Urine collection Flashcards
Why is urine sample and collection so important
Sample MUST be collected and stored properly
* Can lead to an incorrect diagnosis/treatment or a condition can be missed completely
When collecting a urinary sample, you want to avoid:
- Injury to the urinary tract system
- Injury to the reproductive system
- Inadvertent introduction of an infection
Goal of urine collection
- Obtain a urine sample, which when tested, will produce results that reflect its characteristics in the animal
- You want to make sure to collect enough urine to run all the possible tests required
- ~ 5 mls for small animals
- ~ 10 mls for large animals
What is Important when collecting for culture
Make sure it is collected using aseptic technique and put in a sterile container
What is the best practice to keep aseptic technique when taking urine
- Collect your sample –> Aseptically transfer a small amount (~ 1 cc) to a sterile container (red- top tube or transport media tube) to be saved in case of culture –> Run other tests on rest of sample
Containers for urine collection
Can be disposable or reusable
* If storage is required a tight fitting lid is essential
* Must be dry and free of chemical residue
* Transparent containers help with the physical exam of the urine but are not essential
Micturition is
Free catch/voided/midstream
What are the sample collection methods
- Natural micturition (free catch)
- Manual expression
- Cystocentesis
- Catheterization
* Each has its advantages and disadvantages
* Regardless of which method is used you must make note of it in the record and remember what implications it will have on results
What is micturition
This is collecting a urine sample as the patient voids it
* Morning sample is preferred
* Midstream free catch is ideal
* Cannot be used for samples that need to be cultured but is fine for routine urinalysis
* Bacteria not necessarily from the bladder
Advantages of micturition
No known risks
o Clients can collect it
o Provides information on urethra
Disadvantages of micturition
Sample is likely to be contaminated with flora from urethra, prostate and seminal glands, vagina, vulva, prepuce
o You may see increased epithelial cells, mucus content, bacteria, and other debris
Cells should not be clumped in a normal sample
o Doesn’t always occur when needed
Procedure when collecting urine via micturition
- When performing in clinic clean external genitalia first
- Try to avoid the first portion of the sample, this will help remove some contaminants
- Place a clean dry container under the pet when it urinates
- Make sure to ask the owner if their pet has a pee command such as:
“Go pee”, “Do your business”, etc.
How to make sure owners bring proper free catch samples
Owners will often collect samples at home and then bring them in
* Make sure they bring them in in an appropriate container or send them home with one.
* Sample needs to be refrigerated if not
examined or dropped off at the clinic right away
* Nosorb (little plastic pellets) can be used in place of kitty litter to collect sample
Inappropriate free catch containers are
- Old pill vials
- Make up containers
- Vinegar jugs
- Tin cans, etc.
Manual expression is
- Using external pressure to cause the bladder to release urine
- Used in dogs and cats
- Only works if under anesthesia or had certain bladder pathology such as decreased nerve control of bladder
Advantages of manual expression
Low level of risk
Disadvantages of manual expression
- If care is not taken it can result in bladder or kidney damage
- Should never be used on patients with possible blockage of the urethra or fragile bladder walls
- May cause them to rupture
- Sample will contain flora from lower urinary tract (same as free catch)
- May result in trauma to bladder wall causing increased RBCs and epithelial cells that are artifacts
Procedure with manual expression
- Clean the external genitalia
- Patient can be standing or in lateral recumbency
- Palpate the bladder in the caudal abdomen
- Apply steady gentle pressure over a large area of the bladder to express urine
- Be patient it may take a few minutes for the sphincter muscles to relax
AVOID EXCESSIVE PRESSURE
Cystocentesis is
Using a sterile needle to remove urine directly from the bladder through the abdominal wall
* Relatively common
* Can be performed by DVM or RVT
* Gold standard is to use an ultrasound to assist in finding the bladder
* The bladder must be relatively full in order to perform with least risk
How to preform manual expression with LA
In large animals we can stimulate them to urinate by maintaining pressure on the bladder wall through rectal palpation or washing the perianal area
Advantages of cysto
Produces a sample upon demand
* Less likelihood of producing an iatrogenic infection compared to a catheterized sample
* Often better tolerated by patients
* Sterile sample
* Sedation is seldom required
Disadvantages of cysto
Almost always requires two or more people
* May see an increase in RBC’s and hemoglobin content on analysis
* If the animal has a urinary obstruction or is overextended it may cause the bladder to rupture or urine leak into the peritoneum
* Injury can occur if the bladder is too empty or the animal struggles (ultrasound guided)
* May have risk of bleeding (puncture of bladder vessel)
* Risk of iatrogenic infection if intestines are nicked
Contraindications of cysto
Patients with bleeding disorders
Potential pyometra
Pregnant
Obese
Overextended bladder
Empty bladder
Prostatic abscess
Suspected bladder cancer
Required equipment for cysto
Syringe and needle
* Everything must stay sterile
* Syringe: 3 –10 ml depending on size of animal
* Needle:
* Cat 22g (or 23g), 1½”
* Dog 22g (21 – 23g), 1½”
* Skin prep
* Alcohol skin prep
* Sterile collection container
* Red top vacutainers
* Urine cups
* Ultrasound (optional)
* Trained personnel
Procedure with cysto
- Place patient in dorsal recumbency
- Palpate the bladder
* Make sure it contains sufficient urine - Disinfect the skin with 70% isopropyl alcohol
* Male dogs – caudal to the umbilicus and lateral to the sheath
* Female dogs and cats – ventral midline caudal to the umbilicus - Isolate the bladder in front of pubis with your non-dominant hand or off-hand
* Do not squeeze or apply excessive force to the bladder, you are only immobilizing it - Agitate the bladder if tolerated (suspends sediment)
- Prepare syringe:
* Ensure needle is securely attached to syringe
* Loosen cap
* Break plunger seal by pushing into the syringe barrel (do NOT pull back as that will draw contaminated air into the syringe) - Insert needle at the most cranial midline aspect of the bladder
* Direct needle dorso-caudally (towards the neck of the bladder) at a 45°-70̊ angle
* This way as the bladder shrinks the needle tip remains in the lumen
of the bladder - Insert needle smoothly without redirecting or side ways movements
- Transfer to a sterile container
How to collect a cysto sample
Once the needle is inserted through the ventral abdominal wall and into the bladder apply negative pressure
* Pull pack on the syringe plunger in a slow, consistent manner
* Make sure urine comes into the syringe
* If anything other than urine enters syringe stop negative pressure immediately and withdraw the syringe – DO NOT REDIRECT
* Blood, fecal matter, or air
* Get a new needle and syringe and try once more
* Do not try more than twice
* Draw up sample with continuous pressure
* Once the syringe contains an adequate sample stop negative pressure
* Let go of plunger so there is no more negative pressure and withdraw the needle from the bladder
* Remove the needle from the bladder and abdomen following the same path as insertion
* Maintain aseptic technique throughout the
procedure
How to transfer urine into collection tube with cysto
- Detach the needle from syringe aseptically
- If using a vacutainer place a new needle on and puncture lid and let the syringe empty on its own.
- If not a vacutainer, open the lid of the sterile container aseptically
- Make sure not to place the lid onto the counter
- Place the urine into the container aseptically and replace the lid
- Do not touch the inside of the container or lid with your hands or syringe
What to label on urine samples
Patient ID
Date
Time of collection
Method of collection
How to store a urine sample
Ideally – samples analyzed within 30 – 60 minutes
* If not possible:
* Aseptic sample to be stored in fridge (or on ice) ASAP
* Urine strip and microscopic exam should be conducted immediately
* If not possible - store in fridge but bring to room temperature before conducting urinalysis
Catheterization is
- Insertion of a urinary catheter into the bladder via the urethra to remove urine
- Avoid unnecessary catheterization or force when doing the procedure
Advantages of catheterization
- Less contamination then micturition
- Collect it when you need it
- Allows for continuous emptying of the bladder
- Ex: in the event patient cannot relieve themselves
Disadvantages of catheterization
Requires two or more people (one of whom must be well trained) or heavy sedation/anesthesia
* May see cell clumping and increased RBC’s
* May cause trauma to the urinary tract
* High risk of iatrogenic urinary tract infection
Why is catheterization used
Catheterization may be done for other reasons besides collecting urine
* To instil contrast media for radiograph’s
* A Foley catheter (has a wire stylette inside a soft tubing – causes little injury to the urinary tract system) is used to put air into the bladder as a contrast on radiographs
* Used for the administration of certain medications
* To prevent contamination of a surgical site
* During surgical procedures like a nephrectomy or cystotomy
* To facilitate surgical repair of the urethra or surrounding tissues
* Monitoring urine output
* Renal function tests
* Relieve structural or functional urethral obstruction
Special considerations with urinary catheterization
Hematuria associated with catheterization is usually self-limiting but it does predispose the tissues to infection
* The lower urinary tract has a normal flora consisting of many gram negative organisms and mycoplasma
* There is always a risk of infection no matter how well the technique is performed
* You need to encourage the patient to urinate after catheterization to help flush the bladder
What equipment is needed for a urinary catheter
Sterile gloves
* Sterile lubricant
* Sterile appropriate urinary catheter
* Will vary with species and reason for catheterization
* Sterile flush solution (0.9% NaCl)
* Sterile syringes
* Number and size of syringes depends on reason for urinary catheterization
* Sample collection or emptying of bladder
* Sterile container for sample if sending for culture and sensitivity
* Trained personnel
* Female patients a speculum improves visualization of the urethral orifice
How are catheters sized
Catheters are commonly measured on the French (Fr) Scale
* 1Fr = mm⅓ 3Fr catheter = 1mm diameter
* 3Fr is an appropriate starting size for cats
Considerations with catheters
- Catheters need to be smooth, clean, sterile, and the right size.
- DO NOT RE-USE!
- Easiest to purchase single-use catheters
- If sterilizing, often cold sterilization solution is used so MUST FLUSH THOROUGHLY WITH STERILE WATER
- Cold sterilizing solutions leave a residue that causes tissue damage
Types of urinary cathaters
Tomcat catheters
* Open or closed ends
* Open ended are typically only used for unblocking
* For cats and small dogs
* Polypropylene catheter
* Rubber catheters
* Foley Catheters
* Stainless steel catheters (females only)
* Olive-tipped metal catheter (removing urethral blockages only)
What to do once the catheter is placed
- Catheters may be sutured in place after relieving obstructed urine flow (common in cats) to allow for healing
- Indwelling catheter
- These need to be non-traumatic
- Made of soft rubber such as with rubber feeding tubes
Basic procedure with catheters
- Varies with species and gender
- Depending on the patient they may require sedation or general anesthesia
- All require cleaning of the external genitalia
- The use of sterile gloves and the maintenance of a sterile field.
- You must make sure to maintain aseptic technique throughout the procedure
How to place a catheter in a male cat
This is often done under sedation/anesthesia but does not have to be
1. Prepare all materials
2. Place the cat in lateral or dorsal recumbency
3. Don sterile gloves
4. Extrude the penis
5. Wash the end of the penis with an antiseptic soap then rinse with sterile saline
6. Pull the penis straight back caudally (towards the tail) to remove curvature of the urethra and make passage easier
7. Lubricate the catheter tip with sterile lubricant
8. Always maintain sterility of the catheter
9. Gently insert catheter tip into the external urethral orifice and advance until urine flows (in lumen of bladder)
10. Attach a sterile 3 ml syringe and gently aspirate 0.5 to 1 ml of urine, detach syringe and discard*
11. Attach a sterile 5 ml syringe and gently aspirate the remainder of the urine from the bladder
12. Place urine for culture in a sterile container and perform tests on the remainder of the sample
How to extrude a male cats penis
- Push penis caudal and pull prepuce forward
- Maintain this position by gently pinching the prepuce at the base of the penis. Make sure you are not obstructing the urethra with the pressure of your fingers
What to do in a male cat if the catheter is not advancing
- If resistance is met, you can flush the catheter with sterile saline this will alter test results and must be reported
How to lubricate a catheter tip
- From a sterile single use package and place on the tip of catheter from package – make sure not to touch the edges of package to catheter
- From a large tube and discard initial small amount of lube and then put directly on the tip of catheter without touching the catheter
- Put lubricant on a sterile 3 x 3 gauze and wipe the lubricant on the end of the catheter
When is a female cats catheter done
Rarely done
* It is often difficult to find the urethral orifice
* Especially if obese
* Cystocentesis is easier on all involved
Male dog catheterization
- Very easy and done often
- Seldom requires sedation
- Place in lateral recumbency
- Can be placed in dorsal recumbency
- Estimate length of catheter
- Hold the catheter above the dog and measure from the penile tip around the ischial arch to the likely bladder position
- Maintain sterility of the catheter
Procedure when placing a male dogs catheter
- Don sterile gloves
- Extrude penis
- Clean periurethral area with a mild antibacterial soap then rinse with sterile saline
- Lubricate catheter tip with sterile lubricant
- Always maintain sterility of the catheter
- Gently insert the catheter tip into the urethra and advance to the point where urine flows freely
* Do not advance too far and do not force - Attach a sterile 3 ml syringe and gently aspirate 0.5 to 1 ml of urine, detach syringe and discard*
- Attach a sterile 5 – 10 ml syringe and gently aspirate the remainder of the urine from the bladder
- Place urine for culture in a sterile container and perform tests on the remainder of the sample
How to extrude a male dogs penis
- Push penis cranially from the base and pull prepuce caudally off of the penis
- Be careful not to obstruct the urethra with finger pressure
- You may have a second person perform this while you insert the catheter
Why is a female dogs catheterization so different
- The external urethral orifice is located on the ventral floor of the caudal vagina
- In mature small to medium sized dogs, it is 3-5 cm cranial to the vulvar opening (further internal to the clitoral fossa)
- The caudal portion of the vagina is directed dorso-cranial (towards the spine and head)
- Make sure to direct catheter near the dorsal commissure of the vulva to avoid the sensitive clitoral fossa
Female dog catheterization is done in what position
- Usually performed with sedation
- Place the dog in standing position if not sedated or in sternal recumbency with the hind feet draped over the edge of the table
- Best done with the use of a speculum but can be performed without one
Basic procedure with female dog catheterization
- Clean the perivulvar skin and vulva with an antiseptic solution and rinse with sterile saline
- Don Sterile gloves
- Flush the vagina and vestibule with sterile saline using a sterile 5-10 ml syringe
How to use a speculum with female catheterization
- Once passed through the vulvar lips, insert the speculum dorso-cranial
* Avoids the clitoral fossa - Spread the speculum open to visualize the vestibule and vagina
* A light source will make this easier - Identify the urethral orifice
- Lubricate the tip of the urinary catheter
- Gently insert the catheter into the urethral orifice and advance slowly into the lumen of the bladder
- Attach a sterile 3 ml syringe and gently aspirate 0.5 to 1 ml of urine, detach syringe and discard*
- Attach a sterile 5 – 10 ml syringe and gently aspirate the remainder of the urine from the bladder
- Place urine for culture in a sterile container and perform tests on the remainder of the sample
Blind digital technique is used on what dogs
Large breed female dogs
How foes the procedure differ with the blind digit technique
- Lubricate the index finger of your non-dominant hand or off-hand with sterile lubricant
- Insert the index finger into the vagina
* You may be able to palpate the urethral orifice - Lubricate the tip of the urinary catheter
- Gently insert the catheter through the dorsal commissure of the vulva
* Avoid the clitoral fossa - Guide the urinary catheter under the inserted index finger and along the ventral floor into the urethral orifice
- Gently advance the catheter into the lumen of the bladder
- Attach a sterile 3 ml syringe and gently aspirate 0.5 to 1 ml of urine, detach syringe and discard*
- Attach a sterile 5 – 10 ml syringe and gently aspirate the remainder of the urine from the bladder
- Place urine for culture in a sterile container and perform tests on the remainder of the sample
Why is urine sample preservation done and when
- Urine is considered unstable so should be looked at as soon as possible (within 30-60 minutes)
- The longer the sample sits at room temperature the more ureases–producing bacteria proliferate causing the sample to become more alkaline
- Record when the sample was collected and when it was analysed
- Refrigeration is the most common form of short-term storage and preservation – can be used for 6 to 12 hours
How to preserve a sample for over 6 hours
- Samples that require storage for more than 6 –12 hours can be preserved by adding one of the following:
- 1 drop 40% formalin to 29.6 ml of urine
- Must do chemical analysis first
- Toluene sufficient to form a layer on top
- One thymol crystal
- One part 5% phenol to nine parts urine
- Unfortunately, no single preservative agent is satisfactory for all routine U/A tests
Why does urine need to be room temp after being preserved
Remember samples need to be warmed to room temperature before analysis
* Too cool = USG will be increased
= enzyme-based reactions are decreased
= crystals form
*Abnormalities found on stored samples should be
retested on a fresh sample
Closed collection system with urinary catheter is
- Catheter will be sutured/anchored to patient once in place
- Attach catheter to a sterile extension set
- Attach extension set to sterile drip/infusion set
- Attach drip set to sterile IV bag
- Air must be forced out of bag BEFORE attaching to the drip set
- This allows the bag to work as a vacuum
- Ensure an adequate amount of the drip set is left inside the kennel with the patient
- This will allow them to move around without causing traction
- The drip set will need to be anchored to the kennel wall or door in some fashion so that it does not slide down
- The collection bag is appropriately suspended below the level of the patient’s bladder but must not rest on the floor
- Bag can be marked appropriately to monitor collection/drainage
