Surgery / Anesthesia

ASA Physical Status Classification

Classifies a patient's pre-operative physical status, used to communicate baseline health and anticipate perioperative risk.

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What is ASA Physical Status?

Developed by the American Society of Anesthesiologists, this classification communicates a patient's baseline systemic health before anesthesia and surgery, independent of the procedure itself.

The Six Classes

Class	Description
I	Normal healthy patient
II	Mild systemic disease
III	Severe systemic disease with functional limitation
IV	Severe systemic disease, constant threat to life
V	Moribund, not expected to survive without the operation
VI	Declared brain-dead, organ donor

The "E" Suffix

Adding "E" (e.g. ASA IIIE) denotes an emergency operation, which carries higher risk than the same class performed electively.

References

American Society of Anesthesiologists. ASA Physical Status Classification System.

Frequently Asked Questions

Does ASA class predict surgical risk by itself?

It correlates with perioperative risk but reflects baseline health, not the specific procedure's risk — it's typically combined with procedure-specific factors.

Who assigns the ASA class?

Typically the anesthesiologist, during the pre-operative assessment.

Is ASA VI common?

No — it's rare, applying specifically to a declared brain-dead patient undergoing organ procurement.