Pre-hospital predictors of an adverse outcome among patients with dyspnoea as the main symptom assessed by pre-hospital emergency nurses - a retrospective observational study

Advancing a machine learning-based decision support tool for pre-hospital assessment of dyspnoea by emergency medical service clinicians: a retrospective observational study

BACKGROUND

In Sweden with about 10 million inhabitants, there are about one million primary ambulance missions every year. Among them, around 10% are assessed by Emergency Medical Service (EMS) clinicians with the primary symptom of dyspnoea. The risk of death among these patients has been reported to be remarkably high, at 11,1% and 13,2%. The aim was to develop a Machine Learning (ML) model to provide support in assessing patients in pre-hospital settings and to compare them with established triage tools.

METHODS

This was a retrospective observational study including 6,354 patients who called the Swedish emergency telephone number (112) between January and December 2017. Patients presenting with the main symptom of dyspnoea were included which were recruited from two EMS organisations in Göteborg and Södra Älvsborg. Serious Adverse Event (SAE) was used as outcome, defined as any of the following:1) death within 30 days after call for an ambulance, 2) a final diagnosis defined as time-sensitive, 3) admitted to intensive care unit, or 4) readmission within 72 h and admitted to hospital receiving a final time-sensitive diagnosis. Logistic regression, LASSO logistic regression and gradient boosting were compared to the Rapid Emergency Triage and Treatment System for Adults (RETTS-A) and National Early Warning Score2 (NEWS2) with respect to discrimination and calibration of predictions. Eighty percent (80%) of the data was used for model development and 20% for model validation.

RESULTS

All ML models showed better performance than RETTS-A and NEWS2 with respect to all evaluated performance metrics. The gradient boosting algorithm had the overall best performance, with excellent calibration of the predictions, and consistently showed higher sensitivity to detect SAE than the other methods. The ROC AUC on test data increased from 0.73 (95% CI 0.70-0.76) with RETTS-A to 0.81 (95% CI 0.78-0.84) using gradient boosting.

CONCLUSIONS

Among 6,354 ambulance missions caused by patients suffering from dyspnoea, an ML method using gradient boosting demonstrated excellent performance for predicting SAE, with substantial improvement over the more established methods RETTS-A and NEWS2.

Lived experiences of being cared for by ambulance clinicians when experiencing breathlessness-A phenomenological study

BACKGROUND

Breathlessness is a serious and distressing symptom and a common reason why patients require prehospital care by ambulance clinicians. However, little is known about how patients experience this care when they are in a state of breathlessness.

AIM

The aim of this study is to describe the lived experiences of being cared for by ambulance clinicians when experiencing breathlessness.

METHODS

Fourteen lifeworld interviews were conducted with patients who experienced breathlessness and were cared for by ambulance clinicians. The interviews were analysed using a qualitative phenomenological approach.

FINDINGS

The essential meaning of being cared for by ambulance clinicians when experiencing breathlessness is described in two ways: existential humanising care, in which the experience is that of being embraced by a genuine presence or existential dehumanising care, in which feeling exposed to an objectifying presence is the main experience. This meaning has four constituents: surrendering to and trusting in the care that will come; being exposed to an objectifying presence is violating; being embraced by a genuine presence is relieving; and knowing is dwelling.

CONCLUSION

The findings reveal that the ability of ambulance clinicians to provide existential humanising and trustful care, which is the foundation of professional judgement, was essential in how patients responded to and handled the overall situation when breathlessness.

Chief Complaints, Underlying Diagnoses, and Mortality in Adult, Non-trauma Emergency Department Visits: A Population-based, Multicenter Cohort Study

Introduction

Knowledge about the relationship between symptoms, diagnoses, and mortality in emergency department (ED) patients is essential for the emergency physician to optimize treatment, monitoring, and flow. In this study, we investigated the association between symptoms and discharge diagnoses; symptoms and mortality; and we then analyzed whether the association between symptoms and mortality was influenced by other risk factors.

Methods

This was a population-based, multicenter cohort study of all non-trauma ED patients ≥18 years who presented at a hospital in the Region of Southern Denmark between January 1, 2016–March 20, 2018. We used multivariable logistic regression to examine the association between symptoms and mortality adjusted for other risk factors.

Results

We included 223,612 ED visits with a median patient age of 63 and even distribution of females and males. The frequency of the chief complaints at presentation were as follows: non-specific symptoms (19%); abdominal pain (16%); dyspnea (12%); fever (8%); chest pain (8%); and neurologic complaints (7%). Discharge diagnoses were symptom-based (24%), observational (hospital visit for observation or examination, 17%), circulatory (12%), or respiratory (12%). The overall 30-day mortality was 3.5%, with 1.7% dead within 0–7 days and 1.8% within 8–30 days. The presenting symptom was associated with mortality at 0–7 days but not with mortality at 8–30 days. Patients whose charts were missing documentation of symptoms (adjusted odds ratio [aOR] 3.5) and dyspneic patients (aOR 2.4) had the highest mortality at 0–7 days across patients with different primary symptoms. Patients ≥80 years and patients with a higher degree of comorbidity had increased mortality from 0–7 days to 8–30 days (aOR from 24.0 to 42.7 and 1.9 to 2.8, respectively).

Conclusion

Short-term mortality was more strongly associated with patient-related factors than with the primary presenting symptom at arrival to the hospital.

Shedding light into the black box of out-of-hospital respiratory distress—A retrospective cohort analysis of discharge diagnoses, prehospital diagnostic accuracy, and predictors of mortality

Background

Although respiratory distress is one of the most common complaints of patients requiring emergency medical services (EMS), there is a lack of evidence on important aspects.

Objectives

Our study aims to determine the accuracy of EMS physician diagnostics in the out-of-hospital setting, identify examination findings that correlate with diagnoses, investigate hospital mortality, and identify mortality-associated predictors.

Methods

This retrospective observational study examined EMS encounters between December 2015 and May 2016 in the city of Aachen, Germany, in which an EMS physician was present at the scene. Adult patients were included if the EMS physician initially detected dyspnea, low oxygen saturation, or pathological auscultation findings at the scene (n = 719). The analyses were performed by linking out-of-hospital data to hospital records and using binary logistic regressions.

Results

The overall diagnostic accuracy was 69.9% (485/694). The highest diagnostic accuracies were observed in asthma (15/15; 100%), hypertensive crisis (28/33; 84.4%), and COPD exacerbation (114/138; 82.6%), lowest accuracies were observed in pneumonia (70/142; 49.3%), pulmonary embolism (8/18; 44.4%), and urinary tract infection (14/35; 40%). The overall hospital mortality rate was 13.8% (99/719). The highest hospital mortality rates were seen in pneumonia (44/142; 31%) and urinary tract infection (7/35; 20%). Identified risk factors for hospital mortality were metabolic acidosis in the initial blood gas analysis (odds ratio (OR) 11.84), the diagnosis of pneumonia (OR 3.22) reduced vigilance (OR 2.58), low oxygen saturation (OR 2.23), and increasing age (OR 1.03 by 1 year increase).

Conclusions

Our data highlight the diagnostic uncertainties and high mortality in out-of-hospital emergency patients presenting with respiratory distress. Pneumonia was the most common and most frequently misdiagnosed cause and showed highest hospital mortality. The identified predictors could contribute to an early detection of patients at risk.

Patients' lived experiences of breathlessness prior to prehospital care - A phenomenological study

Aims and objectives

The study aimed to describe how breathlessness is experienced by patients prior to prehospital care.

Design

A qualitative phenomenological design.

Methods

Lifeworld interviews were conducted with 14 participants. The analysis was carried out within the descriptive phenomenological framework.

Results

The essential meaning of the breathlessness phenomenon is described as an existential fear in terms of losing control over one’s body and dying, which involves a battle to try to regain control. This is further described by four constituents: being in an unknown body, striving to handle the situation, the ambiguity of having loved ones close and reaching the utmost border.

Conclusions

Patients describe a battling for survival. It is at the extreme limit of endurance that patients finally choose to call the emergency number. It is a challenge for the ambulance clinician (AC) to support these patients in the most optimal fashion.

Prehospital Time Disparities for Rural Patients with Suspected STEMI

BACKGROUND

Rural patients with ST-elevation myocardial infarction (STEMI) may be less likely to receive prompt reperfusion therapy. This study's primary objective was to compare rural versus urban time intervals among a national cohort of prehospital patients with STEMI.

METHODS

The ESO Data Collaborative (Austin, TX), containing records from 1,366 emergency medical services agencies, was queried for adult 9-1-1 responses with suspected STEMI from 1/1/2018-12/31/2019. The scene address for each encounter was classified as either urban or rural using the 2010 US Census Urban Area Zip Code Tabulation Area relationship. The primary outcome was total EMS interval (9-1-1 call to hospital arrival); a key secondary outcome was the proportion of responses that had EMS intervals under 60 minutes. Generalized estimating equations were used to determine whether rural versus urban differences in interval outcomes occurred when adjusting for loaded mileage (distance from scene to hospital) and patient and clinical encounter characteristics.

RESULTS

Of 15,915,027 adult 9-1-1 transports, 23,655 records with suspected STEMI were included in the analysis. Most responses (91.6%, n = 21,661) occurred in urban settings. Median EMS interval was 37.6 minutes (IQR 30.0-48.0) in urban settings compared to 57.0 minutes (IQR 46.5-70.7) in rural settings (p < 0.01). Urban responses more frequently had EMS intervals <60 minutes (89.5%, n = 19,130), compared to rural responses (55.5%, n = 1,100, p < 0.01). After adjusting for loaded mileage, age, sex, race/ethnicity, abnormal vital signs, pain assessment, aspirin administration, and IV/IO attempt, rural location was associated with a 5.8 (95%CI 4.2-7.4) minute longer EMS interval than urban, and rural location was associated with a reduced chance of achieving EMS interval < 60 minutes (OR 0.40; 95%CI 0.33-0.49) as compared to urban location.

CONCLUSION

In this large national sample, rural location was associated with significantly longer EMS interval for patients with suspected STEMI, even after accounting for loaded mileage.

Clinical Predictors of Mortality in Prehospital Distress Calls by Emergency Medical Service Subscribers

(1) Introduction: Most studies rely on in-hospital data to predict cardiovascular risk and do not include prehospital information that is substantially important for early decision making. The aim of the study was to define clinical parameters in the prehospital setting, which may affect clinical outcomes. (2) Methods: In this population-based study, we performed a retrospective analysis of emergency calls that were made by patients to the largest private emergency medical services (EMS) in Israel, SHL Telemedicine Ltd., who were treated on-site by the EMS team. Demographics, clinical characteristics, and clinical outcomes were analyzed. Mortality was evaluated at three time points: 1, 3, and 12 months’ follow-up. The first EMS prehospital measurements of the systolic blood pressure (SBP) were recorded and analyzed. Logistic regression analyses were performed. (3) Results: A total of 64,320 emergency calls were included with a follow-up of 12 months post index EMS call. Fifty-five percent of patients were men and the mean age was 70.2 ± 13.1 years. During follow-up of 12 months, 7.6% of patients died. Age above 80 years (OR 3.34; 95% CI 3.03–3.69, p < 0.005), first EMS SBP ≤ 130 mm Hg (OR 2.61; 95% CI 2.36–2.88, p < 0.005), dyspnea at presentation (OR 2.55; 95% CI 2.29–2.83, p < 0001), and chest pain with ischemic ECG changes (OR 1.95; 95% CI 1.71–2.23, p < 0.001) were the highest predictors of 1 month mortality and remained so for mortality at 3 and 12 months. In contrast, history of hypertension and first EMS prehospital SBP ≥ 160 mm Hg were significantly associated with decreased mortality at 1, 3 and 12 months. (4) Conclusions: We identified risk predictors for all-cause mortality in a large cohort of patients during prehospital EMS calls. Age over 80 years, first EMS-documented prehospital SBP < 130 mm Hg, and dyspnea at presentation were the most profound risk predictors for short- and long-term mortality. The current study demonstrates that in prehospital EMS call settings, several parameters can be used to improve prioritization and management of high-risk patients.

Can a Healthcare Quality Improvement Initiative Reduce Disparity in the Treatment Delay among ST-Segment Elevation Myocardial Infarction Patients with Different Arrival Modes? Evidence from 33 General Hospitals and Their Anticipated Impact on Healthcare during Disasters and Public Health Emergencies

(1) Background: Chest pain center accreditation has been associated with improved timelines of primary percutaneous coronary intervention (PCI) for ST-segment elevated myocardial infarction (STEMI). However, evidence from low- and middle-income regions was insufficient, and whether the sensitivity to improvements differs between walk-in and emergency medical service (EMS)-transported patients remained unclear. In this study, we aimed to examine the association of chest pain center accreditation status with door-to-balloon (D2B) time and the potential modification effect of arrival mode. (2) Methods: The associations were examined using generalized linear mixed models, and the effect modification of arrival mode was examined by incorporating an interaction term in the models. (3) Results: In 4186 STEMI patients, during and after accreditation were respectively associated with 65% (95% CI: 54%, 73%) and 71% (95% CI: 61%, 79%) reduced risk of D2B time being more than 90 min (using before accreditation as the reference). Decreases of 27.88 (95% CI: 19.57, 36.22) minutes and 26.55 (95% CI: 17.45, 35.70) minutes in D2B were also observed for the during and after accreditation groups, respectively. The impact of accreditation on timeline improvement was greater for EMS-transported patients than for walk-in patients. (4) Conclusions: EMS-transported patients were more sensitive to the shortened in-hospital delay associated with the initiative, which could exacerbate the existing disparity among patients with different arrival modes.