The American Society of Anesthesiology (ASA) established a physical status classification. This classification is an instrument used to categorize the physical condition of patients before being treated. This ASA classification was developed to provide common terminology and to facilitate the collection of statistical data.
This classification was originally established by Saklad in 1941. But in 1961 Dripps modified the system and these modifications were adopted by the American Society of Anesthesiology in 1962 and are the system in use today.
Saklad’s first classification in 1941 had 6 original categories and assessed the relationship between surgical risk and physical condition. The 6 categories were:
- Class 1: without organic pathology or patients in whom the pathological process was localized and did not cause any systemic injury.
- Class 2: a moderate but definite systemic injury, caused by the condition that was intervened surgically or that was caused by other previous pathological processes.
- Class 3: Severe systemic injury of any cause or causes.
- Class 4: Extreme systemic disorders that were made life threatening regardless of treatment.
- Class 5: Class 1 or class 2 emergencies.
- Class 6: Class 3 or class 4 emergencies.
The following Dripps classification in 1961 had 5 classes:
- Class 1: a normal health of the patient.
- Class 2: a patient with a mild systemic pathology.
- Class 3: a patient with a severe systemic pathology that did not mean disability.
- Class 4: a patient with a disease with systemic disability.
- Class 5: a dying patient who has no expectation of survival in more than 24 hours with or without operation.
The classification current of ASA of the state fípsycho established in 1962 is based on 5 groups:
- ASA I: a patient in normal, healthy health.
- ASA II: a patient with a mild systemic disease and no functional limitation. Two smokers, patients with controlled arterial hypertension (HT) or with controlled diabetes mellitus (DM) may also be in this category of ASA.
- ASA III: a patient with a severe systemic disease who exhibits limited activity but no disability. Examples in this category would be a patient with ischemic heart disease (angina or infarction) with tolerance to exertion and chronic bronchitis with dyspnea on exertion.
- ASA IV: a patient with a disabling systemic disease with a continuing threat of life. ASA IV patients could be those with chronic bronchitis with dyspnea at rest and hemodialysis patients awaiting kidney transplantation.
- ASA V: a dying patient who has no expectation of survival in more than 24 hours with or without operation.
It is important to recognize the physical condition of the patient we have to treat and intervene in order to anticipate possible complications and estimate the benefit-risk ratio in the treatment to be performed.
