Hi, I am trying to reach out to the community at large. Is there currently in practice, in teaching, in mentorship, taught in medical school, or any textbook of emergency medicine a golden sign for dehydration? or a golden sign for hypovolemic shock? this would be something similar to what beck's triad and cushing's triad is.
I'm not Emergency Medicine, but I'll respond.
There is no golden rule to anything in real-life medicine in general. You have to look at the entire clinical picture. Curbsiders Internal Medicine Podcast had an episode where they talked about a study where nephrologists tried to objectively assess volume status on patients and they were no better (or slightly worse, can't remember which) than random chance.
I'm not going to give actual examples of good rules of thumb I've accumulated because I think it detracts from the main point. You should acquire these on your own journey/experience through medicine instead of being told them because everyone does/perceives things a bit differently and arrive at the right answer in a different way.. As you gain more experience you'll gather more tools.
Look at the history, physical, and labs. You can't hang your hat on one thing.
History:
The history is important too because it usually gives you a story/pattern which if correlated with labs/physical can give you the big picture and prevent recurrences or make diagnoses from pattern recognition. Sometimes (if accurate) it's the most reliable tool for medicine in general. That's why when you have a very functional/reliable patient, you need to gather as much information from them as possible.
Exam:
Each individual exam finding on it's own is not very reliable, but you can pick up things the earliest with the physical exam (i.e UOP, urine color, etc.) because the labs lag behind the exam.
Labs:
Sometimes they can be diagnostic when ordered in the right setting but many times they can be confusing. BNP=/= HF, D-dimer =/= PE, Procalcitonin =/= infection, Troponin =/= MI. FENAs don’t tell you what caused an AKI. Labs need to be ordered for a reason and correlated with the patient’s exam and the history.
Also:
Medications obscure the picture. One last thing that comes with experience is that a patient’s chronic medical conditions change the phenotype which changes what matter. For example, in ESRD patients, a lot of traditional rules for healthy patients don’t apply. Similar with HF and Cirrhosis.
