Influence of Sedation Level and Ventilation Status on the Diagnostic Validity of Delirium Screening Tools in the ICU-An International, Prospective, Bi-Center Observational Study (IDeAS)

Validity and predictability of the confusion assessment method for the intensive care unit for delirium among critically ill patients in the intensive care unit: A systematic review and meta-analysis

OBJECTIVE

To identify the validity and predictability of the confusion assessment method for the intensive care unit (CAM-ICU) for delirium in critically ill patients in the ICU.

METHODS

In this systematic review, PubMed, Embase, Cochrane Central Register of Controlled Trials, and MEDLINE databases were searched for observational studies investigating delirium screening tools for ICU patients. In the meta-analysis, we combined the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the curve (AUC) of SROC to analysis the predictive value of CAM-ICU.

RESULTS

Twenty-nine articles met the inclusion criteria. The pooled sensitivity and specificity values were 0.82 (95% confidence interval [CI]: 0.75-0.87) and 0.95 (95% CI: 0.93-0.97), respectively. The AUC point estimate of the SROC curve was 0.96 (95% CI: 0.94-0.97). Race (Asian or Others) could affect the pooled sensitivity and specificity, and the analysis method (Patient- or Scan-based) and study design were not sources of heterogeneity for pooled sensitivity and specificity.

CONCLUSIONS

The CAM-ICU is a valid and reliable tool for delirium prediction among ICU patients. When introducing CAM-ICU to assess delirium, it is necessary to localize its language and content to improve its predictive efficacy in different countries and different ethnic groups.

RELEVANCE TO CLINICAL PRACTICE

In clinical practice, nurses can use CAM-ICU to evaluate delirium in critically ill patients in ICU. However, it is necessary to debug the language and content according to the application population.

Subsyndromal Delirium in Critically Ill Patients-Cognitive and Functional Long-Term Outcomes

Subsyndromal delirium (SSD) in the Intensive Care Unit (ICU) is associated with an increased morbidity with unknown post-discharge functional and cognitive outcomes. We performed a prospective multicenter study to analyze the mental status of patients during their first 72 h after ICU admission and its trajectory, with follow-ups at 3 and 6 months after hospital discharge. Amongst the 106 included patients, SSD occurred in 24.5% (n = 26) and was associated with the duration of mechanical ventilation (p = 0.003) and the length of the ICU stay (p = 0.002). After the initial 72 h, most of the SSD patients (30.8%) improved and no longer had SSD; 19.2% continued to experience SSD and one patient (3.8%) progressed to delirium. The post-hospital discharge survival rate for the SSD patients was 100% at 3 months and 87.5% at 6 months. At admission, 96.2% of the SSD patients were fully independent in daily living activities, 66.7% at 3-month follow-up, and 100% at 6-month follow-up. Most SSD patients demonstrated a cognitive decline from admission to 3-month follow-up and improved at 6 months (IQCODE-SF: admission 3.13, p < 0.001; 3 months 3.41, p = 0.019; 6 months 3.19, p = 0.194). We concluded that early SSD is associated with worse outcomes, mainly a transitory cognitive decline after hospital discharge at 3 months, with an improvement at 6 months. This highlights the need to prevent and identify this condition during ICU stays.

Advantages of score-based delirium detection compared to a clinical delirium assessment-a retrospective, monocentric cohort study

Purpose

Delirium is an underdiagnosed complication on intensive care units (ICU). We hypothesized that a score-based delirium detection using the Nudesc score identifies more patients compared to a traditional diagnosis of delirium by ICU physicians.

Methods

In this retrospective study, all patients treated on a general medical ICU with 30 beds in a university hospital in 2019 were analyzed. Primary outcome was a documented physician diagnosis of delirium, or a delirium score ≥2 using the Nudesc.

Results

In 205/943 included patients (21.7%), delirium was diagnosed by ICU physicians compared to 438/943 (46.4%; ratio 2.1) by Nudesc≥2. Both assessments were independent predictors of ICU stay (p<0.01). The physician diagnosis however was no independent predictor of mortality (OR 0.98 (0.57–1.72); p = 0.989), in contrast to the score-based diagnosis (OR 2.31 (1.30–4.10); p = 0.004). Subgroup analysis showed that physicians underdiagnosed delirium in case of hypoactive delirium and delirium in patients with female gender and in patients with an age below 60 years.

Conclusion

Delirium in patients with hypoactive delirium, female patients and those below 60 years was underdiagnosed by physicians. The score-based delirium diagnosis detected delirium more frequently and correlated with ICU mortality and stay.

Influence of Patient-Specific Covariates on Test Validity of Two Delirium Screening Instruments in Neurocritical Care Patients (DEMON-ICU)

Background

Delirium screening instruments (DSIs) should be used to detect delirium, but they only show moderate sensitivity in patients with neurocritical illness. We explored whether, for these patients, DSI validity is impacted by patient-specific covariates.

Methods

Data were prospectively collected in a single-center quality improvement project. Patients were screened for delirium once daily using the Intensive Care Delirium Screening Checklist (ICDSC) and the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). Reference was the daily assessment using criteria from the Diagnostic and Statistical Manual, 4th Edition, Text Revision (DSM-IV-TR). In a two-step receiver operating characteristics regression analysis adjusting for repeated measurements, the impact of acute diagnosis of stroke or transient ischemic attack (TIA), neurosurgical intervention, Richmond Agitation Sedation Scale, and ventilation status on test validity was determined.

Results

Of 181 patients screened, 101 went into final analysis. Delirium incidence according to DSM-IV-TR was 29.7%. For the first complete assessment series (CAM-ICU, ICDSC, and DSM-IV-TR), sensitivity for the CAM-ICU and the ICDSC was 73.3% and 66.7%, and specificity was 91.8% and 94.1%, respectively. Consideration of daily repeated measurements increased sensitivity for the CAM-ICU and ICDSC to 75.7% and 73.4%, and specificity to 97.3% and 98.9%, respectively. Receiver operating characteristics regression revealed that lower Richmond Agitation Sedation Scale levels significantly impaired validity of the ICDSC (p = 0.029) and the CAM-ICU in its severity scale version (p = 0.004). Neither acute diagnosis of stroke or TIA nor neurosurgical intervention or mechanical ventilation significantly influenced DSI validity.

Conclusions

The CAM-ICU and ICDSC perform well in patients requiring neurocritical care, regardless of the presence of acute stroke, TIA, or neurosurgical interventions. Yet, even very light or moderate sedation can significantly impair DSI performance.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12028-021-01319-9.