What is the mnemonic for assessing the level of consciousness in an unconscious patient?

AVPU: The Standard Mnemonic for Assessing Level of Consciousness in Unconscious Patients

The AVPU scale (Alert, Verbal, Pain, Unresponsive) is the recommended mnemonic for rapidly assessing level of consciousness in unconscious patients, providing a simple yet effective framework for initial neurological assessment. 1

Understanding the AVPU Scale

AVPU stands for:

• A - Alert: Patient is fully awake, oriented, and responsive
• V - Verbal: Patient responds to verbal stimuli (opens eyes or makes sounds when spoken to)
• P - Pain: Patient responds only to painful stimuli
• U - Unresponsive: Patient shows no response to any stimuli, including pain

This standardized assessment tool is endorsed by international resuscitation committees and is particularly valuable in emergency situations where rapid assessment is critical 1.

Clinical Application of AVPU

When assessing an unconscious patient:

1. Start with verbal stimuli: Speak to the patient in a normal to loud voice
2. Progress to painful stimuli if needed: Apply a standardized painful stimulus (such as trapezius squeeze or sternal rub) if no response to verbal stimuli
3. Document the highest level of response: Record the best response observed

The AVPU scale correlates with mortality outcomes, with 48-hour mortality rates of approximately 1.1% for Alert, 4.3% for Verbal, 17.9% for Pain, and 53.2% for Unresponsive patients 2.

Correlation with Glasgow Coma Scale (GCS)

AVPU correlates with GCS scores as follows 3, 2:

• Alert: GCS 14-15
• Verbal: GCS 11-13
• Pain: GCS 7-10
• Unresponsive: GCS 3-6

This correlation allows healthcare providers to quickly estimate GCS ranges based on AVPU assessment, which is particularly valuable in pre-hospital settings.

Alternative Consciousness Assessment Mnemonics

While AVPU is the primary recommended mnemonic, another similar scale is:

• ACDU: Alert, Confused, Drowsy, Unresponsive 1

The Glasgow Coma Scale (GCS) provides a more detailed assessment but is more complex to apply rapidly in emergency situations.

Advantages and Limitations

Advantages:

• Simple to remember and apply
• Requires minimal training
• Standardized across emergency care settings
• Correlates with mortality outcomes
• Discriminative ability comparable to GCS (AUC 79.7% vs 81.5% for GCS) 2

Limitations:

• Lower accuracy in distinguishing between Alert and Verbal responses (sensitivity 0.81) 4
• Less detailed than GCS for neurological assessment
• May have lower specificity overall (0.74) 4

Important Considerations

• AVPU is most useful for initial rapid assessment and serial monitoring
• For patients with suspected head injury, more detailed neurological assessment tools should follow the initial AVPU assessment 1
• The assessment should be repeated regularly to monitor changes in neurological status
• Deterioration in AVPU score should trigger immediate medical intervention

AVPU provides a standardized, efficient framework for assessing consciousness levels in unconscious patients, making it an essential tool in emergency medicine and critical care settings.