Are prognostic scores and biomarkers such as procalcitonin the appropriate prognostic precursors for elderly patients with sepsis in the emergency department?

Plasminogen System in the Pathophysiology of Sepsis: Upcoming Biomarkers

Severe hemostatic disturbances and impaired fibrinolysis occur in sepsis. In the most serious cases, the dysregulation of fibrinolysis contributes to septic shock, disseminated intravascular coagulation (DIC), and death. Therefore, an analysis of circulating concentrations of pro- and anti-fibrinolytic mediators could be a winning strategy in both the diagnosis and the treatment of sepsis. However, the optimal cutoff value, the timing of the measurements, and their combination with coagulation indicators should be further investigated. The purpose of this review is to summarize all relevant publications regarding the role of the main components of the plasminogen activation system (PAS) in the pathophysiology of sepsis. In addition, the clinical value of PAS-associated biomarkers in the diagnosis and the outcomes of patients with septic syndrome will be explored. In particular, experimental and clinical trials performed in emergency departments highlight the validity of soluble urokinase plasminogen activator receptor (suPAR) as a predictive and prognostic biomarker in patients with sepsis. The measurements of PAI-I may also be useful, as its increase is an early manifestation of sepsis and may precede the development of thrombocytopenia. The upcoming years will undoubtedly see progress in the use of PAS-associated laboratory parameters.

Diagnostic and Prognostic Roles of Procalcitonin and Other Tools in Community-Acquired Pneumonia: A Narrative Review

Community-acquired pneumonia (CAP) is among the most common causes of death and one of the leading healthcare concerns worldwide. It can evolve into sepsis and septic shock, which have a high mortality rate, especially in critical patients and comorbidities. The definitions of sepsis were revised in the last decade as "life-threatening organ dysfunction caused by a dysregulated host response to infection". Procalcitonin (PCT), C-reactive protein (CRP), and complete blood count, including white blood cells, are among the most commonly analyzed sepsis-specific biomarkers also used in pneumonia in a broad range of studies. It appears to be a reliable diagnostic tool to expedite care of these patients with severe infections in the acute setting. PCT was found to be superior to most other acute phase reactants and indicators, including CRP as a predictor of pneumonia, bacteremia, sepsis, and poor outcome, although conflicting results exist. In addition, PCT use is beneficial to judge timing for the cessation of antibiotic treatment in most severe infectious states. The clinicians should be aware of strengths and weaknesses of known and potential biomarkers in expedient recognition and management of severe infections. This manuscript is intended to present an overview of the definitions, complications, and outcomes of CAP and sepsis in adults, with special regard to PCT and other important markers.

The timing of use of risk stratification tools affects their ability to predict mortality from sepsis. A meta-regression analysis

Background: Risk stratification tools (RSTs) are used in healthcare settings to identify patients at risk of sepsis and subsequent adverse outcomes. In practice RSTs are used on admission and thereafter as ‘trigger’ tools prompting sepsis management. However, studies investigating their performance report scores at a single timepoint which varies in relation to admission. The aim of this meta-analysis was to determine if the predictive performance of RSTs is altered by the timing of their use. Methods: We conducted a systematic review and meta-regression analysis of studies published from inception to 31 October 2018, using EMBASE and PubMed databases. Any cohort studies investigating the ability of an RST to predict mortality in adult sepsis patients admitted to hospital, from which a 2x2 table was available or could be constructed, were included. The diagnostic performance of RSTs in predicting mortality was the primary outcome. Sensitivity, specificity, positive predictive value, negative predictive value and area under the receiver-operating curve (AUROC) were the primary measures, enabling further meta-regression analysis. Results: 47 studies were included, comprising 430,427 patients. Results of bivariate meta-regression analysis found tools using a first-recorded score were less sensitive than those using worst-recorded score (REML regression coefficient 0.57, 95% CI 0.07-1.08). Using worst-recorded score led to a large increase in sensitivity (summary sensitivity 0.76, 95% CI 0.67-0.83, for worst-recorded scores vs. 0.64 (0.57-0.71) for first-recorded scores). Scoring system type did not have a significant relationship with studies’ predictive ability. The most analysed RSTs were qSOFA (n=37) and EWS (n=14). Further analysis of these RSTs also found timing of their use to be associated with predictive performance. Conclusion: The timing of any RST is paramount to their predictive performance. This must be reflected in their use in practice, and lead to prospective studies in future.

Tissue Kallikrein Exacerbating Sepsis-Induced Endothelial Hyperpermeability is Highly Predictive of Severity and Mortality in Sepsis

Aim

Sepsis, an acute, life-threatening dysregulated response to infection, affects practically all aspects of endothelial function. Tissue kallikrein (TK) is a key enzyme in the kallikrein–kinin system (KKS) which has been implicated in endothelial permeability. Thus, we aimed to establish a potentially novel association among TK, endothelial permeability, and sepsis demonstrated by clinical investigation and in vitro studies.

Methods

We performed a clinical investigation with the participation of a total of 76 controls, 42 systemic inflammatory response syndrome (SIRS) patients, and 150 patients with sepsis, who were followed-up for 28 days. Circulating TK levels were measured with an enzyme-linked immunosorbent assay. Then, the effect of TK on sepsis-induced endothelial hyperpermeability was evaluated by in vitro study.

Results

Data showed a gradual increase in TK level among controls and the patients with SIRS, sepsis, and septic shock (0.288±0.097 mg/l vs 0.335±0.149 vs 0.495±0.170 vs 0.531±0.188 mg/l, respectively, P <0.001). Further analysis revealed that plasma TK level was positively associated with the severity and mortality of sepsis and negatively associated with event-free survival during 28 days of follow-up (relative risk, 3.333; 95% CI, 2.255–4.925; p < 0.001). With a septic model of TK and kallistatin in vitro, we found that TK exacerbated sepsis-induced endothelial hyperpermeability by downregulating zonula occluden-1 (ZO-1) and vascular endothelial (VE)-cadherin, and these could be reversed by kallistatin, an inhibitor of TK.

Conclusion

TK can be used in the diagnosis of sepsis and assessment of severity and prognosis of disease. Inhibition of TK may be a novel therapeutic target for sepsis through increasing ZO-1 and VE-cadherin, as well as downregulating endothelial permeability.

Clinical Outcome Predictive Value of Procalcitonin in Patients Suspected with Infection in the Emergency Department

Procalcitonin (PCT) may be useful for early risk stratification in the emergency department (ED), but the transposition of published data to routine emergency practice is sometimes limited. An observational retrospective study was conducted in the adult ED of the Reims University Hospital (France). Over one year, 852 patients suspected of infection were included, of mean age 61.7 years (SD: 22.6), and 624 (73.2%) were hospitalized following ED visit. Overall, 82 (9.6%) patients died during their hospitalization with an odds ratio (OR) of 5.10 (95% CI: 2.19-11.87) for PCT ≥ 0.5, in multivariate logistic regression analyses. Moreover, 78 (9.2%) patients were admitted to an ICU, 74 (8.7%) had attributable bacteremia, and 56 (6.6%) evolved toward septic shock with an OR of 4.37 (2.08-9.16), 6.38 (2.67-15.24), and 6.38 (2.41-16.86), respectively, for PCT ≥ 0.5. The highest discriminatory values were found for patients with age <65 years, but PCT lost its discrimination power for in-hospital mortality in patients with a bronchopulmonary infection site or a temperature ≥37.8°C and for ICU admission in patients with severe clinical presentations. PCT could be helpful in risk stratification, but several limitations must be considered, including being sometimes outperformed by a simple clinical examination.

Infections in the older population: what do we know?

The incidence of infections increases with age and results in a higher risk of morbidity and mortality. This rise is not mainly related to chronological age per se but has been linked mostly to individual factors such as immunosenescence; the presence of comorbidities; the occurrence of geriatric syndromes such as poor nutrition, polypharmacy, and cognitive disorders; and the presence of functional impairment concomitant with environmental, healthcare-related and microbiological factors such as the increasing risk of multidrug-resistant microorganisms. The geriatric concept of frailty introduces a new approach for considering the risk of infection; this concept highlights the importance of functional status and is a more comprehensive and multicomponent approach that may help to reverse the vulnerability to stress. The aim of this article is to provide some typical hallmarks of infections among older adults in comparison to younger individuals. The main differences among the older population that are presented are an increased prevalence of infections and potential risk factors, a higher risk of carrying multidrug-resistant microorganisms, an increase in barriers to a prompt diagnosis related to atypical presentations and challenges with diagnostic tools, a higher risk of under- and over-diagnosis, a worse prognosis with a higher risk of acute and chronic complications and a particular need for better communication among all healthcare sectors as they are closely linked together.

The Effects of Initial Procalcitonin Levels on Mortality Rates in Geriatric Patients Undergoing Surgery

Introduction

The aim of the current study is to investigate the relationship between mortality rate in geriatric patients undergoing surgery with preoperative serum levels of procalcitonin, C-reactive protein, and erythrocyte sedimentation rate.

Methods

This was a single-center retrospective study, including three groups with 101 patients, who are older than 65 years of age. A retrospective investigation was carried out from the laboratory information system for all groups from January to December 2018. Group 1 included patients who had surgery and then mortality within 30 days after surgery. Group 2 included hospitalized patients who had surgery and no mortality within 30 days after surgery. Group 3 included outpatient patients, who had suspicion for a bacterial infection and then no surgery or no mortality within 30 days.

Results

When three group comparisons were made for procalcitonin, C-reactive protein, and erythrocyte sedimentation rate values, the p-value of one-way analysis of variance (ANOVA) was higher than 0.05 for procalcitonin and lower than 0.05 for C-reactive protein and erythrocyte sedimentation rate, suggesting that one or more groups were significantly different. When post-hoc multiple comparison methods were applied, there were statistically significant differences between Groups 1 and 3 for C-reactive protein and erythrocyte sedimentation rate.

Conclusions

Procalcitonin levels do not predict mortality following surgery. C-reactive protein and erythrocyte sedimentation rate are more useful biomarkers predicting mortality in geriatric patients undergoing surgery.

Predictive value of C-reactive protein and NT-pro-BNP levels in sepsis patients older than 75 years: a prospective, observational study

INTRODUCTION

Using biomarkers to predict mortality in patients with sepsis is important because these patients frequently have high mortality rates and unsatisfactory outcomes. The performance of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) and C-reactive protein (CRP) to predict clinical outcomes in elderly sepsis patients is unimpressive. We aimed to assess the prognostic value of NT-pro-BNP, CRP and the combination of both in selected medical ICU sepsis patients more than 75 years old.

METHODS

In total, 245 consecutive patients were screened for eligibility and followed during their ICU stays. We collected the patients' baseline characteristics, including their Acute Physiology and Chronic Health Evaluation II (APACHE II) scores and NT-pro-BNP and CRP levels. The primary outcome was ICU mortality. Potential predictors were analyzed for their possible associations with the outcome. We also evaluated the ability of NT-pro-BNP and CRP levels combined with the APACHE II score to predict ICU mortality by calculating the C-index and net reclassification improvement (NRI).

RESULTS

Univariate regression revealed that CRP, NT-pro-BNP, APACHE II score, lactic acid level, NEU count(neutrophil count)and HCT level independently predicted ICU mortality (all P < 0.01). The C-index for the prediction of ICU mortality by the APACHE II score (0.847 ± 0.029; P < 0.001) was greater than that for NT-pro-BNP (0.673 ± 0.039; P < 0.01) or CRP (0.626 ± 0.039; P < 0.01) (all P < 0.01). Compared with the APACHE II score (0.847 ± 0.029; P < 0.001), the combination of CRP (0.849 ± 0.029; P < 0.01) or NT-pro-BNP (0.853 ± 0.028; P < 0.01) or both (0.853 ± 0.030; P < 0.01) with the APACHE II score did not significantly increase the C-index for predicting ICU mortality (all P > 0.05). However, the addition of NT-pro-BNP to the APACHE II score gave an NRI of 8.6% (P = 0.000), the addition of CRP to the APACHE II score provided an NRI of 11.34% (P = 0.012), and the addition of both markers to the APACHE II score yielded an NRI of 29.0% (P = 0.000). In the MOF subgroup (N = 118), CRP (OR = 2.62, P < 0.05) but not NT-pro-BNP (OR = 1.73, p > 0.05) independently predicted ICU mortality, and the addition of CRP to the APACHE II score obviously increased its predictive ability (NRI = 13.88%, P = 0.000). In the non-MOF group (N = 127), neither CRP (OR = 5.447, P = 0.078) nor NT-pro-BNP (OR = 2.239, P = 0.016) was an independent predictor of ICU mortality.

CONCLUSIONS

In sepsis patients older than 75 years, NT-pro-BNP and CRP can serve as independent predictors of mortality, and the addition of NT-pro-BNP or CRP or both to the APACHE II score significantly improves the ability to predict ICU mortality. CRP appears to be useful for predicting ICU outcomes in elderly sepsis patients with multiple-organ failure.

Predicting Prolonged Intensive Care Unit Stay Among Patients With Sepsis-Induced Hypotension

BACKGROUND

Sepsis risk stratification tools typically predict mortality, although stays in the intensive care unit (ICU) of 24 hours or longer may be more clinically relevant for emergency department disposition.

OBJECTIVE

To explore predictors of ICU stay of 24 hours or longer among infected, hypotensive emergency department patients.

METHODS

A secondary analysis of 2 prospective, observational studies of adult patients with severe sepsis or an infection with a systolic blood pressure less than 90 mm Hg in 3 urban, academic emergency departments was performed. Patients with hypotension and infection were included. Patients with emergency department intubation, vasopressor administration, and/or death were excluded. The primary outcome was ICU stay of 24 hours or longer or death in less than 24 hours. Multivariable logistic regression was used to predict ICU stay of 24 hours or longer.

RESULTS

Of 233 patients, 108 (46.4%) had ICU stays of 24 hours or longer. History of heart failure (odds ratio, 3.6; 95% CI, 1.5-8.3), bicarbonate level less than 20 mEq/L (odds ratio, 2.0; 95% CI, 1.1-3.8), respiratory rate greater than 20/min (odds ratio, 2.0; 95% CI, 1.1-3.7), and creatinine level greater than 2.0 mg/dL (odds ratio, 3.6; 95% CI, 1.9-6.7) were independent predictors of ICU stay of 24 hours or longer (area under curve, 0.74). The presence of 1 of these factors predicted ICU stay of 24 hours or longer (area under curve, 0.74) with 82.4% sensitivity and 49.6% specificity.

CONCLUSIONS

These exploratory results show that heart failure, bicarbonate level of less than 20 mEq/L, tachypnea, or creatinine level greater than 2.0 mg/dL increases the likelihood of an ICU stay of 24 hours or longer among infected, hypotensive emergency department patients.

Age-Related Changes in Immunological and Physiological Responses Following Pulmonary Challenge

This review examines the current status of knowledge of sepsis and pneumonia in the elderly population and how the dynamics of the pulmonary challenge affects outcome and consequences. Led by an unprecedented shift in demographics, where a larger proportion of the population will reach an older age, clinical and experimental research shows that aging is associated with certain pulmonary changes, but it is during infectious insult of the lungs, as in the case of pneumonia, that the age-related differences in responsiveness and endurance become obvious and lead to a worse outcome than in the younger population. This review points to the neutrophil, and the endothelium as important players in understanding age-associated changes in responsiveness to infectious challenge of the lung. It also addresses how the immunological set-point influences injury-repair phases, remote organ damage and how intake of drugs may alter the state of responsiveness in the users. Further, it points out the importance of considering age as a factor in inclusion criteria in clinical trials, in vitro/ex vivo experimental designs and overall interpretation of results.

Age-dependent cellular reactions of the human immune system of humanized NOD scid gamma mice on LPS stimulus

Despite sepsis being a life-threatening disease, targeted drugs that improve the therapy of affected patients are still lacking. Infants and adults differ in the maturity level of their immune system and this results in distinct reactions to Gram-negative bacteria. To study reactions of human immune cells in vivo, we used NOD scid gamma mice transplanted with human CD34⁺ stem cells to engraft a functional human immune system. Human cells undergo differentiation and maturation in these mice after transplantation and, accordingly, animals were divided into two groups: 8-13 wk and 15-22 wk after transplantation. Endotoxemia was induced by injecting LPS. Six h later, mice were euthanized. In both groups, LPS stimulation induced a decrease of CD14⁺ monocytes in peripheral blood, an up-regulation of activation markers on different cell subsets such as myeloid dendritic cells, and a release of the human cytokines TNF-α, IL-6 and IL-10. However, significant differences were detected with regard to the amounts of released cytokines, and 8-13-wk-old mice produced more IL-6, while PTX3 was mainly released by 15-22-wk-old animals. Thus, here we provide a potential model for preclinical research of sepsis in infants and adults.

Sepsis and Other Infectious Disease Emergencies in the Elderly

Waning immunity and declining anatomic and physiologic defenses render the elder vulnerable to a wide range of infectious diseases. Clinical presentations are often atypical and muted, favoring global changes in mental status and function over febrile responses or localizing symptoms. This review encompasses early recognition, evaluation, and appropriate management of these common infections specifically in the context of elders presenting to the emergency department. With enhanced understanding and appreciation of the unique aspects of infections in the elderly, emergency physicians can play an integral part in reducing the morbidity and mortality associated with these often debilitating and life-threatening diseases.