Suprapubic aspiration is obtaining a urine sample using a needle inserted into the bladder in the suprapubic region, typically to obtain an uncontaminated urine sample for culture.
(See also Bladder Catheterization and Urinary Tract Infection in Children.)
Indications for Suprapubic Catheterization in a Child
Suprapubic aspiration is done when a clean-catch urine sample cannot be obtained and transurethral bladder catheterization was unsuccessful or not possible. Suprapubic aspiration is done most often in children but can also be done in adults.
A suprapubic catheter may be placed when an indwelling catheter is needed. This procedure is not discussed further here.
Contraindications for Suprapubic Catheterization in a Child
Absolute contraindications
Skin or soft tissue infection* of the abdominal wall over the bladder
* Cellulitis or significant abdominal wall infection, not diaper rash or eczema.
Relative contraindications
Empty bladder
Major genitourinary abnormalities
Bleeding disorder
Massive hepatosplenomegaly
Previous abdominal surgery
Complications for Suprapubic Catheterization in a Child
Suprapubic aspiration is typically safe. Possible complications include
Bleeding
Infection
Bowel perforation (rare, usually in patients with bowel distention from a gastrointestinal disorder). In these patients, ultrasound guidance can reduce the risk of bowel perforation.
Equipment for Suprapubic Catheterization in a Child
Sterile drapes and gloves
An absorbent underpad
For aspiration, a 5-mL syringe, 22-gauge 1.5-inch needle
Sterile cup for urine specimen
Sterile bandage
Additional Considerations for Suprapubic Catheterization in a Child
The bladder should be relatively full (confirmed by physical examination and/or ultrasonography).
Relevant Anatomy for Suprapubic Catheterization in a Child
The bladder lies posterior to the pubic bone and anterior to the uterus in girls and anterior to the rectum in boys.
Positioning for Suprapubic Catheterization in a Child
Place the patient in a supine, frog position (hips and knees partially flexed, heels on the bed, hips comfortably abducted).
Step-by-Step Description of Suprapubic Catheterization in a Child
Locate the bladder by percussion and palpation or using ultrasound.
Locate the point of entry, which is 1 to 2 cm cephalad to the superior edge of the symphysis pubis in the midline.
Place sterile drapes around the area or use a fenestrated sterile drape.
Inject local anesthetic subcutaneously and into the dermis at the planned entry site.
Insert the 22-gauge needle attached to a 5-mL syringe into the entry site vertically into the abdominal wall about the breadth of 2 fingers above the pubic bone in the midline. (This is typically pointing 10 to 20° caudally from the true vertical because the abdominal wall in children slopes down to the symphysis pubis.)
Aspirate while advancing. Urine will appear in the syringe.
If urine is not obtained, withdraw the needle to the subcutaneous tissue but do not withdraw completely. Then redirect the needle closer to the pubic bone in a downwards direction.
Consider using ultrasound to identify the bladder for real-time ultrasound guidance. Place a sterile cover on the ultrasound probe. Place the probe on the abdominal wall just inferior to the planned needle-insertion site. Follow the needle as it advances through the anterior abdominal wall and into the bladder. When the needle is in the bladder, aspirate the urine.
After collecting adequate urine, withdraw the syringe and needle.
Aftercare for Suprapubic Catheterization in a Child
Place a bandage over the puncture site.
Warning and Common Errors for Suprapubic Catheterization in a Child
Microscopic hematuria is common after the procedure; gross hematuria is uncommon.
Tips and Tricks for Suprapubic Catheterization in a Child
Frequently the child may spontaneously urinate stimulated by the procedure. Be prepared to collect this urine in a sterile container.
During pre-procedure examination or ultrasound, apply minimal pressure to the abdominal wall to avoid triggering urination.
If the bladder appears as a hypoechoic area 2 cm in each dimension, it is possible to obtain about 2 mL of urine.
If the bladder cannot be visualized with ultrasound, there is probably not enough urine due to dehydration or recent voiding. Provide hydration if permitted by the patient's clinical condition and repeat the ultrasound after a few minutes.
