A 70 kg 68 y/o male sees his cardiologist for a follow-upfollowing his myocardial infarction 3 months earlier. He has beentaking digoxin and LisinoprilTM since his MI. At thefollow-up, he complains of shortness of breath and has to sleepsitting up in his recliner. He also complains of fatigability andswelling of his ankles and hands. A physical examination finds thathe has distended jugulars and pitting edema in the lower legs. Hisbreathing was rapid 22 breaths/min) and rales were heard in theboth sides at the base of the lungs. He does not have a fever, buthis pulse is 116 bpm and his blood pressure is 110/80. Thephysician immediately admits him and orders a blood and urineanalyses with the results as follows:
Blood | | Urine |
[Na+] | 128 mEq/L | | [Na+] | 150 mEq/L |
[K+] | 3.0 mEq/L | | [K+] | 65 mEq/L |
[Cl-] | 98 mEq/L | | [Cl-] | 120 mEq/L |
[HCO3-] | 21 mEq/L | | [HCO3-] | 15 mEq/L |
Creatinine | 1.2 mg/dl | | Creatinine | 128 mg/dl |
PCO2 | 24 mmHg | | 24 hr volume | 750 ml |
pH | 7.51 | | Osmolality | 600 mOsm |
a) Calculate the volumes of ECF andECV in this Px assuming the total body osmoles of the Px is 12 Osm.Do these volumes have any impact on the symptoms the Px isexhibiting and what is the cause of these changes (ie, what is thepathology)?
b)Â Â How does thispathology alter the renal sodium handling in this Px and what arethe mechanism(s) for developing hyponatremia?
c)  The physician ordersan infusion of 2L of 3% saline with 40 mg of Lasix®given twice a day for three days. Calculate how this treatmentwould impact the Px’s symptoms assuming the osmolarity of the urinedropped to 400 mOsm?
d) What are the renal mechanismsaffected by this treatment. Does this treatment impact the Px’shypokalemia? If so, why?
