The Confusion Assessment Method (CAM) is a diagnostic tool used to identify delirium. Delirium is a serious disturbance in mental abilities that results in confused thinking and reduced awareness of the environment. It is a common and often underdiagnosed condition, especially in hospitalized patients, particularly the elderly.
Developed by Dr. Sharon Inouye and colleagues, the CAM is designed to be a quick, user-friendly method to improve the identification and recognition of delirium. It is based on the Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria and consists of an assessment of four key features:
- Acute Onset and Fluctuating Course: This is usually evidenced by a change in mental status from the patient’s baseline, with the confusion tending to come and go or change in severity.
- Inattention: This is the hallmark feature of delirium and involves the patient having difficulty focusing attention, being easily distractible, or having difficulty keeping track of what is being said.
- Disorganized Thinking: This can manifest as rambling or irrelevant conversation, unclear or illogical flow of ideas, or unpredictable switching from subject to subject.
- Altered Level of Consciousness: This can range from hyperalert to drowsy, lethargic, or difficult to arouse.
For the CAM to indicate delirium, both Feature 1 and Feature 2 must be present, along with either Feature 3 or Feature 4.
The CAM is not a standalone diagnostic tool but rather part of a comprehensive assessment. It is widely used in various healthcare settings due to its simplicity, brevity, and high sensitivity and specificity for delirium when used by trained clinicians. Early identification of delirium is crucial, as it is often a symptom of another, potentially serious, underlying medical condition. Prompt diagnosis and management of delirium can significantly improve patient outcomes.