Do Blended Diets Cause Blockages in Feeding Tubes?
The most straightforward answer to this not so simple question is NO. There is no research showing that using blended food for tube feeding causes blockages in feeding tubes. In fact there is a recent study that showed that feeding tube blockages did not occur when 20 home tube fed adults used blenderized tube feeding for up to 2 years at home. Plus, there are several other blended diet studies where the authors noted that no blockages occurred among any of their study subjects (references listed at the end of this post).
Based on all this, I feel confident that blockages are erroneously perceived as a risk of blended diets and in reality there is no real risk. The only exception may be circumstances where feeding tubes are very small in size (smaller than 12 French) or tubes where there are actually two inner tubes (G-J tubes) or with feeding tubes that have side exit holes. In these cases you should be really careful with your blends or just stick to thin liquids without particles (clear juices, broth, milk) and have most of the nutrition come from formula. Of course, knowing about the design and size of your feeding tube (or your loved one's feeding tube) is essential in order to understand whether tube blockages are a concern.
In the photos below you can see an example of a very tiny tube on the left. In the center is a photo of a G-J feeding tube tip. Although this is a 20 French tube, there are two tubes inside the tube, one shorter tube that allows nutrition to enter into the stomach and the other goes further along the tube and allows nutrition to enter the jejunum. These two internal tubes are probably less than 10 French in size and have side exit hole which are potentially problematic because blended food has to make a 90 degree turn to exit the tube. The photo on the right is another example of side exit holes. It's the tip of a 12 French nasogastric tube.
Blenderized Tube Feeding Research Breakthrough
I mentioned a recent study that showed that there were no tube blockages with the use of blenderized tube feeding over a two year period. What I didn’t mention above is that this was my study. Yes, in addition to my work on Natural Tube Feeding, I continue in my position as a clinical dietitian for the Vancouver Coastal Health Authority and in that role I am also affiliated with the University of British Columbia as I am a Clinical Instructor for the Dietetics Program. This puts me in the very fortunate position of having research opportunities.
As you know, blenderized tube feeding is my passion and my professional focus. I have long suspected that the fear of feeding tube blockages from blended food is unfounded. In my personal experience working with people who use blended food for tube feeding, I have not seen this problem. In fact, I mostly deal with feeding tube blockages in the inpatient hospital setting and almost all of these patients have nasogastric tubes and are fed formula. In my experience, usually tube blockages are due to medications that are not soluble in water and are very hard to administer down the tube. Crushed medication clumps together and therefore poses a legitimate risk of creating a blockage in feeding tubes.
Anyway, back to my research! I knew that opinions about blenderized tube feeding were unlikely to change unless there was solid evidence showing that blended food does not cause feeding tube blockages. As much as I hoped that new studies would come out and have positive findings in this area, I also knew that it’s better to take action than to wait and hope for someone else to do a study. Luckily I have quite a lot of research experience having at that point already conducted 3 studies so I felt comfortable with the idea of doing a study on this topic.
Research is tough to do solo, so I spoke to a colleague of mine at the provincial ALS clinic as I knew that she had quite a few tube fed clients who use blended food at home. We discussed some research ideas and agreed that a retrospective chart review study looking at feeding tube blockages and the potential reasons associated with those blockages would be highly valuable. We were genuinely interested to learn how many of our subjects actually experienced a tube blockage and we wanted to evaluate the impact of each blockage to see if there was a major or minor impact on the patient. In other words, when a blockage occurs, how many patients are able to clear the blockage in a timely manner at home? How many blocked feeding tubes result in a feeding tube replacement and are those replacements done at home or does the patient end up needing to go to the ER for help? These were important questions that we sought to answer with our research.
Study Design and Findings
We then proceeded to design a study where we would review the medical records of all the ALS clinic patients who had used blended food for tube feeding at home over a two year period. Over the next several months we researched this topic extensively, wrote the study protocol, sought support from our health authority leadership, applied and were granted ethics approval, and finally were able to start on the actual study activities.
When we finally finished all the medical chart reviews, we were quite surprised. Not a single one of our patients experienced a tube occlusion during the study period! This was not what we had expected, to be totally honest, but we were happy that this was a very positive finding. We also learned that there were 97 tube fed patients followed by the ALS clinic and of those, 20 (21%) used blended food. This number is fairly large and also reinforced the fact that blenderized tube feeding is being used by a significant number of people. There are lots of details in the study paper if you are curious on our other findings or are looking for a more indepth look at the study. Click on the photo below to read the full paper or go to the Canadian Journal of Dietetic Practice and Research:
Why Were There No Feeding Tube Blockages?
It’s important to keep in mind that all the subjects in this study were adults and therefore their feeding tubes were fairly large. Their tube sizes ranged from 14 to 24 French, with most people having a 20 French sized tube. I suspect that tubes 14 French and higher are extremely unlikely to block up and this may be due to the fact that there are many points in the feeding delivery systems that are smaller than 14 French and therefore any larger food particles would be filtered out of the blend by these narrow points and never make it all the way into the tube itself.
For example, with gravity and pump infusion of BTF, the reservoir bag portion of the feeding set provides the first layer of protection against occlusions, as only food particles small enough to exit the bag can enter into the tubing portion of the administration set and continue to flow towards the feeding tube. Also, the tubing of the feeding set is smaller than a 14 French feeding tube so blended food that can flow through the pump bag tubing would have to be fine enough to easily pass through the feeding tube unless the feeding tube is smaller than 14 French. Read my blog post about feeding tube sizes to learn more.
With syringe feeding, overly viscous blends and those with large food particles would not be easily drawn into the syringe, given the small opening at the syringe tip. Likewise, large food solids would not be able to pass easily out of the syringe tip and into the feeding tube, whether by gravity or push method, so again, unless the feeding tube itself is tiny (less than 14 or 12 French) you don't have much to worry about in regards to feeding tube blockages.
Another important consideration is the connection point from the feeding administration set or syringe, to the feeding tube itself. Whether the ENfit or legacy connector is present, the diameter at the connection point is relatively small in comparison to most feeding tubes. Therefore, blended food that is able to pass through the connection point would be unlikely to contain particles so large as to cause an occlusion in the feeding tube. Similarly, when low-profile (button) tubes are utilized, there is a narrow point where the extension set connects to the feeding tube that further limits flow of food solids into the feeding tube. This design makes it more likely for an occlusion to occur within the disposable extension set than in the feeding tube itself. To learn more you can check out this blog post on button feeding tubes and blended diets.
Another Reason Why Blockages Are Rare With Blends
A final consideration as to the rationale for the absence of feeding tube occlusion in my study is that most subjects received education from a registered dietitian on how to properly prepare blended meals. Generally this would include advice on what texture and viscosity to aim for and how to strain blends if needed. When making blended meals, it's so important to know what you're doing. Not only does this protect you from potential issues with the feeding tube, it also ensures that your blends are nutritionally balanced and contain enough calories.
If you're interested in starting a blended diet, talk to your healthcare team and get their advice. If you want detailed information on blending, I can certainly help you via my Blended Diet Online Course. I cover everything you need to know, including how to determine if your feeding tube carries a risk of getting blocked with blended food, and how to properly prepare blends. I demonstrate how to blend food for tube feeding and discuss in detail how to strain your blends quickly and easily. Plus there's so much more important information covered. Find out about the course here.
Thanks so much for reading. I really hope that no one with an appropriate feeding tube will be refused the option of a blended diet for tube feeding out of fear for feeding tube blockages. There is no real basis to this concern and plenty of evidence to show that blended diets are not associated with feeding tube blockages. If you have questions about my research, please feel free to reach out to me via my contact page.
Claire Kariya RD, CNSC
Kariya C, Vardi L. Blenderized Tube Feeding and Enterostomy Tube Occlusions Among Adults with Amyotrophic Lateral Sclerosis and Primary Lateral Sclerosis. Can J Diet Pract Res. 2021;efirst (pagination pending) doi: 10.3148/cjdpr-2021-019.
Batsis ID, Davis L, Pritchett L, Linxuan W, Shores D, Yeung KA, et al. Efficacy and tolerance of blended diets in children receiving gastrostomy feeds. Nutr Clin Pract. 2020;35(2):282–288. PMID: 31549432. doi: 10. 1002/ncp.10406.
Pentiuk S, O’Flahtery T, Santoro K, Willging P, Kaul A. Pureed by gastro- stomy tube diet improves gagging and retching in children with fundopli- cation. J Parenter Enteral Nutr. 2011;35(3):375–379. doi: 10.1177/ 0148607110377797.
Papakostas P, Tsaousi G, Stavrou G, Rachovistsas D, Tsiropoulos G, Rova C, et al. Percutaneous endoscopic gastrostomy feeding of locally advanced oro-pharygo-laryngeal cancer patients: blenderized or commercial food?. Oral Oncol. 2017;74:135–141. PMID: 29103742. doi: 10.1016/j. oraloncology.2017.10.001.