Approach to Best Practices for Adult DRS: Patient Preparation and Acquisition
Parameter | Best practice |
---|---|
Patient preparation | |
Increase in fluid intake day before and morning of examination | It may be optimal also to have patient avoid natural diuretics, though some experts believe effect is less than fluid consumed |
Withdrawal of prescribed diuretics on morning of examination | Thiazides: hydrochlorothiazide, indapamide, metolazone, chlorthalidone |
Loop diuretics: furosemide, bumetanide, torsemide, ethacrynic acid | |
Potassium sparing: amiloride, spironolactone, triamterene, eplerenone | |
Carbonic anhydrase inhibitors: acetazolamide | |
Oral hydration 30–60 min beforehand | Patient drinks 5–10 mL/kg |
450–900 mL (15–30 oz, or 2–4 cups) for adults weighing 90.7 kg (200 lb) | |
385–770 mL (13–26 oz, or 1.5–3 cups) for adults weighing 77.1 kg (170 lb) | |
Prevoiding | Patient voids immediately before beginning of examination |
Acquisition | |
99mTc-MAG3, 37–185 MBq (1–5 mCi) intravenously | 99mTc-MAG3 is preferred over 99mTc-DTPA despite cost; lower doses are adequate given that flow/arterial phase can be omitted |
Furosemide, 40 mg intravenously | If patient is on higher dose of furosemide at home, increase to match; consider 80–120 mg if known renal insufficiency |
Serum creatinine level > 1.2 ng/dL (women) or > 1.4 ng/dL (men) | |
Estimated GFR < 90 mL/min/1.73 m2 (either sex) | |
Acquisition and timing of diuretic (most common source of variability; remains actively debated topic with no clear best practice for all situations) | F=0 single acquisition or F+20 2-part acquisition; F+10, F+15, and F+30 are also used by many practices, and F+10sp is also considered suitable technique |
Postvoid image (maximizes pressure differential between kidneys and bladder, facilitating physiologic drainage) | Patient stands or walks for 5 min, voids, and then is imaged in same position as examined |
Many quantitative values are dependent on protocol and cannot be universally applied.