Sometimes treating the symptoms is all we can do, such as pain management. We as EMS providers cannot set or reduce fractures, but we can sure make the patient feel better as well as treating the pain of an acute abdomen. I know this is not the focus of the post, but I just wanted to throw out there we generally DO treat symptoms and it is usually not a bad thing. 
With fentanyl (or even other less effective and less safe pain medicines), we can consistently produce a significant change in the surrogate end point (the level of pain). This is a good thing, because when given by a competent provider, it should not harm the patient. Even the rare cases of harm are outweighed by the benefit to the patient. The goal of our treatment is the surrogate end point, as long as we do not make things worse.
As for requiring a competent provider? There is not any good reason to encourage treatments that do not require a competent provider.
On the other hand, with epinephrine, we can only produce a change in the surrogate end point of the presence of a pulse (ROSC - Return Of Spontaneous Circulation). This is not a good thing, because it does appear to harm the patient. Still, the goal of our treatment is the surrogate end point, as long as we do not make things worse.
Almost all of the things we want to avoid doing to the heart, come in the syringe marked epinephrine.
Do we want to increase the oxygen demand in a heart that may already be hypoxic, ischemic, or infarcted?
A heart that may have arrested due to hypoxia, ischemia, or infarction?
A heart that may have experienced arrhythmia due to hypoxia, ischemia, or infarction?
One of the worst antiarrhythmic medications is epinephrine. Epinephrine is proarrhythmic. Epinephrine causes arrhythmias.
Perhaps the best antiarrhythmic medication we have is oxygen, but epinephrine can increase the demand for oxygen even beyond what can be delivered to the heart by work by working the heart harder. This increases the demand for oxygen still more.
This is bad. This violates that very complex rule of medicine, Oxygen is good.
There are some revisions to that rule, but one revision I do not expect to see is, Increasing oxygen demand, beyond what can be provided, is good.
Increasing oxygen demand, beyond what can be provided, also goes by another name. This name is a catchy one that is most often misused on TV and in the movies. That name is Shock. Most medical people seem to agree that shock is not a good thing. Most post-resuscitation care is focused on preventing/reversing shock, but the administration of epinephrine may be the biggest cause of post-resuscitation shock.
Do we have any reason to believe that real survivors, who received epinephrine, would not have survived without epinephrine?
That is the most important question, isn't it? Real survivors, as in people who eventually leave the hospital with minimal to no brain damage - neurologically intact.
The answer is, No.
There is no evidence that patients resuscitated after the administration of epinephrine would not have been resuscitated with only BLS treatment.
There is no evidence that patients resuscitated after the administration of epinephrine have better outcomes because of epinephrine. Zero evidence.
Imagine that you are having a heart attack. The heart attack brings on a cardiac arrest.
You are not having a good day.
You are resuscitated, but before resuscitation you were given epinephrine. The epinephrine is acting as if it is Gunnery Sergeant Hartman and you are Private Pyle. He wants you to get up and run, run faster, and keep running.
That's what epinephrine does.
Does it care that you were just dead?
Does it care that post-resuscitation care is largely about reversing the effects of epinephrine?
Even in standard doses, this may be the worst medicine you could give to a person having a heart attack, but we increase the dose to ridiculous proportions. We have taken homeopathy, flipped it on its head, and thrown in a bit of Nietzsche. If this doesn't kill him nothing will. MwaHaHaHaHa
It is really cool to get a pulse back.
So what if the drug that seems to bring the pulse back also seems to make it go away. We already dropped the patient off at the hospital. If they can't treat a little iatrogenic shock, maybe they should consider a different line of work. Yeah! That's the ticket. The hospital did it. It's the hospital's fault. Killjoys!
What is the most promising post-resuscitation care? If you pray at the Church of Epinephrine, the most consistent treatment would be something along the lines of stress testing. Of course, nobody does stress testing with 1 mg of epinephrine in a real live person, because that might be expected to lead to murder charges. We only do this to people, who are already dead. Law For Dummies 101 - you can't kill a person, who is already dead.
Even epinephrine light (dopamine) and epinephrine extra light (dobutamine) are used with a lot of caution in the live patient with a possible heart attack.
Perhaps the AHA has some naturopaths in their midst. Naturopaths will tell you that their treatments are safe, because they are naturally occurring. Epinephrine is a hormone that naturally occurs in the body. So is potassium, which is used to execute people by lethal injection. Natural does not mean safe. Malaria is natural and kills over a million people a year. Natural does not mean good.
With few exceptions, like, antibiotics, medications are usually not able to cure but treat effects and symptoms. Expecting a medication like epi to not only obtain ROSC but heal their heart or any of the multiple causes of cardiac arrest is truly expecting the ridiculous. We usually cannot treat or heal the cause of SCA until we get ROSC. That is the first step or priority. 
I do not expect epinephrine to heal the heart. Epinephrine is toxic to the heart.
The priority is not to make things worse. This should be pretty easy to accomplish with a dead patient. However, we do not have any evidence that we are not making things worse by giving epinephrine.
These are from the EpiPen autoinjector label:
Large doses or accidental intravenous injection of epinephrine may result in cerebral hemorrhage due to sharp rise in blood pressure. DO NOT INJECT INTRAVENOUSLY. Rapidly acting vasodilators can counteract the marked pressor effects of epinephrine. 
ADVERSE REACTIONS Side effects of epinephrine may include palpitations, tachycardia, sweating, nausea and vomiting, respiratory difficulty, pallor, dizziness, weakness, tremor, headache, apprehension, nervousness and anxiety. Cardiac arrhythmias may follow administration of epinephrine.
OVERDOSAGE Overdosage or inadvertent intravascular injection of epinephrine may cause cerebral hemorrhage resulting from a sharp rise in blood pressure. Fatalities may also result from pulmonary edema because of peripheral vascular constriction together with cardiac stimulation. 
Epinephrine is ordinarily administered with extreme caution to patients who have heart disease. Use of epinephrine with drugs that may sensitize the heart to arrhythmias, e.g., digitalis, mercurial diuretics, or quinidine, ordinarily is not recommended. Anginal pain may be induced by epinephrine in patients with coronary insufficiency.
The effects of epinephrine may be potentiated by tricyclic antidepressants and monoamine oxidase inhibitors.
Some patients may be at greater risk of developing adverse reactions after epinephrine administration. These include: hyperthyroid individuals, individuals with cardiovascular disease, hypertension, or diabetes, elderly individuals, pregnant women, pediatric patients under 30 kg (66 lbs.) body weight using EpiPen, and pediatric patients under 15 kg (33 lbs.) body weight using EpiPen Jr. 
While these are from the EpiPen label (300 mcg of 1:1,000 epinephrine for IM injection), not the 1,000 mcg of 1:10,000 epinephrine for IV injection in dead people, the warnings make it pretty clear - this is a dangerous drug in living human beings. It should only be given when the benefits outweigh the risks, such as in anaphylaxis. A dead patient, who is expected to not be dead any more, is probably a poor choice for this treatment.
The only reason that the risk/benefit profile is considered to be positive, is that there is the presumption that patients resuscitated after receiving epinephrine, would not be resuscitated unless they received epinephrine.
There is no evidence to support the hypothesis that epinephrine improves anything other than the speed of return of a pulse. How impatient are we, that we are willing to compromise survival, just for this quick fix?
I do agree science is always changing, and we want it to, because that is how we advance forward. We need to continually ask questions and challenge current practices. I just think that expecting for a miricle drug to treat all the causes of SCA will never happen. 
If we are going to use any treatment, BLS or ALS, we need to demand evidence that the treatment provides more benefit than harm. In cardiac arrest, epinephrine does not have that evidence.
Without that evidence, we need to be very clear that this treatment - epinephrine in cardiac arrest - is only an experimental treatment.
Epinephrine should not be a standard treatment.
Epinephrine is an experimental treatment.
There are some treatments, where we do not have survival data, but we have good enough surrogate end points to justify the use of these treatments. That will be for another post.
BTW, I thought this was an awesome post and should be published in an EMS journal, if anything to inspire logical thinking. We seem to lack that in EMS, always accepting what we are told. Those in EMS who question currently held/traditional practices are often treated as blasphamous heretics.