Hypoactive Subtype Research Articles

Postoperative delirium: disconnecting the network?

Postoperative delirium: disconnecting the network?

Motoric subtypes of delirium in geriatric patients

Aim of the Study: To study the relationship of delirium motor subtypes with cognitive and non-cognitive symptoms of delirium in geriatric patients referred to consultation-liaison psychiatry services. Materials and Methods: Ninety eight (N = 98) consecutive patients (aged ≥60 years) with diagnosis of delirium as per DSM-IV TR were rated on Delirium Rating scale-Revised-98 version (DRS-R-98) and amended Delirium motor symptom scale (DMSS).Results: On amended DMSS, hyperactive subtype (N = 45; 45.9%) was the most common motoric subtype of delirium, followed by hypoactive subtype (N = 23; 23.5%), and mixed subtype (N = 21; 21.4%). On DRS-R-98, all patients fulfilled the criteria of 'acute (temporal) onset of symptoms', 'presence of an underlying physical disorder' and 'difficulty in attention'. In the total sample, >90% of the patients had disturbances in sleep-wake cycle, orientation and fluctuation of symptoms. The least common symptoms were delusions, visuospatial disturbances and motor retardation. When compared to hypoactive group, significantly higher proportion of patients with hyperactive subtype had delusions, perceptual disturbances, and motor agitation. Whereas, compared to hyperactive subtype, significantly higher proportion of patients with hypoactive subtype had thought process abnormality and motor retardation. When the hyperactive and mixed motoric subtype groups were compared, patients with mixed subtype group had significantly higher prevalence of thought process abnormality and motor retardation. Comparison of hypoactive and mixed subtype revealed significant differences in the frequency of perceptual disturbances, delusions and motor agitation and all these symptoms being found more commonly in patients with the mixed subtype. Severity of symptoms were found to be significantly different across the various motoric subtypes for some of the non-cognitive symptoms, but significant differences were not seen for the cognitive symptoms as assessed on DRS-R-98. Conclusion: In elderly patients, motor subtypes of delirium differ from each other on non-cognitive symptom profile in terms of frequency and severity.

Comparison of symptoms of delirium across various motoric subtypes

The aim of this study was to determine the correlation between delirium motor subtypes and other symptoms of delirium. Three hundred and twenty-one (n = 321) consecutive patients referred to consultation-liaison psychiatry services were evaluated on Delirium Rating scale-Revised-98 version and amended Delirium Motor Symptom Scale. Half of the patients had hyperactive subtype (n = 161; 50.15%) delirium. One-quarter of the study sample met the criteria for mixed subtype (n = 79; 24.61%), about one-fifth of the study sample met the criteria for hypoactive delirium subtype (n = 64; 19.93%), and only very few patients (n = 17; 5.29%) did not meet the required criteria for any of these three subtypes and were categorized as 'no subtype'. When the hyperactive and hypoactive subtypes were compared, significant differences were seen in the prevalence of perceptual disturbances, delusions, lability of affect, thought process abnormality, motor agitation and motor retardation. All the symptoms were more common in the hyperactive subtype except for thought process abnormality and motor retardation. Compared to hyperactive subtype, the mixed subtype had significantly higher prevalence of thought process abnormality and motor retardation. Significant differences emerged with regard to perceptual disturbances, delusions, lability of affect and motor agitation when comparing the patients with mixed subtype with those with hypoactive subtype. All these symptoms were found to be more common in the mixed subtype. No significant differences emerged for the cognitive symptoms as assessed on Delirium Rating scale-Revised-98 across the different motoric subtypes. Different motoric subtypes of delirium differ on non-cognitive symptoms.

Do motor subtypes of delirium in child and adolescent have a different clinical and phenomenological profile?

ObjectiveTo explore the frequency of different motor subtypes of delirium in children and adolescents and to study the relationship of motor subtypes with other symptoms, etiology and outcome of delirium. MethodsForty-nine consecutive patients, aged 8–19 years, diagnosed as having delirium as per DSM-IV-TR were assessed on Delirium Rating Scale-Revised 98 (DRS-R-98), amended Delirium Motor Symptom Scale (DMSS), delirium etiology checklist and risk factors for delirium. Different motoric subtypes of delirium were compared with each other for symptoms of delirium as assessed by DRS-R-98, risk factors, etiology and outcome. ResultsMore than half (53%) of patients were classified as having hyperactive delirium, this was followed by the mixed (26.5%) and the hypoactive (16%) subtype. When the different subtypes were compared with each other, the 3 motor subtypes did not differ from each other in terms of frequency and severity of other symptoms except for minor differences. Hallucinations are more common in patients with hyperactive and mixed subtype. There is no significant difference in the outcome of delirium across different subtypes. ConclusionUnlike in adults, motoric subtypes of delirium in child and adolescents do not differ from each other with respect to other symptoms, risk factors and outcome.

Delirium in the Cardiovascular ICU

Delirium, an acute organ dysfunction, is common among critically ill patients leading to significant morbidity and mortality; its epidemiology in a mixed cardiology and cardiac surgery ICU is not well established. We sought to determine the prevalence and risk factors for delirium among cardiac surgery ICU patients.Prospective observational study.Twenty-seven-bed medical-surgical cardiac surgery ICU.Two hundred consecutive patients with an expected cardiac surgery ICU length of stay >24 hrs.None.Baseline demographic data and daily assessments for delirium using the validated and reliable Confusion Assessment Method for the ICU were recorded, and quantitative tracking of delirium risk factors were conducted. Separate analyses studied the role of admission risk factors for occurrence of delirium during the cardiac surgery ICU stay and identified daily occurring risk factors for the development of delirium on a subsequent cardiac surgery ICU day.Prevalence of delirium was 26%, similar among cardiology and cardiac surgical patients. Nearly all (92%) exhibited the hypoactive subtype of delirium. Benzodiazepine use at admission was independently predictive of a three-fold increased risk of delirium (odds ratio 3.1 [1, 9.4], p = 0.04) during the cardiac surgery ICU stay. Of the daily occurring risk factors, patients who received benzodiazepines (2.6 [1.2, 5.7], p = 0.02) or had restraints or devices that precluded mobilization (2.9 [1.3, 6.5], p < 0.01) were more likely to have delirium the following day. Hemodynamic status was not associated with delirium.Delirium occurred in one in four patients in the cardiac surgery ICU and was predominately hypoactive in subtype. Chemical restraints via use of benzodiazepines or the use of physical restraints/restraining devices predisposed patients to a greater risk of delirium, pointing to areas of quality improvement that would be new to the vast majority of cardiac surgery ICUs.

Acute Confusional States in the Elderly

Delirium is common, has multiple causes and causes distress to numerous patients and their relatives. Selective review of the literature in PubMed and PsycINFO, with reference to selected national and international guidelines. The hypoactive subtype of delirium is commoner than the hyperactive type, and often overlooked. Delirium in an elderly individual is associated with an additional burden, a possible loss of potential for rehabilitation, and a marked increase in mortality. The diagnosis of delirium is primarily clinical. All professionals involved in patient care must be able to recognize the features of delirium. Dementia, dehydration and polypharmacy are particularly strongly associated, in the elderly. A careful history and examination with appropriate investigation allows underlying causes to be detected and treated. Rehabilitation strategies should be initiated without delay. Neuroleptics and benzodiazepines have an established role in the pharmacological treatment even of the hyperactive subtype. Non-pharmacological treatments include the creation of a calm and patient centred environment, and the involvement of relatives. In many cases, delirium can be diagnosed and treated in good time. Prevention is preferable to treatment.

Delirium in critically ill patients

To examine the impact of delirium during intensive care unit stay on long-term health-related quality of life and cognitive function in intensive care unit survivors. Prospective 18-month follow-up study. Four intensive care units of a university hospital. A median of 18 months after intensive care discharge, questionnaires were sent to 1,292 intensive care survivors with (n = 272) and without (n = 1020) delirium during their intensive care stay. The Short Form-36v1, checklist individual strength-fatigue, and cognitive failure questionnaire were used. Covariance analysis was performed to adjust for relevant covariates. Of the 915 responders, 171 patients were delirious during their intensive care stay (median age 65 [interquartile range 58-85], Acute Physiology and Chronic Health Evaluation II score 17 [interquartile range 14-20]), and 745 patients were not (median age 65 [interquartile range 57-72], Acute Physiology and Chronic Health Evaluation II score 13 [interquartile range 10-16]). After adjusting for covariates, no differences were found between delirium and nondelirium survivors on the Short Form-36 and checklist individual strength-fatigue. However, survivors who had suffered from delirium reported that they made significantly more social blunders, and their total cognitive failure questionnaire score was significantly higher, compared to survivors who had not been delirious. Survivors of a hypoactive delirium subtype performed significantly better on the domain mental health than mixed and hyperactive delirium patients. Duration of delirium was significantly correlated to problems with memory and names. Intensive care survivors with delirium during their intensive care unit stay had a similar adjusted health-related quality of life evaluation, but significantly more cognitive problems than those who did not suffer from delirium, even after adjusting for relevant covariates. In addition, the duration of delirium was related to long-term cognitive problems.

Risk factors for incident delirium in acute medical in-patients. A systematic review.

Review question/objective What risk factors are associated with incident delirium in adult patients during an acute medical hospitalisation? More specifically, the objectives are to: Identify and synthesise the best available evidence on the factors which are associated with delirium in adult patients admitted to acute medical facilities. Types of participants This review will consider studies that include adults (defined as 18 years and above) who were admitted to an acute medical setting (e.g. general medical units, stroke units, short stay units and neuromedical units) who were not delirious on admission (in order to differentiate incident delirium) but who developed incident delirium during hospitalisation The review will exclude patients who were: - critically ill and admitted to specialist unit e.g. ICU or CCU - admitted for any type of surgery - admitted for alcohol related reasons - admitted to psychiatric facility These patients will be excluded in order to determine factors that may be exclusive to the medical in patient setting. Types of intervention(s)/phenomena of interest This review will consider studies that evaluate any risk factors that may contribute to the development of delirium during in-patient hospitalisation. The review will look at factors present on admission (predisposing) and also factors that may occur during hospitalisation (precipitating) that contribute to incident delirium. Types of outcomes This review will consider studies that include the following outcome measures: the incidence of delirium as related to individual risk factors.

Risk factors for incident delirium in acute medical in-patients. A systematic review

Risk factors for incident delirium in acute medical in-patients. A systematic review

Incidence and short-term consequences of delirium in critically ill patients: A prospective observational cohort study

BackgroundDelirium is a serious and frequent psycho-organic disorder in critically ill patients. Reported incidence rates vary to a large extent and there is a paucity of data concerning delirium incidence rates for the different subgroups of intensive care unit (ICU) patients and their short-term health consequences. ObjectivesTo determine the overall incidence and duration of delirium, per delirium subtype and per ICU admission diagnosis. Furthermore, we determined the short-term consequences of delirium. DesignProspective observational study. Participants and settingAll adult consecutive patients admitted in one year to the ICU of a university medical centre. MethodsDelirium was assessed using the Confusion Assessment Method-ICU three times a day. Delirium was divided in three subtypes: hyperactive, hypoactive and mixed subtype. As measures for short-term consequences we registered duration of mechanical ventilation, re-intubations, incidence of unplanned removal of tubes, length of (ICU) stay and in-hospital mortality. Results1613 patients were included of which 411 (26%) developed delirium. The incidence rate in the neurosurgical (10%) and cardiac surgery group (12%) was the lowest, incidence was intermediate in medical patients (40%), while patients with a neurological diagnosis had the highest incidence (64%). The mixed subtype occurred the most (53%), while the hyperactive subtype the least (10%). The median delirium duration was two days [IQR 1–7], but significantly longer (P<0.0001) for the mixed subtype. More delirious patients were mechanically ventilated and for a longer period of time, were more likely to remove their tube and catheters, stayed in the ICU and hospital for a longer time, and had a six times higher chance of dying compared to non-delirium ICU patients, even after adjusting for their severity of illness score. Delirium was associated with an extended duration of mechanical ventilation, length of stay in the ICU and in-hospital, as well as with in-hospital mortality. ConclusionsThe delirium incidence in a mixed ICU population is high and differs importantly between ICU admission diagnoses and the subtypes of delirium. Patients with delirium had a significantly higher incidence of short-term health problems, independent from their severity of illness and this was most pronounced in the mixed subtype of delirium. Delirium is significantly associated with worse short-term outcome.

An open trial of aripiprazole for the treatment of delirium in hospitalized cancer patients

The purpose of this study was to examine the efficacy and safety of aripiprazole in the treatment of delirium in hospitalized cancer patients, and to examine differential responses based on delirium subtypes. We conducted an analysis of 21 hospitalized cancer patients at Memorial Sloan-Kettering Cancer Center (MSKCC) who had been evaluated and treated for delirium with aripiprazole, using an MSKCC Institutional Review Board (IRB) approved Clinical Delirium Database. Measures used were the Memorial Delirium Assessment Scale (MDAS), the Karnofsky Scale of Performance Status (KPS), and side effect rating at baseline (T1), 2-3 days (T2), and 4-7 days (T3). All measurements were integrated into the routine clinical care of patients. Doses of aripiprazole were adjusted based on clinical response. Patients treated for delirium with aripiprazole experienced significant improvement and resolution of delirium, with MDAS scores declining from a mean of 18.0 at baseline (T1) to mean of 10.8 at T2 and a mean of 8.3 at T3. KPS scores improved from 28.1 at baseline (T1) to 35.2 at T2 and 41 at T3. Delirium resolved (based on MDAS < 10) in 52.4% of cases at T2 and in 76.2% at T3. The mean dosage of aripiprazole required was 18.3 mg (range of 5-30) daily at T3. In our cohort of patients with hypoactive delirium, we observed a delirium resolution rate of 100% compared to the cohort of patients with hyperactive delirium (58.3% rate of delirium resolution). MDAS scores improved from 15.6 at T1 to 5.7 at T3 in hypoactive delirium and from 19.9 at T1 to 10.2 at T3 in hyperactive delirium. In patients with pre-morbid cognitive deficits and the hyperactive subtype of delirium, we observed a more limited treatment response to aripiprazole treatment for delirium. There were no clinically significant side effects noted. Aripiprazole is effective and safe in the treatment of delirium in hospitalized cancer patients. These preliminary finding suggest that aripiprazole may be most effective in resolving delirium of the hypoactive subtype.

Rest-Activity Patterns in Patients with Delirium

Delirium is a frequent syndrome in elderly hospital patients. Symptoms typically show a fluctuating course during the day, with patients exhibiting disturbances of their sleep-wake rhythm. Delirium is frequently underdiagnosed, especially the so-called hypoactive subtype. Devices measuring 24-hr motor patterns could contribute to the recognition of delirium. The purpose of this paper is two-fold. First, the results of a pilot study are presented, in which 24-hr motor patterns of delirious patients are measured with a wrist-actigraph. Second, studies reporting 24-hr motor patterns in delirious patients are systematically reviewed. The pilot study included 9 patients, 65 years or older, with a hip fracture in need of surgical repair. For the review, MEDLINE and Embase were searched for studies on motor activity assessment in delirious patients. In the pilot study, the 24-hr activity rhythm was severely disturbed during delirium, and most actigraphic sleep parameter estimates indicated significantly worse sleep during delirious nights. The systematic search resulted in 10 papers. In 3 papers, the sleep-wake rhythm of delirious patients was significantly different from that of nondelirious patients. In 5 papers, delirious patients could be classified into delirium subtypes. In the 2 remaining papers, 24-hr motor patterns of delirium subtypes were not significantly different. Activity patterns revealed differences between delirious and nondelirious patients and between the different subtypes, even in small samples of patients. Future studies, with preferably larger sample sizes, should confirm the potential of activity pattern measuring devices in the early detection of delirium.

Hypoactive Delirium After Cardiac Surgery as an Independent Risk Factor for Prolonged Mechanical Ventilation

The authors' intention was to evaluate the incidence of the three subtypes of delirium, the risk factors of the subtypes in cardiac surgery, and the impact of the subtypes on clinical outcomes. A prospective study. A university hospital. A total population of 506 patients undergoing cardiac surgery was screened for delirium. None. Patients undergoing cardiac surgery were screened by using the Intensive Care Delirium Screening Checklist (ICDSC) and the Richmond Agitation and Sedation Scale (RASS). Patients with hypoactive delirium were compared with nondelirious patients. Outcomes measured were the duration of mechanical ventilation and the length of stay in the intensive care unit. The overall delirium incidence was 11.6%, whereas the incidence of the hypoactive subtype was 9%. Age (odds ratio [OR] 1.04; 95% confidence interval [CI], 1.01-1.09, p = 0.02), a history of depression (OR = 3.57; 95% CI, 1.04-10.74; p = 0.03), preoperative therapy with diuretics (OR = 2.85; 95% CI, 1.36-6.35; p < 0.01), aortic clamping times (OR = 1.01; 95% CI, 1.00-1.02; p < 0.01) and blood transfusions (OR = 1.18; 95% CI, 1.05-1.34; p < 0.01) were predictors for the development of hypoactive delirium. Preoperative therapy with β-blockers (OR = 0.32; 95% CI, 0.16-0.65; p < 0.01) and higher hemoglobin before surgery (OR = 0.73; 95% CI, 0.60-0.91; p < 0.01) were associated with a lower prevalence of hypoactive delirium. Hypoactive delirium is an independent predictor for prolonged mechanical ventilation time (OR = 1.56; 95% CI, 1.25-1.92; p < 0.01) and the length of stay in the ICU (OR = 1.42; 95% CI, 1.22-1.65, p < 0.01). Hypoactive delirium itself is a strong predictor for a longer ICU stay and a prolonged period of mechanical ventilation. Some of the risk factors related to the intraoperative and postoperative setting are suitable for preventive action.

A longitudinal study of motor subtypes in delirium: Relationship with other phenomenology, etiology, medication exposure and prognosis

Objective Motor subtypes have promise as a means of identifying clinically relevant delirium subgroups. Little is known about their relationship to etiologies, medication exposure, and outcomes. Methods Consecutive cases of DSM-IV delirium in palliative care patients were assessed twice-weekly throughout their delirium episodes using the Delirium Motor Subtype Scale (DMSS), Delirium Etiology Checklist (DEC) and Delirium Rating Scale Revised-98 (DRS-R98). Results 100 patients [mean age 70.2±10.5] were assessed on 303 visits [range 2–9]. Over the entire episode, mean DRS-R98 Severity scores were 16.2±5.7. The mean number of etiologies per case was 3.4±1.2. Motor subtypes were no subtype throughout (6%), hypoactive subtype throughout (28%), mixed subtype throughout (18%), hyperactive subtype throughout (10%) and variable subtype (38%). DRS-R98 Total and Severity scales differed significantly across categories (highest in mixed) but only motor, sleep–wake cycle, perceptual and language disturbance items differed. The Generalized Estimating Equations (GEE) approach was used to explore the relationship between subtype profile and symptoms, medication exposure and etiology. This showed that apart from motor items, only delusions, affective lability, metabolic disturbance and CVA related to any subtype. Cross-sectional assessments indicated greater use of benzodiazepine and antipsychotics in hyperactive patients but GEE analyses did not identify major associations between motor subtype and medication exposure. Patients with sustained hypoactive subtype were significantly more likely to die within one month of study entry. Conclusions Motor profile in delirium is relatively consistent over episode course and relates more closely to delirium phenomenology than to etiology or medication exposure. Motor subtypes have comparable disturbance of key diagnostic features such as cognitive and thought process abnormalities. Although mixed subtype is the most phenomenologically intense, hypoactives have the poorest prognosis.

Phenomenology of the subtypes of delirium: Phenomenological differences between hyperactive and hypoactive delirium

The purpose of this study was to examine the differences in phenomenology between hypoactive and hyperactive subtypes of delirium, and specifically to determine the comparative prevalence of perceptual disturbances (e.g., hallucinations) and delusions in these two subtypes of delirium. We conducted an analysis of Memorial Delirium Assessment Scale (MDAS) items in a set of 100 delirium cases evaluated and treated at Memorial Sloan-Kettering Cancer Center (MSKCC) utilizing an MSKCC Institutional Review Board (IRB) approved Clinical Delirium Database. Individual MDAS items, reflecting the phenomenology of delirium, were compared in delirious patients classified as to motoric subtype (hypoactive versus hyperactive based on MDAS item no. 9, psychomotor activity). Particular attention was paid to differences between subtypes as to the prevalence of perceptual disturbances (MDAS item no. 7) and delusions (MDAS item no. 8). Significant differences were found between hyperactive and hypoactive subtypes of delirium for the presence and severity of perceptual disturbances and delusions; with perceptual disturbances (e.g., hallucinations) and delusions being significantly more prevalent in hyperactive than in hypoactive delirium. The prevalence of perceptual disturbances was 50.9% and the prevalence of delusions was 43.4% in patients with hypoactive delirium. In patients with hyperactive delirium, the prevalence of perceptual disturbances was 70.2% and the prevalence of delusions was 78.7%. The prevalence of perceptual disturbances and delusions in both subtypes of delirium was significantly correlated with the presence of moderate-to-severe disturbance of consciousness/arousal (MDAS item no. 1) and attention impairment (MDAS item no. 5), but was not correlated with the presence of moderate-to-severe cognitive impairment (MDAS item nos. 2-4). Contrary to earlier studies, which indicated extremely low prevalence rates of perceptual disturbances (e.g., hallucinations) and delusion in hypoactive delirium, our study demonstrates that the prevalence of perceptual disturbances and delusions in hypoactive delirium is much higher than previously reported (50.9% and 43.4%, respectively), and deserving of clinical attention and intervention.

Assessing severity of delirium by the delirium observation screening scale

Delirium is the most common acute neuropsychiatric disorder in hospitalized elderly. Assessment of the severity of delirium is important for adjusting medication. The minimal dose of medication is preferable to prevent side effects. Only few nurse based severity measures are available. The aim of this study was to validate a scale developed to assess symptoms of delirium during regular nursing care, the Delirium Observation Screening (DOS) Scale, for monitoring severity of delirium. Delirious patients of 65 years and older were included. Delirium was diagnosed according to DSM-IV criteria and the Confusion Assessment Method. The DOS Scale was compared to the Dutch version of the Delirium Rating Scale-Revised-98 (DRS-R-98). Global cognitive functioning was assessed by the Informant Questionnaire Cognitive Decline in the Elderly-Short Form (IQCODE-SF) and the KATZ-ADL Scale was used for functional impairment. Ninety seven delirious patients were included: 41 hip fracture patients and 56 medical patients. The correlation between total DRS-R-98 scores and DOS Scale scores was 0.67 (p=0.01). For the cognitive impaired group (IQCODE-SF ≥3.9) this correlation was 0.61 (p=0.01); for the group with no global cognitive impairment, this correlation was 0.67 (p=0.01). Correlations between DRS-R-98 and DOS Scale for hypoactive, hyperactive and mixed delirium subtype were 0.40 (p=0.32), 0.44 (p=0.01) and 0.69 (p=0.05), respectively. The DOS Scale is able to measure severity of delirium. In routine daily clinical practice, the DOS Scale is a time-efficient, easy to use and reliable method for measuring and monitoring severity of delirium by nurses.

Review Article: Terminal Delirium in Geriatric Patients With Cancer at End of Life

Terminal delirium is a common symptom that is frequently underdiagnosed in geriatric patients with cancer at end of life and is a major cause of distress for the patient as well as their family. This article explores the hyperactive and hypoactive delirium subtypes as well as the pathophysiology of terminal delirium and the theory of acetylcholine deficiency and dopamine excess. The causes for terminal delirium underdiagnosis as well as the causes of terminal delirium itself are identified. The use of the Confusion Assessment Method (CAM) is discussed as a means of delirium diagnosis and the Memorial Delirium Assessment scale (MDAS) is presented as a tool to measure its severity. Lastly, nonpharmacologic and pharmacologic treatment measures are reviewed and an algorithm is presented to assist the clinician in the identification and management of terminal delirium.

Validating a new clinical subtyping scheme for delirium with electronic motion analysis

The usefulness of motor subtypes of delirium is unclear due to inconsistency in sub-typing methods and a lack of validation with objective measures of activity. The activity of 40 patients was measured with 24 h accelerometry monitoring. Patients with Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) delirium ( n = 30) were allocated into hyperactive, hypoactive and mixed motor subtypes. Delirium subtypes differed in relation to overall amount of activity, including movement in both sagittal and transverse planes. Differences were greater in the daytime and during the early evening ‘sundowning’ period. Frequency of postural changes was the most discriminating measure examined. Clinical subtypes of delirium defined by observed motor behaviour on the ward differ in electronically measured activity levels.

A classification system for delirium subtyping with the use of a commercial mobility monitor

The usefulness of motor subtypes of delirium is unclear due to inconsistency in subtyping methods and a lack of validation with objective measures of activity. The activity of 40 patients was measured over 24 h with a commercial accelerometer-based activity monitor. Accelerometry data from patients with DSM-IV delirium that were readily divided into hyperactive, hypoactive and mixed motor subtypes, were used to create classification trees that were subsequently applied to the remaining cohort to define motoric subtypes. The classification trees used the periods of sitting/lying, standing, stepping and number of postural transitions as measured by the activity monitor as determining factors from which to classify the delirious cohort. The use of a classification system shows how delirium subtypes can be categorised in relation to overall activity and postural changes, which was one of the most discriminating measures examined. The classification system was also implemented to successfully define other patient motoric subtypes. Motor subtypes of delirium defined by observed ward behaviour differ in electronically measured activity levels.

A Continuous Wavelet Transform and Classification Method for Delirium Motoric Subtyping

The usefulness of motor subtypes of delirium is unclear due to inconsistency in subtyping methods and a lack of validation with objective measures of activity. The activity of 40 patients was measured over 24 h with a discrete accelerometer-based activity monitor. The continuous wavelet transform (CWT) with various mother wavelets were applied to accelerometry data from three randomly selected patients with DSM-IV delirium that were readily divided into hyperactive, hypoactive, and mixed motor subtypes. A classification tree used the periods of overall movement as measured by the discrete accelerometer-based monitor as determining factors for which to classify these delirious patients. This data used to create the classification tree were based upon the minimum, maximum, standard deviation, and number of coefficient values, generated over a range of scales by the CWT. The classification tree was subsequently used to define the remaining motoric subtypes. The use of a classification system shows how delirium subtypes can be categorized in relation to overall motoric behavior. The classification system was also implemented to successfully define other patient motoric subtypes. Motor subtypes of delirium defined by observed ward behavior differ in electronically measured activity levels.