Delirium Assessments
Delirium assessments are often confused with sedation/agitation scores such as the SAS or RASS. However, these scores only test one component of delirium.Two validated delirium assessments are commonly used: CAM-ICU (Confusion Assessment Method for the Intensive Care Unit) and ICDSC (Intensive Care Delirium Screening Checklist).
There has been great debate over which tool is better to evaluate delirium in critically ill patients. The CAM-ICU was originally validated by Ely et al. showing a high sensitivity (93%) and specificity for (89%) for the diagnosis of delirium. Similar sensitivity and specificity were noted by Lin et al. when the CAM-ICU was validated in mechanically ventilated patients. The ICDSC was validated by Bergeron N et al. in ICU patients showing higher sensitivity (99%) compared to the CAM-ICU but a lower specificity (64%).
Both tools have their own personal advantages:
There has been great debate over which tool is better to evaluate delirium in critically ill patients. The CAM-ICU was originally validated by Ely et al. showing a high sensitivity (93%) and specificity for (89%) for the diagnosis of delirium. Similar sensitivity and specificity were noted by Lin et al. when the CAM-ICU was validated in mechanically ventilated patients. The ICDSC was validated by Bergeron N et al. in ICU patients showing higher sensitivity (99%) compared to the CAM-ICU but a lower specificity (64%).
Both tools have their own personal advantages:
CAM-ICU
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ICDSC
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A recent unblinded single-centre prospective cohort study by Tomasi et al. compared the agreement between the CAM-ICU and ICDSC and the associations with outcomes of general ICU patients.
- There was an agreement between the two scales in 147/162 patients, however the agreement was statistically moderate (K= 0.55)
- The CAM-ICU positive delirium patients were more likely to have an increased length of stay and hospital mortality compared to those diagnosed with the ICDSC.
Authors Conclusion: The CAM-ICU is a better predictor of outcome when compared to ICDSC.
Currently, there is insufficient evidence to make a claim for using one tool over the other. Further investigation is required. It is more essential to use either of the validated tools to assess delirium. This website outlines the procedures for both assessment methods and provides you with the tools needed to implement either delirium scoring system at your facility.
- Study population: 162 ICU patients (Included: >18 years of age; Exluded: patients with a RASS score of -4 or -5 due to lack of responsiveness and patients with neurological deficits)
- Intervention: Patients were evaluated for diagnosis of delirium using the CAM-ICU and the ICDSC twice daily while in the ICU by a single unblinded assessor. (Randomization was not required since all patients were tested using both tools)
- Results:
- There was an agreement between the two scales in 147/162 patients, however the agreement was statistically moderate (K= 0.55)
- The CAM-ICU positive delirium patients were more likely to have an increased length of stay and hospital mortality compared to those diagnosed with the ICDSC.
Authors Conclusion: The CAM-ICU is a better predictor of outcome when compared to ICDSC.
- Limitations: This trial had several limitations including very small sample size and relatively low delirium rates. Having an unblinded assessor performing both assessments could have resulted in internal bias. There was also a lack of control, such as a DSM-IV screening for delirium. This resulted in a skewed statistical analysis that seemed to favour the CAM-ICU method.
Currently, there is insufficient evidence to make a claim for using one tool over the other. Further investigation is required. It is more essential to use either of the validated tools to assess delirium. This website outlines the procedures for both assessment methods and provides you with the tools needed to implement either delirium scoring system at your facility.
References:
- Ely W et al. Evaluation of delirium in critically ill patients: validation of Confussion Assessment Method for the Intensive Care Unit (CAM-ICU). Crit Care Med. 2001;33:1726-31.
- Lin SM et al. The impact of delirium on the survival of mechanically ventilated patients . Crit Care Med. 2004;32:2254-9.
- Bergeron N et al. Intensive Care Delirium Screening Checklist: evaluation of a new screening tool. Intensive Care Med. 2001;27:859-64.
- Tomasi CD et al. Comparison of CAM-ICU and ICDSC for the detection of delirium in critically ill patients focusing on relevant clinical outcomes. J of Crit Care. 2002; 27:212-217.