121 | Here’s everything you need to know about GI endoscopy as a veterinary nurse (and no, you won’t break the scope)

PodcastGastroenterologyNursingEndoscopy
Written By Laura Jones

Second to imaging, this is probably THE most common diagnostic procedure performed in internal medicine.

But it’s also the one where most of us have been taught wrong - or not taught enough, and I really want to change that over the next few episodes.

In college (and granted, college was a long time ago for me), we were taught virtually nothing about endoscopy. In practice, the biggest thing I learned about endoscopy was not to break the scope - and based on what most people I’ve worked alongside, taught or spoken to have told me, that seems to be pretty much universal across the profession.

There’s a misconception that looking at the scope the wrong way will break it, and as a result, we end up scared to touch it for fear of it costing our clinics thousands of pounds.

But in reality, there’s so much nursing to be done with patients during endoscopy procedures - and if we spend our careers trying to do anything but touch the scope, we miss out on all of those skills.

So over the next few weeks, we’ll look at the common endoscopic procedures (and some not so common ones). We’ll explore the different scopes available, how they differ, and how to handle, use, and maintain them. And we’ll chat all about the care our patients need from us as they undergo endoscopic procedures - so you can use more of your skills caring for these patients in practice.

Today, we’re starting with gastrointestinal endoscopy. We’ll look at the different GI procedures, the anatomy of a GI scope, and how to monitor, support and nurse your patients.

But first, let me bust a quick myth about endoscopy - one we often hear as vet nurses.

And that’s the ‘don’t break the scope’ fear, because after years of being terrified of them in general practice, I had no choice but to jump in at the deep end when I moved to internal medicine.

When I made that move, I realised something that completely changed how I feel about endoscopy - and that’s how much the scope actually goes through when its inside a patient.

Think about it. When we set up, handle, leak test, and even clean the scope, we’re really handling the scope only for a limited amount of time, and we’re barely manipulating it.

Now compare that to what the scope is expected to do in a procedure. That scope will get torqued (twisted around its long axis), rotated back on itself inside the stomach, have instruments pushed through it, and get pushed through a pylorus that really doesn’t want to let it through. That’s a completely routine procedure for our scopes to go through, and it should do that time and time again, day after day, week after week.

By comparison, wiping it over, carefully brushing the channels, and submerging it is far less damaging (assuming we’re doing it correctly).

Don’t get me wrong, scopes DO get damaged - but it’s usually not from careful routine handling and cleaning.

It’s things like the mouth gag slipping out and the tube getting bitten. 

Or the end of the tube sliding out of a patient and banging against the table or the floor. 

Or getting trapped in a cupboard door. 

Or being left dirty for too long so proteinaceous material dries inside the channels.

Or being stored inside its case, so the tubing is coiled and ends up permanently bent.

And all of these things we can easily prevent, if we’re confident at handling our scopes, helping our team during endoscopic procedures, and nursing our patients during endoscopy.

With that out of the way, let’s start by looking at the anatomy of our endoscope. 

There are a huge variety of endoscopes used in practice, and by the end of this series, we’ll have covered pretty much all of them - but in general, there’s only one scope used for GI endoscopy, and that’s our gastroscope.

Some places will have a colonoscope - these are exactly the same as gastroscopes, they’re just a bit longer, and so ‘gastroscope’ ends up being a bit of a catch-all term for both.

A gastroscope is a flexible endoscope that consists of two tubes (the insertion tube and the umbilical tube) attached to a handpiece. These are the three main parts, and within them are a network of channels, angulation wires, and other structures that allow our scope to actually function.

The handpiece of a gastrointestinal endoscope

The handpiece is also known as the body of the scope - it’s the bit our clinician holds, and it’s designed for the left hand. It contains two angulation wheels which control the direction of the insertion tube, allowing us to navigate through the patient. The larger outer wheel moves the end of the scope up and down; the smaller inner wheel is left and right, and both have a brake allowing the position to be locked in place. 

The handpiece also contains our air/water and suction buttons, and a cap covering the instrument channel.

The upper button (which is usually red) is suction, and the lower one (usually blue) is air and water. This button has a hole over it - if you cover the hole (but do not push he button down) you get air, and when you push the button down, you get water. 

Depending on the technology your scope uses - whether you need to attach an external camera to it, or whether it connects directly to a video source - you may have programmable buttons on the handpiece too. These allow us to capture still images and video, and adjust some functions without the endoscopist moving their hand, putting the scope down, or asking an assistant to do it for them.

The insertion tube of a gastrointestinal endoscope

The insertion tube is the bit that actually goes inside the patient. Usually this is around 6-8mm in diameter, depending on the species you’re treating, and inside this <8mm tube are lots of different components.

These include fibreoptic bundles that transmit light, the air, water and suction channels, the instrument channel, wires that move the scope in response to the angulation dials, and protective covering.

The end of the insertion tube is known as the distal tip, and the last few centimetres of the scope is the bending section - the bit that moves when we adjust the angulation dials. GI scopes can move up, down, left and right, and they can move upwards but at least 180 degrees, allowing them to turn back on themselves entirely.

The umbilical tube within a GI endoscope

The umbilical tubing, as the name suggests, is the bit that carries the necessary functions to the rest of the scope. It’s the tube that doesn’t enter the patient, but instead plugs into the light source, the air pump, a suction machine, and the video screen/scope tower. A bottle containing distilled water is also attached to the end of the umbilical tube, and you’ll also find a pressure compensation port on the light guide connector, which is what you attach a manometer to for leak testing.

What kit do you need for GI endoscopy?

Scope size

A scope for upper and lower GI work should be around 140 to 150cm for dogs and cats, and around 8mm in diameter, depending on the size of your patient. The clinicians I work with use a 7.9mm GI scope, which has a 140cm insertion tube, to scope both cats and dogs (including entering the small intestine from both directions).

Channel size

We also need to think about instrument channel size, because this will impact the size of the biopsies we can obtain - and also the instruments we need to order. Ideally we want an instrument channel size of at least 2.2mm (ideally at least 2.5mm); in my case, our scope has a 2.8mm channel, and we use 2.3mm biopsy forceps down it, allowing decent size samples while minimising the risk of channel damage.

Fibrescope or videoscope?

I also briefly mentioned that there are different technologies across our GI scopes - some need an external camera head, whereas others don’t. If you need to attach an external camera to your scope, so it has an eyepiece the camera clips on to, you’ve got a fibrescope. If you don’t, if your scope plugs straight in and does not have an eyepiece, you’ve got a videoscope.

Fibrescopes carry the image through glass fibre bundles to an eyepiece, which gives a slightly pixelated picture, and damaged individual fibres show up as black spots. Videoscopes have a chip in the distal tip and give a far better image. Videoscopes cost more, but give a much better - and larger - image.

Ancillary kit

Then we’ve got our ancillary kit. This is all the instruments and consumables we need alongside the scope to carry out our procedures, such as:

  • Biopsy forceps

  • Foreign body retrieval instruments (rat-tooth forceps, alligator forceps, three-prong graspers, baskets, snares)

  • Injection needles

  • Balloon catheters

On the topic of biopsy forceps, fenestrated cups produce larger samples with less crush artefact, and oval cups give you a bigger sample than round ones of the same diameter - so order these ones if you can, because you’ll get much better samples as a result.

OK, so that’s what you need to know about the scope itself. But what procedures do we actually perform in our GI patients, and why?

Endoscopy is one of many tools when diagnosing GI patients, and it isn’t the first we reach for. As we discussed in our GI series - especially episode 116 on chronic GI disease, we’ve usually performed bloodwork, imaging, and diet trials before reaching for the scope.

Of course, there are exceptions to this - foreign bodies are a classic example of this, because in these patients, we want to scope as soon as we can, while that foreign body is still in the stomach (or oesophagus) and easy to reach.

And there are some other more specific indications for endoscopy, such as patients with strictures who need treatment with endoscopic ballooning, or placement of a PEG tube.

In most cases, though, we’re using it to diagnose chronic GI disease in patients with things like ongoing vomiting, diarrhoea, and weight loss.

While endoscopy is a great option for most patients, there are some cases where it isn’t the best choice.

In general, the jejunum - the middle portion of the small intestine - can’t be reached endoscopically. Realistically, in cats, we can sometimes reach the proximal jejunum, but in most patients, if there’s something like a discrete jejunal abnormality or mass needing sampling, this will need to be done surgically.

In most patients, endoscopic biopsies are sufficient for diagnosis - even for things like lymphoma. However, if full-thickness biopsies of the GI tract are specifically required, these need to be collected surgically. And of course, we can’t reach other organs, such as the liver or lymph nodes - but laparoscopy capn be used to target these in a minimally-invasive way where needed.

There are three main endoscopic procedures in GI patients - upper GI endoscopy, lower GI endoscopy, and both upper AND lower GI endoscopy.

Upper GI endoscopy

An upper GI scope visualises the oesophagus, stomach, and duodenum.

The oesophagus is where we look for oesophagitis, strictures, foreign bodies, masses, and supporting evidence for things like megaoesophagus, vascular ring anomalies and hiatal hernias. 

Then we move into the stomach, where we're assessing rugal folds, looking for things like inflammation, erosions, ulcers, neoplasia and foreign material. Then through the pylorus into the duodenum, which is usually the hardest part of the procedure.

Usually, the stomach only gets a quick look on the way IN. The full examination and the biopsies happen on the way back out, after the duodenum. That's because prolonged insufflation and poking about in the stomach stimulates the pylorus to close, making intubation harder. 

Lower GI endoscopy

With lower GI endoscopy, we’re looking at the rectum, descending, transverse and ascending colon, the ileocolic sphincter, and where possible the ileum.

Indications are large bowel signs, plus ileoscopy for chronic small bowel signs - and this is important because wherever possible, we want to biopsy the ileum as it often shows different results to other areas, even compared with the duodenum. 

Ileal intubation is often possible in dogs. It can be challenging in cats, depending on the size of scope you have. If it isn’t possible, often the clinician will collect blind ileal biopsies through the sphincter where safe to do so.

Both

Many patients with chronic GI signs get both upper and lower GI endoscopy, where we look at all of those areas in one procedure. It’s of course a longer procedure as a result, and also a longer anaesthetic, which changes our perianaesthetic nursing considerations for these patients - especially around things like temperature support.

Sample collection during gastrointestinal endoscopy - how many biopsies are needed, and where should we take them from?

Looking at the macroscopic appearance of the GI tract only gives us so much information, and actually many patients will look quite normal by eye, but then turn out to have significant disease on histology.

This means that biopsies are ALWAYS indicated during diagnostic endoscopy, and there are guidelines on how many samples should be taken from each area.

Ideally, we want:

  • Six good quality samples from the stomach in both species

  • Ten to fifteen from the duodenum in dogs

  • Six from the duodenum in cats

  • Three to five from the ileum in both

  • And nine to twelve from the colon

A good quality sample is one with full thickness mucosa with three or four intact villi where possible, ideally with submucosa included.

This is also an area where our role is really important as vet nurses, because we need to be on it with things like labelling, counting, and evaluating samples - telling our vet if they need to collect more, or if a sample looked quite superficial and potentially less diagnostic.

Handling is also an important part of our role during sampling. It’s easy to inadvertently crush or damage a biopsy, limiting its diagnostic quality. To protect your sample, wash it off the forceps into isotonic saline by shaking the tip of the forceps, or rinse it out with a stream of saline. 

Don't tease it out with a needle, because it damages both the tissue and the instrument. At the end of the procedure, you can draw your samples up into a syringe (carefully) and then transfer them into formalin.

It’s also a good idea to send the endoscopy findings with the samples, as this will help the lab come back with the best possible information. The WSAVA has free upper and lower GI endoscopy report forms on their website, and I’d really recommend your team using these if they aren’t already - I’ll leave them in the description below the episode if you’re interested.

Nursing considerations for gastrointestinal endoscopy - what does our role look like?

Before the procedure

When setting up the scope, we want to visually inspect the endoscope, leak test it, and then connect the endoscope to the tower, light source, suction and water.

We also need to test the functions before the patient is anaesthetised, checking the air is working, the water is flowing freely, and the suction is working OK. Then do a white balance before hanging the scope up securely where it can’t be knocked or damaged. 

Then we need to check our instruments - so our forceps, snares, baskets, whatever we might need for the procedure. Check the jaws open, there’s no damage, and that the diameter is right for the specific endoscope.

Then get your consumables ready, so things like mouth gags, swabs, sterile lubricant, sampling pots, enema equipment, etc - and you’re good to go.

Patient preparation

Depending on the procedure, patients will have varied pre-anaesthetic fasting times, with longer fasts for lower GI procedures to empty the colon. Bowel cleansing solutions and enemas are also used for lower GI scopes, to clean the colon and evacuate as much faecal material as possible before the procedure.

If your patient has had a barium study, we need to delay their GI scope by at least 24 hours for upper GI scopes, and 72 hours for lower - because barium can damage the scope significantly. 

Procedure support

These patients have an increased risk of things like reflux, and are often in poor body condition or hypoproteinaemic as a result of their disease. So from an anaesthesia point of view, we need to consider aspiration, fluid balance, blood pressure and temperature especially.

During an upper GI endoscopy, the stomach will be inflated to allow visualisation and sample collection. This can impair ventilation, so monitoring respiratory rate and end tidal CO2 are particularly important - I will often push on the stomach at various intervals (when appropriate) to see how tympanic it is, and alert the vet if I’m concerned for overinflation.

At the end of the procedure, we also need to ensure all air is suctioned out so the patient does not recover feeling distended and uncomfortable - if you’ve ever had trapped wind, you’ll know how painful it can be, and the last thing we want is our patients waking up with that experience.

If you’re assisting with sample collection, agree commands with your endoscopist. We use ‘open’ and ‘close’ when they want each sample collected, and I always use closed-loop communication so they know when to push against the mucosa and pull back with the sample. The last thing you want is to open the forceps too early and damage the scope, so I will also always watch to ensure the entire jaws of the forceps are out before opening them.

Cleaning and maintaining the scope

After the procedure, suction cleaning solution through the channels to prevent blockage. Dried mucous and protein inside the channels can solidify quickly, and over time, if they build up, they can cause corrosions as well as blockages.

Then perform another leak test before cleaning the scope - because damage could have occurred during the procedure. 

Once the leak test has been passed, use an appropriate detergent solution to clean the exterior of the scope and brush and flush through the channels.

Repeat this in a high-level endoscope disinfectant solution, rinse with distilled water, and dry thoroughly before hanging the scope vertically in a dedicated cupboard. 

Buttons, valves, caps and other accessories should be cleaned separately and stored alongside the scope, rather than attached to it, because they can trap residual moisture in the channels - a bit like putting your finger over the end of a capillary tube.

So, there you have it - GI endoscopy, and how to manage it as a veterinary nurse.

This episode has been a lot, so let me briefly recap the most important points of what we’ve discussed.

GI endoscopy is used to investigate patients with chronic gastrointestinal signs - such as vomiting, diarrhoea, and weight loss - after things like imaging, bloodwork and diet trials where appropriate.

It’s also used therapeutically, to do things like remove foreign bodies, and dilate strictures.

A flexible gastroscope is used to image either the upper GI tract, lower GI tract, or both, depending on the individual patient - allowing us to visualise these areas and collect biopsies.

Our role as veterinary nurses and technicians is vast, including preparation of both the patient and the equipment, anaesthetic support and monitoring, sample collection and handling, and equipment cleaning and maintenance.

And most importantly, these scopes are built to do this. Yes, they need careful handling and they are fragile - but they’re nothing to be afraid of. So if the first thought that pops into your head is ‘don’t break the scope!’ when you’re helping with a procedure, please remember that the kit is put through its paces far more by the vets during use, than by us during cleaning.

What that scope needs from us is careful inspection, a leak test, correctly-sized instruments and a good, thorough clean as soon as possible. It’s that simple.

Did you enjoy this episode? If so, I’d love to hear what you think. Take a screenshot and tag me on Instagram (@vetinternalmedicinenursing) so I can give you a shout-out and share it with a colleague who’d find it helpful!

Thanks for learning with me this week, and I’ll see you next time!

References and Further Reading

Laura Jones
Next

120 | Feline pancreatitis and triaditis: what do we REALLY need to know about it to nurse these patients confidently?