigations showing that ProCT and its related peptides may have mediator relevance point to the need for evaluating therapeutic countermeasures and studying the pathophysiologic effect of hyperprocalcitonemia in serious infection and sepsis.

A comparison of high-mobility group-box 1 protein, lipopolysaccharide-binding protein and procalcitonin in severe community-acquired infections and bacteraemia: a prospective study

Introduction

High-mobility group box-1 protein (HMGB1) has been known as a chromosomal protein for many years. HMGB1 has recently been shown to be a proinflammatory cytokine with a role in the immunopathogenesis of sepsis. Lipopolysaccharide-binding protein (LBP) has a central role in the innate immune response when the host is challenged by bacterial pathogens. Procalcitonin (PCT) has been suggested as a marker of severe bacterial infections and sepsis. The aim of the present study was to investigate levels of HMGB1, LBP and PCT in a well-characterised sepsis cohort. The study plan included analysis of the levels of the inflammatory markers in relation to the severity of infection, to the prognosis and to the ability to identify patients with bacteraemia.

Methods

Patients suspected of having severe infections and admitted to a department of internal medicine were included in a prospective manner. Demographic data, comorbidity, routine biochemistry, microbiological data, infection focus, severity score and mortality on day 28 were recorded. Plasma and serum were sampled within 24 hours after admission. Levels of all studied markers (HMGB1, LBP, PCT, IL-6, C-reactive protein, white blood cell count and neutrophils) were measured with commercially available laboratory techniques.

Results

A total of 185 adult patients were included in the study; 154 patients fulfilled our definition of infection. Levels of HMGB1, LBP and PCT were higher in infected patients compared with a healthy control group (P < 0.0001). Levels of HMGB1, LBP and PCT were higher in the severe sepsis group compared with the sepsis group (P < 0.01). No differences were observed in levels of the inflammatory markers in fatal cases compared with survivors. Levels of all studied markers were higher in bacteraemic patients compared with nonbacteraemic patients (P < 0.05). PCT performed best in a receiver–operator curve analysis discriminating between bacteraemic and nonbacteraemic patients (P < 0.05). HMGB1 correlated to LBP, IL-6, C-reactive protein, white blood cell count and neutrophils (P < 0.001). LBP correlated to PCT, IL-6 and C-reactive protein (P < 0.001).

Conclusion

Levels of HMGB1, PCT and LBP were higher in infected patients compared with those in healthy controls, and levels were higher in severe sepsis patients compared with those in sepsis patients. Levels of all studied inflammatory markers (HMGB1, LBP, PCT, IL-6) and infection markers (C-reactive protein, white blood cell count, neutrophils) were elevated among bacteraemic patients. PCT performed best as a diagnostic test marker for bacteraemia.

Relationship between procalcitonin values and infection in brain-dead organ donors

BACKGROUND AND AIMS

An association between the inflammatory reactions estimated by several biomarkers and organ dysfunction has been reported in brain-dead organ donors (BDOD). Procalcitonin (PCT), a biomarker of inflammation due to bacterial infection, is increased among BDOD. However, is not known whether infection changes PCT values in BDOD.

MATERIALS AND METHODS

We retrospectively analyzed 82 BDOD including several demographic and clinical parameters, bacterial culture results, antibiotics prescription, and plasma values of PCT measured before organ harvesting. Infection was diagnosed to be either a positive bacterial culture (restricted definition) and/or prescription of antibiotics (extended definition).

RESULTS

The median PCT value was 1.5 (interquartile range [IQR], 0.4 to 6.9; range, 0 to 526 ng/mL; n=82). Thirty-eight (46%) and 24 (29%) patients had PCT values>2 ng/mL and >5 ng/mL, respectively. Median PCT values among infected (1.18; IQR, 0.27 to 6.55 ng/mL) versus noninfected (1.57; IQR, 0.53 to 7.15 ng/mL) BDOD (restricted definition) were not different (P=.36). The area under the receiver operating characteristic curve using PCT to predict infection (restricted definition) was 0.52. Specificity of PCT to predict infection was above 80% at PCT values>9 ng/mL.

CONCLUSION

Our results confirmed PCT values are increased in BDOD, suggesting that this was not related to an infectious cause (whatever definition was used) unless PCT values are high.

Procalcitonin for the clinical laboratory: a review

Procalcitonin measurement has been claimed as a helpful marker in bacterial infection and sepsis. It has obtained FDA approval and is now widely marketed in the United States and Europe. This review summarises the current assays available, the evidence for its use and possible future applications of the assay.

Accuracy of procalcitonin for sepsis diagnosis in critically ill patients: systematic review and meta-analysis

Procalcitonin is widely reported as a useful biochemical marker to differentiate sepsis from other non-infectious causes of systemic inflammatory response syndrome. In this systematic review, we estimated the diagnostic accuracy of procalcitonin in sepsis diagnosis in critically ill patients. 18 studies were included in the review. Overall, the diagnostic performance of procalcitonin was low, with mean values of both sensitivity and specificity being 71% (95% CI 67-76) and an area under the summary receiver operator characteristic curve of 0.78 (95% CI 0.73-0.83). Studies were grouped into phase 2 studies (n=14) and phase 3 studies (n=4) by use of Sackett and Haynes' classification. Phase 2 studies had a low pooled diagnostic odds ratio of 7.79 (95% CI 5.86-10.35). Phase 3 studies showed significant heterogeneity because of variability in sample size (meta-regression coefficient -0.592, p=0.017), with diagnostic performance upwardly biased in smaller studies, but moving towards a null effect in larger studies. Procalcitonin cannot reliably differentiate sepsis from other non-infectious causes of systemic inflammatory response syndrome in critically ill adult patients. The findings from this study do not lend support to the widespread use of the procalcitonin test in critical care settings.

The role of procalcitonin in a decision tree for prediction of bloodstream infection in febrile patients

Bloodstream infection (BSI) in febrile patients is associated with high mortality. Clinical and laboratory variables, such as procalcitonin (PCT), may predict BSI and help decision-making concerning empirical treatment. This study compared two models for prediction of BSI, and evaluated the role of PCT vs. clinical variables, collected daily in 300 consecutive febrile inpatients, for 48 h after onset of fever. Multiple logistic regression (MLR) and classification and regression tree (CART) models were compared for discriminatory power and diagnostic performance. BSI was present in 17% of cases. MLR identified the presence of intravascular devices, nadir albumin and thrombocyte counts, and peak temperature, respiratory rate and leukocyte counts, but not PCT, as independent predictors of BSI. In contrast, a peak PCT level of >2.45 ng/mL was the principal discriminator in the decision tree based on CART. The latter was more accurate (94%) than the model based on MLR (72%; p <0.01). Hence, the presence of BSI in febrile patients is predicted more accurately and by different variables, e.g., PCT, in CART analysis, as compared with MLR models. This underlines the value of PCT plus CART analysis in the diagnosis of a febrile patient.

Procalcitonin as a diagnostic test for sepsis in critically ill adults and after surgery or trauma: a systematic review and meta-analysis

OBJECTIVE

To quantify the accuracy of serum procalcitonin as a diagnostic test for sepsis, severe sepsis, or septic shock in adults in intensive care units or after surgery or trauma, alone and compared with C-reactive protein. To draw and compare the summary receiver operating characteristics curves for procalcitonin and C-reactive protein from the literature.

DATA SOURCE

MEDLINE (keywords: procalcitonin, intensive care, sepsis, postoperative sepsis, trauma); screening of the literature.

STUDY SELECTION

Meta-analysis of all 49 published studies in medical, surgical, or polyvalent intensive care units or postoperative wards. Children, medical patients, and immunocompromised patients were excluded.

DATA EXTRACTION

Thirty-three studies fulfilled inclusion criteria (3,943 patients, 1,828 males, 922 females; mean age: 56.1 yrs; 1,825 patients with sepsis, severe sepsis, or septic shock; 1,545 with only systemic inflammatory response syndrome); eight studies could not be analyzed statistically. Global mortality rate was 29.3%.

DATA SYNTHESIS

Global odds ratios for diagnosis of infection complicated by systemic inflammation were 15.7 for the 25 studies (2,966 patients) using procalcitonin (95% confidence interval, 9.1-27.1) and 5.4 for the 15 studies (1,322 patients) using C-reactive protein (95% confidence interval, 3.2-9.2). The summary receiver operating characteristics curve for procalcitonin was better than for C-reactive protein. In the 15 studies using both markers, the Q* value (intersection of summary receiver operating characteristics curve with the diagonal line where sensitivity equals specificity) was significantly higher for procalcitonin than for C-reactive protein (0.78 vs. 0.71, p = .02), the former test showing better accuracy.

CONCLUSIONS

Procalcitonin represents a good biological diagnostic marker for sepsis, severe sepsis, or septic shock, difficult diagnoses in critically ill patients. Procalcitonin is superior to C-reactive protein. Procalcitonin should be included in diagnostic guidelines for sepsis and in clinical practice in intensive care units.

A case of fulminant post-transplant lymphoproliferative disorder and septicemia

The fulminant form of post-transplant lymphoproliferative disorder (PTLD) is very uncommon and occurs in approximately 1% of PTLD patients. Approximately 85% of these lesions are of B-cell origin, and most of them are associated with Epstein-Barr virus infection. Fulminant PTLD is frequently associated with a systemic inflammatory response syndrome, and may be difficult to differentiate from septicemia. We describe the case of a 59-yr-old man who suffered from prolonged septicemia in the immediate post-transplant period, and presented again four months after cardiac transplantation with fever, painful liver edge and gastrointestinal bleeding. The diagnosis of fulminant PTLD with advanced multiorgan infiltration by a diffuse large-cell lymphoma of B-cell phenotype was made. During treatment with rituximab, the patient died from Enterococcus faecium septicemia. The sequence of septicemia, PTLD and, finally again, septicemia is an unusual challenge and urges for an aggressive diagnostic approach, where markers like procalcitonin may aid in the discrimination of fulminant PTLD from septicemia.

Regional analgesia in the critically ill

OBJECTIVE

The objective of this review is to analyze and describe the use of regional analgesia in the critically ill.

DATA SOURCE

A Medline search from 1966 to 2004 using the search terms critically ill, nerve blocks, regional analgesia, and regional anesthesia, as well as a search in the Cochrane library, was performed, and standard international textbooks related to critical care and regional anesthesia were searched for practice recommendations.

STUDY SELECTION

Studies, case reports, and review articles relevant to the topic were included.

DATA EXTRACTION AND SYNTHESIS

Data were extracted and analyzed in a descriptive fashion.

CONCLUSION

Regional analgesia using single-injection regional blocks and continuous neuraxial and peripheral catheters can play a valuable role in a multimodal approach to pain management in the critically ill patient to achieve optimum patient comfort and to reduce physiologic and psychological stress. By avoiding high systemic doses of opioids, several complications like withdrawal syndrome, delirium, mental status changes, and gastrointestinal dysfunction can be reduced or minimized. Because of limited patient cooperation during placement and monitoring of continuous regional analgesia, indications for their use must be carefully chosen based on anatomy, clinical features of pain, coagulation status, and logistic circumstances. High-quality nursing care and well-trained physicians are essential prerequisites to use these techniques safely in the critical care environment.

Pilot study evaluating C-reactive protein levels in the assessment of response to treatment of severe bloodstream infection

We evaluated the usefulness of monitoring daily C-reactive protein (CRP) levels after initiation of antimicrobial therapy in 44 patients with bloodstream infection. The ratio of the CRP level during therapy to the level at the start of antimicrobial therapy (CRP ratio) was measured. A CRP ratio of >0.58 at day 4 of therapy was a marker of poor outcome (sensitivity, 0.89; specificity, 0.69). The recognition of a pattern of CRP-ratio response was useful in the prediction of individual clinical course.