Wikipedia:Reference desk/Archives/Science/2021 March 16

= March 16 =

How do surgeons measure blood loss?
How do surgeons tell blood loss from a wounded patients? I always wonder how do they tell that patient require blood. Rizosome (talk) 04:40, 16 March 2021 (UTC)


 * Emergency Physician Estimation of Blood Loss (basically, they have a look at how much has been spilled and guess). Alansplodge (talk) 09:04, 16 March 2021 (UTC)


 * Having experienced blood loss in a way that they could not measure by looking at a spill and guess, it's more complicated than that. I had an upper intestinal ulcer, so by the time I was admitted to the hospital, most of my blood loss was down the toilet. I had bad diarrhea, didn't know that black diarrhea was something to be concerned about as I didn't know I had an ulcer. I was incredibly exhausted and could barely hold my head up, but just thought I had a stomach flu or something until vomited blood the following morning. There was no spill for doctors to look at. Your article mentions hematocrit which, while not great, is better than nothing, and that was one of the things they used for me. Mine was quite low. Blood pressure can also be used. I'm sure there are other techniques as well, but those two were used with me. --OuroborosCobra (talk) 15:13, 16 March 2021 (UTC)
 * Bleeding describes the symptoms of various levels of blood loss, which can be used to estimate its severity. As OuroborosCobra notes, bleeding into the gut (Gastrointestinal bleeding) can't be quantified by looking; ... although looking and smelling can help in the case of melena. Klbrain (talk) 22:18, 16 March 2021 (UTC)
 * Surgeons cause blood loss, they don't diagnose it; Emergency physicians or anesthesiologists need something to do! Klbrain (talk) 22:18, 16 March 2021 (UTC)

RBMK, again
I've already asked these questions once before, but they haven't been answered because the conversation got sidetracked by discussions of the proper name for the reactor ("RBMK reactor" vs. simply "RBMK") and the possibility or impossibility of an actual nuclear explosion at Chernobyl: (1) Is it true that the RBMK main coolant pumps are designed to automatically cut out if the voltage and/or frequency of their power supply falls below a certain level for a certain period of time? (2) If so, is it plausible that at least some of the increase in reactivity at Chernobyl which had been attributed in the INSAG-7 report to the graphite tips in the control rods was instead due to the abrupt stoppage of the pumps (which would have stopped the removal of heat from the reactor and therefore led to a rapid increase in boiling rate and thus a spike in the void fraction)? 2601:646:8A01:B180:E833:FA18:DC58:5668 (talk) 07:11, 16 March 2021 (UTC)
 * Although I must confess to being involved in the eartlier sidetrack, I suspect that your main questions have not been addressed because no-one on this Desk knows the answers, or enough about the subject to be able to find them. Russian nuclear engineers might well know, but perhaps be reluctant to discuss such details if they have not been officially published. {The poster formerly known as 87.81.230.195} 2.221.80.5 (talk) — Preceding undated comment added 22:15, 16 March 2021 (UTC)
 * By chance, I read an article by Dominic Lawson in The Sunday Times on March 14, available . He said (among other things) that "What happened at the Soviet plant was so bizarre — an experiment in which one of the reactors was made to run at dangerously low level, the emergency cooling unit disconnected and the emergency safety mechanism switched off — it might have been thought overambitious by a genuine saboteur." I don't know his source for these assertions but he had been reading the UNscear report on the Fukushima meltdown, so probably an earlier report from them. I conclude that your question is difficult to answer! You could contact Lawson at dominic.lawson@sunday-times.co.uk which is given at the bottom of his article. Mike Turnbull (talk) 12:22, 19 March 2021 (UTC)