Patient Injury & Complications In Veterinary Dentistry

The nature of anesthesia brings risk in general. In veterinary medicine, during dental procedures, pets are often placed in vulnerable positions which can lead to increased risk of injury and medical complications.

These risks can be minimized or entirely avoided with careful consideration, and proper training and continuing education of staff. Listed are a few of the more common injuries that can occur during a dental procedure.

Aspiration Pneumonia

Aspiration pneumonia in pet patients occurs when the patient inhales a foreign substance and develops lung inflammation and infection as a result.

The most common occurrence during dentistry is water and debris entering an unprotected airway, hence allowing fluid and debris to enter the lungs. This can occur from an underinflated tracheal tube, or repositioning during the procedure that allows fluid to enter the airway.

Aspiration pneumonia can also occur if the patient vomits or regurgitates during anesthetic recovery.. To reduce the incidence of dental-related aspiration pneumonia, maintaining the patient on their back during the procedure, and avoiding repositioning has proven to not only lessen the risk of aspiration but also lessens the amount of anesthesia needed during the procedure.

In addition, antiemetic medications given during the premedication phase can help reduce the incidence of post-anesthetic nausea and vomiting. Caution should be taken during the recovery phase to wait until the patient is alert and responsive enough to deflate the cuff and remove the tracheal tube.

Tracheal rupture

Tracheal rupture in dogs and cats are more frequent during dental procedures than any other medical procedure. Seventy-five percent of tracheal ruptures are thought to be associated with oral surgical procedures with the incidence more common in cats than dogs.

Tracheal injury can cause symptoms such as mild dyspnea, and even death. The most likely cause of tracheal rupture is thought to be due to an overinflated tracheal cuff, as well as failing to detach the tracheal tube from the anesthesia hose during repositioning, which can cause a torque on the inflated cuff resulting in a tear of the dorsal membrane of the trachea.

Another common cause of tracheal rupture is a patient that is not adequately anesthetized and coughs or lunges upward during intubation, tearing the trachea.

Pressure from an overinflated cuff can cause pressure necrosis of the trachea, showing delayed symptoms of inflammation and scarring.

Avoiding over-inflation of the cuff, using new tracheal tubes, testing the cuff to ensure proper inflation prior to use, avoiding repositioning as much as possible, and ensuring a level plane of anesthesia prior to intubation can help minimize the risk of tracheal rupture.

Artery Damage during Tooth Extractions

Arterial damage to arteries such as the palatine artery which runs the length of the mandible can accidentally occur during routine tooth extractions where the instrument can slip from the practitioner’s hand.

These injuries can be mild to more severe requiring surgical intervention.

The most effective way to avoid this type of injury is to implement extraction techniques involving gingival flaps where the roots are exposed, and more easily undermined, and extracted. 

Written by: Dr. Tammy Powell, DVM

Ultrasound-Guided Cystocentesis: How and Why to Do One

There are several ways to collect a urine sample from your patient, including free catching, using a urinary catheter, and doing a cystocentesis.

A cystocentesis—which involves obtaining a urine sample via a needle placed directly into the bladder—may be the preferred method in many cases.

This is especially true when you need a sterile urine sample, such as for culture and sensitivity testing for UTIs. And in general, a cystocentesis will provide more accurate results than a free catch urine sample, since it reduces contamination from cells or pathogens of the skin.

It’s possible to perform a cystocentesis by palpating the bladder or using anatomical landmarks alone. However, an ultrasound can make the process easier by removing the guesswork and allowing you to visualize everything.

Here’s how it works…

How to perform an ultrasound-guided cystocentesis for dogs and cats

1. Prepare for the procedure.

   • Use an appropriate size syringe (usually 3ml to 12ml) based on the size of your patient.

   • Choose a needle size and length based on your patient size. A 22g needle works well for many patients.

   • Use a towel, trough, or other cushioning to make your patient more comfortable during the procedure. This may help minimize their movement.

2. Use appropriate patient restraint.

   • For some dogs and cats, this could mean having a trained team member hold them. For very anxious or fractious patients, this might mean chemical restraint.

   • Dorsal recumbency is generally the best way to position your patient.

   • Be sure to clean the area of skin where you’ll be performing the cystocentesis. If needed, consider clipping the fur, too. 

3. Estimate the bladder location.

   • You’ll use your ultrasound to see the bladder, but anatomical landmarks will give you a good starting point for where to place the probe. Try one of these methods…

     • Locate the caudal four mammary nipples and mentally draw an ‘X’ between them. The bladder will often be near the cross point of the ‘X’.

     • Place a small amount of alcohol on the caudal abdomen so it pools. Often, the bladder is located directly under where the alcohol naturally pools on the midline.

4. Visualize the bladder.

   • Place your probe onto the caudal abdomen. You should be able to see the urinary bladder on the screen—it’s a fluid-filled structure that has the appearance of a ‘black balloon’ with gray or white walls.

5. Check for any abnormalities.

   • You could focus on just doing the cystocentesis. However, while you’re visualizing the bladder, it may help to do a cursory exam (or even a more in-depth evaluation, if indicated) to look for any problems contributing to the patient’s urinary symptoms. 

     • For example, note if you see any thickenings, masses, calculi, or other issues in the urinary bladder.

6. Obtain the urine sample.

   • Place the needle directly through the abdominal wall, just in front of the ultrasound probe.

   • Aim the needle slightly caudally.

   • You should see the needle on your ultrasound screen. Use this visual to guide you, to be sure you get a good, clean sample rather than aspirating part of the bladder wall.

7. Prepare your sample for analysis.

   • Right after the cysto, replace the needle on the syringe with a sterile one.

   • Then, divide and prepare the sample in a timely manner (the fresher the sample, the better for testing) for any tests you need to perform, whether that’s in-house or at an outside lab.

In many veterinary hospitals, cystocentesis is safely performed several times per day, and complications are very rare. However, as with all medical procedures, some risks exist.

These may include…

• Hematuria (usually mild and transient).

• Much rarer complications such as bladder injury, leakage of urine into the abdomen, puncture of internal organs or blood vessels, or vagal reactions (retching, panting, hypersalivation, collapse). 

• Seeding of tumors.

  • If you suspect your patient has a bladder tumor such as transitional cell carcinoma, it may be best to avoid a cystocentesis. Otherwise, the needle could ‘seed’ the tumor as you withdraw your sample from the bladder, allowing cancer to spread into the abdominal cavity.

An ultrasound may help you to notice abnormalities such as bladder tumors during the procedure, in which case your recommendation to the client may change.

Fortunately for most pets, a cystocentesis is a quick outpatient procedure that provides a lot of valuable information. And many dogs and cats don’t show any side effects at all.

For patients with urinary symptoms, a cystocentesis is often the way to go for the most accurate diagnostic testing results and to get to the bottom of the issue faster for healthy pets and happy clients.

Written by: Dr. Tammy Powell, DVM

5 Tips for Radiation Safety During Uncertain Times

Your x-ray unit is something you use frequently—probably every day, or multiple times per day—in your practice.

You know radiation safety is important. But recently, if you’ve had to reduce the number of team members in the building at any given time, maybe it feels like there aren’t enough hands on deck for patient restraint and positioning.

The good news is, some of the same principles that reduce radiation exposure can also help your team operate more efficiently.

Here are some tips to maintain safety, even when you’re shorthanded…

A.L.A.R.A.: A Brief Reminder

A.L.A.R.A. stands for “As Low As Reasonably Achievable,” and it’s the guiding set of principles that help you reduce radiation exposure to yourself, your staff, and your patients.

This is important because ionizing radiation from x-rays can damage cells, and cumulative exposure can lead to health risks such as cancer and genetic damage to reproductive cells.

To minimize exposure, there are 3 principles to keep in mind:

• Time

• Distance

• Shielding

Decreasing exposure times, increasing the distance between your team and the x-ray source, and using PPE, all can help to decrease radiation exposure.

Tips for Radiography Safety and Efficiency

Hands-Free Restraint

Increasing the distance between your team members and the x-ray source is one of the most effective ways to decrease x-ray exposure.

Think of the inverse square law, which states that doubling your distance away from the x-ray source results in ¼ of the dose of x-ray radiation.

That’s a significant decrease!

Also, scatter radiation comes from the patient—so by not touching the patient, you’re reducing your exposure.

This can be accomplished by using:

• Chemical restraint.

• Positioning aids such as sandbags and tape.

• A combination of both.

In addition to contributing to safety, hands-free restraint also increases staffing efficiency.

Especially for large or wiggly patients, it takes fewer staff members to position the patient when hands-free restraint is used.

Patient Comfort

A patient who wiggles at the last moment can lead to a crooked radiographic image—and thus, the need to retake that view.

The more shots you take, the higher the x-ray exposure to your team members.

Keeping a dog or cat’s comfort in mind can help you get the shot you need the first time—and decrease the need for retakes.

Here’s how you can do this…

• Minimize fear and pain (for example, pain from stretching a sore leg to get the right position) by using chemical restraint. 

• Use a trough or other aid for comfort. Lying with their back on a cold, hard table can cause even the most cooperative of pets to squirm. Giving them a cozy place to settle into can really help.

• Play white noise or background music. This helps make the big buzzing and beeping sounds from the x-ray machine less startling to a dog or cat.

In addition to a better patient experience and less x-ray exposure, these methods help save your staff time by getting your views more quickly.

Getting Things Right the First Time

The fewer images you take, the less radiation exposure there will be.

In addition to the measures listed above, here are some ideas for taking the fewest views possible…

• Good planning. Be sure to know exactly which views you need ahead of time and what position the patient needs to be in for those views. Communicate these expectations clearly with your staff.

• Proper measurement. Measure the patient in the position they will be in during the shot (lying down rather than standing).

• Have a technique chart, or use appropriate settings in your digital unit. Teach team members how to make quick and accurate adjustments in settings, too.

• Use collimation. In addition to producing a higher-quality image, collimation decreases scatter radiation.

A thorough understanding of x-ray positioning and machine settings will save your staff time and headaches—in addition to minimizing radiation exposure.

Who Should Be in the X-Ray Suite?

Only the team members taking the radiographs should be near the machine. Clients shouldn’t be in the x-ray suite, and other team members should be fulfilling other duties—especially when you’re shorthanded.

Rotating the staff you have on x-ray duty can also help minimize their cumulative exposures. 

So, it’s smart to invest in training multiple team members. That way, you’ll also avoid delays if your “go-to” x-ray staff member ever needs to call out sick or otherwise miss a day.

PPE Care and Use

Even though the nature of your daily practice may have changed, it’s still important to keep up with x-ray safety measures, such as making sure your PPE is in good condition.

Experts recommend checking PPE every six months, and this includes radiographing your aprons, gloves, and thyroid shields to check for cracks. Of course, check and replace sooner if there are any notable defects.

Uncertain times may be stressful, but you and your team can continue to help the patients who need you while keeping yourselves safe.

Written by: Dr. Tammy Powell, DVM