A paradigm shift in the way I think about pH: a thread

The important physiology of pH stressed to me in AP biology was:
• Deviations from our body’s normal pH lead to changes in our protein’s tertiary/quaternary structure
• Changes in protein structure renders enzymes ineffective
• Ineffective enzymes cannot maintain homeostasis

Essentially:
Change in pH = change in protein shape = change in protein function = no homeostasis = DEATH

This was (and still is) my understanding of pH. 4 years of college + 4 years of med school, and yet, I still think about pH in this very basic way.

But by that above logic, all acidemias should be bad. Right???
And severe acidemias of any kind should cause death. Right???

But then why do my patients in DKA with a pH of 6.8 often fare better than my patients in septic shock with a pH of 7.0?

Is it possible that not all acidemias are the same?

I know the etiology of acid production is different:
In DKA, keto-acids are created by disruptions in metabolism.
In septic shock, lactate is a result of profound hypoperfusion

(yes, I know keto-acid & lactic acid production is more complicated, but you get the point)

But maybe pH doesn’t EXACTY work the way I thought it did. And maybe I shouldn’t be using pH (subconsciously at times) to treat or even prognostic (unless there’s data behind this?)

To put it more simply - maybe we should (as @SaraCrager once said at #ResusX20) “treat the underlying acidosis, not the acidemia”

I hope I look back at this thread in a few years & say “wow, you really had to think about this very basic concept?”

But the basics in medicine are important. We so often get caught up w/ the complicated stuff that basic concepts need to be rethought and retaught #medtwitter