Aimless
Forum Newbie
Topics: 1
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Hiya! I've found this forum to be very useful in my revising, so today I thought I'd repay you guys by sharing with you what is quite probably my favourite case from our physiology course. It's not in USMLE question format, but might be a fun challenge =P
A previously healthy 25-y-o woman comes into a bar, I mean your ward, severely dehydrated and exhibiting kussmaul breathing. Initial tests find the following:
B-glucose: 50 mmol/l (norm. < ca. 6.5)
B-urea: 30 mmol/l (<8.9)
B-HCO3-: 12 mmol/l (24-30)
Plasma ketone bodies (not sure of the exact translation =P): 8 mmol/l (<0.1)
B-pH: 7.21 (7.35-7.45)
We conclude that this is severe diabetic ketoacidosis, and whisk her off to receive insulin + 6l of saline (I think... isotonic). As a result of this, her ECF (measured by magic) increases from 10 to 15 l.
Over the course of the first 4 hrs, she excrete 1 L of urine, and a new test shows the following:
B-glucose: 25 mmol/l
B-urea: 24 mmol/l
U (urine) urea: 250 mmol/l
U-glucose: 250 mmol/l
The nurse (or your student :P) asks you, "Does she need more insulin??"
Dissect and discuss this case based on what you know of physiology and some basic medical biochemistry. Whether or not she needs insulin isn't the only pertinent question... see if you can formulate some more!
This is my favourite case because it is simple, and yet does a wonderful job of integrating several aspects of human physiology. Wish you the best of luck with it 
-- P
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| new_n_lost
Politically InCorrect
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I m sorry this question doesnt meet the criteria for the USMLE standard so if u have a MCQ regarding it then it might be answered. but in this format it will take time for anyone to answer it.
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FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
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| Fyred-up
Forum Newbie
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perviously healthy and "walks" in with severe d.acidosis.. doesnt happen like that in wards usually.. ketones are the last resort for the brain.. she would've been symptomatic before (1-2wk) advance.. weakness, shortness of breath, polyuria, polydipsia, psychosis, dementia.. even if its her 1st attack. nehoo.. provided it is hypothetical.. lets start w/ how much insulin did you give in the first place. are we to assume they gave K+ along with it? whats her body weight (to see whether 10-->15 ecf is significant or not)? bp? shes already in a less likely to depolarize state, so diluting the na would make it worse so monitoring electrolytes are very imp. checking ekg's is essential. resp. compensation levels? what percentage of dextrose was added to the saline.. for her to be urinating that much glucose. shes hyperglycemic already, it wasnt needed in the first place.
Edited by Fyred-up on 11/29/07 - 08:22 PM
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Matrix 101 - The Medical school http://www.youtube.com/watch?v=mdJyyJ2qur0
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