Psychometric properties of the Arabic version of the confusion assessment method for the intensive care unit (CAM-ICU)

Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) for the diagnosis of delirium in adults in critical care settings

BACKGROUND

Delirium is an underdiagnosed clinical syndrome typified by an acute alteration of mental state. It is an important problem in critical care and intensive care units (ICU) due to its high prevalence and its association with adverse outcomes. Delirium is a very distressing condition for patients, with a huge impact on their well-being. Diagnosis of delirium in the critical care setting is challenging. This is especially true for patients who are mechanically ventilated and are therefore unable to engage in a verbal interview. The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) is a tool specifically designed to assess for delirium in the context of ICU patients, including those on mechanical ventilation. CAM-ICU can be administered by non-specialists to give a dichotomous delirium present/absent result.

OBJECTIVES

To determine the diagnostic accuracy of the CAM-ICU for the diagnosis of delirium in adult patients in critical care units.

SEARCH METHODS

We searched MEDLINE (Ovid SP, 1946 to 8 July 2022), Embase (Ovid SP, 1982 to 8 July 2022), Web of Science Core Collection (ISI Web of Knowledge, 1945 to 8 July 2022), PsycINFO (Ovid SP, 1806 to 8 July 2022), and LILACS (BIREME, 1982 to 8 July 2022). We checked the reference lists of included studies and other resources for additional potentially relevant studies. We also searched the Health Technology Assessment database, the Cochrane Library, Aggressive Research Intelligence Facility database, WHO ICTRP, ClinicalTrials.gov, and websites of scientific associations to access any annual meetings and abstracts of conference proceedings in the field.

SELECTION CRITERIA

We included diagnostic studies enrolling adult ICU patients assessed using the CAM-ICU tool, regardless of language or publication status and reporting sufficient data on delirium diagnosis for the construction of 2 x 2 tables. Eligible studies evaluated the diagnostic performance of the CAM-ICU versus a clinical reference standard based on any iteration of the Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria applied by a clinical expert.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected and collated study data. We assessed the methodological quality of studies using the QUADAS-2 tool. We used two univariate fixed-effect or random-effects models to determine summary estimates of sensitivity and specificity. We performed sensitivity analyses that excluded studies considered to be at high risk of bias and high concerns in applicability, due mainly to the target population included (e.g. patients with traumatic brain injury). We also investigated potential sources of heterogeneity, assessing the effect of reference standard diagnosis and proportion of patients ventilated.

MAIN RESULTS

We included 25 studies (2817 participants). The mean age of participants ranged from 48 to 69 years; 15 of the studies included critical care units admitting mixed populations (e.g. medical, trauma, surgery patients). The percentage of patients receiving mechanical ventilation ranged from 11.8% to 100%. The prevalence of delirium in the studies included ranged from 12.5% to 83.9%. Presence of delirium was determined by the application of DSM-IV criteria in 13 out of 25 included studies. We assessed 13 studies as at low risk of bias and low applicability concerns for all QUADAS-2 domains. The most common issue of concern was flow and timing of the tests, followed by patient selection. Overall, we estimated a pooled sensitivity of 0.78 (95% confidence interval (CI) 0.72 to 0.83) and a pooled specificity of 0.95 (95% CI 0.92 to 0.97). Sensitivity analysis restricted to studies at low risk of bias and without any applicability concerns (n = 13 studies) gave similar summary accuracy indices (sensitivity 0.80 (95% CI 0.72 to 0.86), specificity 0.95 (95% CI 0.93 to 0.97)). Subgroup analyses based on diagnostic assessment found summary estimates of sensitivity and specificity for studies using DSM-IV of 0.79 (95% CI 0.72 to 0.85) and 0.94 (95% CI 0.90 to 0.96). For studies that used DSM-5 criteria, summary estimates of sensitivity and specificity were 0.75 (95% CI 0.67 to 0.82) and 0.98 (95% CI 0.95 to 0.99). DSM criteria had no significant effect on sensitivity (P = 0.421), but the specificity for detection of delirium was higher when DSM-5 criteria were used (P = 0.024). The relative specificity comparing DSM-5 versus DSM-IV criteria was 1.05 (95% CI 1.02 to 1.08). Summary estimates of sensitivity and specificity for studies recruiting < 100% of patients with mechanical ventilation were 0.81 (95% CI 0.75 to 0.85) and 0.95 (95% CI 0.91 to 0.98). For studies that exclusively recruited patients with mechanical ventilation, summary estimates of sensitivity and specificity were 0.91 (95% CI 0.76 to 0.97) and 0.98 (95% CI 0.92 to 0.99). Although there was a suggestion of differential performance of CAM-ICU in ventilated patients, the differences were not significant in sensitivity (P = 0.316) or in specificity (P = 0.493).

AUTHORS' CONCLUSIONS

The CAM-ICU tool may have a role in the early identification of delirium, in adult patients hospitalized in intensive care units, including those on mechanical ventilation, when non-specialized, properly trained clinical personnel apply the CAM-ICU. The test is most useful for exclusion of delirium. The test may miss a proportion of patients with incident delirium, therefore in situations where detection of all delirium cases is desirable, it may be best to repeat the test or combine CAM-ICU with another assessment. Future studies should compare different screening tests proposed for bedside assessment of delirium, as this approach will reveal which tool yields superior accuracy. In addition, future studies should consider and report the flow and timing of the tests and clearly report key characteristics related to patient selection. Finally, future research should focus on the impact of CAM-ICU screening on patient outcomes.

Point prevalence of delirium among critically ill patients in Saudi Arabia: A multicenter observational study

Background:

Delirium in critically ill patients is independently associated with poor clinical outcomes. There is a scarcity of published data on the prevalence of delirium among critically ill patients in Saudi Arabia. Therefore, we sought to determine, in a multicenter fashion, the prevalence of delirium in critically ill patients in Saudi Arabia and explore associated risk factors.

Methods:

A cross-sectional point prevalence study was conducted on January 28, 2020, at 14 intensive care units (ICUs) across 3 universities and 11 other tertiary care hospitals in Saudi Arabia. Delirium was screened once using the Intensive Care Delirium Screening Checklist. We excluded patients who were unable to participate in a valid delirium assessment, patients admitted with traumatic brain injury, and patients with documented dementia in their medical charts.

Results:

Of the 407 screened ICU patients, 233 patients were enrolled and 45.9% were diagnosed with delirium. The prevalence was higher in mechanically ventilated patients compared to patients not mechanically ventilated (57.5% vs. 33.6%; P < 0.001). In a multivariate model, risk factors independently associated with delirium included age (adjusted odds ratio [AOR], 1.021; 95% confidence interval [CI], 1.01–1.04; P = 0.008), mechanical ventilation (AOR, 2.39; 95% CI, 1.34–4.28; P = 0.003), and higher severity of illness (AOR, 1.01; 95% CI, 1.001–1.021; P = 0.026).

Conclusion:

In our study, delirium remains a prevalent complication, with distinct risk factors. Further studies are necessary to investigate long-term outcomes of delirium in critically ill patients in Saudi Arabia.

Diagnostic accuracy of the CAM-ICU and ICDSC in detecting intensive care unit delirium: A bivariate meta-analysis

BACKGROUND

Delirium is a critical and highly prevalent problem among critically ill patients. The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) and the Intensive Care Delirium Screening Checklist (ICDSC) are the most recommended assessment tools for detecting intensive care unit (ICU) delirium.

OBJECTIVES

To synthesize the current evidence and compared the diagnostic accuracy of the two tools in the detection of delirium in adults in ICUs.

DESIGN

Systematic review and meta-analysis.

DATA SOURCE

A comprehensive search of the following electronic databases was performed using PubMed, Embase, CINAHL and ProQuest Dissertations and Theses A&I. The date range searched was from database inception to April 26, 2019.

REVIEW METHODS

Two researchers independently identified articles, systematically abstracted data and evaluated the sensitivity and specificity of the CAM-ICU or the ICDSC against standard references. Bivariate diagnostic statistical analysis with a random-effects model was performed to summarize the pooled sensitivity and specificity of the two tools.

RESULTS

In total, 29 CAM-ICU and 12 ICDSC studies were identified. The pooled sensitivity was 0.84 and 0.83 and pooled specificity was 0.95 and 0.87 for the CAM-ICU and the ICDSC, respectively. The CAM-ICU had higher summary specificity than the ICDSC did (p = 0.04). The percentage of hypoactive delirium, ICU type, use of mechanical ventilation, number of participants, and female percentage moderated the accuracy of the tools. Most of the domains of patient selection, index test, reference standards, and flow and timing were rated as having a low or unclear risk of bias.

CONCLUSIONS

Although both the CAM-ICU and the ICDSC are accurate assessment tools for screening delirium in critically ill patients, the CAM-ICU is superior in ruling out patients without ICU delirium and detecting delirium in patients in the medical ICU and those receiving mechanical ventilation. Further investigations are warranted to validate our findings. The study protocol is registered at PROSPERO (CRD42020133544).

Diagnostic Performance of Delirium Assessment Tools in Critically Ill Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Critical care nurses are in the best position to detect and monitor delirium in critically ill patients. Therefore, an optimum delirium assessment tool with strong evidence should be identified with critical care nurses to perform in the daily assessment.

AIM

To evaluate and compare the diagnostic performance of delirium assessment tools in diagnosing delirium in critically ill patients.

METHODS

We searched five electronic databases including the Cochrane Library, PubMed, Embase, CINAHL, and a Chinese database for eligible diagnostic studies published in English or Mandarin up to December 2018. This diagnostic test accuracy meta-analysis was limited to studies in intensive care unit (ICU) settings, using the Diagnostic and Statistical Manual of Mental Disorders (DSM) as a standard reference to test the accuracy of delirium assessment tools. Eligible studies were critically appraised by two investigators independently. The summary of evidence was conducted for pooling and comparing diagnostic accuracy by a bivariate random effects meta-analysis model. The pooled sensitivities and specificities, summary receiver operating characteristic curve (sROC), the area under the curve (AUC), and diagnostic odds ratio (DOR) were calculated and plotted. The possibility of publication bias was assessed by Deeks' funnel plot.

DATA SYNTHESIS

We identified and evaluated 23 and 8 articles focused on CAM-ICU and ICDSC, respectively. The summary sensitivities of 0.85 and 0.87, and summary specificities of 0.95 and 0.91 were found for CAM-ICU and ICDSC, respectively. The AUC of the CAM-ICU was 0.96 (95% CI, 0.94-0.98), with DOR at 99 (95% CI, 55-177). The AUC of the ICDSC was 0.95 (95% CI, 0.92-0.96), and the DOR was 65 (95% CI, 27-153).

LINKING EVIDENCE TO ACTION

CAM-ICU demonstrated higher diagnostic test accuracy and is recommended as the optimal delirium assessment tool. However, the results should be interpreted with caution due to the between-study heterogeneity of this diagnostic test accuracy meta-analysis.

A Tunisian version of the confusion assessment method for the intensive care unit (CAM-ICU): translation and validation

BACKGROUND

Delirium is common in critically ill patients and it is associated with poor outcomes. In Tunisia, however, it is still underdiagnosed as there is no validated screening tool. The aim of this study was to translate and to validate a Tunisian version of the CAM-ICU.

METHODS

For the validation and inter-rater reliability assessment of the Tunisian CAM-ICU, two trained intensivists independently evaluated delirium in the patients admitted to the ICU between October 2017 and June 2018. All the patients consecutively admitted to the ICU for more than 24 h and having a Richmond Agitation-Sedation Scale greater than or equal to "-3" were assessed for delirium excluding those with stroke, dementia, psychosis or persistent coma. The results were compared with the reference evaluation carried out by a psychiatrist using the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) criteria. The inter-rater reliability was calculated using the kappa (κ) statistic. The CAM-ICU concurrent validity was assessed using Cronbach's α coefficient, sensitivity, specificity as well as positive and negative predictive values (PPV and NPV, respectively) for the two Tunisian CAM-ICU raters.

RESULTS

The study involved 137 patients [median (IQR) age: 60 [49-68] years, male sex (n = 102), invasive mechanical ventilation (n = 49)]. Using the DSM-V criteria evaluations, 46 patients were diagnosed with delirium. When applying the Tunisian version of the CAM-ICU, 38(27.7%) patients were diagnosed with delirium for the first rater and 45(32.6%) patients for the second one. The Tunisian CAM-ICU showed a very-high inter-rater reliability for both intensivists (κ = 0.844, p < 0.001). Using the DSM-V rater as the reference standard, the sensitivity of the two intensivists' evaluations was 80.4 vs. 95.7%. Specificity was 98.9% for both. The Cronbach's α of the first and second raters' evaluations using the Tunisian version of the CAM-ICU were 0.886 and 0.887, respectively.

CONCLUSIONS

The Tunisian version of the CAM-ICU showed almost perfect validity and reliability in detecting delirium in critically ill patients. It could therefore be used in Tunisian ICUs or where Tunisian translators are available following appropriate training.

TRIAL REGISTRATION

Not applicable.

Adjunct low-dose ketamine infusion vs standard of care in mechanically ventilated critically ill patients at a Tertiary Saudi Hospital (ATTAINMENT Trial): study protocol for a randomized, prospective, pilot, feasibility trial

Background

A noticeable interest in ketamine infusion for sedation management has developed among critical care physicians for critically ill patients. The 2018 Pain, Agitation/sedation, Delirium, Immobility, and Sleep disruption guideline suggested low-dose ketamine infusion as an adjunct to opioid therapy to reduce opioid requirements in post-surgical patients in the intensive care unit (ICU). This was, however, rated as conditional due to the very low quality of evidence. Ketamine has favorable characteristics, making it an especially viable alternative for patients with respiratory and hemodynamic instability. The Analgo-sedative adjuncT keTAmine Infusion iN Mechanically vENTilated ICU patients (ATTAINMENT) trial aims to assess the effect and safety of adjunct low-dose continuous infusion of ketamine as an analgo-sedative compared to standard of care in critically ill patients on mechanical ventilation (MV) for ≥ 24 h.

Methods/design

This trial is a prospective, randomized, active controlled, open-label, pilot, feasibility study of adult ICU patients (> 14 years old) on MV. The study will take place in the adult ICUs in the King Faisal Specialist Hospital and Research Center (KFSH&RC), Riyadh, Saudi Arabia, and will enroll 80 patients. Patients will be randomized post-intubation into two groups: the intervention group will receive an adjunct low-dose continuous infusion of ketamine plus standard of care. Ketamine will be administered over a period of 48 h at a fixed infusion rate of 2 μg/kg/min (0.12 mg/kg/h) in the first 24 h followed by 1 μg/kg/min (0.06 mg/kg/h) in the second 24 h. The control group will receive standard of care in the ICU (propofol and/or fentanyl and/or midazolam) according to the KFSH&RC sedation and analgesia protocol as clinically appropriate. The primary outcome is MV duration until ICU discharge, death, extubation, or 28 days post-randomization, whichever comes first.

Discussion

The first patient was enrolled on 1 September 2019. As of 10 October 2019, a total of 16 patients had been enrolled. We expect to complete the recruitment by 31 December 2020. The findings of this pilot trial will likely justify further investigation for the role of adjunct low-dose ketamine infusion as an analgo-sedative agent in a larger, multicenter, randomized controlled trial.

Trial registration

ClinicalTrials.gov: NCT04075006. Registered on 30 August 2019. Current controlled trials: ISRCTN14730035. Registered on 3 February 2020.

Arabic intensive care delirium screening checklist's validity and reliability: A multicenter study

PURPOSE

To develop an Arabic version of Intensive Care Delirium Screening Checklist (ICDSC) and assess its validity and reliability among critically ill patients.

MATERIALS AND METHODS

Multicentered study of convenience sample of adult ICU patients. Arabic translation was performed with rigorous back-to-back translation methods. Concurrent validity was established by calculating the sensitivity and specificity of two examiner assessments compared to a psychiatric evaluation. Kappa coefficients describe interrater reliability, whereas Cronbach α and composite reliability depict internal consistency.

RESULTS

Three hundred critically ill patients were enrolled. Of these, validity testing was assessed in 180 patients. ICDSC screening was positive for delirium in 11% of enrolled patients. The area under the receiver operator characteristic (ROC) curve is 0.9413, with predicted sensitivity 70% (95% confidence interval [CI]: 60-81%) and specificity 99% (95% CI: 98-100%). The Arabic ICDSC showed acceptable internal consistency (Cronbach α = 0.63 and composite reliability = 0.64). Interrater agreement was excellent (Kappa coefficient [ҡ] = 0.85).

CONCLUSIONS

Arabic ICDSC is a valid and reliable delirium-screening tool among Arabic-speaking ICU population. Future studies could address whether these findings are generalizable to a higher proportion of mechanically ventilated patients, and address acceptability and reliability in other Arabic language critical care settings.