Evaluation of delirium in elderly: A hospital-based studyggi_

Geriatr Gerontol Int 2011; 11: 467 473 ORIGINAL ARTICLE: EPIDEMIOLOGY, CLINICAL PRACTICE AND HEALTH Evaluation of delirium in elderly: A hospital-based studyggi_710 467..473 Vishal Khurana, Indrajeet Singh Gambhir and Dhiraj Kishore Department of General Medicine, Institute of Medical Sciences (IMS), Banaras Hindu University (BHU), Varanasi, India Aim: The study aimed to study the prevalence, etiologies, clinical profile and outcome of delirium in hospitalized elderly in medicine wards. Methods: Four hundred elderly patients of more than 60 years of age admitted with delirium in the emergency and medicine wards of Sir Sunderlal Hospital Varanasi, India, were evaluated and managed. The Hindi version of the Mini-Mental Status Examinations, a vernacular (Hindi) version of the Mini-Mental State Examination, was used for evaluation of cognitive function status of patients and Confusion Assessment Method (CAM), a screening instrument based on the third edition of the Diagnostic and Statistical Manual of Mental Disorders was used for diagnosis of delirium. Results: A total of 400 hospitalized elderly delirious patients were included in the study aged 61 105 years. The mean age of the subjects was 70.87 1 9.26 years and 70.81 1 8.4 years amongst males and females, respectively. The mortality rate was 14.75%. Out of nine CAM features, all the cases had all three essential features, 78.75% had four features, 58.5% had five features, 44.5% had six features and 9.25% had all nine features. There was a high prevalence of hypoactive delirium (65%) as compared to hyperactive (25%) or mixed (10%). Most common etiologies were sepsis followed by metabolic abnormalities. 70% had 2 or more etiologies. Conclusion: Sepsis and metabolic abnormalities were the most common etiologies of delirium in this study. The maximum patients had more than one etiology and this emphasizes the multifactorial nature of delirium and need for thorough evaluation to unravel them. Most of the causes were treatable and have favorable outcome (83% recovered). Geriatr Gerontol Int 2011; 11: 467 473. Keywords: cognition, delirium, elderly, geriatrics, sepsis. Introduction Delirium is an acute confusional disorder involving cognitive and affective aspects. 1,2 Delirium occurs in 14 56% of elderly hospitalized medical patients. 3 It has a high rate Accepted for publication 21 March 2011. Correspondence: Dr Vishal Khurana MBBS MD, c/o Professor I S Gambhir, Department of General Medicine, Institute of Medical Sciences (IMS), Banaras Hindu University (BHU), Varanasi, UP 221005, India. Email: vishdoc24@gmail.com Author contribution: V. K. and I. S. G. were involved in diagnosis, evaluation, management, data analysis and writing of this manuscript. D. K. helped in writing and revision of manuscript. of associated morbidity and mortality, nursing home placement and longer, costlier hospitalization. 4 The research on delirium from India is scarce. Prompted by this scarcity of data, the present research aimed to study the prevalence, etiology and clinical profile of delirium in hospitalized Indian elderly in medicine wards. Method Study subjects The present study was conducted from September 2007 to July 2009 at the Department of General Medicine of Sir Sunder Lal Hospital, Banaras Hindu University 2011 Japan Geriatrics Society doi: 10.1111/j.1447-0594.2011.00710.x 467

V Khurana et al. (BHU), Varanasi. Four hundred elderly patients of more than 60 years of age were selected on the basis of the following features: acute onset; fluctuating course; difficulty in focusing; maintaining or shifting attention; and disorganized thinking/altered levels of consciousness (fourth edition of the Diagnostic and Statistical Manual of Mental Disorders criteria of delirium). 5,6 Patients with dementia, psychosis or incommunicability were excluded. Study design For every patient included, information about education, place of abode (community or nursing home), previous cognitive status and past medical history including previous hospitalizations was sought from family members and caregivers, and by inspection of previous medical and nursing notes. Drugs used by patients prior to hospitalization were recorded, especially high-risk medications, including benzodiazepine, anticholinergics, antidepressants and anti-parkinsonians. All patients were examined for symptoms of delirium at admission. This was followed by thorough general and systemic examination. All participants were monitored every 12 h until discharge or death. Delirium was categorized as: (i) hypoactive if the patient was hypoaroused, hypoalert or lethargic; (ii) hyperactive if patients was hyperaroused, hyperalert, hallucinated, had delusions, was agitated or disorientated; and (iii) mixed type if the patient was having alternating features of the hyper- and hypoactive subtypes. 7 Assessment tools Hindi (vernacular) version of Mini-Mental State Examination (HMSE) 8 The HMSE is a validated tool, developed by the IndoUS Cross-National Dementia Epidemiology Study for illiterate persons, composed of 22 items which examine various cognitive capacities (orientation to time and place, memory, attention, concentration, recognition of objects, language function, comprehension and expressive speech, motor functioning and praxis). It has been validated in dementia in various studies, with a score of less than 23 having sensitivity and specificity of 94% and 98%, respectively. 9 It was used to follow delirium cases for improvement or deterioration of cognitive feature. HMSE evaluation was done twice daily in all patients, in the morning between 08.00 and 10.00 hours and in the evening between 18.00 and 20.00 hours. Confusion Assessment Method (CAM) 10 The CAM is a screening instrument based on the third edition of the Diagnostic and Statistical Manual of Mental Disorders. It has nine features. Using the CAM algorithm, diagnosis of delirium was made by the presence of acute onset and fluctuating course, inattention and either disorganized thinking or altered level of consciousness. This is a previously validated instrument with a sensitivity rate ranging 94 100% and a specificity rate ranging 90 95%. Laboratory studies Tests done in all patients were complete blood cell count, electrolytes, blood glucose, renal and liver functions, urine analysis (urine routine microscopy, urine culture and sensitivity) and electrocardiogram. Tests done as per indication were thyroid function studies, tests for bacteriological and viral etiologies, neuroimaging, electroencephalogram, chest X-ray, lumbar puncture and arterial blood gas analysis. Data analysis All the data were reported as mean 1 standard deviation if they were normally distributed. The c 2 -test was used to assess the significance. P < 0.05 was taken as significant. The c 2 -test was used to compare rates and proportions between groups. Pearson s correlation was used to find correlation between days of delirium and HMSE score or number of CAM features present at admission. Spearman s rank correlation coefficient was used between HMSE score and number of CAM features. Subgroup analysis was done using unpaired Student s t-test between two groups. Data were analyzed by the Sigma Stat software version 3.5. McNemar s test was used to determine if there is significantly different among causes for having hypoactive or hyperactive delirium. Results Four hundred elderly patients of more than 60 years of age with delirium admitted to the Medicine Ward of Sir Sunderlal Hospital, Banaras Hindu University (BHU), were studied based on a preformed clinical Performa. Prevalence of delirium was 27.47%. Mean age of the whole population was 70.865 1 8.862 years. The maximum number of cases belonged to the age group of 61 65 years (34%; 135/400) followed by 23% (93/400) in the age group between 66 70 years while elderly population of more than 85 years were few in number (6.5%; 26/400). The maximum number of men and women belonged to the age group of 61 65 years. There was a trend towards male preponderance in all of the age groups except in the age group of 81 85 years in which women were predominate (13:7). Hospitalized delirious men constituted 56% (226/400) of the total delirious cases while 44% (176/400) were women. Male 468 2011 Japan Geriatrics Society

Delirium in elderly to female ratio was 1.27:1. Mean age of the males was 70.87 1 9.26 years and that of females was 70.81 1 8.4 years. Of the total delirium cases, 85.5% had delirium at admission while the remaining 14.5% developed it after hospitalization. Mean number of days a patient remained hospitalized was 5.87 1 2.1 days. Men remained hospitalized for 5.85 1 2.19 days, whereas women remained hospitalized for 5.9 1 2.0 days. The maximum (n = 150) number of patients remained hospitalized for 4 6 days, followed by 6 8 days. Mean number of days a patient remained delirious before hospitalization was 2.32 1 1.84 days, however, after hospitalization they were delirious for 3.03 1 1.62 days. The maximum (102/400) number of patients were delirious for less than 1 day before hospitalization, followed by 1 2 days (75/400). However, after hospitalization, the maximum number of patients (115/400) remained delirious for 1 2 days followed by more than 4 days (95/400). Eighty-three percent of patients improved following hospitalization and 14.75% patients expired, with the remaining 3.25% were discharged in delirium or left against medical advice. Overall, delirium persisted for 5.42 1 2.36 days among improved patients (332; 83%). The maximum number of improved patient, approximately 32%, belonged to the 4 6-day group (107) followed by 2 4 days (91; 21%). Thirteen patients (3%) were discharged in delirium or left against medical advice. Those who expired (55; 14.75%) had delirium for 5.00 1 2.17 days. Of the patients, 32.7% expired after 4 6 days of delirium, followed by 31% after 2 4 days. The HMSE score at admission was 25.485 1 4.625. Mean HMSE score at discharge was 30.4. More than half of the cases (57.5%) had a score of less than 28, whereas 23.25% had a score of less than 23. Mean CAM features present at admission was 5.475 1 2.016. All the cases had all three essential features, 78.75% had four features, 58.5% had five features, 44.5% had six features and only 9.25% had all nine features. Sixty-five percent of patient had the hypoactive type of delirium whereas 25% had the hyperactive and 10% had the mixed type. Mixed type was predominately seen in men (69% vs 30.77%) (Table 1). Common etiologies (Table 2) found in this study were sepsis (36.5%), metabolic abnormalities (35%), cerebrovascular diseases (26.5%), congestive heart failure (26.5%), renal failure (21.5%), inflammatory brain diseases (12%) and malaria (12%). In three patients, no cause could be found but they improved after hospitalization. Common metabolic abnormalities (Table 3) found in this study were hyponatremia (37.14%) followed by hypoglycemia (35.72%), hyperglycemia (13.57%), hypernatremia (11.43%) and hypocalcemia (2.14%). Common infectious etiologies (Table 4) found in this study were urinary tract infections (41.18%) followed by respiratory tract infections (30.15%), skin and soft tissue infections (19.11%), and abscesses (9.56%). Among the cerebrovascular diseases, hemorrhage was responsible for 55.7% of cases and infarct for 36.7% of cases. In the six patients with transient ischemic attack, delirium improved in 1 day. Of poisoning cases, 83.33% were from pesticides and two cases were due to carbon monoxide poisoning. Fifty-six percent of inflammatory brain disease cases were meningitis and 39.58% cases encephalitis. Antidepressants and sedatives were the most common drug causing delirium in this study. The mean number of etiologies (Table 5) found in this study was 2.572 1 1.536. The maximum number of patients had two (29.75%) followed by single etiology (28.25%) while 12.5% had more than four etiologies. Sepsis with metabolic abnormality was the most common combination of two etiologies present in this study contributing 23.5% of total cases with only two etiologies (Table 6). Congestive heart failure with renal failure with electrolyte abnormalities was the most common combination of three etiologies present in this study contributing 21.2% of total cases with only three etiologies (Table 7). Discussion The geriatric age group is the fastest increasing age group worldwide. In our study, ages ranged 61 105 years. The mean age of men in our study group was 70.87 1 9.26 and the mean age of women was 70.81 1 8.4 years. Male to female ratio was 1.27:1. This is at variance with the Western world where women outnumber men. This may be due to lower life expectancy of Indian women due to various socioeconomic factors (women are given less priority) and poor health attention in the community. Also, the male to female Table 1 Types of delirium Type of delirium Male (%) Female (%) Total Hypoactive 143 (55.21%) 116 (44.79%) 259 (65%) Hyperactive 54 (52.94%) 48 (47.05%) 102 (25%) Mixed 27 (69.23%) 12 (30.77%) 39 (10%) Total 224 (56%) 176 (44%) 400 (100%) 2011 Japan Geriatrics Society 469

V Khurana et al. Table 2 Etiological factors and type of delirium according to etiology Etiological factors Number of patients % Hypoactive, n Hyperactive, n Sepsis 146 36.5 67 65 14 Metabolic abnormalities 140 35 85 37 18 Inflammatory brain disease 48 12 35 13 2 Malaria 48 12 28 8 12 Cerebrovascular accident 106 26.5 77 23 6 Acute exacerbation of chronic obstructive 58 14.5 27 28 3 pulmonary disease Congestive heart failure 106 26.5 49 32 25 Renal failure/uremia 86 21.5 66 18 2 Chronic liver disease 28 7 24 3 1 Neoplastic (cranial) disorders 60 15 45 14 1 Seizure related 10 2.5 4 5 1 Hypertensive encephalopathy 14 3.5 7 6 1 Medications 32 8 8 10 14 Endocrine cause 56 14 27 17 12 Urinary retention 40 10 8 30 2 Alcohol intoxication/withdrawal 10 2.5 2 7 1 Head trauma 6 1.5 1 1 4 Physical restraint 4 1 1 3 0 Hypothermia 1 0.25 1 0 0 Hyperthermia 2 0.5 1 1 0 Poison 12 3 4 8 0 Heatstroke 4 1 1 2 1 Hospitalization 2 0.5 1 1 0 Undiagnosed 3 0.75 1 1 1 Mixed, n Table 3 Metabolic conditions Table 4 Sepsis etiologies Metabolic conditions n % of metabolic causes Hypoglycemia 50 35.72 Hyperglycemia 19 13.57 Hyponatremia 52 37.14 Hypernatremia 16 11.43 Hypocalcemia 3 2.14 Total 140 100 Infections n % Urinary tract 56 38.36 Respiratory tract 41 28.08 Skin and soft tissue 26 17.81 Abscess 13 8.90 Other 10 6.85 Total 146 100 Others include dysentery and cholangitis. ratio in the elderly Indian population is approximately 1:1. Camus et al. in a case series of 183 elderly patients observed a mean age of 84.1 years. 11 We studied 400 patients fulfilling the diagnostic criteria of delirium. In our study, number of days a patient remain hospitalized was 5.87 1 2.2 days (range 0 14). This is in contrast to the 12.1 days reported by Francis et al. 15 On average, a patient presented to us after 2.32 1 1.84 days (range 0 9 days) of becoming delirious; however, after hospitalization they were delirious for 3.03 1 1.62 days (0 8). Improved patients remained delirious for a mean of 5.42 1 2.36 days (range 0 14) whereas expired patient were delirious for 5.0 1 2.17 days (range 0 13). This may be due to early recovery due to reversible infective or metabolic causes. In our study, 14.5% of patients developed delirium during hospital stays (incident cases). Ritchie et al. concluded that 14.6% of the patients had become delirious at some point during their inpatient stay. 16 Patten et al. found an estimated incidence proportion of 2.14%. 17 HMSE is as simplified version of the Mini-Mental State Examination (MMSE) made for Indian populations. On average, a score of 25.48 1 4.625 was obtained at time of admission. Webster and Holroyd 14 found a mean MMSE 470 2011 Japan Geriatrics Society

Delirium in elderly Table 5 Number of etiologies Number of etiologies Number of patients % Undiagnosed etiology 3 0.75 1 113 28.25 2 119 29.75 3 66 16.50 4 41 10.25 >4 58 14.50 Mean 1 standard 2.572 1 1.536 deviation Range 1 8 Table 6 Commonly associated two etiologies Etiology combinations n % Cerebrovascular accident + sepsis 15 12.61 Renal failure + electrolyte 16 13.45 abnormalities Congestive heart failure + metabolic 23 19.33 abnormalities Sepsis + metabolic abnormalities 28 23.52 Miscellaneous 37 31.09 Total 119/400 100 score of 11.0 1 9.6 for delirious patients. This may be because the HMSE is made for illiterate persons excluding a number of features of higher cognitive ability screening. The mean HMSE score at discharge was 30.4. Sixty-five percent of patient had the hypoactive type of delirium whereas 25% had hyperactive and 10% had mixed types. This is in contrast to more than half of the cases being of mixed type reported by Koponen and Riekkinen, 13 Liptzin et al. 18 and Maegher et al. 19 Ryuichi et al. in their study of cancer patients observed that the hyperactive type of delirium constituted 58% while 14% had hypoactive delirium. 12 Camus et al. 11 observed that the hyperactive subtype was more frequent (46.5%) and that the hypoactive subtype was present in 26.2%. This may be because the most common etiology reported in these studies (e.g. medication) which commonly present with hyperactive features as compared to our study where sepsis and metabolic disturbances were commonest; metabolic disturbances presented commonly with hypoactive delirium and sepsis did not show any predilection to hypoactive or hyperactive delirium. In our study, cerebrovascular diseases, inflammatory brain disease, congestive heart failure, malaria, liver failure and electrolyte imbalance were associated with the hypoactive type of delirium (McNemar s test correlation was clinically significant with a confidence level of 95%). The hypoactive type of delirium, in several studies, is correlated with hypoxia, 20 metabolic disturbances 21 and conditions triggering anticholinergic mechanisms. 19 In our study, the hyperactive type is correlated with alcohol intoxication/withdrawal and urinary retention (McNemar s test correlation was clinically significant with a confidence level of 95%). The hyperactive type is correlated with alcohol and drug withdrawal 19,21 and drug intoxication or drug side-effect. 20 O Keefe noted that there was no clear link between infection, the most common etiological factor in his study, and a particular subtype, even though alcohol withdrawal and metabolic disturbances led, respectively, to hyper- and hypoactive delirium as expected. Similar to O Keeffe s study, we also found no specific pattern of the delirium subtype in sepsis (the most common etiological factor in our study) and acute exacerbation of chronic obstructive pulmonary disease. In our study, the mixed type was the predominate feature of drugs and head trauma with delirium. In our study, 28.25% of patients had a single etiological cause, 29.75% had two, 16.5% had three, 10.25% had four and 14.5% had more than four. Therefore, 71% patients had more than one cause. On average, 2.57 etiological causes were present in a delirious patient. The number of etiological factors found by Camus et al. 11 was one etiological factor in 16% and 84% had two or more etiologies. Webster and Holroyd 14 in their study observed that 49.3% of delirium cases have multiple etiologies. Ryuichi et al. 12 found that two or more etiologies were present in more than 40%. Grover et al. in their study on psychiatric referral found two or more etiologies in 20.7%. 22 Camus et al. 11 showed that the most frequent etiologies were drug toxicity (56%), acute cardiovascular disease (48%), and acute metabolic and endocrine disease (43%) (Table 7). In our study, the most common etiology was sepsis (36.5%), followed by metabolic abnormalities (35%), cerebrovascular accident (26.5%), renal failure (21.5%) and inflammatory brain disease (12%). The most frequently observed etiologies of delirium in various Western studies are drug intoxication and withdrawal, brain injury, low perfusion state, infection and metabolic disturbances. The most common etiologies for delirium were stroke, infections and metabolic disorders. 13 Sepsis with metabolic abnormality was the most common combination of two etiologies present in this study contributing 23.5% of total cases with only two etiologies. Congestive heart failure with renal failure with electrolyte abnormalities was the most common combination of three etiologies present in this study contributing 21.2% of total cases with a combination of three etiologies. There is no such detail of multiple etiology combinations from other studies. Eighty-three percent of patients improved following management whereas 14% expired and 3% were discharged in delirium or left against medical advice. 2011 Japan Geriatrics Society 471

V Khurana et al. Table 7 Most common observed etiologies in various studies Study title Most common etiology observed 1st 2nd 3rd Cerebrovascular accident (26.5%) Metabolic abnormalities (35%) Sepsis and infections (36.5%) Our study Evaluation of delirium in elderly: A hospital-based study Acute metabolic and endocrine disease (43%) Medications (56%) Acute cardiovascular disease (48%) Camus et al. Etiologic and outcome profiles in (2000) 11 hypoactive and hyperactive subtypes of delirium. Opioids (29%) Inflammation (27%) Dehydration and/or sodium level abnormalities (15%) Ryuichi (2009) 12 Etiologies of delirium and their relationship to reversibility and motor subtype in cancer patients. Stroke Infections Metabolic disorders A prospective study of delirium in elderly patients admitted to a psychiatric hospital. Koponen and Riekkinen (1993) 13 Medication effect (15.9%) Infection (8.4%) Metabolic disarray (6.6%) Webster and Prevalence of psychotic symptoms Holroyd (2000) 14 in delirium Mortality rates reported in various studies range 9 23.9%. 23,24 The crucial factor in management of delirium is early diagnosis and management. 25 The mortality rate in our study was in the lower half of the collective range of various studies because we had a large number of cases with sepsis and metabolic abnormalities which are potentially treatable causes as compared to other studies in which common causes were chronic diseases or strokes. This study of delirium in hospitalized elderly revealed that delirium is a common health problem in elderly patients and is associated with high mortality. Sepsis and metabolic abnormalities were the most common etiologies of delirium in this study. The hypoactive subtype was commonest in our study which is one of the causes of misdiagnosis of delirium. Timely detection and effective treatment of delirium should help reduce hospital costs and mortality. Serial examination and thorough evaluation is important, as delirium is usually multifactorial and a fair number of elderly patients develop delirium during hospital stay. Most of the causes were treatable and had a favorable outcome (83%). HMSE scoring was not very distinctive in identifying delirium. Acknowledgments We do not have any conflict of interest. References 1 Inouye SK. Delirium in older persons. N Engl J Med 2006; 354: 1157 1165. 2 Saxena S, Lawley D. Delirium in the elderly: a clinical review. Postgrad Med J 2009; 85: 405 413. 3 Feldman J, Yaretzky A, Kaizimov N, Alterman P, Vigder C. Delirium in an acute geriatric unit: clinical aspects. Arch Gerontol Geriatr 1999; 28: 37 44. 4 Inouye SK, Viscoli CM, Horwitz RI, Hurst LD, Tinetti ME. A predictive model for delirium in hospitalized elderly medical patients based on admission characteristics. Ann Intern Med 1993; 119: 474 481. 5 American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 4th edn. Washington, DC: American Psychiatric Association, 1994; 127 169. 6 American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR), 4th edn. Washington, DC: American Psychiatric Association, 2000. 7 Lipowski ZJ. Delirium in the elderly patient. N Engl J Med 1989; 320: 578 582. 8 Ganguli M, Ratcliff G, Chandra V et al. A Hindi version of the MMSE: the development of a cognitive screening instrument for a largely illiterate rural elderly population in India. Int J Geriatr Psychiatry 1995; 10: 367 377. 9 Tsolaki IM, Iakovidou V, Navrozidou H, Aminta M, Pantazi T, Kazis A. Hindi Mental State Examination (HMSE) as a screening test for illiterate demented patients. Int J Geriatr Psychiatry 2000; 15: 662 664. 10 Monette J, Galbaud du Fort G, Fung SH, Massoud F, Moride Y, Arsenault L, Afilalo M. Evaluation of the 472 2011 Japan Geriatrics Society

Delirium in elderly confusion assessment method (CAM) as a screening tool for delirium in the emergency room. Gen Hosp Psychiatry 2001; 23: 20 25. 11 Camus V, Gonthier R, Dubos G, Schwed P, Simeone I. Etiologic and outcome profiles in hypoactive and hyperactive subtypes of delirium. J Geriatr Psychiatry Neurol 2000; 13: 38 42. 12 Ryuichi S, Tatsuo A, Toru O, Megumi U, Toshiaki AF. Etiologies of delirium and their relationship to reversibility and motor subtype in cancer patients. Jpn J Clin Oncol 2009; 39: 175 182. 13 Koponen HJ, Riekkinen PJ. A prospective study of delirium in elderly patients admitted to a psychiatric hospital. Psychol Med 1993; 23: 103 109. 14 Webster R, Holroyd S. Prevalence of Psychotic Symptoms in Delirium. Psychosomatics 2000; 41: 519 522. 15 Francis J, Martin D, Kapoor WN. A prospective study of delirium in hospitalised elderly. JAMA 1990; 263: 1097 1101. 16 Ritchie J, Steiner W, Abrahamowicz M. Incidence of and risk factors for delirium among psychiatric inpatients. Psychiatr Serv 1996; 47: 727 730. 17 Patten SB, Williams JVA, Haynes L, McCruden J, Arboleda Florez J. The incidence of delirium in psychiatric inpatient units. Can JPsychiatry 1997; 42: 858 863. 18 Levkoff SE, Evans DA, Liptzin B et al. Delirium: the occurrence and persistence of symptoms among elderly hospitalised patients. Arch Intern Med 1992; 152: 334 340. 19 Meagher DJ, Hanlon DO, Mahony EO, Casey PR, Trzepacz PT. Relationship between symptoms and motoric subtype of delirium. J Neuropsychiatry Clin Neurosci 2000; 12: 51 56. 20 O Keeffe ST, Mulkerrin EC, Nayeem K, Varughese M, Pillay I. Use of serial Mini Mental State Examinations to diagnose and monitor delirium in elderly hospital patients. J Am Geriatr Soc 2005; 53: 867 870. 21 Ross CA, Peyser CE, Shapiro I, Folstein MF. Delirium: phenomenologic and etiologic subtypes. Int Psychogeriatr 1991; 3: 135 147. 22 Grover S, Subodh B, Avasthi A et al. Prevalence and clinical profile of delirium: a study from a tertiary-care hospital in north India. PGI Chandigarh. Gen Hosp Psychiatry 2009; 31: 25 29. 23 Inouye SK. Delirium in hospitalized older patients: recognition and risk factors. J Geriatr Psychiatry Neurol 1998; 11: 118 125. 24 Navinés R, Gómez E, Franco JG, de Pablo J. Delirium in a consultation-liaison psychiatry unit of a general hospital. Actas Esp Psiquiatr 2001; 29: 159 164. 25 Wu CJ. Acute confusional state in type 2 diabetic patient: non-convulsive status epilepticus. Geriatr Gerontol Int 2009; 9: 89 91. 2011 Japan Geriatrics Society 473

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