Screening for delirium within the Emergency Department

Date First Published:
May 12, 2016
Last Updated:
February 11, 2017
Report by:
L K Beales, ACCS Emergency Medicine CT2, (Sheffield Teaching Hospitals)
Search checked by:
M Mecuri, Sheffield Teaching Hospitals
Three-Part Question:
In [patients, greater than 75 years, presenting to the emergency department] is [an abbreviated mental test score assessment better than other cognitive screening tools] at [identifying delirium]?
Clinical Scenario:
A confused patient presents to the ED. Is the abbreviated mental test score the best method to screen for delirium/acute confusional state?
Search Strategy:
MEDLINE 1946 to June week 2 2016, EMBASE 1974–June 2016 and the COCHRANE LIBRARY (2016).

[exp delirium/or impaired cognition.mp. or acute confusional state.mp.] AND [Emergency Department.mp]
Outcome:
In total, 129 papers were identified, and 14 were relevant to the clinical question
Relevant Paper(s):
Study Title Patient Group Study type (level of evidence) Outcomes Key results Study Weaknesses
Evaluation of the confusion assessment method (CAM) as a screening tool for Monett J, Galbaud du Fort G, Fung SH, et al. 2001 Canada N=110 age>66 years patients within a ED. Prospective convenience sample, cases and controls hand picked Geriatrician and lay interviewer conducted assessment with CAM Using the geriatrician-conducted CAM as the gold standard, the diagnostic sensitivity of the lay interviewer was 96%, specificity 100% Convenience sample taken and screening of patients before entering study. Therefore, population was not representative of ED.
Geriatrician-conducted CAM not compared with other diagnostic tools
The effect of mental status screening on the care of elderly emergency Hustey FM, Meldon SW, Smith MD, et al. 2003 USA N=271. Age>70 years within a urban Teaching Hospital ED. Prospective convenience sample study Prevalence of delirium and cognitive impairment as measured by CAM and OMC (orientation-memory-concentrated test) 71/271 (26%) had +ve OMC 35/271 (13%) had +ve CAM 16 had both +ve OMC and CAM No details of definition criteria for delirium and cognitive impairment
No gold standard applied
Assessing cognition in elderly patients presenting to the emergency. Hare M, Wynaden D, McGowan S et al 2008 Australia N=28, Patients aged greater than 65 years. Prospective convenience sample study AMT (abbreviated mental test) assessment of cognitive deficit and CAM in all patients who were positive for a cognitive deficit as measured by AMT 9/22 (41%) patients had an AMT <8 1/9 of these patients had delirium diagnosed using the CAM Small sample size
Only nine patients had the CAM assessment
No assessment of either AMT or CAM as a diagnostic tool
Delirium in older emergency department patients: recognition, risk factors, and psychomotor subtypes. Han JH, Zimmerman EE, Cutler N. 2009 USA 303 ED patients aged >65 years
Non-English speakers and those with dementia excluded		 Prospective convenience sample CAM-ICU (confusional assessment method-ICU) performed at 0 and 3 h of presentation 25/303 identified as having delirium Convenience sampling
CAM-ICU not compared with other diagnostic tools
Four sensitive screening tools to detect cognitive dysfunction in geriatric emergency department patients: brief Alzheimer's Screen, Short Blessed Test, Ottawa 3DY, and the caregiver-completed AD8. Carpenter CR, Bassett ER, Fischer GM et al. 2010 USA 163 ED patients >65 years who were English speakers, non-critically ill and without sedation Prospective convenience sample Performance of the Ottawa 3DY (O3DY), CAM-ICU, Brief Alzheimer's Screen (BAS), short blessed test (SBT) and caregiver AD8 (cAD8) mini-mental status examination (MMSE) score ≤23 as the gold standard Cognitive dysfunction was present in 60/163 (37%) according to the MMSE Sensitivity O3DY 95% (85–99) Sensitivity BAS 95% (88–98) Sensitivity SBT 95% (88–98) Sensitivity cAD8 83% (71–91) Specificity O3DY 51% (46–53) Specificity BAS 52% (48–54) Specificity SBT 65% (61–67) Specificity cAD8 63% (55–68) Convenience sample
The Clinical Utility of the Clock Drawing Test in Detecting Delirium in Older Emergency Department Patients. Emerson G, Carlson R, Nicolson SE et al. 2014 USA 406 ED patients >65 years Prospective convenience sample Clock face drawing scored by the emergency physician using the CAMDEX or Schulman scoring methods Sensitivity Shulman<5 100% Sensitivity Shulman <1 62% Sensitivity CAMDEX <3 94% Sensitivity CAMDEX <1 64% Specificity Shulman <5 20% Specificity Shulman <1 78% Specificity CAMDEX <3 43% Specify CAMDEX <1 78% Convenience sampling
Same cohort as Han et al7 2013
Screening, detection and management of delirium in the emergency department – a pilot study on the feasibility of a new algorithm for use in older emergency department patients: Grossmann F, Hasemann W, Graber A, et al. 2014 Switzerland 207 ED patients aged >65 years Before–after study Identification of delirium with mCAM (modified confusional assessment method) The gold standard was the emergency physician's assessment Delirium diagnosed in 16% of patients Populations were analysed before and after an educational intervention; however, the sensitivity of physician mCAM-recognised delirium was only 0.40 postintervention and specificity 0.94 Emergency physicians did not assess all the patients, but only those who the research assistants thought had delirium
Prevalence and detection of delirium in elderly emergency department patients. Elie M, Rousseau F, Cole M, et al. 2000 Canada 447 ED patients >70 years with four or fewer incorrect answers with the Short Portable
Mental Status Questionnaire		 Prospective cohort study Prevalence of confusion assessment method (CAM) score of 4 or 5 out of 5 Prevalence of delirium 28/447 (9.6%, 95% CI 6.9% to 12.4%) Study reports the prevalence of CAM-diagnosed delirium. No comparison with other diagnostic tools
Diagnosing delirium in older emergency department patients: validity and reliability of the delirium triage screen and the brief confusion assessment method. Han JH, Wilson A, Vasilevskis EE, et al. 2013 USA 406 ED patients >65 years who had been in the ED for <12 h and not in a hallway bed Prospective convenience sample Performance of the delirium triage score (DTS) and brief confusion assessment method (bCAM) A consultant psychiatrist assessed for delirium as the gold standard Delirium diagnosed in 50/406 (12%) patients by the psychiatrist Physician administered DTS Sensitivity 98% (90–100) Specificity 55% (50–60) Physician administered bCAM Sensitivity 84% (72–92) Specificity 96% (93–97) Convenience sample
Delirium risk prediction, healthcare use and mortality of elderly adults in the emergency department. Kennedy M, Enander RA, Tadiri SP, et al. 2014 USA 676 ED patients aged >65 years who had been in the ED for <4 h and spoke English Prospective convenience sample Derivation of a clinical model to predict delirium (as diagnosed by CAM) Age, dementia, prior stroke, respiratory rate >20, suspected infection and diagnosis of intracranial haemorrhage C statistic 0.79 (0.73–0.84) Well conducted
This was a trauma centre, which may explain the presence of intracranial haemorrhage in the model
Validation of the confusion assessment method for the intensive care unit in older emergency department patients. Han JH, Wilson A, Graves AJ, et al. 2014 USA 406 ED patients aged >65 years who had been in the ED for <12 h and not in a hallway bed Prospective convenience sample Performance of physician-administered CAM-ICU A consultant psychiatrist assessed for delirium as the gold standard Sensitivity 72% Specificity 96% Convenience sampling
Same cohort as Han et al 2013
Aspects and assessment of delirium in old age. First data from a German interdisciplinary emergency department. Singler K, Thiem U, Christ M, et al. 2014 Germany 133 consecutive ED patients aged >75 years who spoke German and were in a stable condition Prospective cohort Prevalence of CAM-diagnosed cognitive impairment 19/133 (14%) No comparison of the CAM score to another diagnostic tool
The diagnostic performance of the richmond agitation sedation scale for detecting delirium in older emergency department patients. Han JH, Vasilevskis EE, Schnelle JF, et al. 2015 USA 406 ED patients aged >65 years who had been in the ED for <12 h and not in a hallway bed Prospective convenience sample Performance of physician-administered Richmond agitation sedation score (RASS) diagnosing delirium A consultant psychiatrist assessed for delirium as the gold standard RASS either >0 or <0 as a +ve score Sensitivity 82% Specificity 85% Convenience sampling
Same cohort as Han et al. 2013
Prospective validation of the Ottawa 3DY scale by geriatric emergency management nurses to identify impaired cognition in older emergency department patients. Wilding L, Eagles D, Molnar F, et al. 2016 Canada 238 ED patients >75 without history of cognitive impairment Prospective convenience sample O3DY and animal fluency test (AFT) MMSE was the gold standard to diagnose cognitive impairment (<25) O3DY sensitivity 94% (78–99) O3DY specificity 73% (66–79) AFT sensitivity 91% (74–98) AFT specificity 39% (33–46) Convenience sampling
Author Commentary:
Sensitivity of delirium detection in the ED is variable. Various factors could cause this, for instance, patients presenting with hypoactive delirium are difficult to identify. The ideal ED screening instrument would be time efficient and require minimal operator training while providing high levels of specificity to ensure accurate exclusion of disease. Many screening tools have been studied including the confusional assessment method, which can take less than 5 min to complete. The abbreviated mental test is reported to take 3 min, and the Ottawa 3DY, less than 5 min. The CAM-ICU has been documented to take less than 1 min.
Bottom Line:
The abbreviated mental test score has been largely adopted as a delirium screening tool within UK hospitals and there is little evidence in the literature evaluating its use within the ED setting.
References:
  1. Monett J, Galbaud du Fort G, Fung SH, et al. . Evaluation of the confusion assessment method (CAM) as a screening tool for
  2. Hustey FM, Meldon SW, Smith MD, et al. . The effect of mental status screening on the care of elderly emergency
  3. Hare M, Wynaden D, McGowan S et al. Assessing cognition in elderly patients presenting to the emergency.
  4. Han JH, Zimmerman EE, Cutler N.. Delirium in older emergency department patients: recognition, risk factors, and psychomotor subtypes.
  5. Carpenter CR, Bassett ER, Fischer GM et al.. Four sensitive screening tools to detect cognitive dysfunction in geriatric emergency department patients: brief Alzheimer's Screen, Short Blessed Test, Ottawa 3DY, and the caregiver-completed AD8.
  6. Emerson G, Carlson R, Nicolson SE et al. . The Clinical Utility of the Clock Drawing Test in Detecting Delirium in Older Emergency Department Patients.
  7. Grossmann F, Hasemann W, Graber A, et al.. Screening, detection and management of delirium in the emergency department – a pilot study on the feasibility of a new algorithm for use in older emergency department patients:
  8. Elie M, Rousseau F, Cole M, et al. . Prevalence and detection of delirium in elderly emergency department patients.
  9. Han JH, Wilson A, Vasilevskis EE, et al. . Diagnosing delirium in older emergency department patients: validity and reliability of the delirium triage screen and the brief confusion assessment method.
  10. Kennedy M, Enander RA, Tadiri SP, et al. . Delirium risk prediction, healthcare use and mortality of elderly adults in the emergency department.
  11. Han JH, Wilson A, Graves AJ, et al.. Validation of the confusion assessment method for the intensive care unit in older emergency department patients.
  12. Singler K, Thiem U, Christ M, et al. . Aspects and assessment of delirium in old age. First data from a German interdisciplinary emergency department.
  13. Han JH, Vasilevskis EE, Schnelle JF, et al. . The diagnostic performance of the richmond agitation sedation scale for detecting delirium in older emergency department patients.
  14. Wilding L, Eagles D, Molnar F, et al. . Prospective validation of the Ottawa 3DY scale by geriatric emergency management nurses to identify impaired cognition in older emergency department patients.