Large-volume regurgitation is an uncommon airway problem, which is mostly encountered in the prehospital setting, ED, or ICU. It is sufficiently rare that it is commonly ignored. An average clinician might encounter severe regurgitation once every 2-5 years, which is infrequent enough to write it off as a “freak” event that doesn't mandate practice change (1). However, this may be fatal, so despite its rarity it deserves to be addressed systematically. Perhaps the easiest systematic practice change would be to improve our choice and utilization of suction catheters.
The Yankauer catheter sucks at intubation
The Yankauer suction catheter was designed by Sidney Yankauer around 1907 to facilitate clearing the surgical field during tonsillectomy. The tip of the Yankauer has small holes, to allow the gentle removal of blood without traumatizing delicate tissue.
The Yankauer fails to manage large-volume regurgitation. The flow rate is proven to be lower than large-bore suction catheters (Andreae 2016). The small holes of the Yankauer are easily clogged with debris (Kei 2017). The ideal suction tool for intubations is debatable, but it seems clear that the Yankauer is a poor choice. Persistent use of the Yankauer suction catheter for airway management represents a profession-wide failure in our ability to manage large-volume regurgitation.
Requisite features of any suction device used for intubation
An ideal suction tool for intubation should have the following features:
- Appropriate geometry for deployment during direct or indirect laryngoscopy.
- Large internal diameter and hole size, which largely eliminates clogging by particulate matter.
- Ability to pass a bougie or airway exchange catheter through the suction device (more on this below).
The Yankauer has feature #1, but lacks #2-3. The large-bore suction devices discussed below satisfy all three of these criteria.
Some suction catheters have a safety vent hole on their side, which prevent the catheter from suctioning too hard. This may be desirable for delicate surgical procedures, but it's a design flaw with regards to intubation. The vent hole must be occluded by the operator's finger to achieve optimal suction during intubation. However, during simulated intubations, operators often failed to occlude the vent hole promptly, thereby extending the procedure duration (Cox 2017). An ideal suction catheter would lack any such hole. However, if your catheter does have a hole, this problem is easily fixed by wrapping tape around the hole before the procedure begins.
Basic maneuvers with a large-bore suction device
Three basic strategies are as follows:
This is the most common way to use a suction catheter. The operator inserts the suction catheter to clear the airway, then removes the suction catheter prior to inserting the endotracheal tube. This works fine for the vast majority of intubations. However, if regurgitation is ongoing, then intermittent suctioning will fail (as soon as the operator removes the suction catheter, the oropharynx rapidly fills with vomitus).
This technique is useful to manage a situation with ongoing regurgitation. The suction catheter is inserted and left in place while the endotracheal tube is being placed. Thus, the suction catheter can continuously remove fluid from the oropharynx throughout the entire procedure. Dr. Ducanto has dubbed this technique the “Salad Park Technique” in reference to “parking” the suction catheter at the left side of the laryngoscope (illustrated in the video below). This technique may also be facilitated by having a second operator maneuver the suction catheter during intubation.
A large-bore suction device may facilitate intubation using a Seldinger technique, with a bougie (or airway exchange catheter) acting as the “guidewire:”
- First, the large-bore suction catheter is inserted through the vocal cords into the upper trachea
- A bougie is then inserted through the suction catheter, into the trachea.
- The suction catheter is removed, while keeping the bougie in place within the trachea.
- An endotracheal tube is advanced over the bougie into the trachea.
This technique may be helpful in the following situations:
- The patient has a small mouth which doesn't allow for simultaneous passage of a suction catheter and endotracheal tube (making the continuous-suction technique described above impossible).
- Waves of vomitus are threatening to completely occlude the view of the glottis. In this situation, immediately inserting the suction catheter into the trachea will secure access to the trachea and also simultaneously suction out fluid that may be in the trachea. This avoids the risk of losing visualization of the glottis and then being unable to intubate the patient. The concept is that while you have a view of the glottis you should take the shot, because you could lose visualization later. This scenario is demonstrated in the following instructional video (2):
Commercial large-bore suction devices
Two leading commercial suction catheters are shown above. The Hi-D “big stick” catheter has a geometry suitable for direct laryngoscopy (mostly straight, with mild angulation at the end). The DuCanto catheter has a more graded curve, which facilitates use with hyperangulated videolaryngoscopy.
Both of these catheters are available for ~$2 each, which is only trivially more than a Yankauer catheter (~$1). My opinion is that the Yankauer should be banned from use in airway management, replaced instead by routine use of large-bore devices such as these.
MacGyvered large-bore suction devices
Endotracheal tube suction using a meconium aspirator
Many hospitals lack commercial large-bore suction devices, which has led to the creation of a variety of work-arounds. This was first proposed by Scott Weingart, who described how to create a large-bore suction device using an endotracheal tube connected to a meconium aspirator (figure below). The stylet can be shaped into any configuration desired, to accommodate either a straight-to-cuff geometry (for direct laryngoscopy) or a more gradual curve (for hyperangulated videolaryngoscopy). This is elegant, but it does have the drawback of requiring a swivel adaptor and meconium aspirator.
Endotracheal tube suction without an adaptor
A similar strategy has been described more recently by Han 2016. This involves attaching the suction catheter directly to the endotracheal tube. The stylet may be allowed to poke out of a hole in the suction catheter (figure above). Alternatively, the stylet may be straightened out, so that it fits entirely within the suction catheter. Depending on the specifics of your suction tubing and endotracheal tubes, this can be a bit tricky to construct.
Suction tubing taped to a stylet
The simplest way to create a large-bore suction catheter is to tape suction tubing directly to an endotracheal tube stylet (figure below). The main advantage of this strategy is that it is very easy to set up using universally available materials. It also provides the largest-bore suction which is possible to create, without any junctions which may allow particulate material to lodge and occlude the suction device (5).
- Pass the suction catheter through the cords into the trachea
- Cut off the tubing of the suction catheter (this will sacrifice the ability to use this device for suction).
- Pass a bougie through the suction catheter, into the trachea.
- Remove the suction catheter, keeping the bougie in the trachea.
- Pass an endotracheal tube over the bougie into the trachea.
- Yankauer suction wasn't developed for intubation, nor does it work well for this situation. Persistent use of the Yankauer for airway management represents a system-wide failing of modern medicine to manage regurgitation.
- Large-bore suction catheters are less likely to be clogged by vomitus and may allow for securing the airway directly using a Seldinger maneuver.
- Commercial large-bore suction catheters are only trivially more expensive than Yankauer catheters and should replace Yankauer suction devices for routine use in airway management (because it's impossible to predict regurgitation with 100% certainty).
- For practitioners who lack access to commercial large-bore suction devices, there are various ways to MacGyver a large-bore suction device. This may be reasonable for selected situations where a patient is at higher risk for large-volume regurgitation.
- Novel set-up to allow suctioning during direct endotracheal intubation (EMCrit)
- Having a vomit SALAD with Dr. Jim Ducanto (EMCrit) – including numerous links at the bottom of this page.
- Large-volume regurgitation has recently gained a lot of attention in the FOAMed community, largely due to the work of Dr. DuCanto and his large-volume regurgitation simulator. However, many emergency and critical care providers continue to have little awareness of this issue.
- The take-the-shot strategy admittedly didn't work well in this video, illustrating the importance of using this approach only if you have a clean shot (i.e. good visualization of the glottis and vocal cords).
- If the bend at the tip of the suction catheter is too sharp, the bougie will hang up at this angle and will not pass. For this reason, the suction catheter should generally be shaped with a gentle angle (e.g. closer to ~15% than ~30%). It may also be easier to pass an airway exchange catheter instead of a bougie, because the airway exchange catheter is smaller and floppier. This may also depend on the exact diameter and pliability of the suction tubing that you are using (if you are using small-bore tubing this will cause problems on multiple levels).
- There's not much literature about large-volume regurgitation, because this is too rare of an entity to study thoroughly. The rarity of this event also makes it difficult for any practitioner to get extensive experience with it. I make no claim to be an expert on this topic, but instead look forward to a discussion which may pool the experience of many airway experts.
- The internal diameter of this suction device is equal to the internal diameter of the suction tubing itself. This is the largest bore suction device which can possibly be created. In theory you *could* design a larger-bore catheter, but that wouldn't work any better (because the suction would still be limited by the internal diameter of the suction tubing).
Conflicts of Interest: The SSCOR company provided me with two free DuCanto catheters as a promotional offer which is publically and freely available to anyone. I don't think this is a significant COI, but you can be the judge.
- IBCC chapter:Guide to APRV for COVID-19 - April 8, 2020
- PulmCrit Theoretical Post – The COVID Severity Index (CSI 1.0) - April 2, 2020
- PulmCrit wee – Why the SCCM/AARC/ASA/APSF/AACN/CHEST joint statement on split ventilators is wrong. - March 29, 2020