Episode #324 Endotracheal Tubes Are Not All The Same

Opening Clip: Are you near an anesthesia cart? If so, open the drawer for the endotracheal tubes. What do you see? Are you seeing the same endotracheal tubes that you are familiar with using or something else, a different kind of endotracheal tube?

This is the Anesthesia Patient Safety Podcast and I’m your host, Alli Bechtel. We had a nice run of interview shows recently, but there are some new APSF Newsletter articles that we need to check out. Spoiler alert, we will be talking about endotracheal tubes on the show today.

Before we dive further into the episode today, we’d like to recognize Medtronic, a major corporate supporter of APSF. Medtronic has generously provided unrestricted support to further our vision that “no one shall be harmed by anesthesia care”. Thank you, Medtronic, – we wouldn’t be able to do all that we do without you!”

Our featured article is “Endotracheal Tube Materials and Design: Navigating Airway Safety Amid Supply Chain Instability” by Morgan Brown. This article was published online August 13^th, 2026. To follow along with us, head over to APSF.org and click on the Newsletter heading. The first one down is APSF Newsletter articles. Then, scroll down until you get to our featured article and I will include a link in the show notes.

When we think about endotracheal tubes, we may be thinking, do we need a tube to help protect the airway, what type of tube do we need, single-lumen, double lumen, reinforced, and what size do we need. We may not always be thinking about endotracheal tube supply and supply chain disruptions. But if there are supply chain disruptions, then the next time you reach for an endotracheal tube it may be an unfamiliar brand of type of ETT that you are not familiar with. Before intubation, it is important to make sure that the appropriate endotracheal tube is used for every patient and that’s what we’ll be talking about today.

Endotracheal tube supply may be affected by supply chain instability, product recalls, material reformulations, and manufacturing discontinuations. This means that the endotracheal tubes in your airway cart may be different then what you have used before and this is a threat to anesthesia patient safety. The author cautions us that we cannot be complacent when it comes to endotracheal tubes, thinking about them as interchangeable pieces of equipment. Instead, we need to consider that endotracheal tubes are complex and variable medical devices with distinct performance characteristics and safety profiles. This is especially important when providing anesthesia care for paediatric patients. Even small changes in tube size, design, material, or geometry can have big implications and clinical consequences. Understand endotracheal tube design is an important consideration for keeping patients safe during anesthesia care and we’re here to help provide that foundation.

Let’s start with the endotracheal tube components. Materials used to make tubes in the past included solid metal, rubber, and vinyl-acrylic resin plastic. Modern endotracheal tubes are often constructed with plastic, specifically polyvinyl chloride or PVC. Then, to try to soften the plastic and create a more flexible tube, additional chemicals were added like di-(2-ethylhexy) phthalate or DEHP. But there were concerns about these additional chemicals leaching out from the PVC over time since they were not tightly bound to the PVC plastic. As a result, regulators advocated for a phase out of these chemicals use back in 2001 citing concerns for the risk of endocrine disruption especially in neonates. We don’t have data for the amount and impact of phthalates released from endotracheal tubes and there has been variable compliance with this recommendation by endotracheal tube manufacturers. Then, in May of 2025, a large ETT manufacturer discontinued several types of endotracheal tubes that contained DEHP to try to eliminate the use this chemical. This then led to newer endotracheal that were less flexible and had larger cuffs. As you may imagine, this was a noticeable change especially in smaller ETT that are used for neonates, infants, and toddlers.

Now, let’s talk about the design characteristics for these tubes. This is a bit of a refresher…the size of the tube is defined by the internal diameter and this size determines airflow resistance and suction capability. The outer diameter measurement, wall thickness of the tube, and manufacturing tolerances are other variables that may have important clinical implications. We can see this in action during the 2025 food and drug administration, FDA, recall of infant-sized ETTs due to reduced internal diameter which led to increased resistance and impaired ventilation…there were multiple reports of respiratory events before the recall. Even slight differences due to manufacturing variability can make airway management difficult for paediatric patients or those with anatomical variations when even slight differences can lead to complications. Check out Figure 1 in the article where you can 3 different 2.5 endotracheal tubes and all 3 have different external diameters ranging from 3.5 to 4mm.

We have transitioned from uncuffed endotracheal tubes to using cuffed ETTs for most paediatric cases. The cuff provides a seal so that we can provide adequate ventilation while at the same time minimizing mucosal injury. There is no standard cuff design. There may be differences in shape, which may be barrel, tapered, or cylindrical, the material which may be PVC or polyurethane and contact surface area. These difference influences the seal and effectiveness of ventilation as well as the risk for micro aspiration. For example, there is a study that evaluated cuff leakages in simulated tracheas and endotracheal tubes with a barrel shaped cuff, which had the most surface area on the tracheal were more occlusive. Plus, the cuffs made from polyurethane instead of PVC plastic were also more occlusive. Check out Figure 2 in the article to see 3 different size 3 cuffed endotracheal tubes all with different shaped cuffs and difference in marking lines.

When was the last time you thought about the pilot balloon system? This is actually a part of the endotracheal tube that may failure and thus a critical part of the design and function. Incompetent valves or micro perforations in the balloon can cause the cuff to failure. Figure 3 in the article shows an endotracheal tube with leaks in the pilot line and pilot balloon. Another important consideration for smaller ETTs, the 2.5 cuffed tubes, is the space taken up by the pilot line which can affect the diameter of the internal lumen. In clinical practice, this means that you may not be able to pass a size 5/6 Fr suction catheter through the 2.5 cuffed endotracheal tube which may lead to a functional airway obstruction, which is not something you want to happen when you are taking care of an infant. You can see this in Figure 4 in the article. This defective design was reported to the FDA and manufacturer, but so far, nothing has been done. It is so important to do more than a quick visual inspection, but to do a preoperative functional assessment as well.

But wait, there’s more. Did you know that the distal end of the tube can also influence the performance? Options include the standard left-facing bevel that facilitates visualization during direct laryngoscopy. There is also the Flex-Tip which was designed to help decrease airway trauma and improve navigation. But these design modifications can introduce a weakness in the tube…if the flexible tip is deformed, this could partially obstruct the endotracheal tube leading to impaired ventilation. The Murphy eye is present on some endotracheal tubes as a secondary ventilation pathway in the event of tip occlusion, but you will notice that it is not present on all tubes, like the Micro cuff tubes which do not have a murphy eye.  It seems like the Murphy eye may not be a necessary component for ETT design, but there are reports of endotracheal tube obstruction requiring emergent replacement of the tube when there is no Murphy eye present. This is really a time when seconds count.

After the rest of our discussion today, you will probably not be surprised to hear that the markings on endotracheal tubes, the radiopaque lines and depth indicators, are not standardized across manufacturers. The manufacturer’s name or trademark, the size of the tube, and the words single use for non-reusable tubes are different as well. Yup, that’s right, more variations. These variations can have an impact on confirmation of tube positioning. We have another picture for you. Figure 5 shows the radiopaque markers in a magnified image of a postop check Xray in a child following cardiac surgery. The radiologist read this Xray that the child had been extubated since the markers on the tube were no faint. The yellow dots reveal the positioning of the ETT.

Rather than just leave you with all of these things to be on the look out for, the author also provides information about what to do when an endotracheal tube defect is detected. The Manufacturer and User Facility Device Experience, or MAUDE, database of the FDA contains reports of the possible safety issues with all types of medical devices and recalls of products. Manufacturers, importers, and device user facilities are all required to submit reports if there is a concern about a device malfunction or if there was a patient death or serious injury associated with the device. In addition, health care professionals and patients can submit voluntary reports regarding adverse events or complications as well. There are some limitations here since individual reports are no verified by the FDA and in reality, there is limited reporting due to under-reporting, inaccurate reporting, and incomplete data. There are major national databases for adverse events in anesthesia, but none are specific to products, devices, or equipment and as well all know, near-misses are not usually reported. Tracking adverse events due to a lot or specific type of tube is difficult since the lot number is not routinely recorded.

This is an area that deserves some time and attention since it is predicted that product availability will be an ongoing issue for anesthesia professionals. And this may have a disproportionate impact on paediatric patients who are especially vulnerable to small design changes leading to placement and use challenges or failures. The author writes, “All products, including ETTs, which are going to be used in a patient, must be well understood to be used in the safest manner possible.” Thank you to Dr. Brown for submitting this article and highlighting this important consideration for safe anesthesia care.

Before we wrap up for today, I’m going to read a statement that was published on the APSF Website on August 21, 2026, “Anesthesiology Organizations Express Concern for Patients Harmed, Reaffirm Safety of Spinal Anesthesia. This statement is in response to the medication errors that harmed patients in Nashville, Tennessee. The Society for Obstetric Anesthesia and Perinatology, the ASPF, and the ASA reaffirmed that spinal anesthesia remains a safe and essential anesthestic technique when administered with appropriate medication. These devastating events must be seriously addressed, without calling into question the safety of this well-established form of care. SOAP, APSF, and the ASA extend their deepest concern and compassion to the patients and families who suffered harm in these events and encourage switch and thorough evaluation of the events and processes that contributed to these tragedies.

Spinal and epidural anesthesia are safe, well-established, and commonly used techniques that provide important benefit for millions of patients during childbirth, having surgery or other procedures. Although the circumstances of these events reportedly remain under investigation, serious events such as these reinforce the importance of rigorous investigation, transparency, and learning. A medication error involving neuraxial administration is distinct from an inherent complication of spinal or epidural anesthesia.

SOAP, APSF and ASA have previously highlighted the risks of wrong-drug and wrong-route medication errors and the importance of systems designed to prevent them. These include standardized and clearly labelled medications, separation of high-alert medications from those intended for neuraxial use, technology-assisted verification where available, and safeguards throughout pharmacy preparation, dispensing, and administration.”

Check out the show notes for a link to the full statement.

If you have any questions or comments from today’s show, please email us at [email protected]. Please keep in mind that the information in this show is provided for informational purposes only and does not constitute medical or legal advice. We hope that you will visit APSF.org for detailed information and check out the show notes for links to all the topics we discussed today.

If you can, we would love for you to subscribe to the podcast and maybe share it with a friend or a colleague or anyone you know who is interested in anesthesia patient safety. Thanks so much for listening.

Until next time, stay vigilant and stay informed so that no one shall be harmed by anesthesia care.

© 2026, The Anesthesia Patient Safety Foundation