American Society of Anesthesiologists Staging

Issues of Concern

A concern commonly encountered with assigning ASA scores is that there is often significant variation in how providers classify the same patient. Assessment and evaluation of patients can vary between providers in different specialties compared to the staff anesthesiologists, causing a significant increase in standard deviation even when participants had access to the same medical records. This situation proves to be a problem that is more prevalent outside the specific specialty, posing a potential threat to the success of healthcare teams composed of multiple providers from multiple specialties.[2] Studies have shown that adding examples for each respective score aided anesthesia and non-anesthesia providers in accurately classifying patients.[3] In 2014, the ASA provided access to a catalog of examples for simplification when assigning an ASA score, increasing accuracy and decreasing inter-observer variation.[4]

Clinical Significance

Using the ASA Physical Status Classification System to evaluate and prepare for possible adverse events remains 1 of the most widely used pre-operative screening methods for all providers worldwide[5]. The ASA Physical Status Classification System has been shown to predict the frequency of perioperative morbidity and mortality. Research has shown that the implementation of the classification system correctly predicts the frequency and severity of adverse events, which improves patient outcomes[5]. The ASA score is assigned based on a patient's presence and severity of systemic disease. Examples of some disease processes commonly encountered are listed with their respective score assignment. The letter E may be added to any category (ie, ASA IIE) to denote an emergency.

• ASA I: a healthy patient with no evidence of active or chronic disease processes, non-smoker, and BMI under 30.[6]
• ASA II: a patient with mild systemic disease. Examples include a patient who has no functional limitations and well-controlled disease, BMI under 35, is a social drinker or smokes cigarettes, or has well-controlled hypertension.[6]
• ASA III: a patient with severe systemic disease that is not life-threatening. Examples include patients with functional limitations as a result of systemic disease, poorly treated hypertension or diabetes, renal failure, BMI greater than 40, stable angina, or pacemaker.[6]
• ASA IV: A patient with severe systemic disease that is a constant threat to life. Examples include patients with functional limitations as a result of severe systemic disease such as unstable angina, poorly controlled COPD, symptomatic CHF, recent MI, or stroke less than 3 months prior.[6]
• ASA V: A moribund patient who is not expected to survive without surgical intervention. Examples include ruptured abdominal aortic aneurysm, massive trauma, or extensive intracranial bleeding with mass effect.[6]
• ASA VI: A patient declared brain-dead who is a transplant donor. 

Nursing, Allied Health, and Interprofessional Team Interventions

During perioperative care, the actions of the nurse contribute not only to patient outcomes but also to preventing and monitoring adverse events. Nurses should not only understand what may place a patient in a specified category but also should be able to interpret any complications each patient may face as a result of their assigned score and/or illness. With the education and utilization of the ASA Physical Status Classification System, a nurse can intervene when necessary and collaborate with other providers to ensure the best possible clinical outcome. Interpretations of a patient's categorization are important to nursing staff as they use the complete clinical evaluation to guide their patient monitoring and communicate effectively with other anesthesia care team members.[7] This categorization also applies to pharmacists and other health professionals who may be contributing to a patient's care plan. Studies have shown that interprofessional team communication failures continue to be a leading cause of adverse outcomes.[8] Therefore, an increased effort toward improving collaboration between nurses and physician anesthesia providers ultimately improves patient care.[9][10]

Nursing, Allied Health, and Interprofessional Team Monitoring

Nurses provide pre- and postoperative care in addition to monitoring changes in the anesthetic plan. As stated, nurses must understand the ASA Physical Classification System and what conditions patients may have that might increase their chance of adverse outcomes during the perioperative period. Nurses play a vital role in perioperative care as they closely monitor patients in the PACU for possible adverse outcomes. Nurses should integrate the patient's ASA categorization into their perioperative care plan and monitor for any adverse outcomes that may be associated with their illness.