Fundamentals - Practice & Skills, part 23: Bladder Scanner Use and Urinary Catheters


This article covers bladder scanners and different types of urinary catheters as well as some important considerations when using them. You can follow along with our Fundamentals of Nursing flashcards, which are intended to help RN and PN nursing students study for nursing school exams, including the ATI, HESI, and NCLEX.

Bladder scanners

A bladder scanner is a portable ultrasound device used to measure urinary retention, that is, the volume of urine within the bladder. This can help diagnose things like urinary retention or if the patient is having a large post-void residual (aka “PVR,” the amount of urine that remains in the bladder after urination). An abnormal PVR could indicate a blockage in the urinary tract, an enlarged prostate, or possible side effects from medications the patient may be taking.

Instructions for using a bladder scanner

  1. Encourage the patient to void (if possible) in order to assess the PVR amount.
  2. Turn on the scanner and select the button that indicates whether or not the patient has a uterus (this is important because it will cause the machine to recalibrate accordingly).
  3. Apply ultrasound gel to the patient’s abdomen. Place the scanner 1-inch above the symphysis pubis, a unique joint consisting of a fibrocartilaginous disc sandwiched between the articular surfaces of the pubic bones. Point the scanner toward the bladder. Note that it is important that the scanner is placed above the symphysis pubis because we want to scan the bladder, not the bone mass around it.
  4. Press the SCAN button. Adjust the probe location to center the bladder image on the crosshairs shown on the scanner screen.
  5. Press DONE when satisfied with the results, then print the results.

Urinary catheters

Urinary catheters allow for the drainage of urine from the bladder. These include indwelling catheters, straight or intermittent catheters, and suprapubic catheters, as well as other external collection devices.

Indwelling catheters

An indwelling catheter is a tube inserted into the urethra to allow for continuous drainage of urine from the bladder. It may be called by its brand name, a Foley catheter (but use “indwelling” when referring to these catheters in nursing school).

Indications for use of an indwelling catheter

Indwelling catheters are indicated for patients who may require strict monitoring of intake and output, due to cardiac problems, heart failure, or in a patient who is comatose. They are also indicated for urinary retention, urinary obstruction, bladder irrigation, and severe perineal or sacral wounds.

Risks when using an indwelling catheter

The use of an indwelling catheter increases the risk of CAUTI (catheter-associated urinary tract infection), which can cause pain or even urethral injury. Remember, the longer an external device is inside a patient, the more likely they are to get an infection. The catheter creates a bridge from the outside of the body to the inside, putting the patient at risk.

Indwelling urinary catheter care

The following best practices should be followed when administering a patient’s indwelling catheter.

  • Insert an indwelling catheter using sterile technique and equipment.
  • Hang the bag below the level of the bladder, and place the bag on the bed frame. Do not lay the bag on the floor.
  • To avoid obstruction, frequently check the tubing for kinks and dependent loops. Dependent means affected by gravity, so these are loops in the tubing that obstruct the urine from flowing into the bag. A dependent loop can cause the urine to backflow into the patient, which can cause an infection. Also: ensure the patient is not lying on top of any of the tubing.
  • Clean around the meatus (the point where urine exits the urethra) daily and after each bowel movement. Clean from the meatus outward.
  • If leakage or disconnection occurs, replace both the catheter and collection system.
  • Empty the bag into a graduated container to accurately measure urine output.
  • Remove an indwelling catheter as soon as appropriate. Remember, a nurse’s job is to be the patient’s best advocate, and that can mean advocating to remove an indwelling catheter as soon as it is appropriate. This is to decrease the patient’s risk for infection.

Straight or intermittent urinary catheters

A straight or intermittent catheter is used to drain the bladder a single time or intermittently in the case of chronic urinary retention. It utilizes a narrower tube and, unlike an indwelling catheter, this catheter does not remain in the patient (it goes “straight in” and comes out again immediately after use).

Indications for use of straight or intermittent catheters

Straight or intermittent catheters are indicated for chronic retention (e.g., neurogenic bladder (the nerves that connect the bladder and the spinal cord and brain are not functioning properly) often due to a spinal cord injury) or urine sampling (if unobtainable otherwise). Ideally, after a single use, the patient will be able to void naturally, once the urgent acute retention is relieved.

Risks when using straight or intermittent catheters

As with indwelling catheters, using a straight or intermittent catheter increases the risk of CAUTI.

Suprapubic catheters

A suprapubic catheter is a drainage tube inserted surgically into the bladder through a small incision above the symphysis pubis. This provides long-term continuous bladder drainage.

Indications for use of suprapubic catheters

Suprapubic catheters are indicated for urethral stricture or injury and severe BPH, (benign prostatic hyperplasia, also known as prostate gland enlargement).

Risks when using suprapubic catheters

Because suprapubic catheters are placed surgically, they can increase the risk for infection.

External urine collection devices

External urine collection devices include:

Condom catheters for males

A condom catheter is a rubber sheath rolled down the shaft of the penis and connected to a drainage bag.

Wicking devices for females

A wicking device employs a tube placed between the labia made of wicking material that is attached to suction, actively removing the urine as it is expelled from the body.

Indications for use of external urine collection devices

These kinds of devices are good at reducing the risk of infection. They are indicted for incontinence, but they are not effective in the case of obstruction or retention.

Risks when using external urine collection devices

Because the skin is possibly sitting in moisture for a prolonged period of time, the patient is at increased risk for skin breakdown, especially with condom catheters.

Full Transcript: Fundamentals - Practice & Skills, part 23: Bladder Scanner Use and Urinary Catheters

Hi, I'm Meris. And in this video, we're going to be talking about bladder scanners and different types of urinary catheters and important considerations for them. I'm going to be following along using our Fundamentals of Nursing flashcards. These are available on our website, But if you already have your own, I'd invite you to follow along with me. I'm starting on card number 120. Let's get started. So before we start, I wanted to tell you that if you stay until the end, I'm going to tell you a really important piece of advice that my fundamental skills professor taught me when I was in nursing school that I want to pass along to you. So let's go ahead and talk about bladder scanners. As you can see here on this card, we do have a step-by-step list of how to use a bladder scanner. I'll let you look at that in your own time. But the most important thing that I want to get across to you is, why do we use a bladder scanner? So the bladder scanner uses ultrasonography to assess how much fluid, how much urine, is in a patient's bladder. So this can help us diagnose things like urinary retention or if they're having a large post-void residual. The big, bold, red stuff here on this card is telling you about the placement of the transducer. You want to make sure that it is above the pubic symphysis because we're not trying to scan bone, so about one inch above that and point it down towards the bladder. Another thing I want to point out is to make sure that you use the button on the machine to select whether or not your patient has a uterus because this changes how the machine calculates or what it looks for. So be sure to think about that when you're using a bladder scanner.

All right. So now, let's talk about different types of urinary catheters. Here on card 121 we talk about the difference between an indwelling catheter and a straight or intermittent catheter. So indwelling is what the name suggests. It stays in. That's where it dwells for a while. So you might hear this called a Foley catheter sometimes, but Foley is actually a brand name. So indwelling catheters is what you should be calling it in nursing school. So this is really helpful for patients who have things like the need for really strict intake and output, things like cardiac problems, heart failure, a patient who's comatose, all of those different indications. But what's your biggest concern when you think about a patient with an indwelling catheter? What's your biggest concern? Pause the video and think about it. I hope you paused it. If you did, it should be a catheter-associated UTI. The longer an external device is inside your patient, the more likely they are to get an infection. You're creating a bridge from the outside to the inside, so this puts your patient at risk for a CAUTI, catheter-associated UTI.

Now, a straight or intermittent catheter, again, what it sounds like. It goes straight in and back out, so it doesn't stay in there. This is much skinnier, much shorter duration of use. And usually, this is used to get a sterile specimen or to treat a patient's urinary retention with the hopes that they're going to be able to void after the urgent acute retention is relieved. Now, if you look on card 122, we talk about two other types of catheters. I'm not going to go super in-depth into these. I'll let you look into them in your own time, but this is suprapubic, so meaning above the pubic bone. Supra is above and external, meaning not inside your patient. So suprapubic catheters are going to be placed surgically. They go through the skin, so a big, big risk for infection. External catheter's really great at decreasing the risk of infection. But now if I have my skin possibly sitting in moisture for a prolonged period of time, what am I at risk for? Pause the video and think about it. I'm at risk for skin breakdown especially with what we call a condom catheter. There are also external devices such as wicking devices for a patient who does not have a penis. So these actually are connected to suction, and they actively remove the urine as it is expelled from the body.

All right. This card 123 is one that I would say really, really focus and spend your time on. This has to do with the care of an indwelling urinary catheter. So a lot of important stuff to know, such as when we put it in, we use sterile technique, not clean technique, sterile. The bag should always hang below the level of the bladder, and we want it to be on the bed frame. We want to check for any kinks in the tubing. And we always want to make sure that we don't have any dependent loops. Dependent means affected by gravity, so any loops where we can't get the urine to go into the bag. Because basically, if I have a loop, the urine from the patient is going to have to have enough force to go around the loop to get into the bag. We don't want that because now we're at risk for urine backflowing into our patient and, again, infection. Other things to know is that we need to remove these catheters as soon as appropriate. So as the nurse, your job is to be your patient's best advocate. You need to advocate to remove an indwelling catheter as soon as it is appropriate to decrease your patient's risk for infection. Be sure to look over the other important points on that card, but those are definitely the highlights.

All right. So that is it for our review of bladder scanners and urinary catheters. I hope it was helpful. If it was, please, go ahead and like the video. And I would love to hear any advice or tips or ways to remember things that you might have. If you want to leave me a comment, I would love to read them. Be sure to subscribe to our channel. You want to be the first to know when our new videos come out. Next up, we're going to be talking about constipation, diarrhea, and ostomies. Thanks so much, and see you next time.

Okay. So when I was in fundamental skills, my professor told me that you don't have to empty the Foley drainage bag before removing it. You can remove the Foley first and then empty the drainage bag. But she told me that it's her experience and her best advice that you should always drain the bag first before removing the catheter. Because one time, she removed the catheter then went to empty the bag, and the catheter flopped down and hit her in the face. So immediately, that was seared into my memory for the rest of my life. I will never remove a Foley without emptying the bag first, so that way, you empty it. You can measure it. And then you remove the Foley and put it immediately in the disposal. You don't want to be touching that anymore. You don't want it resting on the bed. So maybe that helps you. But if you have any other really good advice, I want to hear it.

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