Delirium in the intensive care unit: a review

Aim:  The aim of this paper was to review the current discourse in relation to intensive care unit (ICU) delirium. In particular, it will discuss the predisposing and contributory factors associated with delirium's development as well as effects of delirium on patients, staff and family members.
Background:  Critically ill patients are at greater risk of developing delirium and, with an ageing population and increased patient acuity permitted by medical advances, delirium is a growing problem in the ICU. However, there is a universal consensus that the definition of ICU delirium needs improvement to aid its recognition and to ensure both hypoalert-hypoactive and hyperalert-hyperactive variants are easily and readily identified.
Relevance to clinical practice:  The effects of ICU delirium have cost implications to the National Health Service in terms of prolonged ventilation and length of hospital stay. The causes of delirium can be readily classified as either predisposing or precipitating factors, which are organic in nature and commonly reversible. However, contributory factors also exist to exacerbate delirium and having an awareness of all these factors promises to aid prevention and expedite treatment. This will avoid or limit the host of adverse physiological and psychological consequences that delirium can provoke and directly enhance both patient and staff safety.
Conclusions:  Routine screening of all patients in the ICU for the presence of delirium is crucial to its successful management. Nurses are on the front line to detect, manage and even prevent delirium.     

A stronger approach to weakness in the intensive care unit

ICU-acquired limb and respiratory muscle weakness is a common, serious ICU syndrome, increasing in frequency with prolonged ICU stay and sepsis. A systematic approach facilitates precise localization of the problem within central or peripheral nervous system. Most cases relate to critical illness polyneuropathy or myopathy or a combination of both (critical illness neuromyopathy). Within the latter entity, the relative contribution of neuropathy versus myopathy varies considerably among affected patients. Muscle enzyme testing, electromyography-nerve conduction and muscle biopsy are valuable investigative tests. Nerve biopsy is less commonly needed, but is useful when vascultis is suspected.     

Emotional consequences of intensive care unit delirium and delusional memories after intensive care unit admission: a systematic review

Purpose

The aim of this study was to review literature exploring the emotional consequences of delirium and delusional memories in intensive care unit patients.

Methods

A systematic review was performed using PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature, and PsychINFO.

Results

Fourteen articles were eligible for this review. Five of them assessed delirium during intensive care unit admission, and the remainder assessed delusional memories during or after admission. No association was found for delirium and adverse emotional outcome. Data regarding delusional memories and emotional outcome were heterogenic. Some studies presented worse scores on posttraumatic stress disorder screening tools in patients with delusional memories, whereas other studies found better scores in patients with delirium or delusional memories.

Conclusions

Based on current literature, no relationship could be shown for delirium and emotional outcome. Regarding delusional memories and adverse emotional outcome, results were in contradiction.     

ICU 患者谵妄危险因素分析

目的：通过评分系统分析患者ICU谵妄发生的危险因素。方法对440例患者分别在入ICU即刻与出ICU时应用焦虑自评量表（ SAS）、抑郁自评量表（ SDS）及ICU谵妄筛查表（ ICDSC）进行评价,同时记录发生ICU综合征的各种可能危险因素及入ICU及出ICU时的急性生理与慢性健康评分（ APACHEⅡ）。分别对危险因素与出ICU时SAS、SDS及ICDSC评分的关系进行多元线性回归分析。结果患者转出ICU后,APACHE Ⅱ评分、SAS、SDS及ICDSC各项评分分别为（9．8±3．2）,（43．8±11.3）,（43．1±10．8）与（2．43±2．00）分,进入ICU时分别为（17．3±5．5）,（48．3±12．7）,（48．5±12.3）,（1．36±0．81）分,差异有统计学意义（t值分别为7．549,3．004,3．780,－3．329;P＜0．05）。逐步多元回归分析显示,SAS评分与住院天数、出院 APACHE Ⅱ评分、引流管数量相关（R2＝0．515,F ＝14.139,P＜0．001）;SDS评分与住院天数、引流管数量相关（R2＝0．444,F＝16．395,P＜0．001）;ICDSC评分与文化程度、住院天数、机械通气时间、出院APACHE Ⅱ评分相关（ R2＝0．803,F＝39．769,P ＜0.001）。结论 ICDSC诊断ICU谵妄的敏感性较高,可用于ICU谵妄的筛查。随着住ICU天数的增加,发生ICU谵妄的可能性增加。     

Brain autopsy findings in intensive care unit patients previously suffering from delirium: A pilot study

Purpose

Delirium affects 50% to 80% of intensive care unit (ICU) patients and is associated with increased risk of mortality. Given the paucity of data reporting the neuropathologic findings in ICU patients experiencing delirium, the purpose of this pilot, hypothesis-generating study was to evaluate brain autopsies in ICU patients who suffered from delirium to explore possible neuroanatomical correlates.

Materials and Methods

Using delirium databases at Vanderbilt University, we identified patients who had delirium in the ICU and subsequently died and received a brain autopsy during the same hospitalization. Brain autopsy reports were collected retrospectively on all 7 patients who met these criteria.

Results

Patients' mean age was 55 (SD ± 8.4) years, and median number of days spent with delirium was 7 (±5 interquartile range). In 6 (86%) of 7 patients, pathologic lesions normally attributed to hypoxia or ischemia were noted in the hippocampus, pons, and striatum. Hippocampal lesions represented the most common neuropathologic site of injury, present in 5 (71%) of 7 patients.

Conclusions

Hypoxic ischemic injury in multiple locations of the brain was a common finding. The biological plausibility of hippocampal lesions as a contributor to long-term cognitive impairment warrants postmortem investigation on a larger scale with comparison to patients not experiencing ICU delirium.     

Oral care intervention to reduce incidence of ventilator-associated pneumonia in the neurologic intensive care unit

Ventilator-associated pneumonia (VAP) is a preventable secondary consequence of intubation and mechanical ventilation. VAP is pneumonia that develops in an intubated patient after 48 hours or more of mechanical ventilator support. Mechanically ventilated patients in neurologic and other intensive care units (ICUs) are at an increased risk of VAP due to factors such as decreased level of consciousness; dry, open mouth; and microaspiration of secretions. VAP can be prevented by initiating interventions from the Institute of Healthcare Improvement's VAP bundle, including (a) elevating the head of the bed of ventilated patients to 30 degrees, (b) preventing venous thromboembolism through use of sequential compression devices or anticoagulation, (c) administering gastric acid histamine2 blockers, (d) practicing good hand hygiene, (e) initiating early mobilization, and (f) performing daily sedation interruption at 10 am to evaluate neurologic status. The one intervention not included in the IHI bundle is oral hygiene. The purpose of this project is to support the premise that oral care, including timed toothbrushing, combined with the VAP bundle can mitigate and prevent the occurrence of VAP. Our project specifically addressed timed oral care of mechanically ventilated patients on a 24-bed stroke, neurologic, and medical ICU. Patients were randomized into a control group that performed usual oral care or an intervention group that brushed teeth every 8 hours. The results were immediate and startling, as the VAP rate dropped to zero within a week of beginning the every-8-hours toothbrushing regimen in the intervention group. The study was so successful that the control group was dropped after 6 months, and all intubated patients' teeth were brushed every 8 hours, maintaining the zero rate until the end of the study.     

Self-efficacy of caring for patients in the intensive care unit with delirium: Development and validation of a scale for intensive care unit nurses

BackgroundImproving the self-efficacy of intensive care unit nurses for delirium care could help them adapt to the changing situation of delirium patients. Validated measures of nurses' self-efficacy of delirium care are lackingObjectivesThe objective of this study was to develop a Delirium Care Self-Efficacy Scale for assessing nurses' confidence about caring for patients in the intensive care unit and to examine the scale's psychometric properties.MethodsDraft scale items were generated from a review of relevant literature and face-to-face interviews with intensive care unit nurses; content validity was conducted with a panel of five experts in delirium. A group of nurses were recruited by convenience sampling from intensive care units (N = 299) for item analysis of the questionnaire, assessment of validity, and reliability of the scale. Nurse participants were recruited from nine adult critical care units affiliated with a hospital in Taiwan. Data were collected from August 2020 to July 2021.ResultsContent validity index was 0.98 for the initial 26 items, indicating good validity. The critical ratio for item discrimination was 14.47–19.29, and item-to-total correlations ranged from 0.67 to 0.81. Principal component analysis reduced items to 13 and extracted two factors, confidence in delirium assessment and confidence in delirium management, which explained 66.82% of the total variance. Cronbach's alpha for internal consistency was 0.94 with good test–retest reliability (r = 0.92). High scale scores among participants were significantly associated with age (≥40 years), work experience in an intensive care unit (≥10 years), delirium education, and willingness to use delirium assessment tools.ConclusionsThe newly developed Delirium Care Self-Efficacy Scale demonstrated acceptable reliability and validity as a measure of confidence for intensive care nurses caring for and managing patients with delirium in the intensive care unit.     

Validation of the Intensive Care Delirium Screening Checklist in nonintubated intensive care unit patients in a resource-poor medical intensive care setting in South India

Objective

Delirium is a common, difficult-to-diagnose clinical condition in critical care units. The lack of recognition of delirium often results in increased morbidity and mortality. The study aimed to determine the validity and reliability of the Intensive Care Delirium Screening Checklist (ICDSC) in a resource-poor medical intensive care setting in South India.

Materials and methods

Fifty-three patients admitted into the medical intensive care unit of a teaching hospital who were neither mute nor intubated were recruited for the study. Trained residents administered the ICDSC to screen for delirium. A consultant psychiatrist used the International Classification of Diseases, 10th Revision diagnostic criteria for research to determine the presence of delirium.

Results

The optimal threshold for screening, as ICDSC total score of 3 or more, was obtained by using a receiver operating characteristic curve. Although a sensitivity and specificity of 75% and 74%, respectively, were obtained at the original cutoff of 4, a sensitivity of 90% and specificity of 61.54% were achieved with a cutoff of 3. In a subsample of 21 patients, interrater reliability was evaluated and found to be 0.947 (95% confidence interval, 0.870-0.979). The ICDSC had good internal consistency, with Cronbach α of .754 and Guttman split-half coefficient of 0.71. Factor analysis revealed a 2-factor structure, namely, altered sensorium/psychopathology and sleep-wake cycle problems.

Conclusions

Our findings indicate that in nonintubated intensive care unit patients, the ICDSC can be used to screen for delirium but should not be used as a diagnostic instrument in this patient population and that residents can be trained in the use of the instrument in resource-poor critical care settings. Using a different threshold for positivity of 3 rather than 4 appeared to offer improved screening characteristics in this resource-poor critical care setting.     

Incidence of pressure ulcers in a neurologic intensive care unit

OBJECTIVES: To determine the risk factors for pressure ulceration in an intensive care setting, to evaluate the Braden scale as a predictor of pressure ulcer risk in critically ill patients, and to determine whether pressure ulcers are likely to occur early in the hospital stay. DESIGN: Cohort study of patients with no preexisting ulcers with a 3-month enrollment period. SETTING: The neurologic intensive care unit and the neurologic intermediate unit at a primary care/referral hospital with a level I trauma center. PATIENTS: A total of 186 patients entered the study. INTERVENTION: Within 12 hrs of admittance, initial assessment, photographs, and Braden score were completed. Patients were re-examined every 4 days or at discharge from the unit, whichever came first. MAIN OUTCOME MEASURES: Determining risk factors for pressure ulcers, performing detailed statistical analyses, and testing the usefulness of the Braden score as a predictor of pressure ulcer risk. RESULTS: Twenty-three of 186 patients developed at least one pressure ulcer (incidence = 12.4%) after an average stay of 6.4 days. The Braden scale, which measures six characteristics of skin condition and patient status, proved to be a primary predictor of ulcer development. No ulcers developed in the 69 patients whose Braden score was 16 or higher. The likelihood of developing a pressure sore was predicted mathematically from the Braden score. However, being underweight was a significant and distinct factor in pressure ulcer development. CONCLUSIONS: Pressure ulcers may develop within the first week of hospitalization in the intensive care unit. Patients at risk have Braden scores of < or = 16 and are more likely to be underweight. These results suggest that aggressive preventive care should be focused on those patients with Braden scores of < or = 13 and/or a low body mass index at admission.     

The training needs of Korean intensive care unit nurses regarding delirium

ObjectivesThe aim of this study was to investigate high-priority training needs by analysing the perceived importance and self-reported performance of nurses’ delirium care competency.DesignA cross-sectional survey with a convenience sample of 255 Korean intensive care units nurses.SettingIntensive care units in the Republic of Korea.Main outcome measuresIntensive care unit nurses’ delirium care competency.ResultsExploratory factor analysis of the Nurse Delirium Care Competency Scale showed a six-factor structure, which accounted for 67.51% of the variance in nurses’ delirium care competency: management algorithm, prevention, communication, nursing management, assessment, and collaboration. The self-reported performance scores of all six factors were significantly lower than their perceived importance scores. The delirium assessment factor was identified as a high training priority on the importance-performance matrix for new graduate nurses.ConclusionTraining programmes should be developed considering the six delirium care competency factors identified in this study. Further, nurse educators must adopt active educational modalities such as case-based small group learning and simulation-based learning to improve nurse competency in recognising and managing delirium.     

Nurses' and physicians' approaches to delirium management in the intensive care unit: A focus group investigation

BackgroundDelirium in the intensive care unit (ICU) is common, but reliable evidence-based recommendations are still limited.ObjectivesThe aim of our study was to explore nurses' and physicians' experiences and approaches to ICU delirium management.MethodOur study had a qualitative multicentre design using interdisciplinary focus groups and framework analysis. Participants were strategically selected to include nurses and physicians with experience in delirium management at five ICUs in four out of five regions in Denmark.ResultsWe conducted eight focus group interviews with 24 nurses and 15 physicians; median ICU experience was 9 years (range 1–35). The main issues identified were (1) the decision to treat or not to treat ICU delirium based on delirium phenotype, (2) the decision to act based on experience or evidence, and (3) the decision to intervene using nursing care or medications. ICU delirium was treated with pharmacological interventions in patients with signs of agitation, hallucinations, and sleep deprivation. The first choice of agent was haloperidol or olanzapine. Agitated and combative patients received benzodiazepines, propofol, or dexmedetomidine. Calm delirious patients were managed with non-pharmacological solutions. Physicians recommended pro re nata (PRN) orders to prevent over medication, whereas nurses opposed PRN orders with the fear that it would increase their responsibilities.ConclusionOur study described an algorithm of contemporary delirium management in Danish ICUs based on qualitative inquiry. When evidence-based solutions are unclear, nurses and physicians rely on personal experience, collective experience, and best available evidence to determine which patients to treat and what methods to use to treat ICU delirium. Delirium management still needs clear objectives and guidelines with evidence-based recommendations for first-line treatment and subsequent treatment options.     

An exploration of the reliability and usability of two delirium screening tools in an Australian intensive care unit: A pilot study

ObjectiveTo compare the inter-rater reliability and usability of two delirium screening tools designed for use in ICU; the Confusion Assessment Method for ICU and the Intensive Care Delirium Screening Checklist.Research methodology/designA multiple methods design was used. The intra and inter rater reliability of the tools were evaluated using Kappa statistics and intra class correlation coefficients. Focus groups were conducted to explore ICU staff perceptions of the usability of the tools and feasibility of delirium screening.SettingPrivate hospital ICU, Melbourne Australia.Results66 patients were assessed for delirium; median age of 71 (IQR 62–75) years. Seventeen patients (26%) scored positive for delirium using the screening tools and 11 (17%) had delirium confirmed on the medical ICU discharge summary. Ten nurse assessors performed 99 paired assessments using the two tools sequentially, demonstrating the intra and inter-rater agreement and reliability of the tools was moderate to high.Four focus groups were conducted with 16 participants. Content analysis identified three themes: (i) current recognition of delirium, (ii) benefits of delirium screening, and (iii) future directions for delirium management. Time and medical staff indifference were identified as barriers to screening, facilitators were education and having a follow-up plan.ConclusionThis study found that the reliability and usability of the CAM-ICU and ICDSC were acceptable and that using structured delirium screening was feasible as part of a wider, multi-disciplinary delirium management plan.     

Nonpharmacological interventions for agitation in the adult intensive care unit: A systematic review

BackgroundPerson-centred nonpharmacological strategies should be used whenever possible to reduce agitation in the intensive care unit due to issues related to an overreliance on physical restraints and psychoactive drugs. However, the effect of nonpharmacological interventions to reduce agitation is unclear.ObjectivesThe objectives of this study were to systematically review studies that evaluate the effectiveness of nonpharmacological interventions designed to prevent and minimise or manage patient agitation in the adult intensive care unit.MethodsThis systematic review was conducted following the Joanna Briggs Institute's Systematic Review of Effectiveness method and a priori PROSPERO protocol. Quantitative studies were identified from seven databases, including MEDLINE, EmCare, CINAHL, Web of Science, PsycINFO, Scopus, and Cochrane Library. In addition, grey literature from several repositories and trial registers was searched. The primary outcome of interest was the effect on prevention, minimisation, and management of agitation. The quality of the evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE).ResultsEleven studies were included (n = 882). Meta-analyses of two studies demonstrated significantly lower levels of agitation (measured with the Richmond Agitation Sedation Scale) in the group receiving a multicomponent nonpharmacological intervention than in those receiving usual care. Individual studies showed a significant effect of nature-based sounds, music, foot reflexology, healing touch, and aromatherapy. The type of the endotracheal suction system did not affect levels of agitation. Overall, the certainty of the findings was rated very low. Harms and adverse effects were not reported in any studies.ConclusionsNonpharmacological interventions have the potential to reduce levels of agitation in the intensive care unit. However, inconsistencies in reporting, low quality of methodological designs, and small sample sizes impact the certainty of the results. Future trials must include larger sample sizes, use rigorous methods to improve knowledge in this field, and consider a range of other outcomes.     

Clinical approach to the weak patient in the intensive care unit

Motor weakness in a patient in the intensive care unit (ICU) may be related to (1) pre-existing neuromuscular disorder that leads to ICU admission, (2) new-onset or previously undiagnosed neurological disorder, or (3) complications of non-neuromuscular critical illness. Neuromuscular syndromes related to ICU treatment consist of critical illness polyneuropathy, critical illness myopathy, and prolonged neuromuscular blockade, and are now recognized as a frequent cause of newly acquired weakness in ICU patients. Clinical features include quadriparesis, muscle wasting, and difficulty weaning from the ventilator. Evaluation of these patients is based on knowledge of clinical setting and predisposing factors, focused neurological examination, detailed electrophysiological investigation, serum creatine kinase level, other laboratory studies as needed, and histological examination of muscle biopsy. If a central nervous system (brain or spinal cord) lesion is suspected, neuroimaging studies are required. In addition to conventional nerve conduction and needle electromyography, phrenic nerve conduction, diaphragm electromyography, blink reflex, and (recently) the technique of direct muscle stimulation have been employed. Critical illness polyneuropathy is an axonal motor and sensory neuropathy that often follows sepsis and multiorgan failure. Risk factors for critical illness myopathy are corticosteroids and neuromuscular blocking drugs, acute respiratory illness, and organ transplant. Three subtypes (acute necrotizing myopathy, thick myosin filament loss myopathy, and type II fiber atrophy) are recognized. Major differential diagnoses of critical illness related paralysis are incidental Guillain-Barré syndrome and unmasked myasthenia gravis. Rarely, atypical presentation of amyotrophic lateral sclerosis, polymyositis or other myopathies, and precipitation of porphyria or rhabdomyolysis due to drugs used in the ICU have been described. Recently a poliomyelitis-like flaccid paralysis due to West Nile virus infection was reported. A subgroup of patients with myasthenia gravis with muscle-specific tyrosine kinase antibody is noted to present as respiratory crisis. Muscle biopsy in ICU paralysis syndromes may be helpful in arriving at a specific diagnosis or to classify the type of critical illness myopathy. Nerve biopsy is only rarely indicated.