“Hi doctor. Will you please tell my wife that our baby does not need antibiotics again?” You put on your best mediator smile and ask, “What seems to be going on with your little princess today?” Dad thinks their 6-month-old daughter has simply caught one of the viral infections that has been going around, as both parents and two of her older siblings are also sick. She’s had a fever up to 101.5 for the past few days, but has been eating and drinking at her baseline. Other than an intermittent dry cough, clear rhinorrhea, and being a bit more fussy than usual, the patient has been doing just fine. Mom had taken her earlier this morning to one of those “Doc-In-A-Box” clinics that opened up near the local Wal-Mart, and was surprised when they diagnosed the baby with a urinary tract infection. She told the Dad about her concerns, and now they’re here before you seeking your words of wisdom / second opinion. Mom hands you a copy of the normal chest X-ray results, doctor’s discharge instructions, and the antibiotic prescription from their earlier evaluation. You notice that they had “bagged” the baby for the urine specimen, and that the urine was contaminated by a large number of squamous cells.Dad explains that the baby has been put on antibiotics three times this past winter for “bladder infections” and he’s not too keen on doing it again. You are halfway through explaining how you would like to catheterize the baby for a better urine specimen when Mom interjects and tells you “It’s impossible”. On further evaluation, you discover that the baby has had problems with labial adhesions and her overzealous antibiotic-loving doctors have been treating her based on “bagged” specimens because catheterization has never been successful. She may have had a “true” urinary tract infection when she was younger, but the parents don’t recall the specifics, and they haven’t been able to afford any follow-up other than sporadic visits to local clinics.
You don’t want to miss a urinary tract infection in a young patient who has significant risk factors, but you’re not about to go along with the other practitioner’s plan to “empirically treat” a contaminated urine, at least not without a fight. You have an idea. Thank goodness you’ve been working on your ultrasound skills! You explain that there is a third way to obtain urine, and even though it sounds scary, it is just as safe as the other ways. You then obtain consent to perform a suprapubic bladder aspiration, and go gather your trusty ultrasound machine and supplies. With the ultrasound probe resting gently across the suprapubic region, you obtain the image depicted in Figure 1 showing a full bladder. After you prep the patient and transducer in a sterile fashion, you capture the following image during your aspiration attempt (Figure 2).
Figure 1
Figure 2
1.Bladder aspiration via the suprapubic approach can be performed using anatomical landmarks or direct ultrasound guidance. Studies have shown that ultrasound guidance helps maximize the chances of a successful tap, meanwhile minimizing the risk of complications such as peritoneal or bowel injury.2. Minimize your chances of a dry tap or a procedural complication. Before starting, utilize bedside ultrasound to determine whether or not there is sufficient anechoic urine in the bladder to perform a successful suprapubic bladder aspiration. If the bladder appears empty or contracted, encourage fluid intake and repeat the scan after some time has passed.3. Use a phased array or curvilinear transducer to map out the urinary bladder and surrounding organs using a suprapubic approach. Although it is possible to perform an ultrasound-guided bladder aspiration using endovaginal views, in most clinical scenarios, a suprapubic scan will be more comfortable for the patient and easier for the practitioner.
4. Prior to starting, prep the skin with chlorhexidine (preferred) or betadine. A small amount of local anesthetic may be used depending on physician and/or patient preference. Remember to prep and cover your ultrasound transducer in a sterile fashion before performing an aspiration under dynamic ultrasound guidance. The entire procedure should be performed in a completely sterile fashion.
5. If sterile probe sleeves are temporarily unavailable, use a sterile glove as a substitute sleeve instead. Gel packets (such as Surgilube) can also be used in lieu of other commercially available sterile ultrasound gels when supplies are running low.
6. Ultrasound can be used to help visualize the needle trajectory and location during the aspiration process. During the procedure, angle your needle so that it bisects the ultrasound beam a few centimeters below the skin’s surface. Check this in two perpendicular planes to best position your needle tip right in the center of the bladder, thus minimizing the chance of complications. Determine the needle’s course and trajectory by observing tissue movement and artifacts such as ring down.
7. If you are using a smaller gauge needle, or if the patient possesses a thick bladder wall, you will observe a slight compression of the hyperechoic bladder wall before you feel the “pop” of the needle entering into the bladder lumen.
8. If you are having difficulty aspirating fluid, scan through the bladder in multiple planes to determine the exact position of the needle tip. To ensure that you are not abutted against a fold or side of the bladder wall, gently withdraw or reposition the needle while continuously pulling back on the syringe plunger. Scan through the entire bladder to help determine the redirection angle.
9. Remember that Practice Makes Proficient: With bedside ultrasound there is no substitute for experience.