Physiological Adaptation Q 58
A teen patient is admitted to the hospital by his physician who suspects a diagnosis of acute glomerulonephritis. Which of the following findings is consistent with this diagnosis? Select all that apply.
A. Urine specific gravity of 1.040.
B. Urine output of 350 ml in 24 hours.
C. Brown ("tea-colored") urine.
D. Generalized edema.
E. Periorbital swelling.
Correct Answer: A, B, C & E
Acute glomerulonephritis is characterized by high urine specific gravity related to oliguria as well as dark “tea-colored” urine caused by large amounts of red blood cells. As the glomerular filtration rate (GFR) is decreased, symptoms like edema and hypertension occur, majorly due to the subsequent salt and water retention caused by the activation of the renin-angiotensin-aldosterone system.
Option A: Glomerulonephritis and pyelonephritis cause a decreased urine volume and low specific gravity. In these diseases, damage to the kidney’s tubules affects the ability of the kidney to reabsorb water. As a result, the urine remains dilute.
Option B: About half of the people with acute glomerulonephritis have no symptoms. If symptoms do occur, the first to appear are tissue swelling (edema) due to fluid retention, low urine volume, and production of urine that is dark because it contains blood.
Option C: When kidneys are failing, the increased concentration and accumulation of substances in urine lead to a darker color which may be brown, red or purple. The color change is due to abnormal protein or sugar, high levels of red and white blood cells, and high numbers of tube-shaped particles called cellular casts.
Option D: There is periorbital edema, but generalized edema is seen in nephrotic syndrome, not acute glomerulonephritis. Edema may first appear as puffiness of the face and eyelids but later is prominent in the legs. This is reported in approximately 85% of pediatric patients; edema may be mild (involving only the face) to severe, bordering on a nephrotic appearance.
Option E: Patients often have a normal physical examination and blood pressure; most frequently, however, patients present with a combination of edema, hypertension, and oliguria. The physician should look for signs of fluid overload, like periorbital and/or pedal edema.