Preparation of the patient for 24-hour urine catecholamines determination

Quantitative determination of catecholamine content (norepinephrine, epinephrine, and dopamine) in urine is performed using high-performance liquid chromatography (HPLC) with an electrochemical detector, a technique that is the gold standard in laboratory diagnostics. This technique enables accurate and reliable chromatographic quantification of all three parameters from a single sample.

Patient Preparation

• One day before collection, avoid consuming: coffee, cola, bananas, oranges, chocolate, tomatoes, pineapples, hazelnuts, kiwi, and avocado.
• Five days before urine collection, it is preferable to discontinue medications containing adrenaline or similar compounds: dopamine, methyldopa (Aldomet, Aldoril, Dopegit, Dopamet), as well as tetracyclines, ampicillin, erythromycin, quinine, aspirin, and beta-blockers.
• You can obtain a urine collection bottle at the BioDiagnostica reception desk or prepare yourself a dark bottle with a capacity of 1.5-2 liters. Add preservative to the bottle (10-15 ml of 25% HCl). Consult the laboratory staff for the preservative!

• Discard the first morning urine. Collect each subsequent urine during the day and night into the bottle. Also, collect the first morning urine of the next day into the bottle, which completes the urine collection. Record the start and end times of urine collection.
• During collection, keep the bottle with preservative cold (4-8 °C); bring the collected urine to the laboratory as soon as possible.
• If possible, measure the amount of collected urine, record the value, pour a portion of 50-100 ml, and bring it to the laboratory. If it is not possible to measure the exact amount of collected urine, bring the entire amount to the laboratory.
• The preserved urine sample can be kept for up to 5 days at temperatures of 2-8 °C. For longer storage (up to 6 months), the sample is kept at -20 °C.
• If it is difficult or impossible to collect a 24-hour urine sample, “spot” urine samples can be analyzed, and in that case, the results are expressed in relation to the concentration of creatinine in the urine.