Urinary Cystocentesis

Question 1

What is the definition of cystocentesis?

Answer 1

A procedure where a needle is inserted through the abdominal wall into the urinary bladder to withdraw urine.

Question 2

What is the primary diagnostic advantage of cystocentesis over other collection methods?

Answer 2

It results in less contamination of the sample from the urethra and genital tract.

Question 3

Name four contraindications for performing a cystocentesis.

Answer 3

1. Empty bladder
2. Suspected bladder neoplasia (tumors)
3. Bleeding disorders
4. Patient struggling/lack of restraint

**per lecture, too full of a bladder, cancer, bleeding disorder.

Question 4

What major blood vessel lies dorsal to the bladder and is at risk of laceration during this procedure?

Answer 4

The aorta.

Question 5

What are two potential iatrogenic complications of cystocentesis?

Answer 5

Rupturing the bladder or lacerating the aorta.

Question 6

Can cystocentesis be used for anything other than diagnostics?

Answer 6

Yes, it has therapeutic uses (e.g., relieving pressure in a blocked patient).

Question 7

What are the three common restraint positions for performing a cystocentesis?

Answer 7

Lateral recumbency, dorsal recumbency, or standing (in some dogs).

Question 8

Where is the anatomical landmark for palpating the bladder in a female patient?

Answer 8

On the ventral midline, between the caudal mammary glands.

Question 9

What must you do with the prepuce in a male dog before inserting the needle on the midline?

Answer 9

Reflect it laterally (move it to the side) away from the ventral midline.

Question 10

Where in the abdomen is the urinary bladder located?

Answer 10

The caudal abdomen.

Question 11

What is the role of the non-dominant hand during a blind cystocentesis?

Answer 11

To gently isolate the bladder and elevate it closer to the body wall/skin.

Question 12

What are the two main ways to prepare the skin site before needle insertion?

Answer 12

Clip excess hair (if necessary) and clean the area with alcohol/antiseptic squares.

Question 13

What is the correct needle insertion angle for a patient in dorsal recumbency?

Answer 13

Approximately a 45° angle, directed dorso-caudally.

Question 14

What is the correct needle insertion angle for a patient in lateral recumbency?

Answer 14

Perpendicular (90-degree angle) into the isolated bladder.

Question 15

What is the “Crucial Step” to perform before withdrawing the needle from the bladder?

Answer 15

Always release suction (stop pulling back on the plunger).

Question 16

Why is it vital to release suction before removing the needle?

Answer 16

To avoid transferring urine into the abdomen or pulling blood/abdominal contents into your sample.

Question 17

What should you do if you fail to aspirate urine on the first attempt?

Answer 17

Withdraw the needle and use a new needle/syringe set before trying again.

Question 18

Which way should the indicator notch on the ultrasound probe point during cystocentesis?

Answer 18

Cranially (toward the patient’s head).

Question 19

What is the ultrasound landmark for locating the bladder in a female patient?

Answer 19

An imaginary “X” connecting the two most-caudal nipple pairs.

Question 20

Where is the ultrasound probe placed to locate the bladder in a male dog?

Answer 20

Cranial to the prepuce and slightly off-midline, or lateral to the prepuce.

Question 21

At what angle and position should the needle be introduced relative to the probe?

Answer 21

At a ~45-degree angle, just cranial to the transducer probe.

Question 22

How does the needle appear on an ultrasound screen?

Answer 22

As a hyperechoic (bright white) streak.

Question 23

How does urine/fluid appear on an ultrasound screen?

Answer 23

Anechoic (black).

Question 24

What type of transducer probe is typically used for this procedure?

Answer 24

A micro-convex transducer probe.

Question 25

What technique might be required to penetrate the bladder if the wall is thickened?

Answer 25

An intentional jab of needle pressure.

Question 26

When might pseudo-thickening of the bladder wall occur on ultrasound?

Answer 26

When the bladder is empty or if pathology is present.

Question 27

Name three types of pathology that can be identified via ultrasound during the procedure.

Answer 27

Cystoliths (stones), sedimentation, or tumors.

Question 28

What should you do if sediment or blood clots obstruct your needle during aspiration?

Answer 28

Release suction and bounce the probe on the abdomen to shift contents (without moving the needle).

Question 29

Which two anatomical structures can often be visualized below (dorsal to) the bladder?

Answer 29

The descending aorta and the descending colon.

Question 30

Which urine collection method is the least optimal and has the highest contamination?

Answer 30

Off the floor.

Question 31

What is the preferred technique for a free catch (voided) sample to minimize contamination?

Answer 31

A mid-stream catch.

Question 32

Which specific cells are commonly seen in free catch samples?

Answer 32

Squamous epithelial cells (and contaminating bacteria).

Question 33

What type of cells might be seen in a catheterized sample, particularly if the procedure was traumatic?

Answer 33

Transitional epithelial cells.

Question 34

Why is cystocentesis generally the preferred method for urine collection?

Answer 34

It provides a more sterile sample with the least amount of contamination.

Question 35

What are three major risks associated with performing a cystocentesis?

Answer 35

1. Accidental aortic puncture 2. Vagal response 3. Bladder rupture

Question 36

Why is lateral recumbency preferred for cats and small patients during cystocentesis?

Answer 36

To help avoid puncturing the aorta and for comfort.

Question 37

What is a vagal response?

Answer 37

A reflex of the vagus nerve that causes a sudden drop in heart rate (bradycardia) and blood pressure (hypotension).

Question 38

What can trigger a vagal response during cystocentesis?

Answer 38

Pain, stress, or pressure/manipulation of the abdominal organs.