CPCP: Rapid Two Step Screen for Delirium by Medical Students

socwell

Laura Socwell, M3

funk

Emily Funk, M4

Hey, another excellent Clinical Problems in Consultation Psychiatry (CPCP) coming your way by stellar medical students Laura Rocwell, in her 3rd year and still deciding on what medical specialty she’ll pursue, and Emily Funk, a 4th year student who is looking forward to a career in Family Medicine. Their presentation is about the new delirium two step screening based on the paper about the use of the Delirium Triage Screen and the abbreviated Confusion Assessment Method (bCAM, actually based on the CAM-ICU) [1]. Also take a look at the recent post about this.

One of the central caveats is that delirium fluctuates, so it’s important to bear that in mind when you consider the 3 hour lag time between initial screens and the psychiatrist’s assessment. if you have as much time as the psychiatrists had to do the assessment–you need a second job.

Again, why is the Delirium Triage Screen copyrighted? You don’t need to use the RASS because the only relevant level of consciousness is the normal one for the purpose of the DTS. Hey, lots of words can be spelled backward as a screening item. What makes “lunch” special (and don’t say thuringer)?

And we’re not sure why the psychiatrists rather long assessment should be the gold standard. There are other standards besides the Diagnostic and Statistical Manual (DSM)-5 criteria. See my Delirium Blogroll.

And about that abbreviated Confusion Assessment Method (bCAM)? Recall that’s actually based on the CAM-ICU developed by Dr. Wes Ely and colleagues and it was found to be insensitive in the Neufeld study when administered to patients on a non-ICU unit [2]. The CAM-ICU works great in critical care units; it has high sensitivity and specificity there. However, it’s important to point out that the bCAM seemed to work well in hospitalized patients in this study.

One of the features of the bCAM, which should read “acute” change in mental status rather than simply “altered” in order to emphasize the acute onset, involves calling or speaking with a relative or friend in order to confirm the acute change. This reminds me of the SQiD (Single Question in Delirium) test, which compared so well with the CAM in one study in terms of sensitivity and specificity that it begs the question of whether a two step screen is really necessary [3]. What’s the single question? Just ask if the patient has seemed confused lately. That’s pretty much all there is to it.

In order to see the picture galleries of photos or powerpoint slides, click on one of the slides, which will open up the presentation to fill the screen. Use the arrow buttons to scroll left and right through the slides or up and down to view any annotations.

 

1. Han, J. H., A. Wilson, et al. (2013). “Diagnosing Delirium in Older Emergency Department Patients: Validity and Reliability of the Delirium Triage Screen and the Brief Confusion Assessment Method.” Annals of emergency medicine 62(5): 457-465.

Delirium is a common form of acute brain dysfunction with prognostic significance. Health care professionals caring for older emergency department (ED) patients miss delirium in approximately 75% of cases. This error results from a lack of available measures that can be performed rapidly enough to be incorporated into clinical practice. Therefore, we developed and evaluated a novel 2-step approach to delirium surveillance for the ED. This prospective observational study was conducted at an academic ED in patients aged 65 years or older. A research assistant and physician performed the Delirium Triage Screen (DTS), designed to be a highly sensitive rule-out test, and the Brief Confusion Assessment Method (bCAM), designed to be a highly specific rule-in test for delirium. The reference standard for delirium was a comprehensive psychiatrist assessment using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria. All assessments were independently conducted within 3 hours of one another. Sensitivities, specificities, and likelihood ratios with their 95% confidence intervals (95% CIs) were calculated. Of 406 enrolled patients, 50 (12.3%) had delirium diagnosed by the psychiatrist reference standard. The DTS was 98.0% sensitive (95% CI 89.5% to 99.5%), with an expected specificity of approximately 55% for both raters. The DTS’s negative likelihood ratio was 0.04 (95% CI 0.01 to 0.25) for both raters. As the complement, the bCAM had a specificity of 95.8% (95% CI 93.2% to 97.4%) and 96.9% (95% CI 94.6% to 98.3%) and a sensitivity of 84.0% (95% CI 71.5% to 91.7%) and 78.0% (95% CI 64.8% to 87.2%) when performed by the physician and research assistant, respectively. The positive likelihood ratios for the bCAM were 19.9 (95% CI 12.0 to 33.2) and 25.2 (95% CI 13.9 to 46.0), respectively. If the research assistant DTS was followed by the physician bCAM, the sensitivity of this combination was 84.0% (95% CI 71.5% to 91.7%) and specificity was 95.8% (95% CI 93.2% to 97.4%). If the research assistant performed both the DTS and bCAM, this combination was 78.0% sensitive (95% CI 64.8% to 87.2%) and 97.2% specific (95% CI 94.9% to 98.5%). If the physician performed both the DTS and bCAM, this combination was 82.0% sensitive (95% CI 69.2% to 90.2%) and 95.8% specific (95% CI 93.2% to 97.4%). In older ED patients, this 2-step approach (highly sensitive DTS followed by highly specific bCAM) may enable health care professionals, regardless of clinical background, to efficiently screen for delirium. Larger, multicenter trials are needed to confirm these findings and to determine the effect of these assessments on delirium recognition in the ED.

2. Neufeld, K. J., Hayat, M. J., Coughlin, J. M., Huberman, A. L., Leistikow, N. A., Krumm, S. K., & Needham, D. M. (2011). Evaluation of Two Intensive Care Delirium Screening Tools for Non-Critically Ill Hospitalized Patients. Psychosomatics, 52(2), 133-140. doi: 10.1016/j.psym.2010.12.018

3. Sands, MB, Dantoc, BP, Hartshorn, A., Ryan, CJ, & Lujic, S. (2010). Single Question in Delirium (SQiD): testing its efficacy against psychiatrist interview, the Confusion Assessment Method and the Memorial Delirium Assessment Scale. Palliative Medicine, 24(6), 561-565. doi: 10.1177/0269216310371556

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