Send Various Calculated with airSlate SignNow

Send various calculated

hey guys it's medical is perfection Ellis with a new video in our series about fluids and electrolytes acid-base disturbance in previous videos we have talked about osmosis and osmolality all of what we have talked about is the measured osmolarity but today I think it's time to talk about the calculated osmolality and now let's get started [Music] this is my sixth video in the series these lectures are intended to be watched in order so make sure to watch them before watching this video let me answer the previous question on his first day in the hospital medical student administers 100% water to a patient instead of normal saline what are the consequences okay the plasma so here are the red blood cells let's do them red and here is the nice plasma the plasma osmolality is supposed to be 290 if you were to administer normal saline you keep the osmolarity of plasma at 290 but now this stupid student administered 100% water so now here is water the osmolarity of the plasma is gonna decrease below 290 what's the normal osmolality inside the red blood cell it has to be 290 to be in equilibrium with the plasma that is 290 at least before this stupidity occurs now outside is hypo a smaller or hypertonic than the inside what's gonna happen is fluid is gonna go to the red blood cell water is going to flow by osmosis into the red blood cell because now they're a good cell has higher solute concentration and it will swell and swell and swell until boom it bursts so the correct answer is be quick review on previous videos osmosis simple diffusion of water osmotic pressure the pressure near to stop osmosis how small osmosis caused by a mould osmolality the amount of force per volume measured Emily Osment per kilogram how about milli Osmel per liter we call this thing osmolarity and I had a mnemonic in the previous video oh and here is the mnemonic osmolarity per kilogram osmolarity per liter which one is more accurate osmolarity which much more practical osmolarity as you know all of osmolarity that we have talked about until now is the measured osmolarity you draw some blood and send to the lab in the lab they have a machine called a SMAW meter it's going to measure many osmoles are in the plasma and it will give you a number normally it's 290 meli oz moles per liter calculated osmolality on the other hand requires you not to use a machine but to use your brain and to calculate it using this equation calculated Osmel T equals okay calculus multi is dependent on what we call the big three sodium glucose and blood urea nitrogen the biggest of the biggest is the sodium why two times sodium because sodium is always combining to something else let's say chloride so one for the sodium and one for the chloride that's why we multiply it by 2 so 2 times sodium plus glucose over 18 to make it easier let's do it glucose over 20 18 is very close to 20 at least where I grew up bo n which is blood urea nitrogen over two point eight which is kind of close to three just to make it easier very nice so normally measured osmolality in the lab should equal calculate osmolarity using the equation they should equal to 90 milli as moles per liter and as you know osmolarity and the ICF should equal automotives the plasma should equal the Oz multi in the interstitial because otherwise water is gonna flow to a certain compartment until you burst no no they have to be equal and we call this homeostasis okay now mnemonic time here is your arrogant doctor and he says these lab technicians are mediocre they just measure the osmolality using the Osmo meter and to complete the no Monica can you say using the Machine the Machine also starts with an M but I am a competent doctor I calculate the osmolarity using my cerebral hemispheres oh this guy is educated depending on the sodium because C and s has the same sound which is the main care time okay so calculate osmolarity depends on the sodium two times sodium plus glucose over 20 plus mu n over 3 now pause the video and this equation without looking like ten times straight do this until you never forget it again so here is another mnemonic the big three sodium is the main ECF cation glucose is the main source of energy bo n is the main source of bleep I'm not gonna say it because I'm a good person so let's summarize measured osmolality using the lab as mama to calculate osmolality using this equation so let's calculate it you know what's the normal plasma sodium concentration you remember the role of force it's 140 how about glucose it's about 100 how about Bo n normally it's less than 20 so let's say 15 let's do it 2 times 140 is 280 100 over 20 is 5 15 over 3 is 5 280 plus 5 plus 5 equals to the 290 Mellie as moles per liter under normal normal circumstances measured osmolarity should equal calculated osmolarity it could be that measured osmolarity is higher than calculate osmolarity by let's say 1 2 3 points for points but if it's like 20 points like more than 10 houston we have a serious problem if these videos help you please consider supporting this channel on patreon you will get my notes you can view download print and enjoy thank you so much for watching this is medicals perfection Alice be safe stay happy and study hard in the next video we're going to talk about the a small gap