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Preliminary Surgical Assessment for the CPE

Updated: Apr 27

This post was inspired by a colleague of mine who graduated from an international veterinary school, who is preparing for licensure in Canada. The PSA (preliminary skills assessment) is the first practical exam (not like the sit-down exam of the NAVLE).

In addition to this site, I’ve compiled some YouTube videos. If there are any skills in there that I do differently, I will let you know.

1) Prepare a cadaver (or simulation model) in a sterile manner for a laparotomy (essentially sterile prep for a spay procedure).

In veterinary school, we don’t do the CPE as one big exam. We are evaluated over our four years on our clinical skills. Year 1, we had to learn how to suture, as well as the names of instruments and what they were used for. Year 2 we are scrubbing ourselves and our ’patients‘ aka cadavers. Year 3 we are doing actual surgery!

For the PSA, you will need to demonstrate that you can prepare your patient to prevent infection.

Just like washing your hands, scrubbing your patient is about contact time. If your patient comes in filthy, you will need to do an initial scrub, then a sterile scrub.

The technician in the video below does a great job at demonstrating scrubbing the patient, first by starting at the midline where you will make your incision, and circling outwards. Since it is about contact time, you will want to keep doing this for a three minute scrub. Many technicians will do an initial scrub in their induction room, then move the patient into the OR for a final scrub. You should not be clipping the hair in the OR.

Since I scrub myself differently than the doctor in this video, use this video as a guide for preparing your patient for its spay procedure, not for preparing yourself.

2) Prepare yourself for a sterile surgical procedure

This will include a sterile scrub of your hands/arms and sterile ‘Gowning and Gloving’

When you are preparing for a spay, you need to have your scrubs or whatever else you wear, covered with a sterile gown. This is something that takes practice, especially with how to put on your gloves while maintaining sterility.

In school, the first thing we would do is find our glove size, open the gown pack, open the gloves in a sterile fashion, drop the sterile gloves on the gown’s sterile field, then go scrub ourselves. One thing to note, there seems to be some variability in veterinary clinics, but the gowns should be double wrapped. Just don’t be surprised if they are not. If they are double wrapped, open each layer in a sterile fashion. The tab of the flap furthest away from you is opened first! Then the sides, then the tab closest to you, in order to not have your dirty arms hang over the sterile field.

What I didn’t like about that first video above was that the doctor opened his gloves to the side (which would be ok for an open-gloved technique), and the scrub brush was on his sterile gown which he had to pick up with his dirty hands.

The five-minute sterile scrub can be separated into one minute per hand, one minute per arm, then a final minute of contact time on your hands.

Above are the scrub sponges we used. Prewash your hands. Open the package for the scrub sponge. Then clean your finger nails first (this is not included in the five minutes of contact time). Toss the pick. Pick up the sponge and wet it to get suds. Scrub all four sides of every finger and thumb, palm, back of the hand. You can watch the clock, or count the passes of the scrub brush on each side of your fingers to pass the time. Then switch hands. Then go from the wrist towards the elbow in a circumferential manner, and switch arms. Taking some of the chlorhexidine from the sponge, drop the sponge, then rub the suds on your hands for the final minute. Do this all while not touching the sink or faucet, and keeping your hands up so the suds go from hands to elbows.

Here’s a great video that shows surgical scrubbing nicely.

After you have scrubbed, it’s time to dry off. In the video below, the technician does a great job at drying so have a look and listen.

This video shows how to don your gloves in the closed glove gowning technique, including some common mistakes people make. The only thing it does not include, is how to open the sterile pack that your gown is kept in.

Practice, practice! Have a friend watch you and give you tips. They should point out where and when you broke sterility.

3) Perform a ventral midline celiotomy/laparotomy and close the ventral midline celiotomy, subcutaneous tissue and skin on cadaver.

Now that you are sterile it’s time for surgery. Your pack will be partially opened by your technician, and you open the last wrap in the same fashion as above (the flap away from you first). If for some reason the pack is on the table or mayo stand in the opposite direction, you can ask for assistance to turn the table, but hopefully they do not try to trick you.

You will drape your patient, either with a single slit drape, or using four separate drapes to cover the dirty part of the patient. Use the towel clamps to secure your drape(s). You may have the option for four drapes, and a slit drape. So drape the four sides first, clamp, then place the slit drape. When opening the slit drape, open away from you first, then towards you. Make sure to never reach your sterile gloved hands under the drape edges.

To see one way to drape using four drapes and a large one (which you cut the slit on) here.

Once your patient is draped, you’re ready to start surgery.

The celiotomy is essentially opening up the body cavity of your patient in preparation for a spay (or any other abdominal procedure, like an exploratory laparotomy). Then closing the body cavity in three layers.

In school, we were taught to incise the skin with a #10 scalpel blade, and switch the scalpel handle to a #15 to enter the peritoneal cavity. The reason for this is that the skin is clean, but not sterile. The peritoneum is sterile (in your healthy spay patient). Depending on who is evaluating you, you should be prepared to switch blades after the skin is incised.

When entering the peritoneal cavity, don’t forget to tent the linea alba so that you don’t accidentally stab the organs underneath. Depending on your schooling, you may extend the linea using scissors, or how I learnt was to use thumb forceps as a guide to lift the linea away from structures and use my #15 scalpel blade to extend the incision.

Here’s a video on opening the abdomen.

Once you’re in, you’re going to close the body wall for this preliminary part of the exam.

Closure is in three layers:

1) linea alba

2) subcutaneous layer

3) skin

Closing the linea

Again, depending on who taught your surgical skills training will depend on how you close. I close in a simple continuous and rarely close any other way.

Some tips include:

  • start closing at 3-5 mm caudal to the incision, and end 3-5 mm cranial to the incision. This helps prevent a space between the end of the incision and the knot.

  • Clear the linea, especially the ends, of the subcutaneous tissue, or it may be difficult to see when you go to close.

  • Take bites only through the rectus sheath, remember, muscle does not hold suture and will tear through.

  • If using a continuous pattern, ensure you have the correct number of throws to provide a secure knot on both ends (6-8, depending on if you used a surgeons knot or not)

  • Choose the right suture size for the amount of weight it needs to hold (3-0 Monocryl or PDS might be ok for a cat, but not a large dog)

This is a lengthy video and she is using a laser, which you are unlikely to have for your exam. So maybe ignore that for the time being. If you scroll to minute 49 or so, you will see an example of a three layer closure, using a simple continuous pattern on the linea. I also like that she demonstrates checking the linea for any spaces that could lead to herniation of internal organs. If there is a space, just add a simple interrupted ligature in that spot.

This video shows closure of the linea using a cruciate pattern.

Closing the Subcutaneous Layer

The purpose of closing the subcutaneous layer is to minimize the dead space. You can prevent seroma formation if you bring the tissues together.

There are different ways to close the SQ just as there are for the linea, just stick with what you are comfortable with. Use this layer to help bring the two edges of the skin closer together for your skin closure.

Closing the skin

For the skin on a spay, I like to make things pretty. This is the part the pet owner sees. For a healthy spay I always close with an intradermal pattern. I’ll use a 3-0 reverse cutting needle, or sometimes in young cats a 4-0 as it is less bulky.

Make sure you practice burying the knot!

For one example of burying the knot for simple interrupted visit here.

My final tip for preparing for the PSA is: If possible, job shadow a veterinarian to help with your clinical skills.

Good luck on your examination!

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