11-13-2007, 07:02 PM
39. A 63-year-old man is brought to the emergency
department 3 hours
after the acute onset of severe right-sided flank
pain. He has a
9-year history of gout. His blood pressure is 110/84
mm Hg, pulse is
78/min, and respirations are 16/min. Examination
shows normal bowel sounds
and no abdominal tenderness or masses. Urinalysis
shows 40
erythrocytes/hpf. Intravenous pyelography confirms a
right ureteral calculus.
Which of the following is the most likely underlying
mechanism of this
patient's urolithiasis?
A
) An increase in urinary pH
B
) Damage to the epithelial lining of the ureters
C
) Lack of inhibitors of crystal formation
D
) Presence of urease-splitting bacteria
E
) Urinary supersaturation with uric acid
department 3 hours
after the acute onset of severe right-sided flank
pain. He has a
9-year history of gout. His blood pressure is 110/84
mm Hg, pulse is
78/min, and respirations are 16/min. Examination
shows normal bowel sounds
and no abdominal tenderness or masses. Urinalysis
shows 40
erythrocytes/hpf. Intravenous pyelography confirms a
right ureteral calculus.
Which of the following is the most likely underlying
mechanism of this
patient's urolithiasis?
A
) An increase in urinary pH
B
) Damage to the epithelial lining of the ureters
C
) Lack of inhibitors of crystal formation
D
) Presence of urease-splitting bacteria
E
) Urinary supersaturation with uric acid