NBME 22 Glucose and sodium (NBME Answers)

Retired NBME 22 Answers

nbme22/Block 2/Question#14 (reveal difficulty score)
A previously healthy 12-year-old boy is ...
Glucose and sodium 🔍 / 📺 / 🌳 / 📖
tags:

+6 upvote downvote
submitted by ∗armymed88(49)

get full access to all content ⋅ pick a username

Glucose is co-transported into enterocytes of SI via sodium

get full access to all content ⋅ pick a username

toxoplasmabartonella That makes that glucose needs to be given with sodium. But, what about bicarb? Isn't the patient losing lots of bicarb from diarrhea? +4

pg32 Had the same debate. I knew glucose/sodium was the textbook answer for rehydration but also was wondering if we just ignore the bicarb loss in diarrhea...? +4

makinallkindzofgainz @pg32 - Sure, they are losing bicarb in the diarrhea, and yes this can effect pH, but it doesn't matter that much. You're not going to replace the bicarb for simple diarrhea in a stable, but hydrated previously healthy 12 year old. You're gonna give him some oral rehydration with a glucose/sodium-containing beverage. Don't overthink the question :) +2

makinallkindzofgainz *dehydrated +

baja_blast Here's a pic: https://www.researchgate.net/profile/Maciej_Malinowski2/publication/265193258/figure/fig1/AS:295989702348808@1447580852271/Model-of-the-secondary-active-glucose-absorption-by-the-enterocyte-Glucose-together-with.png +2

teepot123 salt and sugar, that's all the kid needs when ill simple +1

mtkilimanjaro Hm I put bicarb/K+ since thats lost in diarrhea, but I think the key thing in this Q is that its only 6 hours of acute diarrhea and nothing else. You would prob give bicarb and K+ in more "chronic" diarrhea over a few days or longer not just a few hours +1

specialist_jello ugh i overthought the question and changed my answer to bicarb/k +

an1 SGLT1 in the gut is a symporter. Glucose is needed to allow Na to enter, water will follow Na into the cell and reduce dehydration. Be sure to give a HYPOtonic ORS solution (more water than salt and sugar), otherwise solutes (move from low to high OSm will leave the tissues and enter the vasculature. +

+6 upvote downvote
submitted by gunnersinchrome(6)

get full access to all content ⋅ pick a username

Easiest way to think of this is that this is Gatorade. Sure everyone thinks that sports drinks have glucose for the energy (which is also true) but they also contain sugar because the Na/Glucose co-transporter in the small intestine helps drive electrolyte intake. Without glucose, you don’t pull in sodium nearly as efficiently in the gut and the first makers of the Gatorade formula at UF found that once they gave glucose and electrolytes instead of just water to the football team during practice, they didn’t get as dehydrated and their electrolyte balance was a lot more stable.

get full access to all content ⋅ pick a username

usmleboy Gaaaaaatttoooraaddeeee! Water sucks! It really really sucks! +3

mumenrider4ever You're drinking the wrong water https://www.youtube.com/watch?v=7I2-14y6-jM +1

rockodude go gators, we made that shit +

username go dawgs +

skonys Any hydrohomies? My patient's will be getting straight RO water to the neck. None of that heretical devil-drink. +

chaosawaits @rockodude, if only FSU had made it; we'd all be drinking Seminole Fluid ;) +1

impostersyndromel1000 @chaosawaits underrated comment +

+6 upvote downvote
submitted by ∗hello(429)

get full access to all content ⋅ pick a username

The patient is dehydrated. Need to give water to rehydrate.

Water follows solute. If sodium is added to the solution, water will follow the sodium. Now, enterocyte uptake of sodium is mediated by Sodium-Glucose transporter. Hence, the solution needs to contain sodium and glucose in order to have the enterocytes take up the sodium.

get full access to all content ⋅ pick a username

+0 upvote downvote
submitted by ∗beto(28)

get full access to all content ⋅ pick a username

Glucose is co-transported into enterocytes of SI via sodium

get full access to all content ⋅ pick a username

Glucose is co-transported into enterocytes of SI via sodium

+3/- beto(28)

-1 upvote downvote
submitted by partybrockk(7)

get full access to all content ⋅ pick a username

Kid probably had cholera -- giving Na+ and glucose takes advantage of sodium-glucose cotransporter thereby replenishing electrolytes and energy.

get full access to all content ⋅ pick a username

hipster_do To add on to the diarrhea kid -- SGLT1 is the Na-glucose symporter and it facilitates movement of water into the enterocytes. Water loves to follow sodium around, I think sodium over other electrolytes purely because sodium is generally the highest concentration electrolyte. +1

Must-See Comments from nbme22

sacredazn on Unrearranged immunoglobulin gene
seagull on Decreased binding of RNA polymerase
seagull on Anticholinergic
mcl on Area labeled ‘D’
liverdietrying on Release of stored thyroid hormone from a ...
kernicterusthefrog on Displacement
keycompany on Negative nitrogen balance
joha961 on Displacement
imgdoc on Area labeled ‘C’ (Abducens nucleus, right)
alwaysanonymous on 25 mL/cm H2O
drdoom on 1 in 600
seagull on Glutamine
yotsubato on Phase variation
bubbles on Acute retroviral infection