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Year : 2020  |  Volume : 18  |  Issue : 4  |  Page : 300-304

Altered mental status in the emergency department, a retrospective analysis

Department of Emergency Medicine, Christian Medical College, Vellore, Tamil Nadu, India

Date of Submission21-Apr-2020
Date of Decision18-May-2020
Date of Acceptance05-Jun-2020
Date of Web Publication19-Oct-2020

Correspondence Address:
Dr. Sai Kiran Cherukuri
Department of Emergency Medicine, Christian Medical College, Vellore - 632 004, Tamil Nadu
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/cmi.cmi_64_20

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Background: Altered mental status (AMS) is a common presentation of patients to the emergency department (ED), posing a significant challenge for the physician to accurately diagnose and begin appropriate management. The etiology of AMS spans a wide variety of clinical syndromes and is not consistent in all countries and regions. Materials and Methods: This was a retrospective analysis of 407 patients presenting to the ED with AMS in the months of January 2013 to April 2013. The details of the presentation, investigations, final diagnosis, and management were extracted from charts in the hospital electronic database. Results: AMS constituted 2.8% of patients registered at the ED during the study period. Of the 407 patients, 254 (62.3%) were male, and 153 (37.5%) were female. Mean age was 52.34 ± 17.84 years. Majority (n = 287; 70.4%) of the patients were in the age group between 18-64 years. Etiological factors were neurological (n = 151; 37.1%), metabolic/endocrine (n = 75; 18.4%), infections (n = 55; 13.5%) system/organ dysfunction (n = 49; 12%), toxicological (n = 39; 9.6%), miscellaneous (n = 19; 4.7%), oncological (n = 12; 2.9%), and psychiatric (n = 7; 1.7%). About 17.9% had mild AMS, 47.4% had moderate AMS, and 34.6% had severe AMS. Majority (65.1%) presented to ED within 24 h of onset of AMS. Total mortality rate was 11.5% (n = 47). Conclusions: This study has conveyed the frequency of various etiologies of AMS and its stratification in regards to age and severity. Neurological conditions remain the most common cause of AMS. Data reveal a large fraction of patients presenting beyond 24 h of onset of AMS. Public education concerning the establishment of support systems for the vulnerable population can lead to faster presentation to the ED and subsequent management.

Keywords: Acute neurology, altered mental status, altered sensorium, computerized tomography scanning, emergency medicine

How to cite this article:
Cherukuri SK, Dhanawade VS. Altered mental status in the emergency department, a retrospective analysis. Curr Med Issues 2020;18:300-4

How to cite this URL:
Cherukuri SK, Dhanawade VS. Altered mental status in the emergency department, a retrospective analysis. Curr Med Issues [serial online] 2020 [cited 2022 Aug 9];18:300-4. Available from: https://www.cmijournal.org/text.asp?2020/18/4/300/298595

  Introduction Top

Altered mental status (AMS) represents a common presentation of patients to the emergency department (ED) with studies reporting 4%–10% of patients in ED diagnosed with it. AMS is defined as a clinical state manifested by conditions ranging from confusion and disorientation to person, place, and time to stupor and deep coma.[1] Etiologies of AMS span a range from primary central nervous system (CNS) disorders to secondary processes with an effect on CNS. On the basis of duration, AMS is divided into acute, subacute, and chronic, i.e., processes of <24 h of duration, those of <1 week of duration, and those of >1-week duration, such as dementia or Alzheimer's disease.[1] Trauma, infections, and toxicological causes are important causes for acute AMS.[2],[3] Patients with acute nontraumatic AMS make up 5% of all patients presenting to EDs with higher rates (20%–25%) among elderly and poisoned patients.[4] AMS is encountered among patients of all age groups. A bimodal age distribution the young adults and the elderly have been observed by some authors.[1],[2] Traumatic and toxicologic causes were more common in the younger adults, whereas neurologic etiologies and organ dysfunction were seen most frequently in the elderly.[5],[6] Among the various etiologies, neurological causes are the most common. Other common causes included infections and metabolic causes.[2],[6]

AMS is a common symptom complex that carries a significant length of hospital stay and mortality.[3] It is important to manage this group of patients with proper allocation of resources from triaging to investigation and treatment at the ED, as it carries a fatality rate ranging from 8% to 10%.[1],[2] As etiologies of AMS can vary geographically, an up-to-date knowledge of the common causes and diagnostic tools at hand will help emergency physicians in the effective management of these patients. The literature search reveals that there is limited published data on the issue of AMS in the ED and the ED approach to these patients. Awareness about the possible causes of AMS in a particular region would facilitate the approach and management of these patients. This study is undertaken to recognize the trend of patients with AMS attending our ED.

  Materials and Methods Top


This study was a retrospective chart analysis of patients presented with AMS.


The study was conducted in the ED of Christian Medical College Hospital, Vellore, which is a tertiary medical care center. The ED is a 49-bed department and tends to about 300 patients per day, including trauma and nontrauma patients.


All patients above the age of 18 years presenting with acute undifferentiated AMS (GCS <15, the onset of symptoms no more than 1 week before the presentation) within the study period of January to April 2013 [Figure 1]. Patients with chronic AMS and traumatic brain injuries were excluded from the study.
Figure 1: STROBE diagram.

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Charts were reviewed using the electronic medical records database and relevant information were recorded into a datasheet, including age, sex, final diagnosis, the severity of AMS (mild: GCS-13-15/15, moderate: 9-12/15, and severe: 3-8/15), time to presentation, and mortality during inpatient admission.


This study is limited due to the retrospective manner of collection of data and reliance on documentation provided by ED physicians.

Study size

Patients were recruited within a study period from January to April 2013.

Laboratory tests

All patients had routine blood investigations and relevant radiological tests based on the initial primary and secondary surveys.

Statistical analysis

All categorical variables were expressed as frequencies and percentages. The data were analyzed using the Statistical Package for the Social Sciences for Windows software released 2015, version 23.0, Armonk, New York, USA.

Ethical considerations

Patient confidentiality was maintained using unique identifiers and by password-protected data entry software with restricted users. The study was approved by the IRB, IRB Min. No. 8341, dated December 12, 2011.

  Results Top

From January 1, to April 30, 2013, a total of 14,448 patients were registered in the ED with 407 patients identified at triage with Glasgow Coma Scale (GCS) score <15. This constituted 2.8% of ED patients. Baseline demographics are tabulated in [Table 1]. The mean age in the present study was 52.3 ± 17.84. There was a male preponderance in this study with 62.3% (n = 254) of our patients being males. Forty percent (n = 163) of patients had type 2 diabetes mellitus and 36.8% (n = 150) had systemic hypertension. History of smoking was recorded in 11% and drinking in 15.4%.
Table 1: Baseline demographics in the study population

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Most (60.9.%, n = 148) of the patients presented within 12 h of onset of AMS. About 17.9% (n = 73) had mild AMS, 47.4% (n = 193) had moderate AMS, and 34.6% (n = 141) had severe AMS, classified on the basis of GCS score at triage. The majority (89.4%) of patients were brought from home.

In the present study, neurological conditions were the most important cause accounting for 37.1% (n = 151) of patients. Other etiologies are shown in [Table 2]. Among the neurological causes, strokes formed 21.3% (n = 87), CNS infections 6.4% (n = 26), seizures and post ictal phase 4.7% (n = 19), intracranial space-occupying lesions 3.7% (n = 15), and unclassified CNS diseases 1% (n = 4) forming the rest. Within metabolic and endocrine causes, hypoglycemia and electrolyte imbalance represented 13.5% (n = 55), and 4.91% (n = 20), respectively. Sepsis was the predominant diagnosis within infectious causes (7.37%, n = 30). Others were acute febrile illness (3.93%, n = 16), TB/HIV (1.22%, n = 5), and viral/rickettsial (0.98%, n = 4). The diagnoses of organ dysfunction seen in this study were gastrointestinal (7.86%, n = 32), cardiovascular (1.22%, n = 5), respiratory (1.71%, n = 7), renal (0.98%, n = 4), and genitourinary (0.24%, n = 1). Among toxicological causes, poisoning was the most common (4.93%, n = 20). Drug overdose (2.45%, n = 10) and alcohol-related (2.22%, n = 9) were other causes. Hanging (3.43%, n = 14) and heat stroke (1.22%, n = 5) were miscellaneous causes adding to the study's population.
Table 2: Etiologies of altered mental status in the study population

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On stratifying against age, displayed in [Table 3], neurological causes were the most common in all the three age groups, i.e., 18–44 years (33.6%, 45), 45–64 years (37.9%, 58), and >65 years (40%, 48). However, in the 18–44 age group toxicologic (22.4%, 30) followed by infections and system and organ dysfunction (15% each) formed other important causes. Above the age of 45 years, metabolic and infections were the common causes besides neurological conditions.
Table 3: Etiologies of acute mental status stratified against age groups

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The use of radiological investigations, namely, computed tomography (CT) of the brain [Table 4], showed CT being ordered for 29%, with an overwhelming majority of them (94%) found to be abnormal.
Table 4: The use of computed tomography of the brain (plain) in the assessment of the altered mental status

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Among the 407 patients, 58% (n = 238) were admitted into the wards and intensive care units [Table 5]. Overall, 85.8% (n = 350) patients were discharged home after a hospital stay, the mean duration of hospital stay was 4.09 ± 5.76 days. The mortality rate within the hospital, among AMS patients in this study, was 11.5% (n = 47).
Table 5: Outcome and disposition of study population

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  Discussion Top

AMS remains a complex syndrome complex for emergency physicians to diagnose accurately and provide useful management. Due to the large spectrum of diseases presenting in this fashion, protocols are difficult to create and integrate into existing systems.[7] As a result, the physician's clinical judgment is highly relied on, especially in situ ations with incomplete or inadequate history from patient's attendants. The purpose of this study was to understand the etiologies, clinical features, and outcomes of adult patients with acute undifferentiated AMS presenting to the ED.

In our study, AMS was a feature in 2.8% of the total population presenting to the ED. Studies done with similar inclusive criteria showed AMS as a presentation in 4%–10% of patients. This discrepancy may be attributed to the fact patients presenting to our emergency include patients referred from far distances for hematological or oncological diagnoses which our hospital has a reputation for. Furthermore, the retrospective nature of this study may have missed milder cases.

In the present study, the majority (70.4%) of patients were in the age group of 18-64 years and 29.5% were >65 years. Our findings were similar to Kanich et al. and Xiao et al.[2],[4] They had observed bimodal age peaks, the first peak at 33 years, and the second peak at 72 years with distinct etiology of AMS among the two groups.[4] The mean age was 77.9 years in Hustey et al.'s study on the elderly population.[8]

In the present study, 17.9% had mild, 47.4% had moderate, and 34.6% had severe AMS on the basis of their GCS score. Kanich et al. found 24% of their patients to be unresponsive, 46% lethargic, 12% agitated, and 18% with unusual behavior. GCS score was <15 in 38% and the Mini-Mental State Examination score <24 in 54.7%.[2] Kekec et al. reported that 40% of their patients were in a deep coma, 11% confused, 20% in agitated confusion, 15% lethargic, and 14% stuporous.[9]

Broadly, the etiology of AMS presenting to the ED is categorized into two factors: primary neurological and nonneurological causes. A study by Kanich et al. reported neurological events to be the most important cause for AMS accounting for about 28% of patients.[2] In the present study as well, neurological conditions were the most important cause, accounting for 37.1% of patients. Other important etiologies were metabolic/endocrine (18.4%), infections (13.5%), system and organ dysfunction (12%), and toxicology, including alcohol and drug overdose (9.6%). Psychiatric diseases contributed only 0.8% of patients in this study. In this study, 2.9% of patients had underlying malignancy as the cause of AMS.

The etiology of AMS varies between countries and different regions. Infections of which cerebral malaria was the primary cause of AMS in a study from Ethiopia.[9] Studies of AMS from the west have found substance abuse to be the prime cause.[5] The etiology of AMS also differs between the elderly and nonelderly age groups. In this study, neurological causes were the most common in all the three age groups. However, in the 18-44 age group toxicologic (22.4%) followed by infections and system and organ dysfunction (15% each) were the second- and third-most common etiologies. Above the age of 45 years, metabolic and infections were more common causes besides neurological conditions.

We used computerized tomography scanning of the brain as an investigative methodology in 28% of cases and most (94%) of them were abnormal. There are no specific guidelines for the efficient ordering of CT scan in AMS patients and a wide variation in its use exists. Our CT-head ordering rate was much lower than in other studies. Lim et al. 2009 found that 56.6% of their patients underwent CT of the brain at the ED and 39.1% were abnormal.[10] This can be explained by the hospital and financial burden seen in India, forcing physicians to be rather judicious with the scans. However, we have not taken into account the CT–head scans ordered at the ward level in this study.

The majority of our patients presented within 24 h (65.5%) with 29.7% coming to the ED within 3 h of onset of symptoms. While this is certainly the majority, perhaps public education on simple syndrome complexes, such as stroke, and construction of support systems for vulnerable populations can decrease the average time to presentation.

In this study, it is apparent that AMS has a high admission rate, with 48% of patients being shifted to the wards and 10.3% being shifted to the ED. This is similar, though not as high, to studies such as Xiao's and Leong's were 70% and 100% of patients were admitted respectively.[1],[4] The mean duration of hospital stay was 4.09 ± 5.76 days. The mortality rate among AMS patients in this study was 11.5%. Mortality rates ranging from 9% to 11% have been reported by Kanich et al., Leong et al., and Xiao et al. in their studies.[1],[2],[4] Higher mortality of 20.1% was reported by Kekec et al. (2008).[8] The mean GCS score in the expired patients was 6.87 in our study.

  Conclusions Top

AMS with its large spectrum of etiologies represents one of the most mentally taxing presentations to diagnose accurately for the emergency physician. This will only increase with time as the world ages and longevity improves with better medical technology. In our study, neurological diseases were the highest, with infections and metabolic following behind, but toxicological causes higher in younger age groups. Knowledge of these common etiologies in different age groups in a particular geographic area may help a physician's ability to quickly diagnose a case and begin appropriate management.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

Research quality and ethics statement

The authors of this manuscript declare that this scientific work complies with reporting quality, formatting, and reproducibility guidelines set forth by the EQUATOR Network. The authors also attest that this clinical investigation was determined to require Institutional Review Board/Ethics Committee review, and the corresponding protocol/approval number is IRB Min. No. 8341, dated December 12, 2011. We also certify that we have not plagiarized the contents in this submission and have done a Plagiarism Check.

  References Top

Leong LB, Jian KH, Vasu A, Seow E. Prospective study of patients with altered mental status: Clinical features and outcome. Int J Emerg Med 2008;1:179-82.  Back to cited text no. 1
Kanich W, Brady WJ, Huff JS, Perron AD, Holstege C, Lindbeck G, et al. Altered mental status: Evaluation and etiology in the ED. Am J Emerg Med 2002;20:613-7.  Back to cited text no. 2
Han JH, Wilber ST. Altered mental status in older patients in the emergency department. Clin Geriatr Med 2013;29:101-36.  Back to cited text no. 3
Xiao HY, Wang YX, Xu TD, Zhu HD, Guo SB, Wang Z, et al. Evaluation and treatment of altered mental status patients in the emergency department: Life in the fast lane. World J Emerg Med 2012;3:270-7.  Back to cited text no. 4
Sporer KA, Mariel S, Durant EJ, Wang W, Wu AH, Rodriguez RM. Accuracy of the initial diagnosis among patients with an acutely altered mental status. Emerg Med J 2013;30:243-6.  Back to cited text no. 5
Koita J, Riggio S, Jagoda A. The mental status examination in emergency practice. Emerg Med Clin North Am 2010;28:439-51.  Back to cited text no. 6
Hustey FM, Meldon SW, Smith MD, Lex CK. The effect of mental status screening on the care of elderly emergency department patients. Ann Emerg Med 2003;41:678-84.  Back to cited text no. 7
Kekec Z, Senol V, Koc F, Seydaoglu G. Analysis of altered mental status in Turkey. Int J Neurosci 2008;118:609-17.  Back to cited text no. 8
Melka A, Tekie-Haimanot R, Assefa M. Aetiology and outcome of non-traumatic altered states of consciousness in north western Ethiopia. East Afr Med J 1997;74:49-53.  Back to cited text no. 9
Lim BL, Lim GH, Heng WJ, Seow E. Clinical predictors of abnormal computed tomography findings in patients with altered mental status. Singapore Med J 2009;50:885-8.  Back to cited text no. 10


  [Figure 1]

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5]


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