Which of the following best methods of urine collection is associated with least contamination :
Answer is A (Suprapubic aspiration) Urine obtained from suprapubic aspiration is least likely to be contaminated- Suprapubic aspiration avoids potential contamination but is rarely used because of its invasiveness It may be indicated in children2 (and selected other patients) Desirable propeies of a voided sample It is best to collect a clean voided mid stream urine sample (First 15-30 ml are discarded and the next 50- 100 ml are collected) The midstream clean catch method reduces the likelihood of contamination with meatal or urethral secretions Freshly voided specimen should be tested (Within one hour of voiding) Urine specimen should not be collected immediately after the patient has eaten (Should be obtained a few hours after the patient has eaten) First voided morning specimen should be obtained for qualitative protein testing (Patients with possible ohostatic proteinuria) and for specific gravity testing.
Suprapubic aspiration
Mid stream collection
Catheterization
Urine Bag specimen