שאלה משלב א׳ בכירורגיה אורולוגית · מועד 2023, שאלה 78

Correct: B — acid urine, hyperuricosuria and a low urine volume. Uric acid is far less soluble in its undissociated form, which predominates below the pKa of 5.5, so a persistently acid urine is the dominant factor — which is why alkalinisation with potassium citrate to a pH of 6.5–7.0 can dissolve existing uric acid stones, the only stone type reliably amenable to chemolysis. Hyperuricosuria and concentrated urine complete the picture, and note that *hyperuricaemia* is neither necessary nor sufficient, so the options invoking it or an alkaline urine are wrong.

מקור: Campbell-Walsh p. p.32 Table3.1 (אין טקסTable סותר, נבדק . יש Table25.1 עמ ' 580 שאינו