CASE STUDY 12.2: A Patient With a Kidney Stone
Patient Complaint: “I was in agony. I woke up in the middle of the night with such a terrible pain in my side and back that I fell out of bed. Then the pain eased up, and I got up to use the bathroom. My urine was pink, then turned red, so I got dressed and came to the emergency room right away. I haven’t had any more pain, but I’m worried about what would cause my urine to be red.”
History of the Present Illness/Review of Systems: The patient is a 53-year-old White man who appears well, but worried. He presents to the ED complaining of an episode of pain that went away, followed by bloody urine. During the episode, the pain was 9/10, which he describes as the worst pain I have ever felt. He denies excessive thirst or urination, burning, urgency, or difficulty with urination. He reports that he has no joint pain or difficulty with movement or walking. He states that he has generally been in good health, with no distress, until he experienced the acute pain in his lower abdomen.
Past Medical/Family History: The patient has a history of hypertension (currently well controlled) and mild obesity. He had an attack of gout a few years ago, but has had no recurrences since he started treatment with allopurinol. In addition to allopurinol 100 mg once daily, he takes amlodipine 10 mg once daily, and occasional OTC naproxen. His mother and brother have hypertension, and his father has gout.
Physical Examination: During your examination, the patient is diaphoretic and short of breath. Just as fast as the pain occurred, it is gone. Blood pressure is 158/98 mm Hg, respirations are 35 breaths/min, heart rate is 100 beats/min, and lungs are clear to auscultation. On examination, the abdomen is soft, without rebound but with slight tenderness in the left lower quadrant. Both rectal and hernia examinations are negative.
Laboratory and Diagnostic Findings: Serum creatinine is 1.3 mg/dL, uric acid is elevated at 8.5 mg/dL, and urine shows 2+ blood on dipstick, with many red blood cells on microscopic inspection. The complete blood count is normal. A flat-plate abdominal x-ray study of the kidneys, ureters, and bladder shows a small white calculus in the left ureter.
CASE STUDY 12.2 QUESTIONS
What are kidney stones made of?
What are the risk factors for stone formation, and how can patients avoid a recurrence of stones?
