A 51-year-old man arrives at the emergency department complaining of sudden, sharp pain in his left flank, nausea, and vomiting. He has not experienced dysuria or hematuria. The patient has no previous medical conditions and does not take any medications on a daily basis. He does not smoke, drink, or use illegal drugs. The temperature is typical. The patient appears to be in severe pain and is unable to find a comfortable position on the bed. There is no abdominal rigidity or rebound, and no palpable masses. The cardiopulmonary exam is normal. There is no edema in the extremities. The exhibit shows a 1-cm calculus in the left proximal ureter at the level of the L3 vertebra; the renal pelvis and proximal ureter are dilated. Which of the following is most likely increased in this patient's left kidney?

Question

A 51-year-old man arrives at the emergency department complaining of sudden, sharp pain in his left flank, nausea, and vomiting. He has not experienced dysuria or hematuria. The patient has no previous medical conditions and does not take any medications on a daily basis. He does not smoke, drink, or use illegal drugs. The temperature is typical. The patient appears to be in severe pain and is unable to find a comfortable position on the bed. There is no abdominal rigidity or rebound, and no palpable masses. The cardiopulmonary exam is normal. There is no edema in the extremities. The exhibit shows a 1-cm calculus in the left proximal ureter at the level of the L3 vertebra; the renal pelvis and proximal ureter are dilated.  Which of the following is most likely increased in this patient's left kidney?

Quizplus · Accepted Answer

Eductional Objective: Urine reflux into the renal tubules and increased tubular hydrostatic pressure are both caused by urinary tract obstruction. The intraglomerular capillary hydrostatic pressure remains constant, resulting in a reduced hydrostatic pressure gradient across the glomerular capillary wall and decreased glomerular filtration. Large plasma proteins that are not filtered across the glomerular capillary basement membrane maintain oncotic pressure; it is unaffected by a urinary tract obstruction.

A 51-Year-Old Man Arrives at the Emergency Department Complaining of Sudden