CAM Delirium Screening
Also known as: CAM, Confusion Assessment Method, Delirium Detection Tool
The Confusion Assessment Method (CAM) is a widely validated diagnostic tool developed by Sharon K. Inouye and colleagues to detect delirium in hospitalized patients. Delirium is an acute change in mental status characterized by inattention, disorganized thinking, and altered consciousness that is often missed in clinical practice. The CAM provides a standardized, reproducible method for identifying delirium, which is associated with increased morbidity, mortality, and hospital costs.
Key highlights
- High sensitivity and specificity for detecting delirium compared to clinical judgment alone
- Brief to administer, requiring only minutes of bedside observation and interview
- Validated across diverse patient populations and care settings
- Based on phenomenological features rather than etiology, allowing identification regardless of underlying cause
- CAM-ICU variant enables detection in non-communicative, mechanically ventilated patients
- Excellent inter-rater reliability with proper training
Intuition
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How it works
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When to use it
Screen all hospitalized patients for delirium, especially elderly patients, those with severe illness, post-operative patients, and patients taking medications affecting cognition. Apply serially to detect new-onset delirium. Use in acute care, intensive care, and long-term care settings. The CAM-ICU variant is used specifically for mechanically ventilated patients.
Strengths & limitations
- High sensitivity and specificity for detecting delirium compared to clinical judgment alone
- Brief to administer, requiring only minutes of bedside observation and interview
- Validated across diverse patient populations and care settings
- Based on phenomenological features rather than etiology, allowing identification regardless of underlying cause
- CAM-ICU variant enables detection in non-communicative, mechanically ventilated patients
- Excellent inter-rater reliability with proper training
- Requires clinical judgment to assess some features such as disorganized thinking
- May miss hypoactive delirium, which is less obvious than hyperactive delirium
- Does not identify delirium etiology, requiring additional investigation
- Accuracy may be reduced in patients with underlying dementia or severe baseline cognitive impairment
- Requires adequate patient cooperation and communication ability
Common pitfalls
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Applications
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Frequently asked
What is the difference between delirium and dementia?
Delirium is acute, with sudden onset and fluctuating course, often reversible if underlying cause is treated. Dementia is chronic, insidious in onset, and progressive. Patients can have both delirium and dementia concurrently. Baseline cognitive function should be known to identify acute delirium.
How reliable is the CAM for delirium diagnosis?
The CAM has high sensitivity (94-100 percent) and specificity (90-95 percent) when used by trained clinicians. Proper training is essential, particularly for assessing disorganized thinking and fluctuation.
What should be done if CAM screening is positive for delirium?
Positive CAM warrants investigation for delirium causes including infection, medications, metabolic abnormalities, hypoxia, pain, and urinary retention. Management addresses underlying causes and provides supportive care and environmental modifications.
Can the CAM detect hypoactive delirium?
Yes, though hypoactive delirium can be missed because it manifests as lethargy rather than agitation. Careful assessment of attention and fluctuation helps identify hypoactive presentations, which carry higher mortality than hyperactive forms.
Sources
- 1.Inouye, S. K., van Dyck, C. H., Alessi, C. A., Balkin, S., Siegal, A. P., & Horwitz, R. I. (1990). Clarifying confusion: The Confusion Assessment Method. A new method for detection of delirium. Annals of Internal Medicine, 113(12), 941-948.
- 2.Ely, E. W., Inouye, S. K., Bernard, G. R., et al. (2001). Delirium in mechanically ventilated patients: validity and reliability of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). JAMA, 286(21), 2703-2710.
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Cite this page
ScholarGate. (2026, June 3). CAM Delirium Screening. ScholarGate. https://scholargate.app/nursing/cam-delirium-screening