24-hour urines: 3 high, 3 low
I was reviewing from my desk an algorithm of how to work through a 24 hour urine result.
Summary
1. Urine volume and creatinine assessment. If the urine volume is low, drink more fluids. Make sure the amount of creatinine is expected for the collection. If low, may be an undercollection
2. Check calcium. If high then review sodium. If calcium and sodium are both high then first most appropriate step is sodium restriction. If sodium is normal consider thiazide diuretic (chlorthalidone, HCTZ).
3. If starting thiazide also consider potassium supplement in the form of potassium chloride or potassium citrate if citrate levels are low
4. If citrate is low, replace it in the form of potassium citrate.
5. If oxalate is high, restrict oxalate foods.
6. If uric acid is high monitor high protein/animal/high purine meats. Consider allopurinol if uric acid is elevated in the blood.
7 If pH is low, especially if uric acid stone former then correction of urinary pH is critical for prevention and dissolution of stones
| 3 Possible Low Values | |
| if volume low | drink more. water is best. |
| if citrate low | replace with potassium citrate |
| if pH is low | correct with potassium citrate or sodium bicarb |
| 3 Possible High Values | |
| if calcium high | sodium restrict, thiazide diuretic |
| if oxalate high | restrict oxalate foods |
| if uric acid high | limit animal proteins, consider allopurinol |