Diagnostic and prognostic values of admission procalcitonin levels in community-acquired pneumonia in an intensive care unit

Targeted treatment for biofilm-based infections using PEGylated tobramycin

Chronic infections often involve biofilm-based bacteria, in which the biofilm results in significant resistance against antimicrobial agents and prevents eradication of the infection. The physicochemical barrier presented by the biofilm matrix is a major impediment to the delivery of many antibiotics. Previously, PEGylation has been shown to improve antibiotic penetration into biofilms in vitro. In these studies, PEGylating tobramycin was investigated both in vitro and in vivo. Two distinct PEGylated tobramycin molecules were synthesized (mPEG-SA-Tob and mPEG-AA-Tob). Then, in a P. aeruginosa biofilm in vitro model, we found that mPEG-SA-Tob can operate as a prodrug and showed 7 times more effectiveness than tobramycin (MIC80: 14 μM vs.100 μM). This improved biofilm eradication is attributable to the fact that mPEG-SA-Tob can aid tobramycin to penetrate through the biofilm and overcome the alginate-mediated antibiotic resistance. Finally, we used an in vivo biofilm-based chronic pulmonary infection rat model to confirm the therapeutic impact of mPEG-SA-Tob on biofilm-based chronic lung infection. mPEG-SA-Tob has a better therapeutic impact than tobramycin in that it cannot only stop P. aeruginosa from multiplying in the lungs but can also reduce inflammation caused by infections and prevent a recurrence infection. Overall, our findings show that PEGylated tobramycin is an effective treatment for biofilm-based chronic lung infections.

Advancements in the Management of Severe Community-Acquired Pneumonia: A Comprehensive Narrative Review

Pneumonia, classified as a lower respiratory tract illness, affects different parts of the bronchial system as well as alveoli and can present with varying severities depending on co-morbidities and causative pathogens. It can be broadly classified using the setting in which it was acquired, namely the community or hospital setting, the former being more common and spreading through person-to-person droplet transmission. Community-acquired pneumonia (CAP) is currently the fourth leading cause of death worldwide, and its high mortality makes continual insight into the management of the condition worthwhile. This review explores the literature specifically for severe CAP (sCAP) and delves into the diagnosis, various modalities of treatment, and management of the condition. This condition can be defined as pneumonia requiring mechanical ventilation in the ICU and/or presenting with sepsis and organ failure due to pneumonia. The disease process is characterized by inflammation of the lung parenchyma, initiated by a combination of pathogens and lowered local defenses. Acute diagnosis of the condition is vital in reducing negative patient outcomes, namely through clinical presentation, blood/sputum cultures, imaging modalities such as computed tomography scan, and inflammatory markers, identifying common causative pathogens such as Streptococcus pneumoniae, rhinovirus, Legionella, and viral influenza. Pathogens such as Escherichia coli should also be investigated in patients with chronic obstructive pulmonary disease. The mainstay of treating sCAP includes rapid ICU admission once a diagnosis has been confirmed, initiating sepsis protocol, and treatment with combined empiric antibiotic regimens consisting of beta-lactams and macrolides. Corticosteroid use alongside antibiotics shows promise in reducing inflammation, but its use has to be judged on a case-by-case basis. New drugs such as omadacycline, delafloxacin, and zabofloxacin have shown valid evidence for the treatment of resistant causative organisms. The main guidelines for preventing sCAP include maintaining a healthy lifestyle, and annual pneumococcal and influenza vaccines are recommended for the most vulnerable patient groups, such as those with COPD and immunosuppression.

Clinical characteristics, risk factors and outcomes of Klebsiella pneumoniae pneumonia developing secondary Klebsiella pneumoniae bloodstream infection

Purpose

The clinical characteristics of Klebsiella pneumoniae (KP) pneumonia and KP bloodstream infection (KP-BSI) are often reported, while the risk factors for KP pneumonia developing into secondary KP-BSI (KP-pneumonia/KP-BSI) are largely unknown. Therefore, this study attempted to investigate the clinical characteristics, risk factors and outcomes of KP-pneumonia/KP-BSI.

Methods

A retrospective observational study was conducted at a tertiary hospital between January 1, 2018, and December 31, 2020. The patients were divided into groups of KP pneumonia alone and KP pneumonia/KP-BSI, and the clinical information were collected from medical records electronic system.

Results

A total of 409 patients were finally recruited. According to the multivariate logistic regression analysis, male sex (adjusted odds ratio [aOR] 3.7; 95% CI, 1.44–9.5), immunosuppression (aOR, 13.52; 95% CI, 2.53,72.22), APACHE II score higher than 21 (aOR, 3.39; 95% CI, 1.41–8.12), serum procalcitonin (PCT) levels above 1.8 ng/ml (aOR, 6.37; 95% CI, 2.67–15.27), ICU stay of more than 2.5 days before pneumonia onset (aOR, 1.09; 95% CI, 1.02,1.17), mechanical ventilation (aOR, 4.96; 95% CI, 1.2,20.5), Klebsiella pneumoniae isolates producing extended spectrum β-lactamase (ESBL-positive KP) (aOR, 12.93; 95% CI, 5.26–31.76), and inappropriate antibacterial therapy (aOR, 12.38; 95% CI, 5.36–28.58) were independent factors of KP pneumonia/KP BSI. In comparison with the patients with KP pneumonia alone, the patients with KP pneumonia/KP BSI showed an almost 3 times higher incidence of septic shock (64.4% vs. 20.1%, p < 0.01), a longer duration of mechanical ventilation, and longer lengths of ICU stay and total hospital stay (median days, 15 vs. 4,19 vs. 6, 34 vs. 17, respectively, both p < 0.01). Additionally, the overall in-hospital crude mortality rate in the patients with KP-pneumonia/KP-BSI was more than two times higher than that in those with KP pneumonia alone (61.5% vs. 27.4%, p < 0.01).

Conclusion

Factors including male sex, immunosuppression, APACHE II score higher than 21, serum PCT levels above 1.8 ng/ml, ICU stay of more than 2.5 days before pneumonia onset, mechanical ventilation, ESBL-positive KP, and inappropriate antibacterial therapy are independent risk factors for KP pneumonia/KP-BSI. Of note, the outcomes in patients with KP pneumonia worsen once they develop secondary KP-BSI, which merits more attention.

Sepsis-induced Coagulopathy: The Different Prognosis in Severe Pneumonia and Bacteremia Infection Patients

Sepsis-induced coagulopathy (SIC) is a critical condition in sepsis patients, with varying outcomes depending on the type of infection. This study aims to analyze the prognosis of different infections in SIC cohort. A retrospective cohort study was conducted on 525 patients diagnosed with SIC in the intensive care unit from December 2013 to December 2022. These patients were divided into four groups: a non-pneumonia or bacteremia group, a severe pneumonia group, a bacteremia group, and a severe pneumonia concomitant with bacteremia group. The 28-day mortality was 18% (49/271) in the other infections group, 31% (33/106) in the lung infections group, 23% (29/126) in the blood infections group and 36% (8/36) in the lung and blood co-infections group, respectively. Pearson correlation analysis showed that procalcitonin (PCT) correlated strongly with all detected hemostatic markers (p < 0.001). The 28-day mortality rate in Lung infections group was significantly higher (p = 0.019), while Blood infections group had a higher incidence of disseminated intravascular coagulation (p = 0.011). By multivariable model analyses, longer duration of ventilation (p = 0.039) and severe pneumonia (p = 0.040) are risk factors associated with mortality. Different infections, including Lung and Blood infections, indicated different conditions in vivo. Longer duration of ventilation is associated with mortality, while Lung infections indicated higher 28-day mortality rate.

Platelet-monocyte interaction amplifies thromboinflammation through tissue factor signaling in COVID-19

Accumulating evidence into the pathogenesis of COVID-19 highlights a hypercoagulability state with high risk of life-threatening thromboembolic complications. However, the mechanisms of hypercoagulability and their link to hyperinflammation remain poorly understood. Here, we investigate functions and mechanisms of platelet activation and platelet-monocyte interactions in inflammatory amplification during SARS-CoV-2 infection. We used a combination of immunophenotyping, single-cell analysis, functional assays, and pharmacological approaches to gain insights on mechanisms. Critically ill patients with COVID-19 exhibited increased platelet-monocyte aggregates formation. We identified a subset of inflammatory monocytes presenting high CD16 and low HLA-DR expression as the subset mainly interacting with platelets during severe COVID-19. Single-cell RNA-sequencing analysis indicated enhanced fibrinogen receptor Mac-1 in monocytes from patients with severe COVID-19. Monocytes from patients with severe COVID-19 displayed increased platelet binding and hyperresponsiveness to P-selectin and fibrinogen with respect to tumor necrosis factor-α and interleukin-1β secretion. Platelets were able to orchestrate monocyte responses driving tissue factor (TF) expression, inflammatory activation, and inflammatory cytokines secretion in SARS-CoV-2 infection. Platelet-monocyte interactions ex vivo and in SARS-CoV-2 infection model in vitro reciprocally activated monocytes and platelets, inducing the heightened secretion of a wide panel of inflammatory mediators. We identified platelet adhesion as a primary signaling mechanism inducing mediator secretion and TF expression, whereas TF signaling played major roles in amplifying inflammation by inducing proinflammatory cytokines, especially tumor necrosis factor-α and interleukin-1β. Our data identify platelet-induced TF expression and activity at the crossroad of coagulation and inflammation in severe COVID-19.

A retrospective observational study of biomarker levels and severity assessment in pediatric community-acquired pneumonia

METHODS

A retrospective chart review was conducted on children (aged 60 days to 18 years) diagnosed with CAP, and admitted to a regional, tertiary hospital (Charleston, WV, USA) for 3 years (2015-2018). Patients were stratified into 2 severity cohorts, mild (no ICU care), and moderate/severe (required ICU care). Biomarker values were then compared between the severity cohorts and area under the curve (AUC), and cut-off values and performance characteristics were calculated.

RESULTS

A total of 108 patients met inclusion criteria with 46% having moderate/severe CAP. Elevated levels of CRP (51.7 mg/L in mild vs. 104.8 mg/L in moderate/severe, P = .003, PCT (0.29 ng/ml in mild vs. 4.02 ng/mL in moderate/severe, P = .001) and band counts (8% in mild vs. 15% moderate/severe, P = .009) were associated with increased pneumonia severity. In predicting moderate/severe CAP, PCT had the highest AUC of 0.77 (P = .001) followed by bands AUC of 0.69 (P = .009) and CRP AUC of 0.67 (P = .003). Cut-off for PCT of 0.55 ng/mL had a sensitivity of 83% and a specificity of 65%. Cut-off level of 53.1 mg/L for CRP had a sensitivity of 79% and specificity of 52%. Cut off level of 12.5% bands had a sensitivity of 61% and specificity of 71%. In a multivariable model controlled for patient demographics and other biomarker levels, only PCT levels significantly predicted moderate/severe CAP (adjusted odds ratio: 1.40 [95% CI, 1.14-1.73], P = .002).

CONCLUSION

Biomarkers, in particular PCT, obtained early in hospitalization may perform as possible predictors for CAP severity in children and be beneficial in guiding CAP management. However, biomarkers in pneumonia should not drive severity assessment or patient management independent of clinical presentation.

ARDS Clinical Practice Guideline 2021

BACKGROUND

The joint committee of the Japanese Society of Intensive Care Medicine/Japanese Respiratory Society/Japanese Society of Respiratory Care Medicine on ARDS Clinical Practice Guideline has created and released the ARDS Clinical Practice Guideline 2021.

METHODS

The 2016 edition of the Clinical Practice Guideline covered clinical questions (CQs) that targeted only adults, but the present guideline includes 15 CQs for children in addition to 46 CQs for adults. As with the previous edition, we used a systematic review method with the Grading of Recommendations Assessment Development and Evaluation (GRADE) system as well as a degree of recommendation determination method. We also conducted systematic reviews that used meta-analyses of diagnostic accuracy and network meta-analyses as a new method.

RESULTS

Recommendations for adult patients with ARDS are described: we suggest against using serum C-reactive protein and procalcitonin levels to identify bacterial pneumonia as the underlying disease (GRADE 2D); we recommend limiting tidal volume to 4-8 mL/kg for mechanical ventilation (GRADE 1D); we recommend against managements targeting an excessively low SpO2 (PaO2) (GRADE 2D); we suggest against using transpulmonary pressure as a routine basis in positive end-expiratory pressure settings (GRADE 2B); we suggest implementing extracorporeal membrane oxygenation for those with severe ARDS (GRADE 2B); we suggest against using high-dose steroids (GRADE 2C); and we recommend using low-dose steroids (GRADE 1B). The recommendations for pediatric patients with ARDS are as follows: we suggest against using non-invasive respiratory support (non-invasive positive pressure ventilation/high-flow nasal cannula oxygen therapy) (GRADE 2D), we suggest placing pediatric patients with moderate ARDS in the prone position (GRADE 2D), we suggest against routinely implementing NO inhalation therapy (GRADE 2C), and we suggest against implementing daily sedation interruption for pediatric patients with respiratory failure (GRADE 2D).

CONCLUSIONS

This article is a translated summary of the full version of the ARDS Clinical Practice Guideline 2021 published in Japanese (URL: https://www.jsicm.org/publication/guideline.html ). The original text, which was written for Japanese healthcare professionals, may include different perspectives from healthcare professionals of other countries.

ARDS clinical practice guideline 2021

BACKGROUND

The joint committee of the Japanese Society of Intensive Care Medicine/Japanese Respiratory Society/Japanese Society of Respiratory Care Medicine on ARDS Clinical Practice Guideline has created and released the ARDS Clinical Practice Guideline 2021.

METHODS

The 2016 edition of the Clinical Practice Guideline covered clinical questions (CQs) that targeted only adults, but the present guideline includes 15 CQs for children in addition to 46 CQs for adults. As with the previous edition, we used a systematic review method with the Grading of Recommendations Assessment Development and Evaluation (GRADE) system as well as a degree of recommendation determination method. We also conducted systematic reviews that used meta-analyses of diagnostic accuracy and network meta-analyses as a new method.

RESULTS

Recommendations for adult patients with ARDS are described: we suggest against using serum C-reactive protein and procalcitonin levels to identify bacterial pneumonia as the underlying disease (GRADE 2D); we recommend limiting tidal volume to 4-8 mL/kg for mechanical ventilation (GRADE 1D); we recommend against managements targeting an excessively low SpO₂ (PaO₂) (GRADE 2D); we suggest against using transpulmonary pressure as a routine basis in positive end-expiratory pressure settings (GRADE 2B); we suggest implementing extracorporeal membrane oxygenation for those with severe ARDS (GRADE 2B); we suggest against using high-dose steroids (GRADE 2C); and we recommend using low-dose steroids (GRADE 1B). The recommendations for pediatric patients with ARDS are as follows: we suggest against using non-invasive respiratory support (non-invasive positive pressure ventilation/high-flow nasal cannula oxygen therapy) (GRADE 2D); we suggest placing pediatric patients with moderate ARDS in the prone position (GRADE 2D); we suggest against routinely implementing NO inhalation therapy (GRADE 2C); and we suggest against implementing daily sedation interruption for pediatric patients with respiratory failure (GRADE 2D).

CONCLUSIONS

This article is a translated summary of the full version of the ARDS Clinical Practice Guideline 2021 published in Japanese (URL: https://www.jrs.or.jp/publication/jrs_guidelines/). The original text, which was written for Japanese healthcare professionals, may include different perspectives from healthcare professionals of other countries.

Serum MCP-1 and NGAL Play an Important Role in the Acute Inflammatory Event of Chronic Obstructive Pulmonary Disease

NGAL is mainly secreted by neutrophils which play the core role in AECOPD. MCP-1 is secreted specifically by monocytes and macrophages. Both biomarkers are involved in the core process of acute inflammatory reaction in COPD. So We analyzed serum NGAL and MCP-1levels to explore their potential clinical values in the chronic obstructive pulmonary disease (COPD) .This study enrolled 97 COPD patients and 50 healthy controls. All participants received blood collection and lung function test and arterial blood gas measurements. The expression levels of serum NGAL and MCP-1 were measured by ELISA. The serum NGAL and MCP-1 levels of COPD with community-acquired pneumonia (COPD-CAP) patients were significantly higher than those of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients and healthy adults. The NGAL levels of the GOLD III and IV groups were significantly higher than those of the GOLD II group. Spearman correlation analysis showed a negative correlation between NGAL and FEV1%pred, FVC% pred. ROC curves indicated that NGAL has a high diagnostic value for both AECOPD and COPD-CAP. NGAL has the value of distinguishing GOLD I and II from GOLD III and IV. MCP-1 have moderate diagnostic value for COPD-CAP and can differentiate COPD-CAP from AECOPD. This study shows NGAL has certain diagnostic value for AECOPD and COPD-CAP, but can not distinguish the two. NGAL is closely related to airway remodeling and can be used as a potential indicator to distinguish the higher GOLD degree. MCP-1 can be used as potential indicator for the diagnosis of COPD-CAP.

The effect of vitamin C on procalcitonin biomarker in community-acquired pneumonia

Introduction

Community acquired pneumonia (CAP) is a prevalent low respiratory infection. Diagnosis is based on clinical symptoms, radiologic evidence and culture. Biomarkers such as IL6, CRP and procalcitonin are helpful in diagnosis. Procalcitonin is a soluble biomarker in serum that increase in systemic inflammation and bacterial infections. People with normal procalcitonin have low risk to infect pneumonia. Patient with CAP have more oxidative stress than normal people. Studies show that receiving vitamin C can reduce incidence of pneumonia. The present study was designed to evaluate the effect of vitamin C supplement on procalcitonin biomarker in patient with CAP.

Methods

Patients with CAP who passed inclusion and exclusion criteria after obtaining informed consent, were assigned randomly in two groups of drug and placebo. The drug group received vitamin C (1000 mg/d) daily and medications that physician prescribed for treating CAP for 10 days and placebo group received placebo and medications that physician prescribed. The serum level of procalcitonin was measured at the beginning of the study and after 10 days of intervention.

Results

35 patients finished the study. Serum level of procalcitonin on the first and tenth day did not show any significant difference between drug and placebo groups.

Conclusions

To clarify the relationship between the effects of vitamin C on procalcitonin in CAP, a larger sample size is required.

Bronchoalveolar Lavage and Blood Markers of Infection in Critically Ill Patients-A Single Center Registry Study

Microbiological sampling is an indispensable targeted antibiotic therapy for critically ill patients. Invasive respiratory sampling by bronchoalveolar lavage (BAL) can be performed to obtain samples from the lower respiratory tract. It is debated as to whether blood markers of infection can predict the outcome of BAL in a medical intensive care unit (ICU). Retrospectively, all ICU patients undergoing BAL from 2009-2018 were included. A total of 468 BAL samples from 276 patients (average age 60 years, SAPS2 47, ICU-mortality 41.7%) were analyzed. At the time of BAL, 94.4% patients were mechanically ventilated, 92.9% had suspected pneumonia, 96.2% were on antibiotic therapy and 36.3% were immunocompromised. Relevant bacteria were cultured in 114/468 (24.4%) cases of BAL. Patients with relevant bacteria in the culture had a higher ICU mortality rate (45.6 vs. 40.4%, p = 0.33) and were significantly less likely to be on a steroid (36 vs. 52%, p < 0.01) or antimycotic (14.9 vs. 34.2%, p < 0.01), while procalcitonin (PCT), C-reactive protein (CRP), and white blood cell (WBC) counts were similar. The area under the receiver operating curve (AUC) values for positive culture and PCT, CRP and WBC counts were low (0.53, 0.54 and 0.51, respectively). In immunocompromised patients, AUC values were higher (0.65, 0.57 and 0.61, respectively). Therefore, microbiological cultures by BAL revealed relevant bacteria in 24.4% of samples. Our data, therefore, might suggest that indication for BAL should not be based on blood markers of infection.

Platelet activation and platelet-monocyte aggregate formation trigger tissue factor expression in patients with severe COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emergent pathogen responsible for the coronavirus disease 2019 (COVID-19). Since its emergence, the novel coronavirus has rapidly achieved pandemic proportions causing remarkably increased morbidity and mortality around the world. A hypercoagulability state has been reported as a major pathologic event in COVID-19, and thromboembolic complications listed among life-threatening complications of the disease. Platelets are chief effector cells of hemostasis and pathological thrombosis. However, the participation of platelets in the pathogenesis of COVID-19 remains elusive. This report demonstrates that increased platelet activation and platelet-monocyte aggregate formation are observed in severe COVID-19 patients, but not in patients presenting mild COVID-19 syndrome. In addition, exposure to plasma from severe COVID-19 patients increased the activation of control platelets ex vivo. In our cohort of COVID-19 patients admitted to the intensive care unit, platelet-monocyte interaction was strongly associated with tissue factor (TF) expression by the monocytes. Platelet activation and monocyte TF expression were associated with markers of coagulation exacerbation as fibrinogen and D-dimers, and were increased in patients requiring invasive mechanical ventilation or patients who evolved with in-hospital mortality. Finally, platelets from severe COVID-19 patients were able to induce TF expression ex vivo in monocytes from healthy volunteers, a phenomenon that was inhibited by platelet P-selectin neutralization or integrin α_IIb/β₃ blocking with the aggregation inhibitor abciximab. Altogether, these data shed light on new pathological mechanisms involving platelet activation and platelet-dependent monocyte TF expression, which were associated with COVID-19 severity and mortality.

Diagnostic markers for community-acquired pneumonia

Community-acquired pneumonia (CAP) is one of the respiratory infectious diseases caused by not only bacteria, but also viruses. Antibiotic agents are needed to treat only bacterial but not viral CAP. In addition, there are some non-infectious respiratory diseases in the differential diagnosis of CAP, such as malignant diseases, interstitial lung diseases, pulmonary edema, and pulmonary hemorrhage. We usually diagnose patients having CAP by comprehensive evaluation of symptoms, vital signs, laboratory examinations, and radiographic examinations. However, symptoms and vital signs are not specific for the diagnosis of CAP; therefore, we also use inflammatory biomarkers for differentiating bacterial from viral CAP and non-infectious respiratory diseases. We have used the white blood cell count, C-reactive protein (CRP), and erythrocyte sedimentation rate as common inflammatory biomarkers, but they are not specific for bacterial infection because they could be increased by malignant diseases and collagen diseases. Recently, some inflammatory biomarkers such as procalcitonin (PCT), soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), pro-adrenomedullin (proADM), and presepsin have been developed as relatively specific biomarkers for bacterial infection. Many reports have evaluated the usefulness of PCT for diagnosing CAP. In this review, the characteristics of each biomarker are discussed based on previous studies.

Procalcitonin as a biomarker for critically ill patients with sepsis: Effects of vitamin D supplementation

Early diagnosis of sepsis is often difficult in clinical practice, whilst it can be vital for positive patient outcomes in sepsis management. Any delay in diagnosis and treatment may lead to significant organ failure and can be associated with elevated mortality rates. Early diagnosis and effective management of sepsis can allow for prompt antibiotic therapy and a potential reduction in mortality; it can also minimize the unnecessary use of antibiotics. Furthermore, vitamin D supplementation, which is commonly used in the intensive care units to reduce mortality, may interfere with the ability to use procalcitonin (PCT) as a means of assessing clinical progression. This paper aims to explore the diagnostic and prognostic value of serum levels of PCT as an early marker of sepsis and to assess whether it can be used as a guide for using antibiotic therapy. Several serum-based biomarkers such as C-reactive protein, lactate, presepsin, and cytokines, such as interleukin-1 (IL-1), and IL-6 have been evaluated as early indicators of sepsis but none have been proven sensitive and/or specific enough to make a definitive diagnosis. Finally the potential benefits and disadvantages of using serum levels of PCT to diagnose and monitor patients with sepsis and septic shock will be briefly discussed.

Procalcitonin Levels in Critically Ill Children With Status Asthmaticus

BACKGROUND

Children with status asthmaticus (SA) often present with fever and are evaluated with chest radiographs (CXRs). In the absence of a confirmatory test for bacterial infection, antibiotics are started whenever there are radiological infiltrates or if there is a suspicion of pneumonia. We undertook this study to determine if serum procalcitonin (PCT) levels at admission are altered in critically ill children with SA. We also sought to determine if serum PCT levels are elevated in children with radiological infiltrates or in children who were treated with antibiotics.

METHODS

This is a prospective single-center observational study evaluating serum PCT levels in critically ill children with SA. Study subjects included children 1 to 21 years old, admitted to a pediatric intensive care unit (PICU) with SA between March 2012 and April 2013. For the purposes of this study, patients whose CXRs were read by the radiologist as probable bacterial pneumonia was defined as having "radiological bacterial pneumonia," whereas patients who received antibiotics by the treating physician were defined as having "clinician-diagnosed pneumonia."

RESULTS

Sixty-one patients with a median age of 7.3 years (interquartile range, 4-10 years) were included in the study. Fifty-one percent were male. Average Pediatric Risk of Mortality III score was 2.7 (SD, 2.9). Three patients (5%) were determined to have radiological bacterial pneumonia, whereas 52 (85%) did not. Six patients (10%) were indeterminate. The mean PCT level for all patients was 0.65 (SD, 1.54) ng/mL, whereas the median PCT level was 0.3 ng/mL. There was no significant difference in the mean PCT levels between the patients with and without clinician-diagnosed pneumonia (0.33 [SD, 0.36] vs 0.69 [SD, 1.67], P = 0.44). Using a PCT cutoff level of 0.5 ng/mL, a significant association was found with the presence of fever (P = 0.004), but no significant association was found with the presence of CXR infiltrates, radiological bacterial pneumonia, hospital length of stay, PICU length of stay, Pediatric Risk of Mortality III scores, or receipt of antibiotics.

CONCLUSIONS

Serum PCT level was not elevated to greater than 0.5 ng/mL in 75% of this cohort of critically ill children with SA admitted to PICU. Presence of CXR infiltrates was not associated with higher PCT levels. Large clinical trials are needed to study the diagnostic and predictive role of PCT in this patient population.

Early prediction of treatment failure in severe community-acquired pneumonia: The PRoFeSs score

PURPOSE

To identify a single/panel of biomarkers and to provide a point score that, after 48 h of treatment, could early predict treatment failure at fifth day of Intensive Care Unit (ICU) stay in severe community-acquired pneumonia (SCAP) patients.

MATERIALS AND METHODS

Single-center, prospective cohort study of 107 ICU patients with SCAP. Primary outcome included death or absence of improvement in Sequential Organ Failure Assessment score by ≥2 points within 5 days of treatment. Biomarkers were evaluated within 12 h of first antibiotic dose (D1) and 48 h after the first assessment (D3).

RESULTS

A model based on Charlson's score and a panel of biomarkers (procalcitonin on D1 and D3, B-natriuretic peptide on D1, D-dimer and lactate on D3) had good discrimination for primary outcome in both derivation (AUC 0.82) and validation (AUC 0.76) samples and was well calibrated (X² = 0.98; df = 1; p = .32). A point score system (PRoFeSs score) built on the estimates of regression coefficients presented good discrimination (AUC 0.81; 95% Confidence Interval 0.72-0.89) for primary outcome.

CONCLUSIONS

In SCAP, a combination of biomarkers measured at admission and 48 h later may early predict treatment failure. PRoFeSs score may recognize patients with poor short-term prognosis.

Procalcitonin is not an independent predictor of 30-day mortality, albeit predicts pneumonia severity in patients with pneumonia acquired outside the hospital

Background

Procalcitonin (PCT) is a useful marker for pneumonia. However, its clinical usefulness in elderly patients has not been studied extensively. This study aimed to assess the relationship between PCT and prognosis and pneumonia severity in elderly patients with pneumonia acquired outside the hospital.

Methods

Data considered relevant to pneumonia severity and prognosis were retrospectively obtained from clinical charts of all patients with pneumonia who were admitted to our hospital from 2010 to 2017. The primary outcome was 30-day mortality in elderly patients (aged ≥75 years), and the relationship between PCT levels and pneumonia severity, as determined by the pneumonia severity index (PSI) was also examined.

Results

Data were collected from 667 patients, of which 436 were elderly patients. Multivariate and receiver operating characteristic curve analysis revealed that albumin, body mass index, and PSI class rather than PCT are important factors related to 30-day mortality in elderly patients. PCT was also not an independent prognostic factor in younger patients. PCT levels significantly differed by pneumonia severity (mild, moderate, and severe) in both younger (p < 0.001) and elderly (p < 0.0001) patients, with levels increasing as severity increased. In contrast, C-reactive protein (CRP) levels and white blood cell counts did not significantly differ by pneumonia severity in younger and elderly patients. A subgroup analysis focused on Streptococcus pneumoniae pneumonia revealed that PCT levels differed by severity in elderly patients (p = 0.03), with levels increasing as severity increased.

Conclusion

PCT was not an independent predictor of 30-day mortality in both of elderly and younger patients. PCT levels, but not CRP levels, significantly increased with increasing pneumonia severity in younger and elderly patients, although the degree of increase tended to be lower in elderly patients compared to younger patients for the same severity. PCT levels also significantly increased with increasing pneumonia severity in elderly patients with Streptococcus pneumoniae pneumonia.

Value of procalcitonin for diagnosing perioperative pneumonia, urinary infections and superficial surgical site infections in patients undergoing primary hip and knee arthroplasty

Serum procalcitonin (PCT) levels may be helpful for the diagnosis of infections during the perioperative period of arthroplasty. However, there is much debate in the literature regarding the appropriate cut-off value for different types of surgery and local bacterial infection. The present study aimed to evaluate serum PCT levels in patients undergoing arthroplasty and to determine the cut-off value that may represent perioperative pneumonia, urinary infections and superficial surgical site infections. The present retrospective study included a total of 500 patients treated between July 2014 and August 2015. The case group contained 25 patients with perioperative infections (pneumonia, urinary and superficial surgical site infections), and the control group contained 25 patients without any post-surgical complications. Serum levels of PCT and white blood cells (WBC) were measured pre-operatively (D0) and at post-operative D4, D6 and D8, and the sensitivity, specificity and predictive value of these parameters were assessed. Regarding the comparison of the mean PCT levels between the case and the control group, a significant difference was seen at D8 (P=0.007), while no significant differences were observed at D0 (P=0.010), D4 (P=0.069) and D6 (P=0.093). No statistically significant differences in WBC levels between groups were observed for (P>0.01). In the control group, the PCT levels at D4 (0.062±0.020 ng/ml) were 2-fold of the mean baseline value, followed by a decrease until D6 (0.051±0.019 ng/ml) and a return close to the normal range by D8 (0.032±0.015 ng/ml). The PCT levels in the case group had rapidly increased on D4 (0.510±1.208 ng/ml). In contrast to the control group, they continuously increased on D6 (0.527±1.360 ng/ml) and D8 (0.686±1.117 ng/ml). From a clinical point of view, infection events were indicated in these patients during post-operative follow-up. For PCT, the area under the receiver operating characteristic curve (AUC) was 0.978 [95% confidence interval (CI), 0.933-1.022], and for WBC, the AUC was 0.562 (95% CI, 0.398-0.0.726). Based on the above data, the PCT value was a significant predictor of infection (AUC>0.9). For PCT, the cut-off point of 0.0995 ng/ml was associated with a sensitivity of 96% and a specificity of 100%. However, WBC were not a significant predictor of infection (0.5<AUC<0.7), and the cut-off value of 7.05×10⁹/l was associated with a sensitivity of 64% and a specificity of 44%. In conclusion PCT was found to be a promising marker for diagnosing bacterial infections post-arthroplasty due to its high specificity. Based on the sensitivity and the specificity, detecting PCT may be more valuable than using WBC in the diagnosis of sepsis-associated pathological changes in the perioperative period.

Prognostic scores and biomarkers for pediatric community-acquired pneumonia: how far have we come?

This article aimed to review the current prognostic and diagnostic tools used for community-acquired pneumonia (CAP) and highlight those potentially applicable in children with CAP. Several scoring systems have been developed to predict CAP mortality risk and serve as guides for admission into the intensive care unit. Over the years, clinicians have adopted these tools for improving site-of-care decisions because of high mortality rates in the extremes of age. The major scoring systems designed for geriatric patients include the Pneumonia Severity Index and the confusion, uremia, respiratory rate, blood pressure, age >65 years (CURB-65) rule, as well as better predictors of intensive care unit admission, such as the systolic blood pressure, multilobar chest radiography involvement, albumin level, respiratory rate, tachycardia, confusion, oxygenation and arterial pH (SMART-COP) score, the Infectious Diseases Society of America/American Thoracic Society guidelines, the criteria developed by España et al as well as the systolic blood pressure, oxygenation, age and respiratory rate (SOAR) criteria. Only the modified predisposition, insult, response and organ dysfunction (PIRO) score has so far been applied to children with CAP. Because none of the tools is without its limitations, there has been a paradigm shift to incorporate biomarkers because they are reliable diagnostic tools and good predictors of disease severity and outcome, irrespective of age group. Despite the initial preponderance of reports on their utility in geriatric CAP, much progress has now been made in demonstrating their usefulness in pediatric CAP.

Elevated Omentin Serum Levels Predict Long-Term Survival in Critically Ill Patients

Introduction. Omentin, a recently described adipokine, was shown to be involved in the pathophysiology of inflammatory and infectious diseases. However, its role in critical illness and sepsis is currently unknown. Materials and Methods. Omentin serum concentrations were measured in 117 ICU-patients (84 with septic and 33 with nonseptic disease etiology) admitted to the medical ICU. Results were compared with 50 healthy controls. Results. Omentin serum levels of critically ill patients at admission to the ICU or after 72 hours of ICU treatment were similar compared to healthy controls. Moreover, circulating omentin levels were independent of sepsis and etiology of critical illness. Notably, serum concentrations of omentin could not be linked to concentrations of inflammatory cytokines or routinely used sepsis markers. While serum levels of omentin were not predictive for short term survival during ICU treatment, low omentin concentrations were an independent predictor of patients' overall survival. Omentin levels strongly correlated with that of other adipokines (e.g., leptin receptor or adiponectin), which have also been identified as prognostic markers in critical illness. Conclusions. Although circulating omentin levels did not differ between ICU-patients and controls, elevated omentin levels were predictive for an impaired patients' long term survival.

Prognostic value of on admission arterial PCO2 in hospitalized patients with community-acquired pneumonia

BACKGROUND

There is little data about the correlation between the outcome of community acquired pneumonia (CAP) and the hypercapnic type respiratory failure. In this study we prospectively investigated the prognostic significance of first arterial CO₂ tension in patients hospitalized with CAP.

METHODS

In this prospective study patients with CAP, admitted to a general hospital were included. PaCO₂ was measured for each subject in an arterial blood sample drawn in the first 2 hours and its correlations with three major outcomes were evaluated: intensive care unit (ICU) admission, duration of admission and mortality in 30 days.

RESULTS

A total of 114 patients (mean age: 60.9±18.3; male: 51.8%) diagnosed with CAP were included. Significant relationship was not found between PaCO₂ and mortality (P=0.544) or ICU admission (P=0.863). However advanced age, associated CHF, high BUN levels, high CURB-65 scores, associated pleural effusion in chest X-ray and being admitted to the ICU (P=0.012, 0.004, 0.003, <0.001, 0.045 and <0.001 respectively) were all significant prognostic factors of higher mortality risks. Prognostic factors for ICU admission were a history of malignancy (P=0.004), higher CURB-65 (P<0.001) scores and concomitant pleural effusion (P=0.028) in chest X-ray. Hypercapnic patients hospitalized for longer duration compared with normocapnic subjects. Furthermore, patients with lower pH (P=0.041) and pleural effusions (P=0.002) were hospitalized longer than the others.

CONCLUSIONS

There was less prominent prognostic value regarding on-admission PaCO₂ in comparison to other factors such as CURB-65. Considering the inconsistent results of surveys conducted on prognostic value of PaCO₂ for CAP outcomes, further investigations are required to reach a consensus on this matter.

Emerging infection and sepsis biomarkers: will they change current therapies?

INTRODUCTION

Sepsis is a heterogeneous syndrome characterized by both immune hyperactivity and relative immune suppression. Biomarkers have the potential to improve recognition and management of sepsis through three main applications: diagnosis, monitoring response to treatment, and stratifying patients based on prognosis or underlying biological response.

AREAS COVERED

This review focuses on specific examples of well-studied, evidence-supported biomarkers, and discusses their role in clinical practice with special attention to antibiotic stewardship and cost-effectiveness. Biomarkers were selected based on availability of robust prospective trials and meta-analyses which supported their role as emerging tools to improve the clinical management of sepsis. Expert commentary: Great strides have been made in candidate sepsis biomarker discovery and testing, with the biomarkers in this review showing promise. Yet sepsis remains a dynamic illness with a great degree of biological heterogeneity - heterogeneity which may be further resolved by recently discovered gene expression-based endotypes in septic shock.

Prognostic value of Pneumonia Severity Index, CURB-65, CRB-65, and procalcitonin in community-acquired pneumonia in Singapore

Objective:

The purpose of this study was to evaluate the performance of three severity scoring tools and procalcitonin (PCT) in severity stratification and mortality prediction among patients with community-acquired pneumonia (CAP) in Singapore.

Methods:

The method used was a retrospective observational study of all the consecutive patients with CAP admitted through the emergency department of Singapore General Hospital between 2012–2013.

Results:

Among 1902 study subjects, the overall 30-day mortality was 15.7%. The mortality rates for Pneumonia Severity Index (PSI) class I–III were 0, 0, and 3.7%, which were comparable to the original published data. CURB-65 and CRB-65 had higher mortality rates in all severity levels. In three levels of risk stratification, the low risk group of PSI (class I–III) included 42.6% of the patients with mortality rate of 1.9%, whereas the low risk group defined by CURB-65 (score 0–1) and CRB-65 (score 0) included 52.0% and 24.4% of the patients with higher mortality rates (7.3% and 4.5% respectively). PSI was the most sensitive in mortality prediction with area under receiver operating characteristic (ROC) curve of 0.82, higher than CURB-65 (0.71), CRB-65 (0.67), and PCT (0.63) ( p<0.001). The initial level of PCT was higher in non-survivors and intensive care unit (ICU)-admitted patients compared to survivors (0.91 vs 0.36 ng/ml, p<0.001) and non-ICU patients (3.70 vs 0.38 ng/ml, p<0.001). Incorporating PCT did not improve the discriminatory power of the scoring tools for mortality prediction.

Conclusions:

PSI was a reliable tool for severity stratification and morality prediction among the patients with CAP in Singapore.

Serial inflammatory biomarkers of the severity, course and outcome of late onset acute respiratory distress syndrome in critically ill patients with or at risk for the syndrome after new-onset fever

AIM

Accurate biomarkers of the acute respiratory distress syndrome (ARDS) may help risk stratification and management. We assessed the relation between several biomarkers and the severity, course and outcome of late onset ARDS in 101 consecutive critically ill patients with new onset fever.

MATERIALS AND METHODS

On study days 0, 1, 2 and 7 we measured angiopoietin-2 (ANG2), pentraxin-3 (PTX3), interleukin-6 (IL-6), procalcitonin (PCT) and midregional proadrenomedullin (proADM). ARDS was defined by the Berlin definition and by the lung injury score (LIS).

RESULTS

At baseline, 48% had ARDS according to the Berlin definition and 86% according to the LIS. Baseline markers poorly predicted maximum Berlin categories attained within 7 days, whereas ANG2 best predicted maximum LIS. Depending on the ARDS definition, the day-by-day area under the receiver operating characteristic curves suggested greatest monitoring value for IL-6 and PCT, followed by ANG2. ANG2 and proADM predicted outcome, independently of disease severity.

CONCLUSION

Whereas IL-6 and PCT had some disease monitoring value, ANG2 was the only biomarker capable of both predicting the severity, monitoring the course and predicting the outcome of late onset ARDS in febrile critically ill patients, irrespective of underlying risk factor, thereby yielding the most specific ARDS biomarker among those studied.

Prognostic value of procalcitonin in pneumonia: A systematic review and meta-analysis

This meta-analysis was performed to determine the accuracy of procalcitonin (PCT) in predicting mortality in pneumonia patients with different pathogenic features and disease severities. A systematic search of English-language articles was performed using PubMed, Embase, Web of Knowledge and the Cochrane Library to identify studies. The diagnostic value of PCT in predicting prognosis was determined using a bivariate meta-analysis model. The Q-test and I(2) index were used to test heterogeneity. A total of 21 studies comprising 6007 patients were included. An elevated PCT level was a risk factor for death from community-acquired pneumonia (CAP) (risk ratio (RR) 4.38, 95% confidence interval (CI) 2.98-6.43), particularly in patients with a low CURB-65 score. The commonly used cut-off, 0.5 ng/mL, had low sensitivity (SEN) and was not able to identify patients at high risk of dying. Furthermore, the PCT assay with functional SEN <0.1 ng/mL was necessary to predict mortality in CAP in the clinic. For critically ill patients, an elevated PCT level was associated with an increased risk of mortality (RR 4.18, 95% CI: 3.19-5.48). The prognostic performance was nearly equal between patients with ventilator-associated pneumonia (VAP) and patients with CAP.

Utility of procalcitonin, C-reactive protein and white blood cells alone and in combination for the prediction of clinical outcomes in community-acquired pneumonia

BACKGROUND

The added value of biomarkers, such as procalcitonin (PCT), C-reactive protein (CRP), and white blood cells (WBC), as adjuncts to clinical risk scores for predicting the outcome of patients with community-acquired pneumonia (CAP) is in question. We investigated the prognostic accuracy of initial and follow-up levels of inflammatory biomarkers in predicting death and adverse clinical outcomes in a large and well-defined cohort of CAP patients.

METHODS

We measured PCT, CRP and WBC on days 1, 3, 5, and 7 and followed the patients over 30 days. We applied multivariate regression models and area under the curve (AUC) to investigate associations between these biomarkers, the clinical risk score CURB-65, and clinical outcomes [i.e., death and intensive care unit (ICU) admission].

RESULTS

Of 925 patients with CAP, 50 patients died and 118 patients had an adverse clinical outcome. None of the initial biomarker levels significantly improved the CURB-65 score for mortality prediction. Follow-up biomarker levels showed significant independent association with mortality at days 3, 5, and 7 and with improvements in AUC. Initial PCT and CRP levels were independent prognostic predictors of adverse clinical outcome, and levels of all biomarkers during the course of disease provided additional prognostic information.

CONCLUSIONS

This study provides robust insights into the added prognostic value of inflammatory markers in CAP. Procalcitonin, CRP, and to a lesser degree WBC provided some prognostic information on CAP outcomes, particularly when considering their kinetics at days 5 and 7 and when looking at adverse clinical outcomes instead of mortality alone.

Polymorphism rs2239185 in vitamin D receptor gene is associated with severe community-acquired pneumonia of children in Chinese Han population: a case-control study

Vitamin D receptor (VDR) is a potential candidate gene for community-acquired pneumonia (CAP). Examining the susceptibility VDR gene for CAP is essential for early intervention, prevention of related complications, and improvement of outcome. A case-control study was performed to examine the association between rs2239185 of VDR gene and CAP among children in Chinese Han population. Polymerase chain reaction and direct sequencing were used to genotype rs2239185 in 91 CAP children and 94 healthy children. For rs2239185, individuals with TT genotype showed a significantly higher risk of CAP than those with CC plus CT genotypes (P = 0.008). The occurrence of T allele of rs2239185 was significantly more frequent in CAP children than those in normal controls (P = 0.045).We found through stratification analysis that CAP children with systemic inflammatory response syndrome (SIRS), leukocyte count (WBC) >10 × 10(9)/L, C-reactive protein (CRP) >25 mg/L, procalcitonin (PCT) >2 ng/mL, and pediatric critical illness score <80 scores showed significantly higher frequency of TT genotype than those in normal controls (P = 0.0012, 0.0035, 0.0005, 0.0002, and 0.0021, respectively).

CONCLUSION

TT genotype of rs2239185 in VDR gene might be one of the potential genetic risk factors for CAP, and T allele of rs2239185 might be associated with the susceptibility to CAP and the severity of CAP.

Procalcitonin, a valuable biomarker assisting clinical decision-making in the management of community-acquired pneumonia

BACKGROUND AND AIM

Community-acquired pneumonia (CAP) is a leading cause of mortality, morbidity and hospital admission, which places strain on our healthcare system. Procalcitonin (PCT) is a biomarker of bacterial infection which may help gauge the severity and prognosis of patients with CAP. In addition to clinical predictors, PCT may assist in decisions pertaining to timing of discharge from hospital and the discontinuation of antibiotics. This study aimed to determine the predictive role of PCT measurement in reducing hospital admissions, length of stay (LOS) and antibiotic (AB) usage in patients with CAP.

METHODS

A prospective, single-blinded, externally controlled study of consenting adult patients admitted with CAP. PCT levels were obtained on day 1 and day 3 (when indicated). Investigator-evaluated clinical parameters, together with results of PCT levels, determined the timing of oral AB switch and discharge from hospital. This process was compared against standard practice, but was not actually implemented, for the purpose of this study.

RESULTS

Sixty patients were included in the study. The mean age was 66.5 ± 21.2 years (56.3% male). The average Pneumonia Severity Index was 93 ± 39 (class IV) and the median CURB-65 was 2. The mean LOS for the standard practice cohort was 5.3 ± 4.6 days versus calculated LOS using the PCT guidance pathway of 3.7 ± 2.8 days. (P = 0.00006).

CONCLUSIONS

Our study supports the hypothesis that by incorporation of PCT levels, hospital admission and LOS in patients with CAP can be reduced. A randomised prospective clinical trial is planned in an attempt to help confirm these findings.

Elevated plasma stromal-cell-derived factor-1 protein levels correlate with severity in patients with community-acquired pneumonia

BACKGROUND

The aim of this study was to investigate differential changes in plasma levels of stromal-cell-derived factor-1 (SDF-1) before and after antibiotic treatment in patients with community-acquired pneumonia (CAP) and observe the association between the severity of CAP and the plasma SDF-1 level.

METHODS

We gathered blood specimens from 61 adult CAP patients before and after antibiotic treatment and from 60 healthy controls to measure the plasma concentrations of SDF-1 by using an enzyme-linked immunosorbent assay.

RESULTS

The plasma SDF-1 concentration was elevated significantly in patients with CAP before receiving treatment compared with the controls and decreased significantly after the patients received treatment. Leukocyte (WBC) and neutrophil counts and C-reactive protein (CRP) levels decreased significantly after antibiotic treatment. Moreover, differences in the plasma concentration of SDF-1 were significantly correlated with PSI, CURB-65, and APACHE II scores (r = 0.389, P = 0.002, and n = 61; r = 0.449, P < 0.001, and n = 61; and r = 0.363, P = 0.004, and n = 61, resp.).

CONCLUSIONS

An elevated plasma SDF-1 concentration can be used as a biological marker for the early diagnosis of CAP and for the early detection of its severity.

Serum C-reactive protein and procalcitonin kinetics in patients undergoing elective total hip arthroplasty

BACKGROUND

The sensitivity and the specificity of different methods to detect periprosthetic infection have been questioned. The current study aimed to investigate the kinetics of C-reactive protein (CRP) and procalcitonin (PCT) in patients undergoing uncomplicated elective total hip arthroplasty (THA), to provide a better interpretation of their levels in noninfectious inflammatory reaction.

METHODS

A total of 51 patients were included. Serum CRP and PCT concentrations were obtained before surgery, on the 1st, 3rd, and 7th postoperative days and after discharge on the 14th and 30th days and at 2 years.

RESULTS

Both markers were confirmed to increase after surgery. The serum CRP showed a marked increase on the 3rd postoperative day while the peak of serum PCT was earlier, even if much lower, on the first day. Then, they declined slowly approaching the baseline values by the second postoperative week. PCT mean values never exceed concentrations typically related to bacterial infections.

CONCLUSIONS

CRP is very sensitive to inflammation. It could be the routine screening test in the follow-up of THA orthopaedic patients, but it should be complemented by PCT when there is the clinical suspicion of periprosthetic infection.

Procalcitonin for diagnosis of bacterial pneumonia in critically ill patients during 2009 H1N1 influenza pandemic: a prospective cohort study, systematic review and individual patient data meta-analysis

Introduction

Procalcitonin (PCT) is helpful for diagnosing bacterial infections. The diagnostic utility of PCT has not been examined thoroughly in critically ill patients with suspected H1N1 influenza.

Methods

Clinical characteristics and PCT were prospectively assessed in 46 patients with pneumonia admitted to medical ICUs during the 2009 and 2010 influenza seasons. An individual patient data meta-analysis was performed by combining our data with data from five other studies on the diagnostic utility of PCT in ICU patients with suspected 2009 pandemic influenza A(H1N1) virus infection identified by performing a systematic literature search.

Results

PCT levels, measured within 24 hours of ICU admission, were significantly elevated in patients with bacterial pneumonia (isolated or coinfection with H1N1; n = 77) (median = 6.2 μg/L, interquartile range (IQR) = 0.9 to 20) than in patients with isolated H1N1 influenza pneumonia (n = 84; median = 0.56 μg/L, IQR = 0.18 to 3.33). The area under the curve of the receiver operating characteristic curve of PCT was 0.72 (95% confidence interval (CI) = 0.64 to 0.80; P < 0.0001) for diagnosis of bacterial pneumonia, but increased to 0.76 (95% CI = 0.68 to 0.85; P < 0.0001) when patients with hospital-acquired pneumonia and immune-compromising disorders were excluded. PCT at a cut-off of 0.5 μg/L had a sensitivity (95% CI) and a negative predictive value of 80.5% (69.9 to 88.7) and 73.2% (59.7 to 84.2) for diagnosis of bacterial pneumonia, respectively, which increased to 85.5% (73.3 to 93.5) and 82.2% (68.0 to 92.0) in patients without hospital acquired pneumonia or immune-compromising disorder.

Conclusions

In critically ill patients with pneumonia during the influenza season, PCT is a reasonably accurate marker for detection of bacterial pneumonia, particularly in patients with community-acquired disease and without immune-compromising disorders, but it might not be sufficient as a stand-alone marker for withholding antibiotic treatment.

Coupled Plasma Filtration and Adsorption (CPFA): A Single Center Experience

Background

Coupled plasma filtration adsorption (CPFA) is a novel extracorporeal blood purification therapy for sepsis which adsorbs both proinflammatory and anti-inflammatory mediators from filtered plasma, thereby achieving early haemodynamic stability and a reduction in inotropic support requirement.

Objectives

The main objective was to review our centers' experience with CPFA in septic patients.

Patients and Methods

A retrospective chart review of all septic patients who received CPFA was performed. All patients were initially treated according to the ‘surviving sepsis care bundle’ with fluid resuscitation, antibiotics, and inotropes as required. CPFA was started as soon as possible after a nephrologists’ assessment.

Results

Twenty five patients with sepsis received CPFA (15 M, 10 F, mean age 49.60 ± 18.97 years). Comorbidities included hypertension (n = 10, 40%), diabetes mellitus (n = 6, 24%), ischemic heart disease (n = 6, 24%), and an immunosuppressed state (n = 10, 40%). All patients received one cycle of CPFA with median duration of 5 (1-10) hours. CPFA was well tolerated but we encountered technical problems, especially filter clotting as CPFA was performed heparin free. 14 (56%) patients died within 28 days of treatment. CRP correlated with PCT (P = 0.040) and had an inverse trend with albumin (P = 0.066). Serum albumin was a strong predictor of mortality.

Conclusions

The high prevalence of fungaemia and mortality could be attributed to many patients on chronic immunosuppressive therapy. Nonetheless, CPFA albeit expensive, does add to our armamentarium of extracorporeal treatment for severe sepsis. Regional citrate anticoagulation with CPFA may overcome problems with filter clotting.

Coupled Plasma Filtration Adsorption (CPFA) plus Continuous Veno-Venous Haemofiltration (CVVH) versus CVVH alone as an adjunctive therapy in the treatment of sepsis

PURPOSE

To compare the efficacy of Coupled Plasma Filtration and Adsorption (CPFA) plus Continuous Veno-Venous Haemofiltration (CVVH) versus CVVH alone as an adjunct treatment of sepsis in terms of haemodynamic stability, inotropic requirement and inflammatory mediators.

DESIGN AND METHODS

Prospective randomized controlled trial involving septic patients with/without acute kidney injury (AKI) whom were randomized to receive CPFA + CVVH or CVVH alone. Haemodynamic parameters including inotropic requirements and inflammatory mediators [procalcitonin (PCT) and C reactive protein (CRP)] were measured.

RESULTS

Twenty-three patients [CPFA + CVVH (n = 11), CVVH (n = 12)] were enrolled. Haemodynamic stability occurred earlier and sustained in the CPFA + CVVH group with an increase in diastolic blood pressure (p = 0.001 vs. p = 0.226) and mean arterial pressure (p = 0.001 vs. p = 0.575) at the end of treatment with no increment in inotropic requirement. Both groups had a reduction in PCT and CRP (CPFA + CVVH: p = 0.003, p = 0.026 and CVVH: p = 0.008, p = 0.071 respectively). The length of intensive care unit stay, hospital stay and 30 day outcomes were similar between the groups. There was an inverse association between serum albumin and CRP (p = 0.018). Serum albumin positively correlated with systolic blood pressure (p = 0.012) and diastolic blood pressure (p = 0.009). We found a trend between CRP and length of hospital stay (p = 0.056). Patients with a lower PCT at 24 h had a better outcome (survival) than those with a higher PCT (p = 0.045).

CONCLUSION

CPFA is a feasible, albeit expensive adjunctive extracorporeal treatment that may be superior to CVVH alone in the treatment of severe sepsis.

Biomarkers in community-acquired pneumonia: a state-of-the-art review

Community-acquired pneumonia (CAP) exhibits mortality rates, between 20% and 50% in severe cases. Biomarkers are useful tools for searching for antibiotic therapy modifications and for CAP diagnosis, prognosis and follow-up treatment. This non-systematic state-of-the-art review presents the biological and clinical features of biomarkers in CAP patients, including procalcitonin, C-reactive protein, copeptin, pro-ANP (atrial natriuretic peptide), adrenomedullin, cortisol and D-dimers.

Blood urea nitrogen to serum albumin ratio independently predicts mortality and severity of community-acquired pneumonia

Background

Early studies of community-acquired pneumonia showed that nonsurvivors had higher blood urea nitrogen levels and lower serum albumin levels than survivors. Therefore, elevation of the blood urea nitrogen to serum albumin (B/A) ratio may identify patients with community-acquired pneumonia who are becoming critically ill. This study investigated the correlation between commonly used laboratory markers, in particular the B/A ratio, and clinical outcomes of community-acquired pneumonia.

Methods

This observational study was performed in consecutive patients with community-acquired pneumonia admitted to our hospital over a period of one year. Blood counts, commonly used laboratory markers, microbiological tests, and calculation of Pneumonia Severity Index (PSI) and CURB-65 were done on admission. The endpoints were mortality within 28 days of admission and requirement for intensive care.

Results

One hundred and seventy-five patients with community-acquired pneumonia were enrolled. Nineteen patients died within 28 days of admission and 29 patients required intensive care. Using multivariate analysis, independent factors associated with mortality were the requirement for intensive care (odds ratio [OR] 14.96, 95% confidence interval [CI] 3.73–60.03, P < 0.001), PSI class (OR 3.55, 95% CI 1.08–11.66, P = 0.037), and B/A ratio (OR 1.10, 95% CI 1.01–1.20, P = 0.037). Similarly, independent factors associated with need for intensive care were PSI class (OR 5.35, 95% CI 1.90–15.06, P = 0.002), CURB-65 (OR 2.37, 95% CI 1.26–4.45, P = 0.007), and B/A ratio (OR 1.27, 95% CI 1.09–1.47, P = 0.002).

Conclusion

The B/A ratio is a simple but independent predictor of mortality and severity of community-acquired pneumonia.

The role of biomarkers in low respiratory tract infections

Low respiratory tract infections (LRTI) represent the leading infectious cause of death worldwide and account for substantial use of healthcare resources. Physicians must adopt practices focused on improving outcomes and serum biomarker can help them in the management of patients with LRTI. Several studies have been carried out or are currently ongoing to evaluate the role of various biomarkers for the differential diagnosis, definition of prognosis, treatment and duration of antibiotic therapy in respiratory infections. The objective of this position paper of the Italian Society of Respiratory Diseases (SIMER) is to provide evidence-based recommendations for the use of biomarkers in routine clinical practice in the management of adult patients with LRTI. These guidelines capture the use of biomarkers both outside and inside the hospital, focused on community-acquired pneumonia, acute exacerbations of chronic obstructive pulmonary disease, hospital-acquired and ventilator-acquired pneumonia.

Usefulness of a semi-quantitative procalcitonin test and the A-DROP Japanese prognostic scale for predicting mortality among adults hospitalized with community-acquired pneumonia

BACKGROUND AND OBJECTIVE

The solid-phase immunoassay, semi-quantitative procalcitonin (PCT) test (B R A H M S PCT-Q) can be used to rapidly categorize PCT levels into four grades. However, the usefulness of this kit for determining the prognosis of adult patients with community-acquired pneumonia (CAP) is unclear.

METHODS

A prospective study was conducted in two Japanese hospitals to evaluate the usefulness of this PCT test in determining the prognosis of adult patients with CAP. The accuracy of the age, dehydration, respiratory failure, orientation disturbance, pressure (A-DROP) scale proposed by the Japanese Respiratory Society for prediction of mortality due to CAP was also investigated. Hospitalized CAP patients (n = 226) were enrolled in the study. Comprehensive examinations were performed to determine PCT and CRP concentrations, disease severity based on the A-DROP, pneumonia severity index (PSI) and confusion, urea, respiratory rate, blood pressure, age ≥65 (CURB-65) scales and the causative pathogens. The usefulness of the biomarkers and prognostic scales for predicting each outcome were then examined.

RESULTS

Twenty of the 170 eligible patients died. PCT levels were strongly positively correlated with PSI (ρ = 0.56, P < 0.0001), A-DROP (ρ = 0.61, P < 0.0001) and CURB-65 scores (ρ = 0.58, P < 0.0001). The areas under the receiver operating characteristic curves (95% CI) for prediction of survival, for CRP, PCT, A-DROP, CURB-65, and PSI were 0.54 (0.42-0.67), 0.80 (0.70-0.90), 0.88 (0.82-0.94), 0.88 (0.82-0.94), and 0.89 (0.85-0.94), respectively. The 30-day mortality among patients who were PCT-positive (≥0.5 ng/mL) was significantly higher than that among PCT-negative patients (log-rank test, P < 0.001).

CONCLUSIONS

The semi-quantitative PCT test and the A-DROP scale were found to be useful for predicting mortality in adult patients with CAP.

Decisional procalcitonin thresholds are not adapted to elderly patients admitted to the emergency room

CONTEXT

Diagnosis of sepsis in elderly is challenging.

OBJECTIVES

We investigated whether procalcitonin concentrations in elderly differed from values for the general population.

METHODS

Procalcitonin measurement was assessed prospectively in 307 apyretic patients ≥75 years visiting the emergency department.

RESULTS

Median age was 86 years [IQR81-90] and 222 (72%) were female. Procalcitonin concentration was 0.057 µg/L [0.040-0.092]; 99th percentile was 0.661 µg/L. Patients with procalcitonin concentrations above decisional thresholds had lower glomerular filtration rate and higher C-reactive protein concentrations.

CONCLUSIONS

Baseline procalcitonin levels are increased in elderly. Elevated values are common and associated to low-grade inflammation and lower eGFR.

Diagnostic and prognostic value of procalcitonin in community-acquired pneumonia

INTRODUCTION

The value of measuring procalcitonin (PCT) in patients with community-acquired pneumonia (CAP) is unclear. The aim of this study was to determine the value of PCT as a marker for microbial etiology and a predictor of outcome in CAP patients.

METHODS

A single-center observational study was conducted with CAP patients. On admission, their leukocyte count, serum C-reactive protein level, and serum PCT level were determined, and microbiological tests were performed. Patients were classified into 4 groups according to the A-DROP scoring system, which assesses the severity of CAP.

RESULTS

A total of 102 patients were enrolled. The pathogen was identified in 60 patients, and 31 patients had streptococcal pneumonia. The PCT levels were significantly higher in those patients with pneumococcal pneumonia than in those patients with other bacterial pneumonias (P < 0.0001). Multivariate regression analysis revealed that high PCT levels were associated with a pneumococcal etiology [odds ratio, 1.68; 95% confidence interval (CI): 1.02-2.81; P = 0.04] after adjustment for disease severity and demographic factors. The PCT levels were correlated with the A-DROP score (r = 0.49; P < 0.0001). The area under the curve for predicting mortality was highest for the A-DROP score (0.97; 95% CI: 0.92-0.99), followed by the area under the curve for PCT (0.82; 95% CI: 0.74-0.89) and C-reactive protein (0.77; 95% CI: 0.67-0.84).

CONCLUSIONS

High PCT levels indicate that pneumococcal pneumonia and PCT levels depend on the severity of pneumonia. PCT measurements may provide important diagnostic and prognostic information for patients with CAP.

Correlation of serum procalcitonin with the severity of skin and skin structure infections - a pilot study

BACKGROUND

Procalcitonin (PCT) is a specific biomarker for early detection of bacterial infections. While the usefulness of procalcitonin in severe conditions such as sepsis is well established, its relevance in the diagnosis and prognosis of localized cutaneous bacterial infections is unknown. Our aim was to initially evaluate if PCT is a useful parameter for predicting the severity of skin and skin structure infections (SSSI). Furthermore, the correlation of PCT levels with C-reactive protein (CRP), leukocyte counts, erythrocyte sedimentation rate (ESR), and body temperature was investigated.

PATIENTS AND METHODS

Serum PCT, routine laboratory parameters, and body temperature were regularly examined in 50 consecutive patients with SSSI requiring inpatient intravenous antibiotic treatment. Patients were classified into 2 groups according to the guidelines developed by the FDA (U.S. Food and Drug Administration) as having either an uncomplicated (SSSI) or a complicated skin and skin structure infection (cSSSI).

RESULTS

No significant correlation could be detected between the length of inpatient antibiotic treatment and PCT on days 1, 2, 3, and the maximum value on these days. The same result was found when uncomplicated SSSI and complicated SSSI (cSSSI) were evaluated separately. However, PCT levels were significantly higher in the latter. Furthermore, PCT levels showed a significant correlation with CRP, leukocyte count, ESR, and body temperature.

CONCLUSION

PCT might be a useful additional tool for initial diagnosis and monitoring of patients with SSSI.

Is mid-regional pro-atrial natriuretic peptide (MRproANP) an accurate marker of bacteremia in pyelonephritis?

INTRODUCTION

Mid-regional pro-atrial natriuretic peptide (MRproANP) increases during systemic infections and could possibly correlate with bacteremia.

METHODS

We determined the characteristics of MRproANP for accuracy to detect positive blood culture.

RESULTS

Bacteremia was positive in 58 (15%) of 347 patients. MRproANP levels increased in patients with bacteremia (98.4 pmol/L [interquartile range (IQR) 68.2-153.1] vs. 66.4 pmol/L [IQR 51.0-90.3], p <0.01). Performance of MRproANP to predict bacteremia [AUC = 0.69, 95%CI: 0.61-0.77] was equivalent to C-reactive protein (0.66 [95%CI: 0.59-0.74], p = 0.53) but less accurate than procalcitonin (0.78 [95%CI: 0.72-0.84], p <0.001).

CONCLUSION

Although MRproANP increased in bacteremic patients with acute pyelonephritis, results of likelihood ratios discarded its use at bedside to predict bacteremia.

Multinational, observational study of procalcitonin in ICU patients with pneumonia requiring mechanical ventilation: a multicenter observational study

Introduction

The intent of this study was to determine whether serum procalcitonin (PCT) levels are associated with prognosis, measured as organ dysfunctions and 28-day mortality, in patients with severe pneumonia.

Methods

This was a multicenter, observational study of critically ill adult patients with pneumonia requiring mechanical ventilation conducted in 10 academic hospitals in Canada, the United States, and Central Europe. PCT was measured daily for 14 days using an immuno-luminometric assay.

Results

We included 175 patients, 57 with community acquired pneumonia (CAP), 61 with ventilator associated pneumonia (VAP) and 57 with hospital acquired pneumonia (HAP). Initial PCT levels were higher in CAP than VAP patients (median (interquartile range: IQR); 2.4 (0.95 to 15.8) vs. 0.7 (0.3 to 2.15), ng/ml, P < 0.001) but not significantly different to HAP (2.2 (0.4 to 8.0) ng/ml). The 28-day ICU mortality rate for all patients was 18.3% with a median ICU length of stay of 16 days (range 1 to 142 days). PCT levels were higher in non-survivors than in survivors. Initial and maximum PCT levels correlated with maximum Sequential Organ Failure Assessment (SOFA) score r² = 0.50 (95% CI: 0.38 to 0.61) and r² = 0.57 (0.46 to 0.66), respectively. Receiver operating curve (ROC) analysis on discrimination of 28-day mortality showed areas under the curve (AUC) of 0.74, 0.70, and 0.69 for maximum PCT, initial PCT, and Acute Physiology and Chronic Health Evaluation (APACHE) II score, respectively. The optimal cut-off to predict mortality for initial PCT was 1.1 ng/ml (odds ratio: OD 7.0 (95% CI 2.6 to 25.2)) and that for maximum PCT was 7.8 ng/ml (odds ratio 5.7 (95% CI 2.5 to 13.1)).

Conclusions

PCT is associated with the severity of illness in patients with severe pneumonia and appears to be a prognostic marker of morbidity and mortality comparable to the APACHE II score.