Exposure to light and darkness and its influence on physiological measures of intensive care unit patients-a systematic literature review.

Sleep-wake patterns are often significantly disturbed in critically ill patients. This disturbance is closely linked to secondary brain dysfunctions in these patients. Sedation not only impairs sleep quality in ICU patients but also has detrimental effects on short- and long-term outcome. In other contexts, light therapy has been proven to be effective in maintaining and resynchronizing circadian rhythmicity in humans. The objective of this systematic review was to analyse studies that investigated the effect of exposure to light or darkness on physiological measures and clinical outcomes of adult ICU patients. Studies were systematically identified by searching electronic bibliographic databases (The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, 2002) and MEDLINE via PubMed). The search algorithm identified a total of 156 articles, 10 of which were taken into final review. These 10 selected articles included 3 were monocentric RCTs, five prospective cohort studies, one retrospective cohort study, and one manuscript that included a partial systematic review of the literature. Included trials were published between 2007 and 2015. Five of these studies used multiple intervention approaches while four trials used a single intervention approach. Among all studies, 1,278 patients were analysed (489 prospectively). There was a high heterogeneity among the studies in terms of applied intervention and outcome measures. The most frequent methodological limitations were a lack of precise definitions regarding the illuminance and the light spectrum utilised. The analyses indicate that further studies including clearly defined interventions with objective outcome measures, as these are currently lacking, would add significant knowledge to this new field of research.

Feasibility of noise reduction by a modification in ICU environment.

Noise is a proven cause of wakefulness and qualitative sleep disturbance in critically ill patients. A sound pressure level reduction can improve sleep quality, but there are no studies showing the feasibility of such a noise reduction in the intensive care unit (ICU) setting. Considering all available evidence, we redesigned two ICU rooms with the aim of investigating the physiological and clinical impact of a healing environment, including a noise reduction and day-night variations of sound level. Within an experimental design, we recorded 96 h of sound-pressure levels in standard ICU rooms and the modified ICU rooms. In addition, we performed a sound source observation by human observers. Our results show that we reduced A-weighted equivalent sound pressure levels and maximum sound pressure levels with our architectural interventions. During night-time, the modification led to a significant decrease in 50 dB threshold overruns from 65.5% to 39.9% (door side) and from 50% to 10.5% (window side). Sound peaks of more than 60 decibels were significantly reduced from 62.0% to 26.7% (door side) and 59.3% to 30.3% (window side). Time-series analysis of linear trends revealed a significantly more distinct day-night pattern in the modified rooms with lower sound levels during night-times. Observed sound sources during night revealed four times as many talking events in the standard room compared to the modified room. In summary, we show that it is feasible to reduce sound pressure levels using architectural modifications.

Multinational development and validation of an early prediction model for delirium in ICU patients.

RATIONALE: Delirium incidence in intensive care unit (ICU) patients is high and associated with poor outcome. Identification of high-risk patients may facilitate its prevention. PURPOSE: To develop and validate a model based on data available at ICU admission to predict delirium development during a patient's complete ICU stay and to determine the predictive value of this model in relation to the time of delirium development. METHODS: Prospective cohort study in 13 ICUs from seven countries. Multiple logistic regression analysis was used to develop the early prediction (E-PRE-DELIRIC) model on data of the first two-thirds and validated on data of the last one-third of the patients from every participating ICU. RESULTS: In total, 2914 patients were included. Delirium incidence was 23.6%. The E-PRE-DELIRIC model consists of nine predictors assessed at ICU admission: age, history of cognitive impairment, history of alcohol abuse, blood urea nitrogen, admission category, urgent admission, mean arterial blood pressure, use of corticosteroids, and respiratory failure. The area under the receiver operating characteristic curve (AUROC) was 0.76 [95% confidence interval (CI) 0.73-0.77] in the development dataset and 0.75 (95% CI 0.71-0.79) in the validation dataset. The model was well calibrated. AUROC increased from 0.70 (95% CI 0.67-0.74), for delirium that developed <2 days, to 0.81 (95% CI 0.78-0.84), for delirium that developed >6 days. CONCLUSION: Patients' delirium risk for the complete ICU length of stay can be predicted at admission using the E-PRE-DELIRIC model, allowing early preventive interventions aimed to reduce incidence and severity of ICU delirium.

Recalibration of the delirium prediction model for ICU patients (PRE-DELIRIC): a multinational observational study.

PURPOSE: Recalibration and determining discriminative power, internationally, of the existing delirium prediction model (PRE-DELIRIC) for intensive care patients. METHODS: A prospective multicenter cohort study was performed in eight intensive care units (ICUs) in six countries. The ten predictors (age, APACHE-II, urgent and admission category, infection, coma, sedation, morphine use, urea level, metabolic acidosis) were collected within 24 h after ICU admission. The confusion assessment method for the intensive care unit (CAM-ICU) was used to identify ICU delirium. CAM-ICU screening compliance and inter-rater reliability measurements were used to secure the quality of the data. RESULTS: A total of 2,852 adult ICU patients were screened of which 1,824 (64%) were eligible for the study. Main reasons for exclusion were length of stay <1 day (19.1%) and sustained coma (4.1%). CAM-ICU compliance was mean (SD) 82 ± 16% and inter-rater reliability 0.87 ± 0.17. The median delirium incidence was 22.5% (IQR 12.8-36.6%). Although the incidence of all ten predictors differed significantly between centers, the area under the receiver operating characteristic (AUROC) curve of the eight participating centers remained good: 0.77 (95% CI 0.74-0.79). The linear predictor and intercept of the prediction rule were adjusted and resulted in improved re-calibration of the PRE-DELIRIC model. CONCLUSIONS: In this multinational study, we recalibrated the PRE-DELIRIC model. Despite differences in the incidence of predictors between the centers in the different countries, the performance of the PRE-DELIRIC-model remained good. Following validation of the PRE-DELIRIC model, it may facilitate implementation of strategies to prevent delirium and aid improvements in delirium management of ICU patients.

[Delirium in the intensive care unit : Overview for nurses and physicians]. / Das Delir auf Intensivstationen : Ein Überblick für Pflegekräfte und Ärzte.

Delirium is a severe but frequent organ dysfunction in intensive care units (ICU) affecting nearly 80% of mechanically ventilated patients and up to 50% of non-ventilated patients. Although guidelines for diagnosis and treatment of delirium exist it often remains underdiagnosed due to the lack of implementation of these guidelines. Therefore, the chance of a positive outcome for patients can be significantly reduced. Delirium results in longer mechanical ventilation, extended hospital stay, more nosocomial infections and an increased mortality. Measures which improve the frequency of diagnosis and increase the quality of treatment will only be successful if physicians, nursing staff and other medical staff on ICUs realize strategies together and raise their awareness on delirium.

Remifentanil reduces the incidence of post-operative delirium.

A secondary exploratory analysis of data from an observational study was used to study the influence of the opioid used for intraoperative anaesthesia on the incidence of post-operative delirium. Patients who had been admitted to the recovery room following elective general anaesthesia were divided into those who had received fentanyl or remifentanil. For unbiased patient analysis, matched pairs were built with respect to gender, age, physical status, anaesthetic type and surgery duration. In 752 patients, the overall incidence of delirium was 9.9% in the recovery room and 3.8% on the first post-operative day. Compared with the remifentanil group, the fentanyl group had a significantly higher incidence of delirium in the recovery room (12.2% versus 7.7%) and on the first post-operative day (5.8% versus 1.9%). Delirium in the recovery room and on the first post-operative day were both associated with a significantly prolonged post-operative hospital stay. The choice of intraoperative opioid influences the incidence of post-operative delirium. Remifentanil was associated with a lower incidence of post-operative delirium in the early post-operative period.

Effects of remifentanil and fentanyl on the cell-mediated immune response in patients undergoing elective coronary artery bypass graft surgery.

This prospective randomized pilot study compared the influence of fentanyl-based versus remifentanil-based anaesthesia on cytokine responses and expression of the suppressor of cytokine signalling (SOCS)-3 gene following coronary artery bypass graft surgery. Forty patients were assigned to receive anaesthesia with either intravenous remifentanil (0.3 - 0.6 microg/kg per min; n = 20) or intravenous fentanyl (5 - 10 microg/kg per h; n = 20). Levels of interleukin (IL)-6, IL-10, tumour necrosis factor-alpha and interferon-gamma (IFN-gamma) and the expression of SOCS-3 were measured pre- and post-operatively. The data from 33 of the patients were analysed. The IFN-gamma/IL-10 ratio after concanavalin A stimulation in whole blood cells on post-operative day 1 and SOCS-3 gene expression on post-operative day 2 were significantly lower in the remifentanil group than in the fentanyl group. The time in the intensive care unit was also significantly lower in the remifentanil group. These findings suggest that remifentanil can attenuate the exaggerated inflammatory response that occurs after cardiac surgery with cardiopulmonary bypass. Further clinical trials are required to define the influence of choice of intra-operative opioid on post-operative outcome.

Comparison of three scores to screen for delirium in the recovery room.

BACKGROUND: Delirium is often seen in the recovery room and is a predictor for postoperative delirium on the ward. However, monitoring to detect delirium in the recovery room as a basic prerequisite for early intervention is rarely used. The aim of this study was to identify a valid and easy-to-use test for early screening of delirium in the recovery room. METHODS: One hundred and fifty-four adult patients admitted to the recovery room during regular working hours were included. A screening assessment for delirium was performed in the recovery room by a trained research team at the time when the patient was judged to be 'ready for discharge'. Delirium monitoring was performed with the Confusion Assessment Method (CAM), the Delirium Detection Score (DDS), and the Nursing Delirium Screening Scale (Nu-DESC). The Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV criteria were used as the gold standard. RESULTS: Delirium in the recovery room was seen in 21 patients (14%) with the DSM-IV criteria, in 11 patients (7%) with the CAM, in four patients (3%) with the DDS, and in 37 patients (24%) with the Nu-DESC. Sensitivity and specificity were 0.43 and 0.98 for the CAM, 0.14 and 0.99 for the DDS, and 0.95 and 0.87 for the Nu-DESC, respectively. CONCLUSIONS: All scores used were very specific, but the CAM and the DDS were less sensitive compared with the gold standard. Overall, the Nu-DESC was the most sensitive test in the recovery room to detect delirium.