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 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.

Delirium in the intensive care setting: A reevaluation of the validity of the CAM-ICU and ICDSC versus the DSM-IV-TR in determining a diagnosis of delirium as part of the daily clinical routine.

BACKGROUND: In the intensive care setting, delirium is a common occurrence that comes with subsequent adversities. Therefore, several instruments have been developed to screen for and detect delirium. Their validity and psychometric properties, however, remain controversial. METHOD: In this prospective cohort study, the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) and the Intensive Care Delirium Screening Checklist (ICDSC) were evaluated versus the DSM-IV-TR in the diagnosis of delirium with respect to their validity and psychometric properties. RESULTS: Out of some 289 patients, 210 with matching CAM-ICU, ICDSC, and DSM-IV-TR diagnoses were included. Between the scales, the prevalence of delirium ranged from 23.3% with the CAM-ICU, to 30.5% with the ICDSC, to 43.8% with the DSM-IV-TR criteria. The CAM-ICU showed only moderate concurrent validity (Cohen's κ = 0.44) and sensitivity (50%), but high specificity (95%). The ICDSC also reached moderate agreement (Cohen's κ = 0.60) and sensitivity (63%) while being very specific (95%). Between the CAM-ICU and the ICDSC, the concurrent validity was again only moderate (Cohen's κ = 0.56); however, the ICDSC yielded higher sensitivity and specificity (78 and 83%, respectively). SIGNIFICANCE OF RESULTS: In the daily clinical routine, neither the CAM-ICU nor the ICDSC, common tools used in screening and detecting delirium in the intensive care setting, reached sufficient concurrent validity; nor did they outperform the DSM-IV-TR diagnostic criteria with respect to sensitivity or positive prediction, but they were very specific. Thus, the non-prediction by the CAM-ICU or ICDSC did not refute the presence of delirium. Between the CAM-ICU and ICDSC, the ICDSC proved to be the more accurate instrument.