Alawi Luetz

Different assessment tools for intensive care unit delirium: which score to use?

Objective: To compare validity and reliability of three instruments for detection and assessment of delirium in intensive care unit (ICU) patients. Delirium in critically ill patients is associated with higher mortality, prolonged duration of ICU stay, and greater healthcare costs. Currently, there are several assessment tools available for detection of delirium, but only a few of these assessment systems are developed specifically to screen for delirium in ICU patients. Design: Prospective cohort study. Setting: ICU at a university hospital. Patients: A total of 156 surgical patients aged ≥60 yrs consecutively admitted to the ICU, with a length of stay of at least 24 hrs. Measurements and Main Results: This study was approved by the institutional ethics committee. Trained staff members performed daily and independently the Confusion Assessment Method for the ICU (CAM-ICU), the Nursing Delirium Screening Scale (Nu-DESC), and the Delirium Detection Score (DDS). These evaluations were compared against the reference standard conducted by a delirium expert (blinded to the study), who used delirium criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). Of 156 patients, 63 (40%) were identified as delirious by the reference standard during the study. Using the CAM-ICU and the Nu-DESC, we measured comparable sensitivities (CAM-ICU, 81%; Nu-DESC, 83%). The specificity of the CAM-ICU was significantly higher than that of the Nu-DESC (96% vs. 81%, p < .01). In contrast, the DDS showed poor sensitivity (30%), whereas the specificity was significantly higher compared with the Nu-DESC (DDS, 91%; Nu-DESC, 81%, p < .05). The interrater reliability was “almost perfect” for the CAM-ICU (&kgr; = 0.89) and “substantial” for DDS and Nu-DESC (&kgr; = 0.79, 0.68). Conclusion: The CAM-ICU showed the best validity of the evaluated scales to identify delirium in ICU patients. The Nu-DESC might be an alternative tool for detection of ICU delirium. The DDS should not be used as a screening tool.

A Comparison of Three Scores to Screen for Delirium on the Surgical Ward

BackgroundPostoperative delirium is associated with adverse outcome. The aim of this study was to find a valid and easy-to-use tool to screen for postoperative delirium on the surgical ward.MethodsData were collected from 88 patients who underwent elective surgery. Delirium screening was performed daily until the sixth postoperative day using the Confusion Assessment Method (CAM), the Nursing Delirium Screening Scale (Nu-DESC), and the Delirium Detection Score (DDS), and the DSM-IV criteria as the gold standard.ResultsSeventeen of 88 patients (19%) developed delirium on at least one of the postoperative days according to the gold standard. The DDS scored positive for 40 (45%) patients, the CAM for 15 (17%), and the Nu-DESC for 28 (32%) patients. Sensitivity and specificity were 0.71 and 0.87 for the DDS, 0.75 and 1.00 for the CAM, and 0.98 and 0.92 for the Nu-DESC. The interrater reliability was 0.83 for the Nu-DESC, 0.77 for the DDS, and 1.00 for the CAM.ConclusionsAll scores showed high specificity but differed in their sensitivity. The Nu-DESC proved to be the most sensitive test for screening for a postoperative delirium on the surgical ward followed by the CAM and DDS when compared to the gold standard.

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 μg/kg per min; n = 20) or intravenous fentanyl (5 − 10 μg/kg per h; n = 20). Levels of interleukin (IL)-6, IL-10, tumour necrosis factor-α and interferon-γ (IFN-γ) and the expression of SOCS-3 were measured pre- and post-operatively. The data from 33 of the patients were analysed. The IFN-γ/IL-10 ratio after concanavalin A stimulation in whole blood cells on postoperative 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 postoperative outcome.

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.

Influence of Granulocyte-Macrophage Colony-Stimulating Factor or Influenza Vaccination on HLA-DR, Infection and Delirium Days in Immunosuppressed Surgical Patients: Double Blind, Randomised Controlled Trial

Purpose Surgical patients are at high risk for developing infectious complications and postoperative delirium. Prolonged infections and delirium result in worse outcome. Granulocyte-macrophage colony-stimulating factor (GM-CSF) and influenza vaccination are known to increase HLA-DR on monocytes and improve immune reactivity. This study aimed to investigate whether GM-CSF or vaccination reverses monocyte deactivation. Secondary aims were whether it decreases infection and delirium days after esophageal or pancreatic resection over time. Methods In this prospective, randomized, placebo-controlled, double-blind, double dummy trial setting on an interdisciplinary ICU of a university hospital 61 patients with immunosuppression (monocytic HLA-DR [mHLA-DR] <10,000 monoclonal antibodies [mAb] per cell) on the first day after esophageal or pancreatic resection were treated with either GM-CSF (250 μg/m2/d), influenza vaccination (Mutagrip 0.5 ml/d) or placebo for a maximum of 3 consecutive days if mHLA-DR remained below 10,000 mAb per cell. HLA-DR on monocytes was measured daily until day 5 after surgery. Infections and delirium were followed up for 9 days after surgery. Primary outcome was HLA-DR on monocytes, and secondary outcomes were duration of infection and delirium. Results mHLA-DR was significantly increased compared to placebo (p < 0.001) and influenza vaccination (p < 0.001) on the second postoperative day. Compared with placebo, GM-CSF-treated patients revealed shorter duration of infection (p < 0.001); the duration of delirium was increased after vaccination (p = 0.003). Conclusion Treatment with GM-CSF in patients with postoperative immune suppression was safe and effective in restoring monocytic immune competence. Furthermore, therapy with GM-CSF reduced duration of infection in immune compromised patients. However, influenza vaccination increased duration of delirium after major surgery. Trial Registration www.controlled-trials.com ISRCTN27114642

Weaning from mechanical ventilation and sedation.

Purpose of review Guidelines for weaning from sedation and weaning from ventilator gained increasing interest in recent years. This includes patients with acute respiratory distress syndrome, as well as other mechanically ventilated patients. This review will give an overview of the current literature and practice guidelines in ventilator and sedation weaning. Recent findings Sedation and ventilator weaning are closely linked. Weaning protocols for both sedation and ventilator weaning should be implemented in daily routine. The essential element of such algorithm should be a daily spontaneous awakening trial and spontaneous breathing trial. Furthermore, regularly monitoring for deepness of sedation and delirium should be implemented. Too deep sedation, as well as prolonged delirium is associated with higher mortality. Summary The most important conclusion we come to from recent randomized controlled trials is that only using an integrative algorithm for sedation and ventilator weaning can improve survival of ICU patients.

Validity of Different Delirium Assessment Tools for Critically Ill Children: Covariates Matter*

Objectives:To evaluate test validity of the Pediatric Confusion Assessment Method for the ICU, the Pediatric Anesthesia Emergence Delirium scale, and the newly developed severity scale for the Pediatric Confusion Assessment Method for the ICU; to prospectively assess covariates and their influence on test validity of the scores. Design:Prospective observational cohort study. Setting:PICU of a tertiary care medical center. Patients:Critically ill patients 5 years old or older ventilated or nonventilated with an ICU length of stay of at least 24 hours. Interventions:None. Measurements and Main Results:Patients were scored with the Pediatric Confusion Assessment Method for the ICU and the Pediatric Anesthesia Emergence Delirium scale once daily for a maximum of 21 days. Validity was determined by comparing scoring results with the evaluations of the delirium experts who used the criteria of the Diagnostic and Statistical Manual, 4th Edition, Text Revision, for delirium diagnosis. Sixty-four patients were enrolled and 214 assessments were conducted and included in data analysis. The first assessments within each patient revealed sensitivities of 69.2% for the Pediatric Anesthesia Emergence Delirium scale, 76.9% for the Pediatric Confusion Assessment Method for the ICU, and 84.9% for the severity scale for the Pediatric Confusion Assessment Method for the ICU. Specificities were 98% for all scores. Considering repeated measurements, sensitivities decreased to 35.9% for the Pediatric Anesthesia Emergence Delirium scale and to 52.3% for the Pediatric Confusion Assessment Method for the ICU. The sensitivity of the severity scale for the Pediatric Confusion Assessment Method for the ICU dropped to 71.8%, which was significantly higher compared to the Pediatric Anesthesia Emergence Delirium scale (p = 0.0008). Receiver operator characteristic regression unveiled that sedation and mechanical ventilation had a significant negative effect on the validity of the Pediatric Anesthesia Emergence Delirium scale and the severity scale for the Pediatric Confusion Assessment Method for the ICU. Age and gender had a significant impact on the receiver operator characteristic curve of the severity scale for the Pediatric Confusion Assessment Method for the ICU. Conclusions:The severity scale for the Pediatric Confusion Assessment Method for the ICU showed the best test validity when used in critically ill children of 5 years old or older. Nevertheless, validity of delirium screening itself depends on patient specific factors. These factors should be taken into consideration when choosing a delirium screening instrument.

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.

Routine delirium monitoring is independently associated with a reduction of hospital mortality in critically ill surgical patients: A prospective, observational cohort study

PURPOSE Although delirium monitoring is recommended in international guidelines, there is lacking evidence for improved outcome due to it. We hypothesized that adherence to routine delirium monitoring would improve clinical outcome in adult critically ill patients. MATERIAL AND METHODS We present the results of a prospective, noninterventional, observational cohort study that was conducted on 2 intensive care units (ICUs) of a tertiary care medical center between July and October 2007 (International Standard Registered Clinical Trial Record identifier: 76100795). We assessed delirium-monitoring and outcome parameters on a daily basis. Besides multivariate logistic and robust linear regression to analyze the relationship between delirium monitoring and outcome, we used the doubly robust augmented inverse probability weighting method for observational data to estimate effect sizes. RESULTS Of 355 screened patients, we included 185 surgical ICU patients into our final analysis, of which 87 were mechanically ventilated. We found an independent association between delirium-monitoring adherence and in-hospital mortality for ventilated patients (odds ratio, 0.973; P= .041). Estimating the effect size, delirium monitoring indicated a reduction of 22% of in-hospital mortality if conducted 50% or more of ICU days per patient. The average ICU length of stay of 46 days was estimated to be reduced by 19 days (P= .031) if patients were sufficiently monitored. CONCLUSION Our data suggest an improved outcome for mechanically ventilated patients being screened for delirium in clinical routine.

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.