Suprapubic Aspiration of Urine in a Child

Indications

• Suprapubic aspiration should be performed in an infant if a urine sample cannot be obtained non-invasively after reasonable waiting or if it is needed urgently (for instance, in a feverish patient who is in a poor condition or an infant with fever).
• A “flying stream sample” suggesting infection obtained from a small infant (below 3 months of age, at least) should be checked by an aspiration sample.
• Urine samples from children should primarily be obtained using non-invasive methods, such as by catching a “flying stream sample” or by collecting a sample from a bowl placed in the front part of the potty.

Equipment

• Lidocaine-prilocaine ointment for anaesthesia if there is time to wait for it to take effect
• Disinfectant for cleansing, sterile dressings
• 10-15 ml syringe and medium-sized injection needle (e.g. 22G with black hub, 0.7 x 40 mm) for drawing the sample
• Chocolate agar plate, blood culture bottle and urine sample tube for the sample
• Keep a sterile container available for a “flying stream sample” in case the child begins to urinate before puncture.
• Adhesive plaster

Procedure

• Video Urine Aspiration Sampling in a Child

1. If lidocaine-prilocaine ointment is used, allow 30-45 min for the skin to be anaesthetized.
2. While waiting, fluid can be given either orally or intravenously.
3. The child lies supine with the legs straight, held by a calm adult. Keep a sterile container available throughout the procedure for a "flying stream sample" in case the child begins to urinate before the aspiration sample is taken.
4. If an ultrasonography device is available, the position and filling of the bladder can be checked just before disinfecting the skin.
5. The procedure should be carried out using careful aseptic technique and sterile instruments. Disinfect the lower abdominal skin with an antiseptic agent.
6. The puncture site is at the deep transverse fold visible above the pubic symphysis, or the site where ultrasonography indicates that the bladder is closest to the abdominal wall (in infants the bladder may be situated unexpectedly high). Insert the needle into the bladder quickly and perpendicular to the skin and aspirate a sample. If no urine is obtained, retract the needle slowly while aspirating gently. Sometimes a specimen is obtained at this stage.
7. Remove the needle and cover the puncture site with an adhesive plaster. If no sample was obtained, administer more fluid and try again after about 30 min.
8. Culture the sample both in an aerobic blood culture bottle and on a chocolate agar plate. Transfer some of the sample to a urine sample tube for particle counting.
9. If faeces is aspirated, withdraw the needle. Although the needle has punctured the bowel, this kind of puncture hole heals without causing complications, and no follow-up is necessary.