See also

Urinary tract infection
Febrile child
Acute pain management

Key Points

1. Suprapubic aspirate (SPA) is the gold standard for obtaining urine specimens for culture in children under 2 years
2. SPA is a simple, safe, rapid and effective procedure
3. The use of ultrasound increases the success of the procedure
4. Any growth of pathogenic bacteria in an SPA specimen is felt to be significant

Background

Indications

• Urine specimen required as part of a septic work-up in an unwell infant and antibiotic administration cannot be delayed while awaiting a clean-catch urine
• For a child ( < 6 months) when it is deemed important to confirm a UTI, eg in a child with recurrent urinary tract infections with positive cultures but minimal cellular response

Contraindications

• Bleeding diathesis
• Abdominal distension
• Massive organomegaly
• Urogenital or gastrointestinal abnormality where SPA may compromise any pelvic/abdominal organs
• Overlying skin infection

Potential complications

• Common: Microscopic haematuria
• Rare: Macroscopic haematuria, bladder haematoma, bladder haemorrhage, intestinal perforation

Equipment

• One assistant to hold the infant (not parent)
• Specimen jar for urine
• 23G needle (25G for premature infants)
• 3 or 5 mL syringe
• Sterile gloves
• Alcohol swab
• Oral sucrose (for infants <3 months) or topical anaesthetic cream
• Ultrasound/Bladder scanner and gel if available

Analgesia, anaesthesia, sedation

• Oral sucrose should be used for infants <3 months, see Acute pain management
• Topical anaesthetic cream should ideally be used for infants >3 months, except where specimens are required urgently eg prior to starting antibiotic treatment in a septic infant

Procedure

General considerations

• Infants often urinate on removal of nappy, keep nappy on until an assistant is available to collect a spontaneous clean catch urine
• Do the SPA before collecting blood or CSF unless the patient recently voided
• Obtain consent, verbal consent is adequate
• If possible, perform bladder ultrasound prior
• A successful SPA is more likely with
  • no voiding in the past 30 minutes, and a dry nappy
  • pre-procedure hydration
  • full bladder

Use of ultrasound for SPA

• Ultrasound helps determine when not to do an SPA (when bladder underfilled).
• There are two types of ultrasounds
  • Real time 2D ultrasound: provides visualisation of bladder and estimates fullness. It is more accurate and should be used in preference if machine and expertise available
  • Automated bladder ultrasound: only provides a urine volume in mL, without visualising the bladder. Unable to accurately detect volumes <20 mL. Only use when 2D ultrasound equipment or expertise is not available
• To minimise likelihood of voiding, it is helpful to use warmed ultrasound gel which should be placed on the ultrasound probe and not directly on the skin
• If bladder appears empty on ultrasound, give the child fluids and wait 30 min to repeat the ultrasound and assess chance of SPA success
• If the bladder appears full, attempt SPA
• If no ultrasound is available, assess bladder fullness based on whether child has voided in previous 30 minutes or if bladder is palpable on exam.
  • If nappy newly wet and bladder not able to be palpated, consider giving the child fluids and waiting 30 minutes prior to attempting SPA

Real time ultrasound images

Full bladder
Transverse image	Longitudinal image
Empty bladder
Transverse image	Longitudinal image

SPA Method

• Assistant to hold the infant supine with legs extended and together (see below)
• Identify insertion point: midline, lower abdominal crease. See images below
• Use standard aseptic non-touch technique with sterile gloves
• Clean overlying skin with an alcohol swab
• Insert needle perpendicular to the skin. Do not aim the tip of the needle down into the pelvic region (a baby's bladder is predominantly intra-abdominal rather than pelvic). Puncture skin quickly as if popping a balloon with a needle. Insert needle to the hub and aspirate. If urine is not immediately aspirated, continue aspirating whilst withdrawing the needle
• If unsuccessful, withdraw the needle to just under the skin, and advance at an angle with the needle aimed further away from the pelvis one more time. Do not repeat this procedure more than once. If SPA unsuccessful, consider using an in & out catheter to obtain a urine sample
• If urine is obtained, place urine into sterile urine jar

Positioning of infant during the procedure

Figure from Dieckmann: Illustrated Textbook of Pediatric Emergency and Critical Care Procedures, 1/E© 1997 Mosby, Inc. Figure 71-2 and 71-3, Page 418, with permission from Elsevier

Post-procedure care

Place small, simple dressing (eg Band-aid®) over site. No specific care is required

Alternatives if procedure not successful

• If SPA cannot be obtained, a catheter sample should be collected
• If urine is unable to be collected in an unwell child, do not delay necessary treatment eg antibiotics. A sample of urine should still be collected as soon as possible for microscopy at an appropriate time

Consider consultation with local paediatric team when

• The child is febrile and <3 months of age
• The child appears unwell and/or may require escalation of care outside of the immediate health care setting

Consider transfer when

Child requiring care above the level of comfort of the local hospital

For emergency advice and paediatric or neonatal ICU transfers, see Retrieval Services

Parent information

Kids Health Info Urine Samples

Last updated March 2025