Weekly Discussion – Urinary System
Since the kidneys perform so many important roles that affect so many different body systems, I thought it would be interesting this week to work on a case study rather than read an article.
A 23-year-old male felt puffy (that is, he had edema (Links to an external site.)), weak, and tired for several months. He suddenly noticed his urine had a red to brown discoloration and the volume was minimal. He went to the emergency room of a nearby hospital to be examined and tested.
The patient was diagnosed with renal failure — in other words, his kidneys have (almost) stopped working.
Patient Normal values
Hematology Serum sodium 125 mEq/L 136 -145 mEq/L
Serum potassium 6 mEq/L 3.6 – 5.1 mEq/L
Serum creatinine 2.6 mg/dL 0.7 – 1.3 mg/dL
BUN (blood urea nitrogen) 24.0 mg/dL 7 – 18 mg/dL
pH (arterial) 7.32 7.35 – 7.45
Hematocrit 25% 41 – 50%
Urinalysis Appearance Red to brown Pale straw yellow
Specific gravity 1.025 1.002 – 1.028
Blood Positive Negative
Glucose Negative Negative
Protein 9.3 mg/dL 0 – 8 mg/dL
Renal Function Tests
GFR (glomerular filtration rate) 40 mL/min 120 – 125 mL/min
RBF (renal blood flow) 280 mL/min 1100 – 1200 mL/min
For your initial post, you should be using your textbook and the information above as your primary sources to answer the questions below. The purpose of this first post is to apply the information that you’re practicing from your learning objectives. Later, in the comments, I will expect you to do a bit of research online and support your comments with evidence, but in your initial post please stick to your textbook and the article(s).
In your initial post, please address each of the following:
- Our patient has very low renal blood flow, which is probably the reason his kidneys are failing. He may have stenosis (narrowing) in the blood vessels leading to the kidney. Which vessels do you think are affected? Why is it is so important for the kidneys to receive a rich blood supply?
- Do you think this patient’s angiotensin II levels will be high or low? Explain briefly.
- Do you think this patient’s aldosterone levels will be high or low? Explain briefly.
- Choose two additional tests (other than RBF or urine protein) from the table that have abnormal results. For each test, briefly explain how the patient’s kidney disease has caused the test to be abnormal. These answers should be short (usually one sentence). For example, you might say “Urine protein is too high because the filtration membrane has been damaged and is allowing proteins through that are normally filtered out.”