Hi,

The combination of abnormal renal function with dyspnea and overall relatively normal respiratory tests evidently out of proportion to the degree of breathing difficulties, combined with generalized weakness would make me concerned that you may have some metabolic problem.
The most likely explanation for the combination of a high Hgb and abnormal renal function is that you are dehydrated. But, this has to be followed and properly assessed.

If I was the doctor in the ER, I would definitely draw an ABG to see the pH.
I would also want a urine test.

Maybe you have got metabolic acidosis, and that is why you are so unwell and having to breath fast.

I don't know what has happened to medicine. When I was in medical school we had a one year course in which we just learned to take a medical history and examine the patient. We had to generate a differential diagnosis only based on that, without even one test.

My son is now studying medicine and not only that they do not have such a course (instead of it they have a course in which they discuss the humanistic aspects of medicine without seeing any real patients), they have seen an MRI of the brain before they saw any patient. They were told about treatment guidelines and state of the art treatments for cardiac diseases, before they were taught how to diagnose those diseases.

It seems that modern medicine is becoming like someone who has a very sophisticated jet plane, but has no maps and no idea where and how to get anywhere with that plane. So, he is just circling around in the sky and looking very impressive, making sure that the plane has comfortable seats and state of the art modern equipment in it. Every now and then he reaches a destination making him feel even more content and even less aware of the lack of direction in his journey.

I am sorry if I sound like a grumpy old physician, remembering how great medicine was when I was young. I know that there have been major advances and breakthroughs since I was a med. student . But, really I think both physicians and patients should wake up and realize that simple is beautiful and we don't need all those sophisticated, expensive tests to know that a patient is unwell.