Q&A Medicine>>>>>Nephrology
Question 10#

A patient with end-stage renal disease caused by diabetic nephropathy is scheduled to start dialysis due to fluid overload and electrolyte abnormalities.

Which of the following best represents the likely changes seen in her laboratory results? (Note: Hb is hemoglobin, PTH is parathyroid hormone, TG is triglycerides.)

A) (A)
B) (B)
C) (C)
D) (D)

Correct Answer is B

Comment:

Increased K+ , Increased POـــ4, Decreased Ca2+ , Decreased Hb, Increased PTH, Increased TG. It is important to recognize and understand the changes that take place in chronic renal failure. Consider some of the important regulatory mechanisms of the kidneys (e.g., salt and water balance, RAAS, waste product secretion, role in vitamin D activation, role in erythropoiesis, etc.), and consider what the changes would be if they failed to work properly. Failure of the RAAS and other mechanisms of salt and water balance lead to fluid overload, hyponatremia, hyperkalemia, and hyperphosphatemia. Hypocalcemia is due to several factors: a loss in the active form of vitamin D (leading to decreased GI absorption and renal reabsorption), high serum phosphate levels, and metabolic acidosis (failure to excrete daily acid load). As a response, serum PTH will be elevated (secondary hyperparathyroidism, which may lead to tertiary hyperparathyroidism with time); consistently elevated PTH will increase burn turnover and produce osteodystrophy. Other changes include anemia due to loss of erythropoietin (EPO) secretion by the kidneys, dyslipidemia (commonly hypertriglyceridemia), and hypertension. Uremia refers to the clinical syndrome that accompanies the elevation in BUN and creatinine and includes nausea, vomiting, anorexia, encephalopathy, pericarditis, and bleeding from platelet dysfunction.