Altered Mental Status in Danish Emergency Department Patients: A Cohort Study of Aetiology and Mortality

Research Article

Austin J Emergency & Crit Care Med. 2023; 7(1): 1070.

Altered Mental Status in Danish Emergency Department Patients: A Cohort Study of Aetiology and Mortality

Mose CP1*; Ovesen SH1,2; Lisby M1,3; Sørensen SF1; Hansen L1; Kirkegaard H1

¹Department of Clinical Medicine, Research Center for Emergency Medicine, Aarhus University, Denmark

²Department of Emergency, Horsens Regional Hospital, Horsens, Denmark

³Department of Emergency, Aarhus University Hospital, Denmark

*Corresponding author: Mose CPResearch Center for Emergency Medicine, Department of Clinical Medicine, Health, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, J103, 8200 Aarhus N, Denmark. Email: Cathrine_mose@hotmail.com

Received: February 14, 2023 Accepted: March 25, 2023 Published: April 01, 2023

Abstract

Objective: Altered Mental Status (AMS) is a common presentation of patients in emergency departments, and it is associated with a high mortality rate. This study aimed to examine the aetiologies and outcomes in emergency department patients with AMS.

Methods: This was a single-centre retrospective cohort study. All patients (age ≥18 years) presenting to the emergency department at Aarhus University Hospital with the chief complaint of AMS from July 2016 to June 2017 was included. Primary end points were aetiology and 30-day mortality. Patients were stratified by age group (18-59 years/+60 years) and hospital admission (yes/no) for further analysis.

Results: A total of 554 patients were included. The most common cause of AMS was unspecific R-diagnosis (22.2%). Among younger adults (18–59 years), intoxication was the most common aetiology, whereas infection was the most common cause in older patients (≥60 years). The total 30-day mortality rate was 10.8%. The odds of dying within 30 days after admission were significantly higher for patients with system/organ dysfunction compared to the rest of the study population (OR: 6.2, 95% CI: 3.0 to 12.6; p<0.001).

Conclusion: Non-neurological disorders appear dominant at all ages. Intoxication was primarily seen among younger adults (18–59 years), while infection was a more common cause among the elderly (>60 years). AMS is associated with a high 30-day mortality rate. Patients with system/organ dysfunction had significantly higher odds of dying within 30 days compared to the rest of the study population.

Keywords: Altered mental status; Impaired consciousness; Emergency department; Danish Emergency Process Triage (DEPT)

Abbreviations: ADAPT: Adaptive Process Triage; AMS: Altered Mental Status; ATS: Australasian Triage Scale; AUH: Aarhus University Hospital; CNS: Central Nervous System; CPR: Civil Personal Registration Number; CT-Scan: Computed Tomography Scan; CTAS: Canadian Triage And Acuity Scale; DEPT: Danish Emergency Process Triage; ECG: Electrocardiogram; ED: Emergency Department; GCS: Glasgow Coma Scale; ICD-10: International Classification Of Diseases, 10th Revision; MTS: The Manchester Triage System; UTI: Urinary Tract Infection

Introduction

Altered Mental Status (AMS) is a common presentation of patients in Emergency Departments (ED) [1]. AMS is a broad term used to describe any alteration in a patient’s baseline level of cognitive ability, level of awareness, or responsiveness to surroundings [2,3]. Acute changes in mental status can be the first sign of a potentially life-threatening condition that requires fast diagnostic workup and rapid decision-making [3]. Often, these patients pose a great diagnostic challenge to ED physicians due to the numerous neurological (e.g., stroke, brain tumour, or neuro infection) and non-neurological (e.g., infection, intoxication, or metabolic disorders) differential diagnoses [1-3]. Moreover, AMS is a concurrent condition associated with other primary complaints [4-6]. Generally, the patient manifests with vague symptoms with no obvious underlying aetiology, and the initial evaluation is based on limited patient information [1]. Workup strategies also lack standardisation; hence, a broad range of diagnostic tests are usually performed in the ED (e.g., CT scans, ECG, etc.) [7].

Previous studies of AMS patients in ED shave reported high mortality rates ranging from 8.1% to 11.5% [1,7-10]. In particular, the elderly have been found to be at an increased risk of adverse outcomes [7-11]. A bimodal distribution of age has been described, and aetiologies vary significantly with age [1,7]. Intoxication and trauma have been described as common causes of AMS among younger adults, whereas neurological disorders and organ dysfunction are more frequent among the elderly [1,7]. However, the results vary between studies, indicating that aetiologies and mortality rates are not consistent in all regions [7]. Furthermore, current knowledge within the field is mainly based on small sample sizes. In general, more knowledge of the underlying aetiologies, mortality rates, and distribution by age is warranted.

Therefore, the primary aim of this study was to examine aetiologies and 30-day mortality in patients admitted to the ED at Aarhus University Hospital with AMS as the chief complaint. Second, we aimed to compare the distribution of aetiologies among age groups and the mortality risk of different aetiologies.

Materials and Methods

Study Design and Setting

This single-centre retrospective cohort study is based on data on all adult patients presenting with AMS upon admission to the ED at Aarhus University Hospital (AUH) in the period from 1 July 2016 to 30 June 2017.

AUH is the largest hospital in the Central Denmark region. The hospital catchment population is around 350,000 inhabitants, and the ED has approximately 45,000 contacts per year. AUH manages all medical emergencies in the local area. Moreover, it functions as a referral hospital, thus receiving patients with major traumas from the entire region. In the inclusion period, all acute patients entered the hospital through the ED, except parturient women, psychiatric patients, and patients suspected of either ST-elevation myocardial infarction or stroke [12].

The ED contains an emergency room for minor surgical or medical injuries, two short-term medical units, and a specialised trauma centre [13]. Patients are initially triaged by an experienced nurse using the Danish Emergency Process Triage system (DEPT) [14]. In short, DEPT is a five-level triage system based on vital signs and one (or two) symptom-based cards (e.g., dyspnoea) related to the patient’s chief complaint [12,14]. The patients are triaged after urgency listing from red (life-threatening condition, requires immediate treatment) through to orange, yellow, green (stable condition, no urgency), and blue (minor injuries). The system is used to determine the priority of patients’ treatments in similarity to other modern triage systems, such as the Manchester Triage system (MTS), the Australasian Triage Scale (ATS), the Canadian Triage and Acuity Scale (CTAS), and Adaptive Process Triage (ADAPT) [15-17].

Selection of Participants

This study included all ED patients’ ≤18 years of age who were triaged with the chief complaint of AMS. Only patients with a Danish personal identification number (CPR number) were included. Patient’s triaged with a blue cardor no triaged colour were excluded. If a patient had multiple visits, only the first contact was included in the analysis.

Data Source

Patient data were retrieved from the regional data warehouse, containing all registered patient-related data (e.g., personal identification, diagnoses, vital signs, and triage level). Vital status was obtained from the Danish Civil Registration System, which enabled the complete follow-up of all included patients.

Outcome Measures

The primary outcomes were the causative aetiologies of AMS and 30-day mortality rates. Aetiology was measured as the final discharge diagnosis (i.e., action diagnosis), or the last diagnosis given in the case of in-hospital death. Diagnoses were reported in accordance with the International Classification of Diseases (ICD-10) guidelines. Mortality was defined as all-cause mortality within 30 days after admission. Second, a comparison of the distributions of aetiologies and their mortality risks in different age groups was conducted. The patients were divided into two subgroups: younger adults (aged 18–59 years) and the elderly (aged 60 or higher). Aetiologies were categorised as either primary neurological or non-neurological, with each classification containing several subgroups.

Analysis

Categorical variables are presented as numbers and percentages. Continuous variables are presented as medians with an interquartile range. To assess the differences in the distribution of the categorical variables between groups, Pearson’s chi-square test or Fischer’s exact test were used as appropriate. The Wilcoxon rank sum test was used for the comparison of continuous variables. Mortality data are presented as the cumulative number of events and incidence proportions with 95% confidence intervals. Multivariate logistic regression, adjusted for sex and age groups, was used to determine the odds ratios. Cumulative mortality was depicted using Kaplan–Meier survival curves, and distributions were compared using the log-rank test. The level of significance was set at P<0.05. All analyses were performed using STATA version 15 (Stata Corp., College Station, Texas, USA).

Ethical Approval

This study was approved by the Danish Data Protection Agency (case no. 1-16-02-317-18) and the Danish Patient Safety Authority (case no. 3-3013-2615). In accordance with Danish law, ethical approval from the Regional Ethics Committee was not required, as this is a register-based study.

Results

Patient Characteristics

During the inclusion period, 38,934 acute contacts were registered at the ED, of which 1.6% were due to AMS (n=607). A total of 554 patients were included in the study, as they fulfilled the inclusion criteria (Figure 1).