Well, almost absolutely nothing. The ASA classification of physical status has been around for decades. Anesthesiologists rank patients every day based on the this system to determine their health risks. Ever since anesthesiology residency I've been doing mental categorization in my head as I talk to my patients to classify them into one of the six levels of the ASA scale. I would present the patients to my attending as a so and so ASA Class X patient presenting for this surgery. Every single anesthesia record has an area where we are supposed to document the ASA physical status of that patient. As you can see, the ASA classification is pretty pervasive in anesthesiology. But why do we do it?
When I went through medical school, I must have presented hundreds of patients to dozens of attendings and not once did I preface my patient with an ASA classification. No other medical fields use this scale to describe their patients. Yet as soon as anesthesiology residency started we were all indoctrinated on the use of this system. If you look at the scale, it is immediately obvious why I don't think it is useful. The ASA classification is just too vague. Daily I rack my head trying to decide if a patient is an ASA 1 or 2, or maybe even a 3. And does any of this matter in how I anesthetize my patient?
In reality 95% of our patients are ASA 1-3 which makes it harder to decide which one a patient belongs to. Let me give you some examples of the difficulty of pigeon-holing countless patients into these few groups.
A 24 year old morbidly obese patient for carpal tunnel repair. The patient has no other medical problems. No hypertension, diabetes, sleep apnea. She is physically active. Is the patient an ASA 1 or 2? Or is she a 3? What if the surgery is more complicated, like spinal fusion? Does that change the ASA class?
A 75 year old male who is physically active, plays tennis three times a week. No history of hypertension, coronary artery disease, or pulmonary disease. Is the patient a 2 or a 3? Or maybe he is a 1? What if the patient is 85 years old who plays golf several times a week and again has no apparent cardiovascular disease. Is an 85 year old an automatic 3?
A 34 year old patient with complex regional pain syndrome who is on massive amounts of narcotics to control her pain. She is poorly functional because of her severe problems. She has no other systemic medical disease. Is the patient a 1 despite her debilitating pain but no systemic illnesses?
Does a patient with diabetes an automatic ASA 3 as some people advocate? What if the patient is 18 years old? If then you decide to make the patient an ASA 2 because of age, when do you advance the patient up to a 3. 30 years old? 50 years old?
I could go on and on about how confusing this system is. The funny thing is the ASA classification isn't really necessary. I can only think of two scenerios where having the ASA classification is useful. One is in research where it is helpful to categorize patients by their ASA status. But since the scale is so subjective, I think this adds little scientific objectivity to a study.
The second case where the ASA classification is useful is when I'm billing the insurance company. An ASA 3 or higher usually gets a higher reimbursement, or a reimbursement at all, because of the supposedly increased complexity of an ASA 3. I've sometimes been advised by our billing company to find ANY potential reasons for upping the severity of patient's illness so that we are more likely to collect payment. However other physicians like hospitalists and internists are able to document a higher complexity patient to receive better reimbursements. Why can't anesthesiologists do the same thing?
Other than that I can't think of any good reasons to keep the ASA physical status classification. It is an antiquated method of evaluating a patient that really has no place in a modern H+P. If you're going to present a patient to me in preop, just give me the facts. Don't skew my assessment of a patient by prefacing it with your opinion of what ASA level he is. I'm a busy doctor. I don't even want to waste ten seconds pondering what ASA class a patient belongs to. I'll give my anesthesia based on the patient's various diseases and how it affects him as a whole, not on whether he is an ASA 2 or 3. Let's just get rid of this system and stop wasting time pondering if they should have invented an ASA 2- or 3+ that would more properly fit my patient's problems. I'm pretty sure not having an ASA classification will not affect my patients' surgical outcomes.