04-23-2008, 07:21 AM
.1.A previously well 18 year old girl is admitted to the ICU because of altered mental status. She does not respond to instructions and her arms are postured in a flexor position. Lab data reveal a serum Na of 125 mmol/L. It is reported to you that she had imbibed a large quantity of water rapidly that morning as she was very thirsty from rough night out during which she had taken ecstacy. Assuming no substance ingestion toxicity issues contribute to her reduction in osmolarity and disregard approximating her salt loss from sweating while under the influence; how much water would she have had to have drunk to produce the observed hyponatremia?
A. 5L
B. 6L
C. 7L
D. 8L
E. 9L
2.Assuming the following: ICF volume = 40% of initial body weight, ECF volume = 20% of initial body weight, molecular weight of NaCl = 58.5 g/mol, no excretion of fluids during the duration of this scenario. A 60 kg male patient appears dehydrated, and after obtaining a plasma sample you find he has hyponaturemia with a sodium concentration of 130 mmol/L and plasma osmolarity of 260 mOsm/L. You decide on a stat treatment of two liters of 2X normal saline before re-evaluating. What is his approximate plasma osmolarity after this NaCl i.v. has osmotically equilibrated?
A. You guessed/goofed and way overshot goal
B. You guessed/goofed and way undershot goal
C. You actually calculated the Na deficit properly and he is now at goal
D. Your guesstimate was close and you are within 5 mOsm™s under goal
E. Your guesstimate was close and you are within 5 mOsm™s over goal
3.A patient is admitted who overdosed on a drug that damaged the proximal tubule NaCl resorbtive capacity. With no change to diet or fluid/electrolyte intake from normal and before the kidney recovers what set of changes would you expect to see? Note AAR means afferent arteriolar resistance.
A. same GFR, same AAR, inc Na excretion
B. dec GFR, inc AAR, inc Na excretion
C. dec GFR, inc AAR, same Na excretion
D. inc GFR, dec AAR, same Na excretion
E. same GFR, same AAR, dec Na excretion
A. 5L
B. 6L
C. 7L
D. 8L
E. 9L
2.Assuming the following: ICF volume = 40% of initial body weight, ECF volume = 20% of initial body weight, molecular weight of NaCl = 58.5 g/mol, no excretion of fluids during the duration of this scenario. A 60 kg male patient appears dehydrated, and after obtaining a plasma sample you find he has hyponaturemia with a sodium concentration of 130 mmol/L and plasma osmolarity of 260 mOsm/L. You decide on a stat treatment of two liters of 2X normal saline before re-evaluating. What is his approximate plasma osmolarity after this NaCl i.v. has osmotically equilibrated?
A. You guessed/goofed and way overshot goal
B. You guessed/goofed and way undershot goal
C. You actually calculated the Na deficit properly and he is now at goal
D. Your guesstimate was close and you are within 5 mOsm™s under goal
E. Your guesstimate was close and you are within 5 mOsm™s over goal
3.A patient is admitted who overdosed on a drug that damaged the proximal tubule NaCl resorbtive capacity. With no change to diet or fluid/electrolyte intake from normal and before the kidney recovers what set of changes would you expect to see? Note AAR means afferent arteriolar resistance.
A. same GFR, same AAR, inc Na excretion
B. dec GFR, inc AAR, inc Na excretion
C. dec GFR, inc AAR, same Na excretion
D. inc GFR, dec AAR, same Na excretion
E. same GFR, same AAR, dec Na excretion