A Patient Has Been Hospitalized for a Subtotal Gastrectomy

A patient has been hospitalized for a subtotal gastrectomy.After the procedure,an infection developed that eventually had to be treated with gentamicin,an aminoglycoside antibiotic.After 3 days of administration,oliguria occurred,and subsequent laboratory values indicated elevated blood-urea-nitrogen and creatinine levels.The patient is transferred to the critical care unit with acute tubular necrosis.The patient is in the oliguric/anuric phase of acute tubular necrosis.Which statement best describes this phase?

A) It is the period of time from insult until cell injury. A decrease in glomerular filtration rate (GFR) results and disrupts the integrity of the tubular epithelium.
B) It is characterized by an increase in GFR in which the kidneys can clear volume and not solutes.
C) It is referred to as the maintenance phase and lasts 5 to 8 days in a nonoliguric patient and 10 to 16 days in an oliguric patient.
D) Renal function slowly returns to normal with a GFR at 70% to 80%.