Trends in vital signs and routine biomarkers in patients with sepsis during resuscitation in the emergency department: a prospective observational pilot study

Predicting deterioration of patients with early sepsis at the emergency department using continuous heart rate variability analysis: a model-based approach

BACKGROUND

Sepsis is a life-threatening disease with an in-hospital mortality rate of approximately 20%. Physicians at the emergency department (ED) have to estimate the risk of deterioration in the coming hours or days and decide whether the patient should be admitted to the general ward, ICU or can be discharged. Current risk stratification tools are based on measurements of vital parameters at a single timepoint. Here, we performed a time, frequency, and trend analysis on continuous electrocardiograms (ECG) at the ED to try and predict deterioration of septic patients.

METHODS

Patients were connected to a mobile bedside monitor that continuously recorded ECG waveforms from triage at the ED up to 48 h. Patients were post-hoc stratified into three groups depending on the development of organ dysfunction: no organ dysfunction, stable organ dysfunction or progressive organ dysfunction (i.e., deterioration). Patients with de novo organ dysfunction and those admitted to the ICU or died were also stratified to the group of progressive organ dysfunction. Heart rate variability (HRV) features over time were compared between the three groups.

RESULTS

In total 171 unique ED visits with suspected sepsis were included between January 2017 and December 2018. HRV features were calculated over 5-min time windows and summarized into 3-h intervals for analysis. For each interval, the mean and slope of each feature was calculated. Of all analyzed features, the average of the NN-interval, ultra-low frequency, very low frequency, low frequency and total power were different between the groups at multiple points in time.

CONCLUSIONS

We showed that continuous ECG recordings can be automatically analyzed and used to extract HRV features associated with clinical deterioration in sepsis. The predictive accuracy of our current model based on HRV features derived from the ECG only shows the potential of HRV measurements at the ED. Unlike other risk stratification tools employing multiple vital parameters this does not require manual calculation of the score and can be used on continuous data over time. Trial registration The protocol of this study is published by Quinten et al., 2017.

National Early Warning Score and New-Onset Atrial Fibrillation for Predicting In-Hospital Mortality or Transfer to the Intensive Care Unit in Emergency Department Patients with Suspected Bacterial Infections

Purpose

There are conflicting data regarding the role of the National Early Warning Score 2 (NEWS2) in predicting adverse outcomes in patients with infectious diseases. New-onset atrial fibrillation (NO-AF) has been suggested as a sepsis-defining sign of organ dysfunction. This study aimed to examine the prognostic accuracy of NEWS2 and whether NO-AF can provide prognostic information in emergency department (ED) patients with suspected bacterial infections.

Patients and Methods

Secondary analyses of data from a prospective observational cohort study of adults admitted in a 6-month period with suspected bacterial infections. We used the composite endpoint of in-hospital mortality or transfer to the intensive care unit as the primary outcome. The prognostic accuracy of NEWS2 and quick sequential organ failure assessment (qSOFA) and covariate-adjusted area under the receiver operating curves (AAUROC) were used to describe the performance of the scores. Logistic regression analysis was used to examine the association between NO-AF and the composite endpoint.

Results

A total of 2055 patients were included in this study. The composite endpoint was achieved in 198 (9.6%) patients. NO-AF was observed in 80 (3.9%) patients. The sensitivity and specificity for NEWS2 ≥5 were 70.2% (63.3-76.5) and 60.2% (57.9-62.4), respectively, and those for qSOFA ≥2 were 26.3% (20.3-33.0) and 91.0% (89.6-92.3), respectively. AAUROC for NEWS2 and qSOFA were 0.68 (0.65-0.73) and 0.63 (0.59-0.68), respectively. The adjusted odds ratio for achieving the composite endpoint in 48 patients with NO-AF who fulfilled the NEWS2 ≥5 criteria was 2.71 (1.35-5.44).

Conclusion

NEWS2 had higher sensitivity but lower specificity and better, albeit poor, discriminative ability to predict the composite endpoint compared to qSOFA. NO-AF can provide important prognostic information.

Frequency of alterations in qSOFA, SIRS, MEWS and NEWS scores during the emergency department stay in infectious patients: a prospective study

BACKGROUND

For emergency department (ED) patients with suspected infection, a vital sign-based clinical rule is often calculated shortly after the patient arrives. The clinical rule score (normal or abnormal) provides information about diagnosis and/or prognosis. Since vital signs vary over time, the clinical rule scores can change as well. In this prospective multicentre study, we investigate how often the scores of four frequently used clinical rules change during the ED stay of patients with suspected infection.

METHODS

Adult (≥ 18 years) patients with suspected infection were prospectively included in three Dutch EDs between March 2016 and December 2019. Vital signs were measured in 30-min intervals and the quick Sequential Organ Failure Assessment (qSOFA) score, the Systemic Inflammatory Response Syndrome (SIRS) criteria, the Modified Early Warning Score and the National Early Warning Score (NEWS) score were calculated. Using the established cut-off points, we analysed how often alterations in clinical rule scores occurred (i.e. switched from normal to abnormal or vice versa). In addition, we investigated which vital signs caused most alterations.

RESULTS

We included 1433 patients, of whom a clinical rule score changed once or more in 637 (44.5%) patients. In 6.7-17.5% (depending on the clinical rule) of patients with an initial negative clinical rule score, a positive score occurred later during ED stay. In over half (54.3-65.0%) of patients with an initial positive clinical rule score, the score became negative later on. The respiratory rate caused most (51.2%) alterations.

CONCLUSION

After ED arrival, alterations in qSOFA, SIRS, MEWS and/or NEWS score are present in almost half of patients with suspected infection. The most contributing vital sign to these alterations was the respiratory rate. One in 6-15 patients displayed an abnormal clinical rule score after a normal initial score. Clinicians should be aware of the frequency of these alterations in clinical rule scores, as clinical rules are widely used for diagnosis and/or prognosis and the optimal moment of assessing them is unknown.

Rethinking animal models of sepsis - working towards improved clinical translation whilst integrating the 3Rs

Sepsis is a major worldwide healthcare issue with unmet clinical need. Despite extensive animal research in this area, successful clinical translation has been largely unsuccessful.

We propose one reason for this is that, sometimes, the experimental question is misdirected or unrealistic expectations are being made of the animal model.

As sepsis models can lead to a rapid and substantial suffering – it is essential that we continually review experimental approaches and undertake a full harm:benefit impact assessment for each study. In some instances, this may require refinement of existing sepsis models. In other cases, it may be replacement to a different experimental system altogether, answering a mechanistic question whilst aligning with the principles of reduction, refinement and replacement (3Rs).

We discuss making better use of patient data to identify potentially useful therapeutic targets which can subsequently be validated in preclinical systems. This may be achieved through greater use of construct validity models, from which mechanistic conclusions are drawn. We argue that such models could provide equally useful scientific data as face validity models, but with an improved 3Rs impact. Indeed, construct validity models may not require sepsis to be modelled, per se. We propose that approaches that could support and refine clinical translation of research findings, whilst reducing the overall welfare burden on research animals.

Early hemodynamic assessment using NICOM in patients at risk of developing Sepsis immediately after emergency department triage

Background

One factor leading to the high mortality rate seen in sepsis is the subtle, dynamic nature of the disease, which can lead to delayed detection and under-resuscitation. This study investigated whether serial hemodynamic parameters obtained from a non-invasive cardiac output monitor (NICOM) predicts disease severity in patients at risk for sepsis.

Methods

Prospective clinical trial of the NICOM device in a convenience sample of adult ED patients at risk for sepsis who did not have obvious organ dysfunction at the time of triage. Hemodynamic data were collected immediately following triage and 2 hours after initial measurement and compared in two outcome groupings: (1) admitted vs. dehydrated, febrile, hypovolemicdischarged patients; (2) infectious vs. non-infectious sources. Receiver operator characteristic (ROC) curves were calculated to determine whether the NICOM values predict hospital admission better than a serum lactate.

Results

50 patients were enrolled, 32 (64 %) were admitted to the hospital. Mean age was 49.5 (± 16.5) years and 62 % were female. There were no significant associations between changes in hemodynamic variables and patient disposition from the ED or diagnosis of infection. Lactate was significantly higher in admitted patients and those with infection (p = 0.01, p = 0.01 respectively). The area under the ROC [95 % Confidence Intervals] for lactate was 0.83 [0.64–0.92] compared to 0.59 [0.41–0.73] for cardiac output (CO), 0.68 [0.49–0.80] for cardiac index (CI), and 0.63 [0.36–0.80] for heart rate (HR) for predicting hospital admission.

Conclusions

CO and CI, obtained at two separate time points, do not help with early disease severity differentiation of patients at risk for severe sepsis. Although mean HR was higher in those patients who were admitted, a serum lactate still served as a better predictor of patient admission from the ED.

Plasma syndecan-1 is associated with fluid requirements and clinical outcomes in emergency department patients with sepsis

BACKGROUND

Degradation of the endothelial glycocalyx is recognized as a major part of the pathophysiology of sepsis. Previous clinical studies, mostly conducted in intensive care settings, showed associations between glycocalyx shedding and clinical outcomes. We aimed to explore the association of plasma syndecan-1, a marker of glycocalyx degradation, with the subsequent fluid requirements and clinical outcomes of emergency department patients with sepsis.

METHODS

This was a post hoc analysis of a randomized trial of fluid resuscitation in the emergency department. The study was conducted in the emergency department of an urban 1500-bed tertiary care center. The data of 95 adults who were diagnosed with sepsis-induced hypoperfusion and had undergone baseline syndecan-1 measurement were included. The syndecan-1 levels at baseline (T0) and hour 6 (T6) were studied to characterize their association with clinical outcomes, including subsequent fluid administration, organ failure outcomes and mortality.

RESULTS

The median syndecan-1 levels at T0 and T6 were 207 (IQR 135-438) and 207 (IQR 128-490) ng/ml, respectively. Syndecan-1 levels at T0 were correlated with baseline sequential organ failure assessment (SOFA) score (ρ = 0.35, p < 0.001). Syndecan-1 levels at both T0 and T6 were correlated with subsequent fluid administration over 24 and 72 h and associated with the diagnosis of septic shock, the maximum dose of vasopressors and the need for renal replacement therapy (p < 0.05). Higher syndecan-1 levels at T6 were associated with higher 90-day mortality (p = 0.03).

CONCLUSIONS

In the emergency department, syndecan-1 levels were associated with fluid requirements, sepsis severity, organ dysfunction, and mortality.

Prognostic value of blood pressure drops during the first 24 h after hospital admission for risk stratification of community-acquired pneumonia: a retrospective cohort study

OBJECTIVES

Current risk stratification in community-acquired pneumonia (CAP) does not incorporate the dynamic nature of CAP evolution. Study aim was to evaluate the predictive value of early blood pressure (BP) drop and its consideration within the CRB-65 score.

METHODS

We performed a retrospective cohort study including consecutive adult hospitalized CAP patients 2013-2014 without documented treatment limitations or direct ICU admission. The CRB-65 score was calculated initially and re-calculated including any BP below the threshold (BP drop) within the first 24 h (CRB-65[BP24]). The primary endpoint was need for mechanical ventilation or vasopressors (MVVS) occurring after 24 h. Prognostic values were evaluated by uni- and multivariate and ROC curve analyses.

RESULTS

28/294 patients (9.5%) met the primary endpoint. Only 3 (11%) of them showed an initial BP of < 90 mmHg systolic or ≤ 60 mmHg diastolic, but 21 (75%) developed a BP drop within the first 24 h. 24/178 (13%) with and only 4/116 (3%) without any low BP during the first 24 h needed MVVS (p = 0.004). After multivariate analysis, the predictive value of BP drop was independent of other score parameters and biomarkers (all p < 0.01). In ROC analysis, the new CRB-65(BP24) showed a better prediction than the CRB-65 score (AUC 0.69 vs. 0.62, p = 0.04). 7/13 patients (54%) with MVVS despite an admission CRB-65 of 0 or 1 showed a BP drop.

CONCLUSIONS

In the evaluated cohort, BP drop within the first 24 h was significantly associated with more need for MVVS in CAP, and its consideration improved the prognostic value of the CRB-65 score.

The utility of brain natriuretic peptides in septic shock as markers for mortality and cardiac dysfunction: A systematic review

OBJECTIVE

To conduct a systematic review evaluating the utility of brain natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) as biomarkers in adult patients with septic shock.

MATERIALS AND METHODS

Pubmed/Medline databases were searched from inception to November 2018 using the search terms: (septic[Title/Abstract] AND shock[Title/Abstract]) AND bnp[Title/Abstract]) and (septic[Title/Abstract]) AND shock[Title/Abstract]) AND natriuretic[Title/Abstract]). No restriction was applied regarding date of publication. Comparative observational studies evaluating BNP and NT-proBNP in patients with septic shock aged ≥18 years were eligible for inclusion. Bibliographies from the extracted articles were also reviewed to identify additional relevant publications.

RESULTS

In total, 46 studies met all eligibility criteria and were included. A strong body of literature has demonstrated that in patients with septic shock, increased values of BNP and NT-proBNP are associated with increased mortality. An increase from baseline BNP values has also been associated with increased mortality, whereas decreases from baseline values are not related to worse outcome. Brain natriuretic peptides have also been associated with cardiac dysfunction in patients with sepsis. Moreover, BNP values have been found to be significantly elevated in septic shock, regardless of cardiac dysfunction, and have been used to distinguish between septic and cardiogenic shock. Furthermore, BNP and NT-proBNP are significantly increased in patients with septic shock, compared to patients with sepsis and severe sepsis.

CONCLUSIONS

BNP and NT-proBNP appear to be reliable predictors of outcome in septic shock.

Sepsis patients in the emergency department: stratification using the Clinical Impression Score, Predisposition, Infection, Response and Organ dysfunction score or quick Sequential Organ Failure Assessment score?

Objective

The aim of this study was to compare the stratification of sepsis patients in the emergency department (ED) for ICU admission and mortality using the Predisposition, Infection, Response and Organ dysfunction (PIRO) and quick Sequential Organ Failure Assessment (qSOFA) scores with clinical judgement assessed by the ED staff.

Patients and methods

This was a prospective observational study in the ED of a tertiary care teaching hospital. Adult nontrauma patients with suspected infection and at least two Systemic Inflammatory Response Syndrome criteria were included. The primary outcome was direct ED to ICU admission. The secondary outcomes were in-hospital, 28-day and 6-month mortality, indirect ICU admission and length of stay. Clinical judgement was recorded using the Clinical Impression Scores (CIS), appraised by a nurse and the attending physician. The PIRO and qSOFA scores were calculated from medical records.

Results

We included 193 patients: 103 presented with sepsis, 81 with severe sepsis and nine with septic shock. Fifteen patients required direct ICU admission. The CIS scores of nurse [area under the curve (AUC)=0.896] and the attending physician (AUC=0.861), in conjunction with PIRO (AUC=0.876) and qSOFA scores (AUC=0.849), predicted direct ICU admission. The CIS scores did not predict any of the mortality endpoints. The PIRO score predicted in-hospital (AUC=0.764), 28-day (AUC=0.784) and 6-month mortality (AUC=0.695). The qSOFA score also predicted in-hospital (AUC=0.823), 28-day (AUC=0.848) and 6-month mortality (AUC=0.620).

Conclusion

Clinical judgement is a fast and reliable method to stratify between ICU and general ward admission in ED patients with sepsis. The PIRO and qSOFA scores do not add value to this stratification, but perform better on the prediction of mortality. In sepsis patients, therefore, the principle of ‘treat first what kills first’ can be supplemented with ‘judge first and calculate later’.

Repeated vital sign measurements in the emergency department predict patient deterioration within 72 hours: a prospective observational study

BACKGROUND

More than one in five patients presenting to the emergency department (ED) with (suspected) infection or sepsis deteriorate within 72 h from admission. Surprisingly little is known about vital signs in relation to deterioration, especially in the ED. The aim of our study was to determine whether repeated vital sign measurements in the ED can differentiate between patients who will deteriorate within 72 h and patients who will not deteriorate.

METHODS

We performed a prospective observational study in patients presenting with (suspected) infection or sepsis to the ED of our tertiary care teaching hospital. Vital signs (heart rate, mean arterial pressure (MAP), respiratory rate and body temperature) were measured in 30-min intervals during the first 3 h in the ED. Primary outcome was patient deterioration within 72 h from admission, defined as the development of acute kidney injury, liver failure, respiratory failure, intensive care unit admission or in-hospital mortality. We performed a logistic regression analysis using a base model including age, gender and comorbidities. Thereafter, we performed separate logistic regression analyses for each vital sign using the value at admission, the change over time and its variability. For each analysis, the odds ratios (OR) and area under the receiver operator curve (AUC) were calculated.

RESULTS

In total 106 (29.5%) of the 359 patients deteriorated within 72 h from admission. Within this timeframe, 18.3% of the patients with infection and 32.9% of the patients with sepsis at ED presentation deteriorated. Associated with deterioration were: age (OR: 1.02), history of diabetes (OR: 1.90), heart rate (OR: 1.01), MAP (OR: 0.96) and respiratory rate (OR: 1.05) at admission, changes over time of MAP (OR: 1.04) and respiratory rate (OR: 1.44) as well as the variability of the MAP (OR: 1.06). Repeated measurements of heart rate and body temperature were not associated with deterioration.

CONCLUSIONS

Repeated vital sign measurements in the ED are better at identifying patients at risk for deterioration within 72 h from admission than single vital sign measurements at ED admission.

Protocol of the sepsivit study: a prospective observational study to determine whether continuous heart rate variability measurement during the first 48 hours of hospitalisation provides an early warning for deterioration in patients presenting with infection or sepsis to the emergency department of a Dutch academic teaching hospital

INTRODUCTION

One in five patients with sepsis deteriorates within 48 hours after hospital admission. Regrettably, a clear tool for the early detection of deterioration is still lacking. The SepsiVit study aims to determine whether continuous heart rate variability (HRV) measurement can provide an early warning for deterioration in patients presenting with suspected infection or sepsis to the emergency department (ED).

METHODS AND ANALYSIS

The protocol of a prospective observational study in the ED. We will include 171 adult medical patients presenting with suspected infection or sepsis and at least two systemic inflammatory response syndrome criteria. Patients with known pregnancy, cardiac transplantation or not admitted to our hospital are excluded.High sample frequency ECG signals (500 Hz), respiratory rate, blood pressure and peripheral oxygen saturation will be recorded continuously during the first 48 hours of hospitalisation using a bedside patient monitor (Philips IntelliVue MP70). Primary endpoint is patient deterioration, defined as the development of organ dysfunction, unplanned intensive care unit admission or in-hospital mortality. The ECG data will be used for offline HRV analysis. We will compare the HRV between two groups (deterioration/no deterioration) and analyse whether HRV provides an early warning for deterioration. Furthermore, we will create a multivariate predictive model for deterioration based on heart rate, respiratory rate and HRV. As planned secondary analyses, we (1) perform a subgroup analysis for patients with pneumosepsis and urosepsis and (2) determine whether HRV using lower sample frequencies (1 Hz or less) suffices to predict deterioration.

ETHICS AND DISSEMINATION

The Institutional Review Board of the University Medical Center Groningen granted a waiver for the study (METc 2015/164). Results will be disseminated through international peer-reviewed publications and conference presentations. A lay summary of the results will be provided to the study participants.

TRIAL REGISTRATION NUMBER

NTR6168; Pre-results.