Phenomenology of delirium among patients admitted to a coronary care unit

Clinical Features of Delirium among Patients in the Intensive Care Unit According to Motor Subtype Classification: A Retrospective Longitudinal Study

PURPOSE

Delirium in the intensive care unit (ICU) poses a significant safety and socioeconomic burden to patients and caregivers. However, invasive interventions for managing delirium have severe drawbacks. To reduce unnecessary interventions during ICU hospitalization, we aimed to investigate the features of delirium among ICU patients according to the occurrence of hypoactive symptoms, which are not expected to require invasive intervention.

MATERIALS AND METHODS

Psychiatrists assessed all patients with delirium in the ICU during hospitalization. Patients were grouped into two groups: a "non-hypoactive" group that experienced the non-hypoactive motor subtype once or more or a "hypoactive only" group that only experienced the hypoactive motor subtype. Clinical variables routinely gathered for clinical management were collected from electronic medical records. Group comparisons and logistic regression analyses were conducted.

RESULTS

The non-hypoactive group had longer and more severe delirium episodes than the hypoactive only group. Although the non-hypoactive group was prescribed more antipsychotics and required restraints longer, the hypoactive only group also received both interventions. In multivariable logistic regression analysis, BUN [odds ratio (OR): 0.993, pH OR: 0.202], sodium (OR: 1.022), RASS score (OR: 1.308) and whether restraints were applied [OR: 1.579 (95% confidence interval 1.194-2.089), p<0.001] were significant predictors of hypoactive only group classification.

CONCLUSION

Managing and predicting delirium patients based on whether patients experienced non-hypoactive delirium may be clinically important. Variables obtained during the initial 48 hours can be used to determine which patients are likely to require invasive interventions.

Delirium Research in India: A Systematic Review

Delirium is the most common psychiatric diagnoses encountered in patients with various medical-surgical illnesses, in all the treatment set-ups, with relatively higher incidence and prevalence in the intensive care units. As delirium is encountered in multiple specialties, it is important to understand the research on this diagnosis. This study aims to assess the research output involving patients of delirium from India. A comprehensive search was undertaken using Medline (PubMed) and other databases. Search words included were “delirium,” “delirious,” “delirium tremens” AND “India.” No filters were used. Internet and hand searches yielded 305 articles. Out of these articles, 151 had the terms “delirium,” “delirious,” “delirium tremens” in the title and these were included for the review. Additionally, 14 articles were included for the review, although these did not have these terms in the title, but delirium was one of the major outcome parameters in these studies. Majority of the papers were original articles ( n = 81), and these were followed by, case reports ( n = 58), review articles ( n = 10), letter to the editor (not as case reports but as a communication; n = 13), editorials ( n = 2) and one clinical practice guideline. Most of the original papers have either focused on epidemiology (incidence, prevalence, outcome, etc.), symptom profile, with occasional studies focusing on effectiveness of various pharmacological interventions. There is a dearth of research in the field of delirium from India. There is a lack of studies on biomarkers, evaluation of nonpharmacological interventions, and evaluation of prevention strategies. It is the need of the hour to carry out more studies to further our understanding of delirium in the Indian context.

Delirium in the intensive care setting dependent on the Richmond Agitation and Sedation Scale (RASS): Inattention and visuo-spatial impairment as potential screening domains

OBJECTIVE

In the intensive care setting, delirium is a common occurrence; however, the impact of the level of alertness has never been evaluated. Therefore, this study aimed to assess the delirium characteristics in the drowsy, as well as the alert and calm patient.

METHOD

In this prospective cohort study, 225 intensive care patients with Richmond Agitation and Sedation Scale (RASS) scores of -1 - drowsy and 0 - alert and calm were evaluated with the Delirium Rating Scale-Revised-1998 (DRS-R-98) and the Diagnostic and Statistical Manual 4th edition text revision (DSM-IV-TR)-determined diagnosis of delirium.

RESULTS

In total, 85 drowsy and 140 alert and calm patients were included. Crucial items for the correct identification of delirium were sleep-wake cycle disturbances, language abnormalities, thought process alterations, psychomotor retardation, disorientation, inattention, short- and long-term memory, as well as visuo-spatial impairment, and the temporal onset. Conversely, perceptual disturbances, delusions, affective lability, psychomotor agitation, or fluctuations were items, which identified delirium less correctly. Further, the severities of inattentiveness and visuo-spatial impairment were indicative of delirium in both alert- or calmness and drowsiness.

SIGNIFICANCE OF RESULTS

The impairment in the cognitive domain, psychomotor retardation, and sleep-wake cycle disturbances correctly identified delirium irrespective of the level alertness. Further, inattentiveness and - to a lesser degree - visuo-spatial impairment could represent a specific marker for delirium in the intensive care setting meriting further evaluation.

Incidence, risk factors, and cumulative risk of delirium among ICU patients: A case-control study

Objectives

Delirium is a common acute cognitive impairment syndrome among intensive care unit (ICU) patients. This study was aimed to investigate the incidence, risk factors, and cumulative risk of delirium among ICU patients.

Methods

A case-control study including clinical records of 452 patients were retrospectively analyzed. Delirium was assessed using the Confusion Assessment Method for the ICU and Richmond Agitation–Sedation Scale.

Results

We found that 163 out of the 452 patients (36.1%) had delirium. Multivariate analysis showed that use of sedatives, length of ICU hospitalization, and physical restraint were independent risk factors for delirium. The additive effect of all three factors resulted to an odds ratio of 30.950.

Conclusion

The incidence of delirium remained high. Thus, nurses shall strengthen the monitoring of delirium, regularly access the patient's level of calmness, and limit the use of physical restraint.

Do the Phenotypes of Symptom Fluctuation Differ Among Motor Subtypes in Patients With Delirium?

CONTEXT

Fluctuation in symptoms is a core feature of delirium. However, it is not well known whether the fluctuating nature would differ or not among the delirium subtype groups.

OBJECTIVE

This study compared phenotypes of diurnal fluctuation among different delirium subtypes using a prospective design.

METHODS

The motor subtypes of delirium patients were determined using the Delirium Motor Subtype Scale, fluctuations in consciousness levels were monitored with the Richmond Agitation-Sedation Scale (RASS), and symptom severity was assessed with the Nursing Delirium Screening Scale (Nu-DESC). All scales were administered at three time points over 24 hours; fluctuations in and phenotypes of symptoms were compared according to subtype of delirium using repeated-measures analysis of variance after adjustment for covariates.

RESULTS

This study included 224 delirium patients. Of this patients, 144 (64.3%) were classified as hyperactive, 25 (11.2%) as hypoactive, 33 (14.7%) as mixed, and 22 (9.9%) as no subtype. Scores on the RASS and Nu-DESC significantly changed during the evening and/or night and there were significant subtype group × time interaction for the RASS and Nu-DESC (F = 9.66, P < 0.001 and F = 5.11, P < 0.001, respectively). Post hoc analyses revealed that the hyperactive and mixed subtype groups had higher mean RASS scores and greater ranges of fluctuation than the other groups. The mixed subtype group was differentiated from hyperactive and hypoactive subtype groups by the range of fluctuation in psychomotor activity.

CONCLUSIONS

The phenotypes of symptom fluctuation differed among the motor subtypes. These findings further support the rationale that fluctuations are a core feature of delirium and could differentiate delirium subtypes.

Screening for delirium with the Intensive Care Delirium Screening Checklist (ICDSC): Symptom profile and utility of individual items in the identification of delirium dependent on the level of sedation

OBJECTIVE

The importance of the proper identification of delirium, with its high incidence and adversities in the intensive care setting, has been widely recognized. One common screening instrument is the Intensive Care Delirium Screening Checklist (ICDSC); however, the symptom profile and key features of delirium dependent on the level of sedation have not yet been evaluated.

METHOD

In this prospective cohort study, the ICDSC was evaluated versus the Diagnostic and Statistical Manual, 4th edition, text revision, diagnosis of delirium set as standard with respect to the symptom profile, and correct identification of delirium. The aim of this study was to identify key features of delirium in the intensive care setting dependent on the Richmond Agitation and Sedation Scale levels of sedation: drowsiness versus alert and calmness.ResultThe 88 delirious patients of 225 were older, had more severe disease, and prolonged hospitalization. Irrespective of the level of sedation, delirium was correctly classified by items related to inattention, disorientation, psychomotor alterations, inappropriate speech or mood, and symptom fluctuation. In the drowsy patients, inattention reached substantial sensitivity and specificity, whereas psychomotor alterations and sleep-wake cycle disturbances were sensitive lacked specificity. The positive prediction was substantial across items, whereas the negative prediction was only moderate. In the alert and calm patient, the sensitivities were substantial for psychomotor alterations, sleep-wake cycle disturbances, and symptom fluctuations; however, these fluctuations were not specific. The positive prediction was moderate and the negative prediction substantial. Between the nondelirious drowsy and alert, the symptom profile was similar; however, drowsiness was associated with alterations in consciousness.Significance of resultsIn the clinical routine, irrespective of the level of sedation, delirium was characterized by the ICDSC items for inattention, disorientation, psychomotor alterations, inappropriate speech or mood and symptom fluctuation. Further, drowsiness caused altered levels of consciousness.

Delirium clinical motor subtypes: a narrative review of the literature and insights from neurobiology

INTRODUCTION

Clinical motor subtypes have been long recognised in delirium and, despite a growing body of research, a lack of clarity exists regarding the importance of these motor subtypes. The aims of this review are to (1) examine how the concept of motor subtypes has evolved, (2) explore their relationship to the clinical context, (3) discuss the relationship between the phenomenology of delirium and motor activity, (4) discuss the application of neurobiology to the theory of delirium motor subtypes, and (5) identify methodological issues and provide solutions for further studies.

METHODS

The following databases were searched: PubMed, PsychInfo, EBSCO, Medline, BioMed central and Science Direct. Inclusion criteria specified peer-reviewed research assessing delirium motor subtypes published between 1990 and 2016.

RESULTS

Sixty-one studies met the inclusion criteria. The majority of studies (n = 50) were found to use validated psychometric tools, while the remainder (n = 11) used clinical criteria. The majority of studies (n = 45) were conducted in the medical setting, while the remainder were in the ICU/post-operative setting (n = 17).

CONCLUSION

Although host sensitivities (e.g. frailty) and exogenous factors (e.g. medication exposure) may determine the type of motor disturbance, it remains unclear to what extent motor subtypes are influenced by other features of delirium. The use of more specialised tools (e.g. delirium motor subtyping scale), may enable researchers to develop an approach to delirium that has a greater nosological consistency. Future studies investigating delirium motor subtypes may benefit from enhanced theoretical considerations of the dysfunctional neural substrate of the delirious state.

Delirium in Intensive Care Unit: Phenomenology, Subtypes, and Factor Structure of Symptoms

AIM

This study aimed to explore the phenomenology, motor subtypes, and factor structure of symptom profile of delirium in patients admitted to the intensive care unit (ICU).

METHODS

Consecutive patients aged ≥16 years admitted in an ICU were screened daily for delirium using confusion assessment method-ICU. Patients diagnosed to have delirium as per Diagnostic and Statistical Manual fourth revision, text revision (DSM-IVTR) criteria were assessed with Delirium Rating Scale-Revised 98 (DRS-R 98) and Memorial Delirium Assessment Scale (MDAS). Motor subtypes of delirium were assessed with amended Delirium Motor Symptom Scale.

RESULTS

Sixty-six patients were evaluated for delirium, of which 45 (68%) patients developed delirium at point of their ICU stay. All patients had sleep-wake cycle disturbances, followed by motor symptoms (retardation - 80%; agitation - 73.3%). As per MDAS assessment, all the subjects had disturbances in the consciousness and sleep-wake cycle disturbances, and a substantial majority also had attention difficulties (93.3%) and motor symptoms (93.3%). Hypoactive subtype (47%) was the most common motoric subtype of delirium. Factor analysis revealed three-factor model for DRS-R 98, MDAS, and combining items of the two.

CONCLUSION

Phenomenology of delirium in ICU setting is similar to that of the non-ICU settings. The factor analysis consistently demonstrated a three factor solution, with a robust attention-arousal factor, and overlapping cognitive (core vs. non-core) motor factors.

Delirium in the intensive care setting and the Richmond Agitation and Sedation Scale (RASS): Drowsiness increases the risk and is subthreshold for delirium

INTRODUCTION

Sedation is a core concept in the intensive care setting, however, the impact of sedation on delirium has not yet been studied to date.

METHODS

In this prospective cohort study, 225 patients with Richmond Agitation and Sedation (RASS) scores of -1 - drowsiness and 0 - alert- and calmness were assessed with the Delirium Rating Scale-Revised 1998 (DRS-R-98) and DSM-IV-TR-determined diagnosis of delirium assessing drowsiness versus alertness.

RESULTS

By itself, drowsiness increased the odds for developing delirium eightfold (OR 7.88 p<0.001) and rates of delirium were 68.2 and 21.4%, respectively. Further, in the drowsy patient, delirium was more severe. In the presence of drowsiness, delirium was characterized by sleep-wake cycle disturbances and language abnormalities. These two features, in addition to psychomotor retardation, allowed the correct classification of delirium at RASS-1. The same features, in addition to thought abnormalities and the impairment in the cognitive domain, orientation, attention, short- and long-term memory representing the core domains of delirium, or the temporal onset were very sensitive towards delirium, however lacked specificity. Conversely, delusions, perceptual abnormalities and lability of affect representing the non-core domain were very specific for delirium in the drowsy, however, not very sensitive. In the absence of delirium, drowsiness caused attentional impairment and language abnormalities.

CONCLUSION

Drowsiness increased the odds for developing delirium eightfold and caused more severe delirium, which was characterized by sleep-wake cycle and language abnormalities. Further, drowsiness by itself caused attentional impairment and language abnormalities, thus, with its disturbance in consciousness was subthreshold for delirium.

Acute Brain Failure: Pathophysiology, Diagnosis, Management, and Sequelae of Delirium

Delirium is the most common psychiatric syndrome found in the general hospital setting, with an incidence as high as 87% in the acute care setting. Delirium is a neurobehavioral syndrome caused by the transient disruption of normal neuronal activity secondary to systemic disturbances. The development of delirium is associated with increased morbidity, mortality, cost of care, hospital-acquired complications, placement in specialized intermediate and long-term care facilities, slower rate of recovery, poor functional and cognitive recovery, decreased quality of life, and prolonged hospital stays. This article discusses the epidemiology, known etiological factors, presentation and characteristics, prevention, management, and impact of delirium.

Validation and Psychometric Properties of the German Version of the Delirium Motor Subtype Scale (DMSS)

Objective: Delirium has been characterized into its subtypes—hypoactive, hyperactive, mixed, or no motor subtype—along with the use of the Delirium Motor Symptom Scale (DMSS). The German version of this scale (DMSS-G), however, has not yet been validated. Method: We determined internal consistency, reliability, and validity of the DMSS-G in the surgical intensive care unit, using DSM-IV-TR criteria and the Delirium Rating Scale–Revised–98. Results: In total, 289 patients were included, and out of these, 122 were delirious. The DMSS-G showed excellent internal consistency (Cronbach’s α = 0.92) and interrater reliability (Fleiss κ = 0.83). Additionally, the overall concurrent validity was substantial (Cramer’s V = 0.69); within subtypes, hyperactive, hypoactive, or mixed, the concurrent validity remained at least substantial (Cohen’s κ = 0.73-0.82) and the sensitivity ranged from 60% to 97%. In contrast, in those with no motor subtype, we found the concurrent validity (Cohen’s κ = 0.31) and sensitivity to be low (22%). Overall, specificity for all individual subtypes was high (82% to 100%). The DMSS was very sensitive in both rating hyperactive and hypoactive motor symptoms of delirium. Conclusion: The DMSS-G is a highly reliable and valid instrument for detecting motor symptoms in delirium, which provides an accurate instrument to classify the motor subtypes of delirium.