How to prepare and support the bronchoscopy patient
Welcome back to another post in our endoscopy series! Today we’re looking at the second-most-common endoscopic procedure we perform in practice - bronchoscopy! These patients require a lot of nursing support and can be a little fear-inducing! We’ll chat through the why’s and how’s of bronchoscopy, as well as how to prepare your patient, how to support them during the procedure, how to collect a broncho-alveolar lavage, and how to nurse the patient in recovery.
If you haven’t already, be sure to check out the rest of the blog posts in our endoscopy series. Ready to jump in? Let’s go…
What is a bronchoscopy?
A bronchoscopy is an endoscopic examination of the lower airways - the trachea, bronchi and bronchioles. It is performed using a narrow, flexible endoscope called a bronchoscope. We also use bronchoscopies to obtain guided samples for cytology and bacterial culture, through a procedure known as bronchoalveolar lavage (BAL). In addition to sample collection, in some cases, the removal of foreign material from the lower airways can be performed endoscopically, avoiding the need for invasive thoracic surgery.
Bronchoscopies can be a little scary as they often require extubation of the patient in order to pass the endoscope through the larynx and into the trachea. This presents a challenge for the veterinary team - providing oxygen, anaesthetic agents and having a patent airway are all things we like to maintain during anaesthesia, in order to prevent complications and maximise patient safety under GA. Luckily, there are some workarounds we can put in place to make their anaesthesia as safe as possible, whilst allowing the clinician to perform the procedure. We’ll go through these together later in this post.
How is it performed?
Following anaesthetic induction and patient preparation, the endoscope is inserted into the mouth and a brief oropharyngeal examination is performed. This allows the team to assess laryngeal function, the soft/hard palates, the tonsils and under and around the tongue.
The endoscope is then advanced into the trachea and the area is examined. The dorsal tracheal membrane is visualised as a line of tissue intersecting the tracheal rings; the clinician keeps this membrane at the top of the screen (dorsal aspect) as they advance the endoscope.
The trachea splits at the level of the carina (tracheal bifurcation) into the left and right mainstem bronchi. These are examined, with the endoscope advanced through the bronchioles as necessary across each lung lobe.
Think of a tree - the trachea is the trunk, the two main branches are the left and right mainstem bronchi, and off of those branches are the bronchioles. More branches shoot off of these two large branches, and a network of branches results, each ending in a leaf - the alveoli.
Whilst performing the bronchoscopy, the clinician is looking out for abnormalities such as:
Strictures (airway narrowings)
Tracheal or bronchial collapse
Masses
Foreign material
Fluid
Alterations to mucosal colour
A BAL may then be collected from a specific area (usually one which will yield a higher number of cells, e.g. where there is evidence of infection or inflammation) on the visual exam. This can either be collected via suction and a mucous ‘trap’ which is attached to the endoscope’s suction port, or via an aspiration catheter and syringe which is manually fed through the instrument channel.
How is the patient prepared?
Ahead of the procedure patients should undergo a pre-anaesthetic fast, according to standard practice protocols. A full clinical examination should be performed, an anaesthetic plan developed, and the patient should then be pre-oxygenated for at least 10 minutes prior to general anaesthesia.
After anaesthetic induction, the patient should be placed in sternal recumbency and maintained in this position for as much time as possible (e.g. before starting the endoscopy, in between radiographs being taken, etc.). Any required imaging such as radiographs or CT scans should be collected, before the patient is positioned on the endoscopy table, head away from the anaesthetic machine, in sternal recumbency.
Monitoring equipment (especially pulse oximetry and capnography) should be attached and long circuit tubing should be prepared and leak-tested ahead of the procedure.
The patient’s neck should be extended and a rolled-up towel or sandbag should be placed underneath their head. The ET tube should be tied in such a way that is easy to remove and replace the tube quickly since multiple intubations will be required throughout the procedure - use quick-release knots.
Depending on the size of your patient, you may be able to advance the endoscope through the centre of the ET tube; however, this only works in larger patients, and care must be taken not to increase the patient’s airway resistance by inserting a bronchoscope through an airway which only just fits the endoscope. In these larger patients, an elbow adapter with a rubber seal can be attached to the ET tube. This diverts the circuit tubing to the side of the patient, whilst providing a port for endoscope access. The seal also helps to prevent breathing around the endoscope, and subsequent oxygen leakage.
Smaller patients will require extubation during their procedure. These patients should be carefully monitored, in order to identify any hypoxaemia at an early stage. Extubated patients should have an SPO2 probe placed in a reliable location (e.g. if the tongue cannot be accessed, considering a reflectance probe against the skin, or in the rectum is useful, or placing the probe over the ear pinna or a paw pad). If you are using sidestream capnography, removing the stylet from an IV catheter, attaching the capnograph line to the catheter, and inserting the catheter into the nostril can provide a good estimate of ETCO2 levels. Flow-by oxygen should be provided by passing a rigid urinary catheter into the trachea alongside the endoscope; an ET tube connector can then be attached to this and connected to the breathing circuit to provide supplemental oxygen.
Anaesthetic gases should not be used for maintenance in bronchoscopy patients (even if an ET tube is present and you are using the endoscope through an elbow connector) due to the risk of environmental/staff contamination and challenges in the physical administration of the gas. Instead, total intravenous anaesthesia techniques should be considered and discussed with the veterinary team.
The actual bronchoscopy procedure is short but close monitoring of the patient is warranted, and if any hypoxaemia is identified, the clinician should pause their endoscopy to allow re-intubation or oxygenation via mask.
It is also advisable to have emergency medications pre-calculated for the patient’s bodyweight and available on-hand, especially when performing feline bronchoscopy (due to the risk of laryngeal spasm and oedema). These may include medications such as injectable steroids (dexamethasone) and bronchodilators (terbutaline), to be used under the direction of the veterinary surgeon if complications arise.
As you can see, bronchoscopy is a riskier endoscopic procedure and preparedness and organisation are vitally important to minimise this risk. A briefing with the team about any anticipated risks is advisable, and steps to mitigate these should be in place before the procedure begins. The veterinary nurse should have only one dedicated role during the procedure (e.g. either the anaesthetist or the endoscopy assistant - not both) to ensure consistent patient monitoring.
On recovery, the patient should recover slowly in a quiet, calm, well-staffed area with supplemental oxygen available. They should remain in sternal recumbency with their neck extended and SPO2 monitoring should continue until the patient is consistently saturating normally on room air. I like to keep an emergency airway kit with my bronchoscopy patients until they are discharged and maintain IV access until just before their discharge appointment.
What about sampling?
A bronchoalveolar lavage (BAL) is the most common method of sample collection during bronchoscopy. With a BAL, a fixed volume of sterile saline is instilled into the patient’s airways, mixed with their airways so that cells, bacteria and other pathogens exfoliate into the fluid, and then retrieved via suction. The sample can then be submitted for cytology and bacterial +/- fungal culture.
Here’s my step-by-step procedure for BAL collection:
Manual Procedure:
Prepare 2 x 10-20ml syringes with an appropriate volume of saline solution in each (depending on patient size). Fill the remaining syringe volume with air.
Aseptically advance a sterile aspiration catheter through the instrument channel when directed by the clinician.
When prompted, instil the contents of the syringe (saline and air) into the airways.
Whilst the endoscopy assistant instils the saline, the anaesthetist performs coupage to mix the cells and saline.
The endoscopy assistant then suctions back on the syringe to retrieve the fluid.
Repeat as necessary for the second attempt (if safe to do so).
Place half of the fluid in an EDTA tube for cytology, and the other half in a plain tube for culture.
Prepare fresh, air-dried smears of the BAL for submission alongside the EDTA and plain samples.
Suction Procedure:
Prepare 2 x 10-20ml syringes with an appropriate volume of saline solution in each (depending on patient size). Fill the remaining syringe volume with air.
Ensure your bronchoscope is sterile.
Attach a sterile mucous trap to the suction port on the bronchoscope.
Attach suction tubing to the suction unit at one end, and the suction port of the mucous trap at the other end.
When prompted, instil the contents of the syringe (saline and air) into the airways through the endoscope instrument channel.
Whilst the endoscopy assistant instils the saline, the anaesthetist performs coupage to mix the cells and saline.
The clinician uses the suction function to retrieve the fluid, where it is trapped in the mucous trap.
Repeat as necessary for the second attempt (if safe to do so).
Place half of the fluid in an EDTA tube for cytology, and the other half in a plain tube for culture.
Prepare fresh, air-dried smears of the BAL for submission alongside the EDTA and plain samples.
So that’s the how’s, what’s and why’s of bronchoscopy! As you can see it can be a daunting procedure but one which careful preparation, organisation and forward planning (aka. Using nurses to their strengths!) can make a huge difference to.
Don’t forget that you can download a full booklet of endoscopy equipment lists to complement this blog series - simply enter your email address below, and the link to our resource library will be sent straight to your inbox, alongside the password to access it!
References and further reading:
Cox, S. 2016. Endoscopy for the Veterinary Technician. Iowa: Wiley-Blackwell.
Merrill, L. 2012. Small Animal Internal Medicine for Veterinary Technicians and Nurses. Iowa: Wiley-Blackwell.
Disclaimer: Individual endoscope use and maintenance protocols may vary depending on your practice, the endoscopes you use, and clinician preference. The above information is intended as a guide only. Veterinary Internal Medicine Nursing is not responsible for any issues which may arise as a result of their use. Any products mentioned or images included within this post are for reference only and are not product endorsements or recommendations.
