THERM: the Resuscitation Management score. A prognostic tool to identify critically ill patients in the emergency department

Internal validation and comparison of the prognostic performance of models based on six emergency scoring systems to predict in-hospital mortality in the emergency department

Background

Medical scoring systems are potentially useful to make optimal use of available resources. A variety of models have been developed for illness measurement and stratification of patients in Emergency Departments (EDs). This study was aimed to compare the predictive performance of the following six scoring systems: Simple Clinical Score (SCS), Worthing physiological Score (WPS), Rapid Acute Physiology Score (RAPS), Rapid Emergency Medicine Score (REMS), Modified Early Warning Score (MEWS), and Routine Laboratory Data (RLD) to predict in-hospital mortality.

Methods

A prospective single-center observational study was conducted from March 2016 to March 2017 in Edalatian ED in Emam Reza Hospital, located in the northeast of Iran. All variables needed to calculate the models were recorded at the time of admission and logistic regression was used to develop the models’ prediction probabilities. The Area Under the Curve for Receiver Operating Characteristic (AUC-ROC) and Precision-Recall curves (AUC-PR), Brier Score (BS), and calibration plots were used to assess the models’ performance. Internal validation was obtained by 1000 bootstrap samples. Pairwise comparison of AUC-ROC was based on the DeLong test.

Results

A total of 2205 patients participated in this study with a mean age of 61.8 ± 18.5 years. About 19% of the patients died in the hospital. Approximately 53% of the participants were male. The discrimination ability of SCS, WPS, RAPS, REMS, MEWS, and RLD methods were 0.714, 0.727, 0.661, 0.678, 0.698, and 0.656, respectively. Additionally, the AUC-PR of SCS, WPS, RAPS, REMS, EWS, and RLD were 0.39, 0.42, 0.35, 0.34, 0.36, and 0.33 respectively. Moreover, BS was 0.1459 for SCS, 0.1713 for WPS, 0.0908 for RAPS, 0.1044 for REMS, 0.1158 for MEWS, and 0.073 for RLD. Results of pairwise comparison which was performed for all models revealed that there was no significant difference between the SCS and WPS. The calibration plots demonstrated a relatively good concordance between the actual and predicted probability of non-survival for the SCS and WPS models.

Conclusion

Both SCS and WPS demonstrated fair discrimination and good calibration, which were superior to the other models. Further recalibration is however still required to improve the predictive performance of all available models and their use in clinical practice is still unwarranted.

Consensus on predictors of clinical deterioration in emergency departments: A Delphi process study

AIM

The study aim was to determine relevance and applicability of generic predictors of clinical deterioration in emergency departments based on consensus among clinicians.

METHODS

Thirty-three predictors of clinical deterioration identified from literature were assessed in a modified two-stage Delphi-process. Sixty-eight clinicians (physicians and nurses) participated in the first round and 48 in the second round; all treating hospitalized patients in Danish emergency departments, some with pre-hospital experience. The panel rated the predictors for relevance (relevant marker of clinical deterioration) and applicability (change in clinical presentation over time, generic in nature and possible to detect bedside). They rated their level of agreement on a 9-point Likert scale and were also invited to propose additional generic predictors between the rounds. New predictors suggested by more than one clinician were included in the second round along with non-consensus predictors from the first round. Final decisions of non-consensus predictors after second round were made by a research group and an impartial physician.

RESULTS

The Delphi-process resulted in 19 clinically relevant and applicable predictors based on vital signs and parameters (respiratory rate, saturation, dyspnoea, systolic blood pressure, pulse rate, abnormal electrocardiogram, altered mental state and temperature), biochemical tests (serum c-reactive protein, serum bicarbonate, serum lactate, serum pH, serum potassium, glucose, leucocyte counts and serum haemoglobin), objective clinical observations (skin conditions) and subjective clinical observations (pain reported as new or escalating, and relatives' concerns).

CONCLUSION

The Delphi-process led to consensus of 19 potential predictors of clinical deterioration widely accepted as relevant and applicable in emergency departments.

The effectiveness of physiologically based early warning or track and trigger systems after triage in adult patients presenting to emergency departments: a systematic review

BACKGROUND

Changes to physiological parameters precede deterioration of ill patients. Early warning and track and trigger systems (TTS) use routine physiological measurements with pre-specified thresholds to identify deteriorating patients and trigger appropriate and timely escalation of care. Patients presenting to the emergency department (ED) are undiagnosed, undifferentiated and of varying acuity, yet the effectiveness and cost-effectiveness of using early warning systems and TTS in this setting is unclear. We aimed to systematically review the evidence on the use, development/validation, clinical effectiveness and cost-effectiveness of physiologically based early warning systems and TTS for the detection of deterioration in adult patients presenting to EDs.

METHODS

We searched for any study design in scientific databases and grey literature resources up to March 2016. Two reviewers independently screened results and conducted quality assessment. One reviewer extracted data with independent verification of 50% by a second reviewer. Only information available in English was included. Due to the heterogeneity of reporting across studies, results were synthesised narratively and in evidence tables.

RESULTS

We identified 6397 citations of which 47 studies and 1 clinical trial registration were included. Although early warning systems are increasingly used in EDs, compliance varies. One non-randomised controlled trial found that using an early warning system in the ED may lead to a change in patient management but may not reduce adverse events; however, this is uncertain, considering the very low quality of evidence. Twenty-eight different early warning systems were developed/validated in 36 studies. There is relatively good evidence on the predictive ability of certain early warning systems on mortality and ICU/hospital admission. No health economic data were identified.

CONCLUSIONS

Early warning systems seem to predict adverse outcomes in adult patients of varying acuity presenting to the ED but there is a lack of high quality comparative studies to examine the effect of using early warning systems on patient outcomes. Such studies should include health economics assessments.

Prognostic value of early warning scores in the emergency department (ED) and acute medical unit (AMU): A narrative review

BACKGROUND

A wide array of early warning scores (EWS) have been developed and are used in different settings to detect which patients are at risk of deterioration. The aim of this review is to provide an overview of studies conducted on the value of EWS on predicting intensive care (ICU) admission and mortality in the emergency department (ED) and acute medical unit (AMU).

METHODS

A literature search was conducted in the bibliographic databases PubMed and EMBASE, from inception to April 2017. Two reviewers independently screened all potentially relevant titles and abstracts for eligibility.

RESULTS

42 studies were included. 36 studies reported on mortality as an endpoint, 13 reported ICU admission and 9 reported the composite outcome of mortality and ICU admission. For mortality prediction National Early Warning Score (NEWS) was the most accurate score in the general ED population and in those with respiratory distress, Mortality in Emergency Department Sepsis score (MEDS) had the best accuracy in patients with an infection or sepsis. ICU admission was best predicted with NEWS, however in patients with an infection or sepsis Modified Early Warning Score (MEWS) yielded better results for this outcome.

CONCLUSION

MEWS and NEWS generally had favourable results in the ED and AMU for all endpoints. Many studies have been performed on ED and AMU populations using heterogeneous prognostic scores. However, future studies should concentrate on a simple and easy to use prognostic score such as NEWS with the aim of introducing this throughout the (pre-hospital and hospital) acute care chain.

Development and Psychometric Evaluation of the Pre-hospital Medical Emergencies Early Warning Scale

Introduction:

The number of requests for emergency medical services (EMSs) has increased during the past decade. However, most of the transports are not essential. Therefore, it seems crucial to develop an instrument to help EMS staff accurately identify patients who need pre-hospital care and transportation. The aim of this study was to develop and evaluate the psychometric properties of the Pre-hospital Medical Emergencies Early Warning Scale (Pre-MEWS).

Materials and Methods:

This mixed-method study was conducted in two phases. In the first phase, a qualitative content analysis study was conducted to identify the predictors of medical patients' need for pre-hospital EMS and transportation. In the second phase, the face and the content validity as well as the internal consistency of the scale were evaluated. Finally, the items of the scale were scored and scoring system was presented.

Results:

The final version of the scale contained 22 items and its total score ranged from 0 to 54.

Conclusions:

Pre-MEWS helps EMS staffs properly understand medical patients' conditions in pre-hospital environments and accurately identify their need for EMS and transportation.

A single-centre cohort study of National Early Warning Score (NEWS) and near patient testing in acute medical admissions

INTRODUCTION

The utility of an early warning score may be improved when used with near patient testing. However, this has not yet been investigated for National Early Warning Score (NEWS). We hypothesised that the combination of NEWS and blood gas variables (lactate, glucose or base-excess) was more strongly associated with clinical outcome compared to NEWS alone.

METHODS

This was a prospective cohort study of adult medical admissions to a single-centre over 20days. Blood gas results and physiological observations were recorded at admission. NEWS was calculated retrospectively and combined with the biomarkers in multivariable logistic regression models. The primary outcome was a composite of mortality or critical care escalation within 2days of hospital admission. The secondary outcome was hospital length of stay.

RESULTS

After accounting for missing data, 15 patients out of 322 (4.7%) died or were escalated to the critical care unit. The median length of stay was 4 (IQR 7) days. When combined with lactate or base excess, NEWS was associated with the primary outcome (OR 1.18, p=0.01 and OR 1.13, p=0.03). However, NEWS alone was more strongly associated with the primary outcome measure (OR 1.46, p<0.01). The combination of NEWS with glucose was not associated with the primary outcome. Neither NEWS nor any combination of NEWS and a biomarker were associated with hospital length of stay.

CONCLUSION

Admission NEWS is more strongly associated with death or critical care unit admission within 2days of hospital admission, compared to combinations of NEWS and blood-gas derived biomarkers.

Comparison of the National Early Warning Score in non-elective medical and surgical patients

BACKGROUND

The National Early Warning Score (NEWS) is used to identify deteriorating patients in hospital. NEWS is a better discriminator of outcomes than other early warning scores in acute medical admissions, but it has not been evaluated in a surgical population. The study aims were to evaluate the ability of NEWS to discriminate cardiac arrest, death and unanticipated ICU admission in patients admitted to surgical specialties, and to compare the performance of NEWS in admissions to medical and surgical specialties.

METHODS

Hospitalwide data over 31 months, from adult inpatients who stayed at least one night or died on the day of admission, were analysed. The data were categorized as elective or non-elective surgical or medical admissions. The ability of NEWS to discriminate the outcomes above in these different groups was assessed using the area under the receiver operating characteristic curve (AUROC).

RESULTS

There were too few outcomes to permit meaningful comparison of elective admissions, so the analysis was constrained to comparison of non-elective admissions. NEWS performed equally well, or better, for surgical as for medical patients. For death within 24 h the AUROC for surgical admissions was 0·914 (95 per cent c.i. 0·907 to 0·922), compared with 0·902 (0·898 to 0·905) for medical admissions. For the combined outcome of any of death, cardiac arrest or unanticipated ICU admission, the AUROC was 0·874 (0·868 to 0·880) for surgical admissions and 0·874 (0·871 to 0·877) for medical admissions.

CONCLUSION

NEWS discriminated deterioration in non-elective surgical patients at least as well as in non-elective medical patients.