Factors associated with the severity of delirium.

BACKGROUND: Various factors affecting the development of delirium have been identified. However, the associations between the severity of delirium and potentially related factors have not been adequately investigated. The aim of the present study was to explore factors associated with the severity of delirium and to identify the reversible contributing factors. METHODS: A total of 577 patients with delirium referred to the Department of Psychiatry during the 5 years from May 2015 to April 2020 at a general hospital were included. The Delirium Rating Scale-revised-98 (DRS-R-98) was used to measure the severity of delirium. Multiple regression analysis was used to determine whether individual factors were associated with the severity of delirium. RESULTS: Intensive care unit admission (p = 0.003), use of benzodiazepines (p = 0.01), dementia (p = 0.02), and older age (p = 0.045) were all positively associated the severity of delirium, while use of ß-blockers (p = 0.001) was negatively associated with the severity of delirium. CONCLUSIONS: Reversible contributing factors, that is use of benzodiazepines, should be avoided as much as possible, especially in elderly patients or patients with dementia or patients who need critical care in ICU. Reducing the dose of benzodiazepines or switching them to other drugs should be a priority.

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.

Subsyndromal delirium in the intensive care setting: Phenomenological characteristics and discrimination of subsyndromal delirium versus no and full-syndromal delirium.

OBJECTIVE: Similar to delirium, its subsyndromal form has been recognized as the cause of diverse adverse outcomes. Nonetheless, the nature of this subsyndromal delirium remains vastly understudied. Therefore, in the following, we evaluate the phenomenological characteristics of this syndrome versus no and full-syndromal delirium. METHOD: In this prospective cohort study, we evaluated the Delirium Rating Scale-Revised, 1998 (DRS-R-98) versus the Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Text Revision (DSM-IV-TR) diagnostic criteria and examined the diagnosis of delirium with respect to phenomenological distinctions in the intensive care setting. RESULTS: Out of 289 patients, 36 with subsyndromal delirium versus 86 with full-syndromal and 167 without delirium were identified. Agreement with respect to the DSM-IV-TR diagnosis of delirium was perfect. The most common subtype in those with subsyndromal delirium was hypoactive, in contrast to mixed subtype in those with full-syndromal delirium versus no motor alterations in those without delirium. By presence and severity of delirium symptoms, subsyndromal delirium was intermediate. The ability of the DRS-R-98 items to discriminate between either form of delirium was substantial. Between subsyndromal and no delirium, the cognitive domain and sleep-wake cycle were more impaired and allowed a distinction with no delirium. Further, between full- and subsyndromal delirium, the prevalence and severity of individual DRS-R-98 items were greater. Although the differences between these two forms of delirium was substantial, the items were not very specific, indicating that the phenomenology of subsyndromal delirium is closer to full-syndromal delirium. SIGNIFICANCE OF RESULTS: Phenomenologically, subsyndromal delirium was found to be distinct from and intermediate between no delirium and full-syndromal delirium. Moreover, the greater proximity to full-syndromal delirium indicated that subsyndromal delirium represents an identifiable subform of full-syndromal delirium.

Brief assessment of delirium subtypes: Psychometric evaluation of the Delirium Motor Subtype Scale (DMSS)-4 in the intensive care setting.

OBJECTIVE: The management of and prognosis for delirium are affected by its subtype: hypoactive, hyperactive, mixed, and none. The DMSS-4, an abbreviated version of the Delirium Motor Symptom Scale, is a brief instrument for the assessment of delirium subtypes. However, it has not yet been evaluated in an intensive care setting. METHOD: We performed a prospective/descriptive cohort study in order to determine the internal consistency, reliability, and validity of the relevant items of the DMSS-4 versus the Delirium Rating Scale-Revised-98 (DRS-R-98) and the original DMSS in a surgical intensive care setting. RESULTS: A total of 289 elderly, predominantly male patients were screened for delirium, and 122 were included in our sample. The internal consistency of the DMSS-4 items was excellent (Cronbach's α = 0.92), and between the DMSS-4 and DRS-R-98 the overall concurrent validity was substantial (Cramer's V = 0.67). Within individual motor subtypes, concurrent validity remained at least substantial (Cohen's κ = 0.65-0.81) and sensitivity high (69.8 to 82.2%), in contrast to those of the no-motor subtype, with less validity and sensitivity (κ = 0.28, 22%). Similarly, total concurrent validity between the DMSS-4 and the original DMSS reached perfection (Cramer's V = 0.83), as did agreement between the subtypes (κ = 0.83-0.92), while sensitivity remained high (88.2-100%). Only in those with delirium with no-motor subtype was agreement moderate (κ = 0.56) and sensitivity lower (67%). Specificity was high across all subtypes (91.2-99.1%). The DMSS-4 yielded very sensitive ratings, particularly for hypoactive and hyperactive motor symptoms, and interrater agreement was excellent (Fleiss's κ = 0.83). SIGNIFICANCE OF RESULTS: We found the DMSS-4 to be a most reliable and valid brief assessment of delirium in characterizing the subtypes of delirium in an intensive care setting, with increased sensitivity to hypoactive and hyperactive motor alterations.

A comparison of the revised Delirium Rating Scale (DRS-R98) and the Memorial Delirium Assessment Scale (MDAS) in a palliative care cohort with DSM-IV delirium.

OBJECTIVE: Assessment of delirium is performed with a variety of instruments, making comparisons between studies difficult. A conversion rule between commonly used instruments would aid such comparisons. The present study aimed to compare the revised Delirium Rating Scale (DRS-R98) and Memorial Delirium Assessment Scale (MDAS) in a palliative care population and derive conversion rules between the two scales. METHOD: Both instruments were employed to assess 77 consecutive patients with DSM-IV delirium, and the measures were repeated at three-day intervals. Conversion rules were derived from the data at initial assessment and tested on subsequent data. RESULTS: There was substantial overall agreement between the two scales [concordance correlation coefficient (CCC) = 0.70 (CI 95 = 0.60-0.78)] and between most common items (weighted κ ranging from 0.63 to 0.86). Although the two scales overlap considerably, there were some subtle differences with only modest agreement between the attention (weighted κ = 0.42) and thought process (weighted κ = 0.61) items. The conversion rule from total MDAS score to DRS-R98 severity scores demonstrated an almost perfect level of agreement (r = 0.86, CCC = 0.86; CI 95 = 0.79-0.91), similar to the conversion rule from DRS-R98 to MDAS. SIGNIFICANCE OF RESULTS: Overall, the derived conversion rules demonstrated promising accuracy in this palliative care population, but further testing in other populations is certainly needed.

New Cutoff Scores for Delirium Screening Tools to Predict Patient Mortality.

BACKGROUND/OBJECTIVES: Detecting delirium is important to identify patients with a high risk of poor outcomes. Although many different kinds of screening instruments for delirium exist, there is no solid consensus about which methods are the most effective. In addition, it is important to find the most useful tools in predicting outcomes such as mortality. DESIGN: Retrospective cohort study. SETTING: University of Iowa Hospitals and Clinics. PARTICIPANTS: A total of 1,125 adult inpatients (mean age = 67.7; median age = 69). MEASUREMENTS: Post hoc analyses were performed based on existing data from the Confusion Assessment Method for Intensive Care Unit (CAM-ICU), Delirium Rating Scale-Revised-98 (DRS), and the Delirium Observation Screening Scale (DOSS). Correlation among these scales and relationships between 365-day mortality and each scale were evaluated. RESULTS: A positive result on the CAM-ICU ("CAM-ICU positive") was associated with higher DRS and DOSS scores. A DRS score = 9/10 was the best cutoff to detect CAM-ICU positive, and DOSS = 2/3 was the best cutoff to detect CAM-ICU positive. CAM-ICU positive was associated with high 365-day mortality. DRS score = 9/10 and DOSS score = 0/1 were found to differentiate mortality risk the most significantly. Higher DRS and DOSS scores significantly coincided with a decrease in a patient's survival rate at 365 days. CONCLUSION: The best DRS and DOSS cutoff scores to differentiate 365-day mortality risk were lower than those commonly used to detect delirium in the literature. New cutoff scores for the DRS and DOSS might be useful in differentiating risk of mortality among hospital patients.

Delirium after a traumatic brain injury: predictors and symptom patterns.

BACKGROUND: Delirium in traumatic brain injury (TBI) is common, may be predictable, and has a multifaceted symptom complex. This study aimed to examine: 1) the sum score of Glasgow Coma Scale (GCS) and if its component scores could predict delirium in TBI patients, and 2) the prominent symptoms and their courses over the first days after TBI. METHODS: TBI patients were recruited from neurosurgical ward inpatients. All participants were hospitalized within 24 hours after their TBI. Apart from the sum score of GCS, which was obtained at the emergency department (ED), the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, diagnostic criteria for delirium were applied daily. The severity of delirium symptoms was assessed daily using the Delirium Rating Scale - Revised-98 (DRS-R-98). RESULTS: The participants were 54 TBI patients with a mean GCS score of 12.7 (standard deviation [SD] =2.9). A total of 25 patients (46.3%) met the diagnosis of delirium and had a mean age of 36.7 years (SD =14.8). Compared with 29 non-delirious patients, 25 delirious patients had a significantly lower mean GCS score (P=0.04), especially a significantly lower verbal component score (P=0.03). Among 18 delirious patients, four symptoms of the DRS-R-98 cognitive domain (orientation, attention, long-term memory, and visuospatial ability) were moderate symptoms (score ≥2) at the first day of admission. After follow-up, three cognitive (orientation, attention, and visuospatial ability) and two noncognitive symptoms (lability of affect and motor agitation) rapidly resolved. CONCLUSION: Almost half of patients with mild to moderate head injuries may develop delirium in the first 4 days after TBI. Those having a low GCS score, especially the verbal component score, at the ED were likely to have delirium in this period. Most cognitive domains of delirium described in the DRS-R-98 were prominent within the first 4 days of TBI with delirium. Three cognitive and two noncognitive symptoms of delirium decreased significantly.

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.

Role of CRP, TNF-a, and IGF-1 in Delirium Pathophysiology.

INTRODUCTION: Delirium is a common and life-threatening neuropsychiatric syndrome. Diagnosing delirium can be challenging, which increases mortality and mortality rates and health care costs. The biologic model of delirium is not definite yet, but evidence supports a cholinergic deficiency model. Delirium may be the result of processes and drugs that trespass a compromised blood-brain barrier. We aimed to evaluate the possible diagnostic utilization and the role of certain biomarkers, such as C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and insulin like growth factor-1 (IGF-1), in delirium etiology. METHODS: A total of 93 inpatients that planned to undergo cardiovascular surgery were informed; 35 of them completed the study. Medical history and current cognitive status were evaluated pre-operatively. Participants were followed using Delirium Rating Scale-Revised-98 Turkish (DRS-R98-T) for delirium symptoms, and blood samples were collected post-operatively. RESULTS: Delirium was developed more in participants who had worse pre-operative cognitive status. Also, low pre-operative IGF-1 levels were detected in the delirium group. Pre-operative CRP and TNF-α levels were not different between groups. CONCLUSION: Low IGF-1 levels can be used to predict delirium after surgery. However, the complex nature of cytokines and delirium itself make it difficult to utilize cytokines to predict delirium instead of psychometric tools.

The predictive value of a change in natural killer cell activity for delirium.

PURPOSE: Few studies looking for an effective biomarker to predict delirium have been performed. This study was designed to investigate whether a change in inflammatory status, indicated by blood natural killer (NK) cell activity, predicts delirium. METHODS: This prospective study, performed in 4 university and 1 general hospital from September, 2011 to October, 2012, included 29 patients. Eligible patients were 65-89years old, newly and emergently admitted. Patients were assessed daily, up to 7days, for occurrence of DSM-IV-defined delirium. The main outcome measure was change in blood NK cell activity between the first and second mornings after admission. RESULTS: The mean change in blood NK cell activity on the second morning, compared to the first morning, in patients developing delirium (n=9) was significantly greater than that in patients without delirium (n=20) (6.0% [SD 8.4] vs. -1.4% [9.0], respectively, t=2.10, P=0.045). Significant difference between the groups was still found after adjusting for age, the history of previous delirium, and the Clinical Dementia Rating score (F=6.63, P=0.017). Of note is that 8 of 9 (89%) patients developing delirium had increased blood NK cell activity, as did only 8 of 20 (40%) patients without delirium, giving measurement of this parameter, for distinguishing the two groups, a sensitivity of 89%, specificity 60%, positive predictive value 50%, negative predictive value 92%, positive likelihood ratio 2.22, and negative likelihood ratio 0.19. When combining this predictor with another predictor, a Delirium Rating Scale-Revised-98 severity score of 5 or more at baseline, positive and negative likelihood ratios were 7.80 and 0.24, respectively. CONCLUSION: Increase in blood NK cell activity may be associated with developing delirium. Further studies including larger numbers of patients are needed to justify the preventive use of drugs for patients meeting criteria for both predictors.