The association between vital signs and clinical outcomes in emergency department patients of different age categories

Evaluating the Reliability of a Remote Acuity Prediction Tool in a Canadian Academic Emergency Department

STUDY OBJECTIVE

There is increasing interest in harnessing artificial intelligence to virtually triage patients seeking care. The objective was to examine the reliability of a virtual machine learning algorithm to remotely predict acuity scores for patients seeking emergency department (ED) care by applying the algorithm to retrospective ED data.

METHODS

This was a retrospective review of adult patients conducted at an academic tertiary care ED (annual census 65,000) from January 2021 to August 2022. Data including ED visit date and time, patient age, sex, reason for visit, presenting complaint and patient-reported pain score were used by the machine learning algorithm to predict acuity scores. The algorithm was designed to up-triage high-risk complaints to promote safety for remote use. The predicted scores were then compared to nurse-led triage scores previously derived in real time using the electronic Canadian Triage and Acuity Scale (eCTAS), an electronic triage decision-support tool used in the ED. Interrater reliability was estimated using kappa statistics with 95% confidence intervals (CIs).

RESULTS

In total, 21,469 unique ED patient encounters were included. Exact modal agreement was achieved for 10,396 (48.4%) patient encounters. Interrater reliability ranged from poor to fair, as estimated using unweighted kappa (0.18, 95% CI 0.17 to 0.19), linear-weighted kappa (0.25, 95% CI 0.24 to 0.26), and quadratic-weighted kappa (0.36, 95% CI 0.35 to 0.37) statistics. Using the nurse-led eCTAS score as the reference, the machine learning algorithm overtriaged 9,897 (46.1%) and undertriaged 1,176 (5.5%) cases. Some of the presenting complaints under-triaged were conditions generally requiring further probing to delineate their nature, including abnormal lab/imaging results, visual disturbance, and fever.

CONCLUSION

This machine learning algorithm needs further refinement before being safely implemented for patient use.

The effect of relative hypotension on 30-day mortality in older people receiving emergency care

Research has observed increased mortality among older people attending the emergency department (ED) who had systolic pressure > 7 mmHg lower than baseline primary care values. This study aimed to (1) assess feasibility of identifying this 'relative hypotension' using readily available ED data, (2) externally validate the 7 mmHg threshold, and (3) refine a threshold for clinically important relative hypotension. A single-centre retrospective cohort study linked year 2019 data for ED attendances by people aged over 64 to hospital discharge vital signs within the previous 18 months. Frailty and comorbidity scores were calculated. Previous discharge ('baseline') vital signs were subtracted from initial ED values to give individuals' relative change. Cox regression analysis compared relative hypotension > 7 mmHg with mean time to mortality censored at 30 days. The relative hypotension threshold was refined using a fully adjusted risk tool formed of logistic regression models. Receiver operating characteristics were compared to NEWS2 models with and without incorporation of relative systolic. 5136 (16%) of 32,548 ED attendances were linkable with recent discharge vital signs. Relative hypotension > 7 mmHg was associated with increased 30-day mortality (HR 1.98; 95% CI 1.66-2.35). The adjusted risk tool (AUC: 0.69; sensitivity: 0.61; specificity: 0.68) estimated each 1 mmHg relative hypotension to increase 30-day mortality by 2% (OR 1.02; 95% CI 1.02-1.02). 30-day mortality prediction was marginally better with NEWS2 (AUC: 0.73; sensitivity: 0.59; specificity: 0.78) and NEWS2 + relative systolic (AUC: 0.74; sensitivity: 0.63; specificity: 0.75). Comparison of ED vital signs with recent discharge observations was feasible for 16% individuals. The association of relative hypotension > 7 mmHg with 30-day mortality was externally validated. Indeed, any relative hypotension appeared to increase risk, but model characteristics were poor. These findings are limited to the context of older people with recent hospital admissions.

Predicting ICU admission and death in the Emergency Department: A comparison of six early warning scores

AIM

To compare the ability of the most used Early Warning Scores (EWS) to identify adult patients at risk of poor outcomes in the emergency department (ED).

METHODS

Single-center, retrospective observational study. We evaluated the digital records of consecutive ED admissions in patients ≥ 18 years from 2010 to 2019 and calculated NEWS, NEWS2, MEWS, RAPS, REMS, and SEWS based on parameters measured on ED arrival. We assessed the discrimination and calibration performance of each EWS in predicting death/ICU admission within 24 hours using ROC analysis and visual calibration. We also measured the relative weight of clinical and physiological derangements that identified patients missed by EWS risk stratification using neural network analysis.

RESULTS

Among 225,369 patients assessed in the ED during the study period, 1941 (0.9%) were admitted to ICU or died within 24 hours. NEWS was the most accurate predictor (area under the receiver operating characteristic [AUROC] curve 0.904 [95% CI 0.805-0.913]), followed by NEWS2 (AUROC 0.901). NEWS was also well calibrated. In patients judged at low risk (NEWS < 2), 359 events occurred (18.5% of the total). Neural network analysis revealed that age, systolic BP, and temperature had the highest relative weight for these NEWS-unpredicted events.

CONCLUSIONS

NEWS is the most accurate EWS for predicting the risk of death/ICU admission within 24 h from ED arrival. The score also had a fair calibration with few events occurring in patients classified at low risk. Neural network analysis suggests the need for further improvements by focusing on the prompt diagnosis of sepsis and the development of practical tools for the measurement of the respiratory rate.

Development and External Validation of the International Early Warning Score for Improved Age- and Sex-Adjusted In-Hospital Mortality Prediction in the Emergency Department

OBJECTIVES

Early Warning Scores (EWSs) have a great potential to assist clinical decision-making in the emergency department (ED). However, many EWS contain methodological weaknesses in development and validation and have poor predictive performance in older patients. The aim of this study was to develop and externally validate an International Early Warning Score (IEWS) based on a recalibrated National Early warning Score (NEWS) model including age and sex and evaluate its performance independently at arrival to the ED in three age categories (18-65, 66-80, > 80 yr).

DESIGN

International multicenter cohort study.

SETTING

Data was used from three Dutch EDs. External validation was performed in two EDs in Denmark.

PATIENTS

All consecutive ED patients greater than or equal to 18 years in the Netherlands Emergency department Evaluation Database (NEED) with at least two registered vital signs were included, resulting in 95,553 patients. For external validation, 14,809 patients were included from a Danish Multicenter Cohort (DMC).

MEASUREMENTS AND MAIN RESULTS

Model performance to predict in-hospital mortality was evaluated by discrimination, calibration curves and summary statistics, reclassification, and clinical usefulness by decision curve analysis. In-hospital mortality rate was 2.4% ( n = 2,314) in the NEED and 2.5% ( n = 365) in the DMC. Overall, the IEWS performed significantly better than NEWS with an area under the receiving operating characteristic of 0.89 (95% CIs, 0.89-0.90) versus 0.82 (0.82-0.83) in the NEED and 0.87 (0.85-0.88) versus 0.82 (0.80-0.84) at external validation. Calibration for NEWS predictions underestimated risk in older patients and overestimated risk in the youngest, while calibration improved for IEWS with a substantial reclassification of patients from low to high risk and a standardized net benefit of 5-15% in the relevant risk range for all age categories.

CONCLUSIONS

The IEWS substantially improves in-hospital mortality prediction for all ED patients greater than or equal to18 years.

Missed nursing care in emergency departments: A scoping review

BACKGROUND

Patient safety is a global health priority. Errors of omission, such as missed nursing care in hospitals, are frequent and may lead to adverse events. Emergency departments (ED) are especially vulnerable to patient safety errors, and the significance missed nursing care has in this context is not as well known as in other contexts.

AIM

The aim of this scoping review was to summarize and disseminate research about missed nursing care in the context of EDs.

METHOD

A scoping review following the framework suggested by Arksey and O'Malley was used to (1) identify the research question; (2) identify relevant studies; (3) select studies; (4) chart the data; (5) collate, summarize, and report the results; and (6) consultation.

RESULTS

In total, 20 themes were derived from the 55 included studies. Missed or delayed assessments or other fundamental care were examples of missed nursing care characteristics. EDs not staffed or dimensioned in relation to the patient load were identified as a cause of missed nursing care in most included studies. Clinical deteriorations and medication errors were described in the included studies in relation to patient safety and quality of care deficiencies. Registered nurses also expressed that missed nursing care was undignified and unsafe.

CONCLUSION

The findings from this scoping review indicate that patients' fundamental needs are not met in the ED, mainly because of the patient load and how the ED is designed. According to registered nurses, missed nursing care is perceived as undignified and unsafe.

THE ASSOCIATION BETWEEN SYSTOLIC BLOOD PRESSURE AND HEART RATE IN EMERGENCY DEPARTMENT PATIENTS: A MULTICENTER COHORT STUDY

BACKGROUND

Guidelines and textbooks assert that tachycardia is an early and reliable sign of hypotension, and an increased heart rate (HR) is believed to be an early warning sign for the development of shock, although this response may change by aging, pain, and stress.

OBJECTIVE

To assess the unadjusted and adjusted associations between systolic blood pressure (SBP) and HR in emergency department (ED) patients of different age categories (18-50 years; 50-80 years; > 80 years).

METHODS

A multicenter cohort study using the Netherlands Emergency department Evaluation Database (NEED) including all ED patients ≥ 18 years from three hospitals in whom HR and SBP were registered at arrival to the ED. Findings were validated in a Danish cohort including ED patients. In addition, a separate cohort was used including ED patients with a suspected infection who were hospitalized from whom measurement of SBP and HR were available prior to, during, and after ED treatment. Associations between SBP and HR were visualized and quantified with scatterplots and regression coefficients (95% confidence interval [CI]).

RESULTS

A total of 81,750 ED patients were included from the NEED, and a total of 2358 patients with a suspected infection. No associations were found between SBP and HR in any age category (18-50 years: -0.03 beats/min/10 mm Hg, 95% CI -0.13-0.07, 51-80 years: -0.43 beats/min/10 mm Hg, 95% CI -0.38 to -0.50, > 80 years: -0.61 beats/min/10 mm Hg, 95% CI -0.53 to -0.71), nor in different subgroups of ED patient. No increase in HR existed with a decreasing SBP during ED treatment in ED patients with a suspected infection.

CONCLUSION

No association between SBP and HR existed in ED patients of any age category, nor in ED patients who were hospitalized with a suspected infection, even during and after ED treatment. Emergency physicians may be misled by traditional concepts about HR disturbances because tachycardia may be absent in hypotension.

The prediction of 24-h mortality by the respiratory rate and oxygenation index compared with National Early Warning Score in emergency department patients: an observational study

BACKGROUND

The ROX index combines respiratory rate and oxygenation to predict the response to oxygen therapy in pneumonia. It is calculated by dividing the patient's oxygen saturation, by the inspired oxygen concentration, and then by the respiratory rate (e.g. 95%/0.21/16 = 28). Since this index includes the most essential physiological variables to detect deterioration, it may be a helpful risk tool in the emergency department (ED). Although small studies suggest it can predict early mortality, no large study has compared it with the National Early Warning Score (NEWS), the most widely validated risk score for death within 24 h.

AIM

The aim of this study was to compare the ability of the ROX index with the NEWS to predict mortality within 24 h of arrival at the hospital.

METHODS

This was a retrospective observational multicentre analysis of data in the Netherlands Emergency Department Evaluation Database (NEED) on 270 665 patients attending four participating Dutch EDs. The ROX index and NEWS were determined on ED arrival and prior to ED treatment.

RESULTS

The risk of death within 24 h increased with falling ROX and rising NEWS values. The area under the receiving operating characteristic curves for 24-h mortality of NEWS was significantly higher than for the ROX index [0.92; 95% confidence interval (CI), 0.91-0.92 versus 0.87; 95% CI, 0.86-0.88; P  < 0.01]. However, the observed and predicted mortality by the ROX index was identical to mortality of 5%, after which mortality was underestimated. In contrast, up to a predicted 24-h mortality of 3% NEWS slightly underestimates mortality, and above this level over-estimates it. The standardized net benefit of ROX is slightly higher than NEWS up to a predicted 24-h mortality of 3%.

CONCLUSION

The prediction of 24-h mortality by the ROX index is more accurate than NEWS for most patients likely to be encountered in the ED. ROX may be used as a first screening tool in the ED.

Using Vital Signs to Place Acutely Ill Patients Quickly and Easily into Clinically Helpful Pathophysiologic Categories: Derivation and Validation of Eight Pathophysiologic Categories in Two Distinct Patient Populations of Acutely Ill Patients

BACKGROUND

Early warning scores reliably identify patients at risk of imminent death, but do not provide insight into what may be wrong with the patient or what to do about it.

OBJECTIVE

Our aim was to explore whether the Shock Index (SI), pulse pressure (PP), and ROX Index can place acutely ill medical patients in pathophysiologic categories that could indicate the interventions required.

METHODS

A retrospective post-hoc analysis of previously obtained and reported clinical data for 45,784 acutely ill medical patients admitted to a major regional referral Canadian hospital between 2005 and 2010 and validated on 107,546 emergency admissions to four Dutch hospitals between 2017 and 2022.

RESULTS

SI, PP, and ROX values divided patients into eight mutually exclusive physiologic categories. Mortality was highest in patient categories that included ROX Index value < 22, and a ROX Index value < 22 multiplied the risk of any other abnormality. Patients with a ROX Index value < 22, PP < 42 mm Hg, and SI > 0.7 had the highest mortality and accounted for 40% of deaths within 24 h of admission, whereas patients with a PP ≥ 42 mm Hg, SI ≤ 0.7, and ROX Index value ≥ 22 had the lowest risk of death. These results were the same in both the Canadian and Dutch patient cohorts.

CONCLUSIONS

SI, PP, and ROX Index values can place acutely ill medical patients into eight mutually exclusive pathophysiologic categories with different mortality rates. Future studies will assess the interventions needed by these categories and their value in guiding treatment and disposition decisions.

Factors associated with unfavorable outcomes in patients with acute abdominal pain visiting the emergency department

BACKGROUND

Unfavorable outcomes occur in patients with acute abdominal pain who visit the emergency department (ED). We aimed to determine the factors associated with unfavorable outcomes in patients with acute abdominal pain visiting the ED.

METHODS

This retrospective cohort study was conducted from July 1, 2015 to June 30, 2016. The inclusion criterion was patients aged older than 18 years who presented to the ED with acute abdominal pain. Significant factors associated with unfavorable outcomes were examined using univariate and multivariate logistic regression analyses.

RESULTS

A total of 951 patients were included in the study. Multivariate logistic regression analysis showed that the ED length of stay (EDLOS) > 4 h (adjusted odds ratio (AOR) 2.62, 95% confidence interval [CI]: 1.33-5.14; p = 0.005), diastolic blood pressure (DBP) < 80 mmHg (AOR 3.31, 95% CI: 1.71-6.4; p ≤ 0.001), respiratory rate ≥ 24 breaths/min (AOR 2.03, 95% CI: 1.07-3.86; p ≤ 0.031), right lower quadrant (RLQ) tenderness (AOR 3.72, 95% CI: 1.89-7.32; p ≤ 0.001), abdominal distension (AOR 2.91, 95% CI: 1.29-6.57; p = 0.010), hypoactive bowel sounds (AOR 2.89, 95% CI: 1.09-7.67; p = 0.033), presence of specific abdominal signs (AOR 2.07, 95% CI: 1.1-3.88; p = 0.024), white blood cell count ≥ 12,000 cells/mm³ (AOR 2.37, 95% CI: 1.22-4.6; p = 0.011), and absolute neutrophil count (ANC) > 75% (AOR 2.83, 95% CI: 1.39-5.75; p = 0.004) were revealed as significant factors associated with unfavorable outcomes.

CONCLUSIONS

The present study revealed that the significant clinical signs associated with the occurrence of unfavorable outcomes were DBP < 80 mmHg, tachypnea (≥ 24 breaths/min), RLQ tenderness, abdominal distension, hypoactive bowel sounds, and presence of specific abdominal signs. Moreover, the associated laboratory results identified in this study were leukocytosis and ANC > 75%. Additionally, patients with abdominal pain visiting the ED who had an EDLOS longer than 4 h were associated with unfavorable outcomes.

External Validation of COVID-19 Risk Scores during Three Waves of Pandemic in a German Cohort-A Retrospective Study

Several risk scores were developed during the COVID-19 pandemic to identify patients at risk for critical illness as a basic step to personalizing medicine even in pandemic circumstances. However, the generalizability of these scores with regard to different populations, clinical settings, healthcare systems, and new epidemiological circumstances is unknown. The aim of our study was to compare the predictive validity of qSOFA, CRB65, NEWS, COVID-GRAM, and 4C-Mortality score. In a monocentric retrospective cohort, consecutively hospitalized adults with COVID-19 from February 2020 to June 2021 were included; risk scores at admission were calculated. The area under the receiver operating characteristic curve and the area under the precision-recall curve were compared using DeLong's method and a bootstrapping approach. A total of 347 patients were included; 23.6% were admitted to the ICU, and 9.2% died in a hospital. NEWS and 4C-Score performed best for the outcomes ICU admission and in-hospital mortality. The easy-to-use bedside score NEWS has proven to identify patients at risk for critical illness, whereas the more complex COVID-19-specific scores 4C and COVID-GRAM were not superior. Decreasing mortality and ICU-admission rates affected the discriminatory ability of all scores. A further evaluation of risk assessment is needed in view of new and rapidly changing epidemiological evolution.

The effect of treatment and clinical course during Emergency Department stay on severity scoring and predicted mortality risk in Intensive Care patients

Background

Treatment and the clinical course during Emergency Department (ED) stay before Intensive Care Unit (ICU) admission may affect predicted mortality risk calculated by the Acute Physiology and Chronic Health Evaluation (APACHE)-IV, causing lead-time bias. As a result, comparing standardized mortality ratios (SMRs) among hospitals may be difficult if they differ in the location where initial stabilization takes place. The aim of this study was to assess to what extent predicted mortality risk would be affected if the APACHE-IV score was recalculated with the initial physiological variables from the ED. Secondly, to evaluate whether ED Length of Stay (LOS) was associated with a change (delta) in these APACHE-IV scores.

Methods

An observational multicenter cohort study including ICU patients admitted from the ED. Data from two Dutch quality registries were linked: the Netherlands Emergency department Evaluation Database (NEED) and the National Intensive Care Evaluation (NICE) registry. The ICU APACHE-IV, predicted mortality, and SMR based on data of the first 24 h of ICU admission were compared with an ED APACHE-IV model, using the most deviating physiological variables from the ED or ICU.

Results

A total of 1398 patients were included. The predicted mortality from the ICU APACHE-IV (median 0.10; IQR 0.03–0.30) was significantly lower compared to the ED APACHE-IV model (median 0.13; 0.04–0.36; p < 0.01). The SMR changed from 0.63 (95%CI 0.54–0.72) to 0.55 (95%CI 0.47–0.63) based on ED APACHE-IV. Predicted mortality risk changed more than 5% in 321 (23.2%) patients by using the ED APACHE-IV. ED LOS > 3.9 h was associated with a slight increase in delta APACHE-IV of 1.6 (95% CI 0.4–2.8) compared to ED LOS < 1.7 h.

Conclusion

Predicted mortality risks and SMRs calculated by the APACHE IV scores are not directly comparable in patients admitted from the ED if hospitals differ in their policy to stabilize patients in the ED before ICU admission. Future research should focus on developing models to adjust for these differences.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03986-2.

Age-adjusted interpretation of biomarkers of renal function and homeostasis, inflammation, and circulation in Emergency Department patients

Appropriate interpretation of blood tests is important for risk stratification and guidelines used in the Emergency Department (ED) (such as SIRS or CURB-65). The impact of abnormal blood test values on mortality may change with increasing age due to (patho)-physiologic changes. The aim of this study was therefore to assess the effect of age on the case-mix adjusted association between biomarkers of renal function and homeostasis, inflammation and circulation and in-hospital mortality. This observational multi-center cohort study has used the Netherlands Emergency department Evaluation Database (NEED), including all consecutive ED patients ≥ 18 years of three hospitals. A generalized additive logistic regression model was used to visualize the association between in-hospital mortality, age and five blood tests (creatinine, sodium, leukocytes, C-reactive Protein, and hemoglobin). Multivariable logistic regression analyses were used to assess the association between the number of abnormal blood test values and mortality per age category (18-50; 51-65; 66-80; > 80 years). Of the 94,974 included patients, 2550 (2.7%) patients died in-hospital. Mortality increased gradually for C-reactive Protein (CRP), and had a U-shaped association for creatinine, sodium, leukocytes, and hemoglobin. Age significantly affected the associations of all studied blood tests except in leukocytes. In addition, with increasing age categories, case-mix adjusted mortality increased with the number of abnormal blood tests. In summary, the association between blood tests and (adjusted) mortality depends on age. Mortality increases gradually or in a U-shaped manner with increasing blood test values. Age-adjusted numerical scores may improve risk stratification. Our results have implications for interpretation of blood tests and their use in risk stratification tools and acute care guidelines.Trial registration number Netherlands Trial Register (NTR) NL8422, 03/2020.

Sex differences in clinical presentation and risk stratification in the Emergency Department: An observational multicenter cohort study

OBJECTIVE

The aim of this study was to investigate whether sex differences exist in disease presentations, disease severity and (case-mix adjusted) outcomes in the Emergency Department (ED).

METHODS

Observational multicenter cohort study using the Netherlands Emergency Department Evaluation Database (NEED), including patients ≥ 18 years of three Dutch EDs. Multivariable logistic regression was used to study the associations between sex and outcome measures in-hospital mortality and Intensive Care Unit/Medium Care Unit (ICU/MCU) admission in ED patients and in subgroups triage categories and presenting complaints.

RESULTS

Of 148,825 patients, 72,554 (48.8%) were females. Patient characteristics at ED presentation and diagnoses (such as pneumonia, cerebral infarction, and fractures) were comparable between sexes at ED presentation. In-hospital mortality was 2.2% in males and 1.7% in females. ICU/MCU admission was 4.7% in males and 3.1% in females. Males had higher unadjusted (OR 1.34(1.25-1.45)) and adjusted (AOR 1.34(1.24-1.46)) risks for mortality, and unadjusted (OR 1.54(1.46-1.63)) and adjusted (AOR 1.46(1.37-1.56)) risks for ICU/MCU admission. Males had higher adjusted mortality and ICU/MCU admission for all triage categories, and with almost all presenting complaints except for headache.

CONCLUSIONS

Although patient characteristics at ED presentation for both sexes are comparable, males are at higher unadjusted and adjusted risk for adverse outcomes. Males have higher risks in all triage categories and with almost all presenting complaints. Future studies should investigate reasons for higher risk in male ED patients.

The difference between the patients' initial and previously measured systolic blood pressure as predictor of mortality in older emergency department patients

PURPOSE

To assess how often baseline systolic blood pressure (SBP) could be retrieved from the Electronic Health Record (EHR) in older Emergency Department (ED) patients. Second, to assess whether the difference between baseline SBP and initial SBP in the ED (ΔSBP) was associated with 30-day mortality.

METHODS

A multicenter hypothesis-generating cohort study including patients  ≥ 70 years. EHRs were searched for baseline SBPs. The association between ΔSBP and 30-day mortality was investigated.

RESULTS

Baseline SBP was found in 220 out of 300 patients (73.3%; 95%CI 68.1-78.0%). In 72 patients with normal initial SBPs (133-166 mmHg) in the ED, fifteen (20.8%) had a negative ΔSBP with 20.0% mortality. A negative ΔSBP was associated with 30-day mortality (AHR 4.7; 1.7-12.7).

CONCLUSION

Baseline SBPs are often available in older ED patients. The ΔSBP has prognostic value and could be used as an extra variable to recognize hypotension in older ED patients. Future studies should clarify whether the ΔSBP improves risk stratification in the ED.