Generally, yes! There's really not a lot you can do to someone even as a layman that's really going to hurt them if you're trying to help, with maybe the exception of moving someone with a broken neck. It gets fuzzier for us doctors who might try to save someone with a procedure in the field that goes wrong, like a cricothyrotomy or c-section.

Yeah, this is a pointless finding because 1) it's not a patient-centered outcome, and 2) it's not done in a medically interesting population

Hey! I'm a doctor and a biochem nerd. Your blood pH is buffered by multiple systems, primarily bicarbonate, as well as lactate and phosphate compounds. That means that swings in the concentration of blood compounds (aspirin, or salicylic acid, for example, is an acid) don't cause significant changes. pH is also tightly controlled by your lungs and kidneys. Your lungs control the amount of CO2 in your blood, and therefore bicarb and carbonic acid content. Your kidneys also retain or excrete bicarb as needed. There are certain processes like lactic acid production, electrolyte abnormalities, and kidney or lung issues that can make you relatively acidic. However, a truly acidic pH of even slightly less than 7 is a pretty profound acidosis and likely life threatening.

Hey doctor who performs amputations, I'm an ER doctor who sees amputated feet. I've always wondered what goes into the decision of whether a part can be reattached. I remember on my trauma rotation the senior resident looked at an amputated foot for two seconds and then just casually threw it in the garbage. I'd be mad if that were my foot.

Any blood caught at the end of the artery will just eddy and swirl until the vessel regresses or grows new connections. It may also clot and get eaten up. It's not a significant concern.

This is a great question! The short, unhelpful answer is do whatever you have to to stop the bleeding. It really depends on the injury as to whether pressure would be a good start. If it's bleeding a lot, put a tourniquet on it, we'll figure it out in the ED. And check out the Stop the Bleed campaign, ask your boss to host a class!

Hey, it appears you don't quite understand how plants function. Plants indeed reduce oxygen to H2O to make ATP, the energy chemical all living things must produce. They do it with the same enzyme, ATP synthase, that every living organism on earth possesses. They do this by oxidizing carbohydrates into CO2 through the same reactios we do.

What plants are also able to do is harvest the energy in sunlight to turn CO2 and water back into carbohydrates. Because most of their structure is made of carbohydrates and carbohydrate compounds, they must do a lot of this, so they net consume CO2 and produce O2.