Time Stamps

  • 02:21 Pearl 1 – Approach to nutritional assessment in a patient
  • 09:36 Pearl 2 – Routes of enteral access
  •  19:20 Pearl 3 – Components of tube feeds
  • 27:03 Pearl 4 – Tube feeds complications
  • 34:50 Pearl 5 – Counseling patients before discharge and medication interactions


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Extended Interviews

Show Notes

Pearl 1: Malnutrition and what are the indications for tube feeds? 

  • Malnutrition is a “nutrition imbalance” (defined ASPEN) and is diagnosed via history and physical exam. 
    • Classification of malnutrition 
    • At least 2 from any of the following are needed to support the diagnosis of malnutrition: 
        • Insufficient energy intake
          • Ex. ≤50% of estimated energy requirement for ≥1 month
        • % weight loss 
          • Ex. >20% in over 1 year
        • Loss of muscle mass 
          • Ex. wasting at temples, clavicles, thigh, calves
        • Loss of subcutaneous fat
          • Ex. loss at orbits, triceps, or fat overlying ribs
        • Fluid accumulation 
          • NOT related to fluid overload from another condition (i.e., heart failure)
          • May mask weight loss
        • Diminished handgrip strength 
    • How do we document the severity of malnutrition for MS-DRGs? 
      • Dietician → Documents the nutrition diagnosis.  
      • Medical provider → Documents the medical diagnosis and malnutrition severity.
    • Can albumin and prealbumin tell us about nutritional status?
      • Acute phase reactants:
        • Decrease in inflammatory conditions
        • So, cannot NOT reliably reflect changes in nutrition status
      • Prealbumin:
        • Actually is transthyretin 
          • Transport protein for thyroid hormone 
          • Only called “prealbumin” since it is the band in front of albumin in protein electrophoresis 
        • Half life of 2-3 days 
          • Whereas albumin has half life of approximately 20 days!
      • BMI: 
        • Poor surrogate marker for malnutrition!
    • Tube feeds (TF) are indicated when patients…
      • Unable to meet at least 50% their nutritional needs orally, and… 
        • Critically ill patients
          • Initiate enteral feed within 24-48 hours 
        • Non-critically ill patients
          • Initiate enteral feed within 5-7 days
      • Have a functioning gut
      • High risk for malnutrition or malnourished
        • Initiate enteral feeding SOONER for these patients!
        • Protracted nutrient losses
          • Malabsorption
          • Enteric fistulas
          • Draining abscesses/wounds
        • Hypermetabolic states
          • Sepsis
          • Trauma
          • Burns
        • Catabolic drugs
          • Steroids
          • Immunosuppressants
          • Anti-tumor chemotherapy
        • Alcohol use
      • Why is initiating ENTERAL tube feeds important?
      • Are there contraindications to enteral tube feeds?
        • YES! 
          • When the gut is not working! 
            • Examples: obstruction, ileus, motility issues, major gastrointestinal ischemia, high-output fistula, active upper GI bleed 
          • When tube feeding doesn’t align with the patient’s goals of care/values!

Pearl 2: How do you choose an enteral access device?

  • Depends on…
    • 1. Duration How long does the patient need tube feeds for? 
      • Pro Tip: If <4 weeks, try a more temporary route!
    • 2. Use
      • Is enteral access needed only for nutrition or also for medications?
    • 3. Decompression 
      • Is enteral access also needed for decompression of the stomach?
    • 4. Location 
      • Where should the tube terminate?
  • What are the options for enteral access?
    • Temporary access (<4-6 weeks):
      • Dobhoff tube, a special type of nasoenteric tube
        • More flexible and comfortable 
        • Uses: Medications and nutrition administration 
      • Nasogastric (NG) tubes 
        • AKA “Salem Sump” 
        • More rigid and larger bore 
        • Uses: Decompression, medication, and nutrition administration
    • More durable access (>4-6 weeks)
      • USES: ALL durable access can all be used for: 
        • Medications 
        • Tube feeds 
        • Decompression
        • The difference for durable access is in:
          • Number of ports (but varies by brands)
          • How its placed 
          • Where it’s placed 
            • G = gastric vs. J = jejunum
      • PEG tube
        • Placement: Inserted (often by GI but hospital-dependent) via endoscopy 
          • Avoid PEG tubes if there is an esophageal obstruction
        • Location: Gastric
      • G-tubes
        • Placement:`Inserted (often by IR or surgery) 
            • With the assistance of a small NG tube 
        • Location: Gastric
      • G-J tubes
        • Number of Ports: THREE
          • ONE for the stomach 
          • ONE  for the jejunum 
          • ONE for the balloon to hold it in place
        • Placement: Inserted (often by IR) 
        • Location: Jejunum
      • J-tube
        • Placement: Inserted (often by surgery but hospital dependent)  
        • Location: Jejunum
      • Remember:  ALL enteral access devices are reversible
        • Even the ones that are more durable like G-tubes!

Pearl 3: What are important components of tube feeds?

  • How do we start tube feeds for our patients?
    • FIRST: Getting ready!
      • Calculate the following for each, individual patient:
        • Calories
        • Protein
        • Fluids
    • SECOND: Initiation!
      • Start at 50% of estimated needs 
        • Caveat: Start at a much lower percentage slower rate in patients at risk of refeeding syndrome or on vasopressors! 
          • Consult dieticians particularly in these situations
  • What are the types of formulas?
    • Understanding formulas:
      • The number after a formula name tell yous calories/milliliter 
        • Most standard formulas are 1-1.2 calories/milliliter 
        • Dense formula are up to 2 calories/mL 
          • Useful  for patients who are fluid sensitive!
        • Tube feeds are 70-85% water depending on the concentration (e.g. 1.0 kcal/mL, 1.5 kcal/mL, 2 kcal/mL) of the formula.
    • Types of formula:
      • Standard Formula: contains whole proteins! 
        • Require normal or near normal digestive and absorptive functions to use polymeric formulas 
        • Example: Isosource HN
      • Semi Elemental Formula: contains amino acids of varying length! 
      • Elemental Formula: contains proteins broken down to the simplest form; 
        • Easiest formula to digest 
        • Helpful in patients that lack brush border enzymes of villi 
          • Severe enteropathy from celiac disease or autoimmune enteropathy
          • REMEMBER: brush border enzymes are needed to break down disaccharides to regular glucose and chains of peptides to amino acids
        • Example:Vivonex
          • NOTE: This formula lacks some essential fatty acids and requires supplementation!
      • Special Formula: specificities of the formulas depend on the hospital
        • Patients with CKD (low electrolyte and low protein) → Suplena
        • Patients on dialysis (low electrolytes, high protein needs) → Nephro
        • Patients with diabetes → Diabetisource
      • Other Formulas
        • Immune modulating 
        • Disease specific 
        • Food-based formulas
          •  Plant-based 
          • Organic 
          • Allergen-free

Pearl 4: Complications

    • Most are from oropharyngeal secretions RATHER than gastric contents
      • Aspiration, in general
        • Risk Factors
          • AMS 
          • Dysphagia 
          • Tube feeds  
          • Frequent emesis 
        • Aspiration pneumonia
          • Estimated prevalence ranging from 45% to 95%
            • Mortality rate = 17%–62%
          • Risk factors: 
            • Upper digestive feeding intolerance 
            • Gastric dysmotility; Esophageal disease 
            • Supine feeding 
      • Current best practice
        • Elevate head of bed (HOB) > 30 degrees 
        • Pause tube feed 30-60 min prior to supine positioning (e.g. for imaging, bathing, turning) after intermittent or bolus feeding
          • Suggested but NOT proven to reduce aspiration risk
        • Sit patient up for 30-45 minutes after intermittent/bolus feeding 
        • NOTE: Postpyloric feeding does NOT reduce  aspiration pneumonia risk!
    • Patients may experience discomfort, cramping, diarrhea, and nausea when tube feeds are introduced!
      • WHY?! Due  to gut atrophy from not eating for a prolonged period of time
        • It’s not the tube feeds fault! 
        • Try at a lower rate as the gut acclimates to tube feeds
    • What do you do if your patient has diarrhea?
      • Rule out alternative causes! 
        • Infection (e.g. C. difficile)
        • Antibiotic-associated diarrhea 
        • Inflammation/IBD
        • Consider adding a bulking agent Fiber 
      • Changing the formula 
      • Slow the rate down 
        • Allows for increased absorption
    • What should we do with residuals?
      • Gastric Residual Volume (GRV) = Routine measurement of GRV  Outdated and NOT recommended to predict aspiration pneumonia!
        • NOTE: ONLY if GRV > 500 cc there is a recommendation to hold feeds for 1 hour, then resume
          • GRV > 500 cc → weakly correlated with aspiration pneumonia, regurgitation, aspiration 
        • If GRV is consistently elevated + feed intolerance (e.g. bloating, nausea, vomiting, GI discomfort), consider:
          • Temporarily holding feed
          • Different type of formula
          • Try prokinetic agent
            • Metoclopramide or erythromycin
              • Can be given combined or as monotherapy

Pearl 5: What are the scheduling options for tube Feeds and do any medications interact with feeds?

  • Continuous feeding: Steady rate usually for 24 hours
    • Most patients will start on continuous feeding 
      • Allows body to adapt to TF at a slow rate 
        • Slower rate may also prevent refeeding or lower the risk of aspiration!
  • Cyclic feeding: 
    • Typically nocturnally 
    • Great option for if there is intolerance (e.g. in delayed gastric emptying)
      • Another alternative to for intolerance → post pyloric access
    • Can be used if poor tolerance to bolus, or if have J tubes to limit infusion time
    • Benefits:
      • Allow for time off pump/oral eating during the day
  • Upon discharge, transition the patients to bolus or gravity!
    • TF can be limited to 3-6 times/day (similar to normal meals)
      • Benefits: 
        • Allows for ambulation!
          • Not connected to pump
        • Facilitates transition to oral diet
  • Bolus feeding:
    • Only given if the tube terminates in the stomach 
      • NOT with a J-tube! 
      • Can use a syringe to push formula through the feeding tube 
  • Gravity feeding
    • Place the formula in a bag and allow gravity to administer feed 
      • Typically over  30 minutes 
  • PRO TIP: Administer free  water flushes IMMEDIATELY after completion of enteral feed/medication administration
    • This helps  flush tube content to prevent clogging
      • Remember to provide hydration at regular intervals
  • PRO TIP: Polyethylene glycol (Miralax) can affect absorption of tube feeds
  • What drugs interact with enteral nutrition?
    • Four medication that need tube feeds held for 30 minutes – 2 hours (check with you pharmacy protocol) after giving these meds:
      • A-Antiepileptics
        • Phenytoin 
        • Carbamazepine 
      • A-Anticoagulation
        • Warfarin 
      • A-Antibiotics
        • Fluoroquinolones 
    • Consider IV routes or alternative medications to avoid inadequate delivery of nutrition! 
    • Medications that cannot be crushed: cannot be administered with a feeding tube!
      • Extended release formulations
      • Paxlovid
    • Some liquid medications with sorbitol: cause diarrhea!
      • Ex. Liquid tylenol


Dr. Maria Romanova: Malnutrition and hospitalized patient associated with high cost, longer stays and increased mortality. The economic burden of malnutrion is huge. The human cost is three times higher in hospital deaths than in those without malnutrition and people with it have twice longer hospital stays.

Dr. Shreya Trivedi: That’s Dr. Maria Romanova, a hospitalist and the Nutrition Support Team physician at the West Los Angeles VA Medical Center. And Welcome to the Core IM 5 Pearls Podcast. I’m Dr. Shreya Trivedi.

Dr. Hina Mehta: And I’m Dr. Hina Mehta, I’m an internist at UT Southwestern. 

Dr. Margaret Lie: I’m Dr. Margaret Lie, an internal medicine resident at BIDMC.

Dr. Shreya Trivedi: And today we are talking tube feeds. You’ll be hearing from four discussants, ranging from dietitians to gastroenterologists to hospitalists who about think a lot about tube feeds.

Dr. Margaret Lie: Yes! So let’s get started with the pearls for this episode.  Test yourself by pausing after each of the 5 questions. 

Dr. Shreya Trivedi: Remember, the more you test yourself, the deeper your learning gains. 

Dr. Margaret Lie: Pearl 1 – Approach to nutritional assessment in a patient. What are the indications for starting tube feeds?

Dr. Shreya Trivedi: Pearl 2 – Routes of enteral access. What are the possible routes and what are the 4 branch points you should think through when deciding which enteral access is best for your patient?

Dr. Hina Mehta: Pearl 3 – Components of tube feeds. What are the differences in different types of tube feeds? 

Dr. Shreya Trivedi: Pearl 4 – Tube feeds complications. How do you think through your patient having diarrhea or having residuals after starting tube feeds? And is there anything we can do to improve aspiration risk?

Dr. Hina Mehta:Pearl 5 – As we progress patients to discharge, how do we counsel our patients for success? And which medications interact with tube feeds?

Pearl 1:  Indications for Tube Feeds/Approach in a nutritional assessment in a patient

Dr. Margaret Lie: You know, why don’t we start with the definition of malnutrition. We hear it all the time, but to me, it’s a somewhat nebulous concept. 

Dr. Maria Romanova: We diagnose malnutrition based on the patient’s physical findings and the history of insufficient energy intake and the weight loss. We can detect malnutrition on physical exam by seeing loss of muscle mass or subcutaneous fat or seeing the edema on the body not related to other causes, not congestive heart failure, not ascites, or cirrhosis. It can also be diagnosed by diminished functional status. So any of those six things, what I mentioned, if you take two of them and patient has two of them present, that’s diagnostic of malnutrition. 

Dr. Shreya Trivedi: Okay, so 2 from those 6 get you to malnutrition, whether history of insufficient intake or physical exam findings of loss of muscle mass or diminished functional status like diminished hand grip.

Dr. Hina Mehta: You know guys, sometimes I see people using labs, like albumin and pre-albumin as objective markers to define malnutrition.

Dr. Maria Romanova: Albumin or prealbumin should not be used for diagnosis. Those are old, old criteria, very old. No, I only use physical exam and history and that’s enough.

Dr. Margaret Lie: The teaching point here is that albumin or prealbumin are negative acute phase reactants that decrease with inflammation. So those acute phase reactants can definitely confound the patient’s nutritional state.

Dr. Shreya Trivedi: Speaking of which, one thing that really surprised me was that  pre-albumin is actually transthyretin (TTR). The only reason it got called prealbumin is because its the band on the gel electrophoresis in the position right before albumin, aka pre-albumin.

Dr. Hina Mehta: Ohhh! I didn’t know that pre-albumin had nothing to do with albumin!

Dr. Shreya Trivedi: Same! It’s fascinating how things are named! So say we are worried about a patient, they have loss of fat, muscle mass, calorie intake, when do we start to think about initiating tube feeds?

Dr. Maria Romanova: Enteral nutrition is indicated in patients who are unable to meet their needs orally even with oral nutrition supplements. And the timeline is 24 to 48 hours for critically ill patients and after one week in non critically ill patients, as long as their gastrointestinal track is safe for use, enteral nutrition should be entertained and offered to these people.

Dr. Margaret Lie: And we also spoke to Cindy Hwang, inpatient dietician in Houston on how she thinks through initiating tube feeds.

Cindy Hwang, RD: If the gut works, we use it. That’s kind of our phrase that we will describe to anybody. If it works, we got to use it. And tube feeding is a way to continue to use the gut tube. The length of time we’d like to look at least from a dietician standpoint is five to seven days of oral intake that’s been less than 50% of their needs. Then looking at are they improving or are they still going to continue to be struggling? You know, is there no improvement in sight just yet. What else is going on?

Dr. Hina Mehta: So where do those time cut offs for initiating tube feeds actually come from? You know the ones that say 2 days for ICU patients and 5- 7 days in non-critically ill patients? 

Dr. Margaret Lie: Yeah, these time cut offs work as a general principle. What we do know is that starting early nutrition in critically ill patients can prevent things like stress ulcers and infectious complications from gut translocation.

Dr. Shreya Trivedi: Yeah some of our reviewer dietitians from Northwestern said they may recommend starting tube feeds it even sooner in patients who are higher risk of malnutrition or more needs. Say in people who have large, non-healing wounds, are post-op or after trauma.

Dr. Margaret Lie: We also talked to Dr. Brian Li, a GI fellow at BIDMC who had another important reason for starting tube feeds early.

Dr. Brian Li: Ideally, we want to feed through the gut. That’s kind what the gut is designed to do, and so you want to maintain that mucosal integrity in the gut and to use the gut as you can. And so that’s kind of another reason why we try to give enteral nutrition. 

Dr. Hina Mehta: Yeah, when I tell my patients that all this time without any food in the gut causes the gut lining to break down, they are much more on board with protecting that from happening by starting tube feeds sooner.

Dr. Margaret Lie: Same. I’ve started to counsel patients on starting tube feeds early and I accidentally started talking villi and definitely got into the weeds.  

Dr. Shreya Trivedi: Oh man that sounds like a painful experience. I think we’ve all been there where we got too much into the weeds. Okay, so now that we’re clear on the indications and the benefits. I’m curious, are there times where we don’t want to initiate tube feeds or we want to delay it?

Cindy Hwang, RD: If the gut is not working, we really don’t want to use it. We don’t want to make things worse. So if there’s any type of intestinal obstructions, even if a partial small bowel obstruction, we want to avoid tube feeding. Ileus or even hypomobility or hypermobility, something that there’s just a dysfunction in the gut process.

Dr. Shreya Trivedi: So avoid tube feeds if the gut is not working say in ileus or obstruction, or there are motility issues. Are there any other contraindications? 

Cindy Hwang, RD: A contraindication would be if their main goals of care does not align with aggressive nutrition support, right.

Dr. Maria Romanova: And I do explain that if this is a situation where a patient has advanced dementia, they often do not suffer from hunger or thirst. And if we try to alleviate suffering, it’s not giving them nutrition that will alleviate suffering. It’s often giving them peace and quiet, which is very hard to do in a hospital. Enteral nutrition I don’t recommend to initiate it on patients with very advanced dementia because there is no evidence that it prolongs life or it prevents aspiration. And those are important things for family to hear. And so I make sure that they hear it.

Dr. Shreya Trivedi: I am glad she brought this up. These end of life convos can be pretty hard and everyone has their own definitions of suffering especially when it comes to food, but I agree things like NG tube may lead to more suffering.  

Dr. Margaret Lie: So let’s recap. Malnutrition is currently diagnosed by history and physical exam showing any 2 of the following: insufficient energy intake leading to weight, muscle mass, or fat loss; localized/generalized fluid accumulation; and lastly if it’s contributing diminished functional status like decreased grip strength. 

Dr. Shreya Trivedi: Yes! In then in order to maintain the mucosal integrity of the gut, we want to generally think of starting TFs within 1 to 2 days in our ICU patients and within a week or so for our floor non-critically ill patients and whose trajectory is not improving and even sooner for patient who are higher risk of malnutrition.

Dr. Hina Mehta: And lastly the two big picture contraindications to tube feeds are if the gut is not working or if its not in line with their goals of care.

Pearl 2:  It’s Time to Start!  What are the possible routes and complications for initial nutritional support?

Dr. Shreya Trivedi: Alright so now we have an idea of when to start tube feeds, what order do you put in the EMR for the route of tube feeds? Do we do a dobhoff? NG? OG? PEG? G-tube? GJ tube? J tube?

Dr. Margaret Lie: Oh, my goodness! It’s crazy that there are that many options!

Dr. Shreya Trivedi: I didn’t know how many there were until we had to list them here!

Dr. Brian Li: When I’m thinking about enteral access, the first branch point is how long is the patient going to need enteral access? Is it something that’s going to be more durable or something that’s more of a temporary, an access that’s just kind of bridging the patient? Branch point is at about four weeks typically is what we recommend. So if the patient is going to need enteral access for less than four weeks, usually we kind of plan for a temporary access. And then if it’s going to be prolonged beyond that, then we’re thinking about something a little bit more durable. 

Dr. Margaret Lie: So we just heard about 1 branch point, temporary if you predict needing tube feeds for less than 4 weeks or durable for more than 4 weeks, but there are 3 other important branch points to also consider! So ask for yourself: ONE! Is enteral access needed only for nutrition or also for medications? TWO! Is enteral access needed to decompress the stomach? And THREE! Where should the tube terminate?

Dr. Shreya Trivedi: Yep why don’t we start with those patients who you think only need tube feeds for a temporary you know <4 weeks and what options we have for each of those 3 branch points, with medications, decompression and how far tube. 

Dr. Brian Li: The one  that people see very commonly on the floors is the dobhoff tube. And this can be either placed from the nose or from the mouth down the esophagus and typically into the stomach. Although it can be advanced post pyloric in general under fluoroscopic guidance. At other institutions they can sometimes do that at the bedside as well. The dobhoff tube is nice because it’s soft, it’s flexible, and it’s in comparison to some of the other tubes, it’s not as uncomfortable. But really its main use is to administer nutrition and medications as well. So you can’t really use it for decompression. In contrast, sometimes people will call a nasogastric tube or NG tube to use for decompression. Usually what they’re referring to is a sump type of tube. So the most common type of sump tube is a Salem sump, and that’s a tube again, that can be placed from the nose or from the mouth. It’s much more rigid, it’s less comfortable. But not only does it allow you to administer medications and nutrition, but it also allows you to decompress the stomach.

Dr. Margaret Lie: And just to clarify, a Dobhoff is technically an nasoenteric tube since it goes from the nose to the stomach as an NG or from the nose to the jejunum as an NJ, but it’s just a bit smaller and more flexible so it has a different name. 

Dr. Shreya Trivedi: And so recap, dobhoff can be used for medications as well as feeds, but NOT decompression. Compare that to an NG tube that is more of a rigid Salem Sump which can be used for decompression as well as meds and tube feeds. 

Dr. Hina Mehta: And technically both Dobhoffs and rigid NG tubes can be advanced post-pylorically.

Dr. Shreya Trivedi: And just to be on the same page the reason one would advance post-pyloric with a dobhoff is either they have gastroparesis where you don’t want to irritate the stomach, or they are not tolerating feeds, which we will get to in Pearl 4, or have pancreatitis, but honestly there is some mixed data on this. 

Dr. Brian Li: The data suggests that there’s not a ton of difference between gastric feeds and jejunal feeding in pancreatitis. That said, there are some attendings that prefer to do NJ tubes, for instance, for post pancreatic feeding. I think it’s a little bit of a stylistic thing.

Dr. Margaret Lie: So now let’s explore the other side of the first branch point: Long-term/more durable access which can be used for 4 weeks or greater! For these cases, we typically think of the PEG tube and G tube.

Dr. Shreya Trivedi: Wait, Margaret, are you saying that PEG and G tubes aren’t the same thing?

Dr. Margaret Lie: Yeah, the differences mainly lie in knowing how PEG and G tubes are placed, and believe it or not, knowing how its inserted helps you know who to consult, either GI or interventional radiology/surgery.

Dr. Brian Li: A PEG tube stands for percutaneous endoscopic gastrostomy tube. And as the name implies, it’s a tube that goes from the skin and it’s placed with endoscopic assistance. And so what happens when a PEG tube is placed is we do an upper endoscopy and get into the stomach, and then from the skin we kind of poke through a needle and put in essentially like a string, and that is then pulled out through the mouth. And you attach that to a long tube. And then you pull the string from the skin side and that tube gets dragged down into the esophagus and gets pulled up against the wall of the stomach. And there’s a little bumper there that kind of keeps the tube in place so you don’t just pull it out through the skin.

Dr. Shreya Trivedi: When we’re talking about PEG tubes, the PEG tube is pulled down endoscopically down the esophagus and percutaneously inserted into the stomach.  

Dr. Hina Mehta: So I imagine if there is an esophageal tumor or obstruction, you can’t get a PEG tube down.  

Dr. Margaret Lie: Yep, for those instances where we can’t mechanically get from the esophagus down to the stomach, we would opt for a G-tube rather than a PEG tube

Brian Li: In contrast, a G-tube, which is placed by IR is done a little bit differently they introduce a needle from the skin into the stomach, and eventually what happens is they kind of anchor the stomach to the wall of the abdomen. They can sometimes use these kind of anchoring buttons. And then when they have a good spot, they place a tube in. 

Dr. Hina Mehta: So it sounds like they are sewing a button from the outside. 

Dr. Shreya Trivedi: Yeah it does, I can just imagine IR doing G-tube using their fancy tools. But it’s jut like sewing. So both PEG and G tubes can be used for medications, nutrition and decompression. All a win! Check, check, check. Are there any other important differences between PEG and G tube besides who places it at your hospital? 

Dr. Margaret Lie: So depending on the brand of PEG or G tube, it may have a different number of ports, but usually a G tube has one more functional port than the PEG tube. 

Dr. Shreya Trivedi: That’s helpful to know cause I imagine having that one extra port for the G tube is good if say one of the ports gets clogged or its good to have another port open to give meds while the other port is getting tube feeds. Which we will get all into medication interactions in Pearl 5. 

Dr. Hina Mehta: Okay! So that’s PEG vs. G tubes, but then how do you think about other long-term options even lower down in the GI tract: like GJ tubes vs J tubes? 

Dr. Brian Li: A GJ tube is kind of similar to a G-tube except it has a longer extension that goes into the small bowel, again, typically placed by IR. And in that case there’ll be three ports on it. There’ll be one for the balloon, one for the stomach, and then one for the jejunum. And then finally a J-tube is typically placed by surgery where they will thread a tube from the skin and then surgically place it into the small bowel and kind of tack it in place

Dr. Hina Mehta: He loves saying that IR or surgery places it! But I bet it’s all hospital dependent who takes ownership of what. 

Dr. Shreya Trivedi: Right, right I bet he spends a lot of time clarifying that! But I am still wondering when do we think of reaching for a GJ or a J tube? And really want to make sure we are having access that down in the GI track. 

Dr. Brian Li: Usually when you’re thinking about a GJ is when there’s something wrong at the pylorus, at the level of the pylorus, or like a gastric outlet obstruction. Most often malignant. What’s usually done when there is a problem at the level of the pylorus, like a gastric outlet obstruction is that you can take the gastric port and just put it to gravity so you’re decompressing whatever oral secretions and so forth. And so they’re not vomiting. And then the J-tube is then theoretically beyond the level of obstruction and you’re administering nutrition and medications and so forth into the J tube. 

Dr. Hina Mehta: Okay! That makes sense to use a GJ for severe gastroparesis. You can feed through the J, aka the jejunum, since the stomach motility is compromised and in gastroparesis, we wouldn’t want to feed through the G, aka the gastric part. 

Dr. Margaret Lie: And that leaves the G part of the GJ tube for decompression if needed.

Dr. Shreya Trivedi: Okay so let me summarize, when starting tube feeds, we have to think if this artificial nutrition, enteral nutrition, is gonna be for less than 4 weeks or not. If it’s less than 4 weeks, we can reach for dobhoffs, especially if you only need it for nutrition, medications, and don’t necessarily need for decompression. You can also advance dobhoffs past the stomach. If you need decompression short-term, then you want to reach for the typical Salem sump NG or NJ tube. 

Dr. Margaret Lie: If you think tube feeds are gonna be needed for more than 4 weeks, you can ask GI to endoscopically place a PEG, which gives you 1 to 2 ports for medications and tube feeds. But you have to make sure that GI can get from the mouth to the stomach without issues. Alternatively, IR or surgery can do a G-tube. Which has an extra port to inflate the ballon and keep the tube in place. If there is a lesion, gastroparesis, or obstruction lower down the post-pylorus, then a GJ tube or J tube may make more sense.

Pearl 3: What are important components of tube feeds?

Dr. Shreya Trivedi: You know, guys, out of everything, I think the biggest blackbox for me is the actual tube feeds itself. The different tube feed formulas really feels like a foreign language and honestly, I am just hoping its at an hour that nutrition is around to help me decide but gosh if it’s after 4 pm or the weekend, then then I feel like i’m just choosing something arbitrarily, yeah, this one for my patient! 

Dr. Hina Mehta: I got you Shreya/we’ve all been there. So big picture whatever we choose, it’s better to start on the lower side. Ideally, starting nutritional support at 50% of a patient’s estimated needs. 

Dr. Margaret Lie: There is a caveat, though. For patients on pressors or those at risk for refeeding syndrome, we want to start tube feeds much less than 50% of their needs and increase the rate much more slowly! I find it’s best to work with the nutritionist during these situations.

Cindy Hwang, RD: So once we do those calculations, we have our numbers, then we will look at the medical picture. Do they have a fluid restriction where then we would have to pick formulas that are more calorie dense. Can they be on a standard formula? Do they need a specialized formula?

Dr. Shreya Trivedi: Alright, so then it sounds like we need to see if they are gonna tolerate a standard formula but, guys, what even is a standard formula?  

Dr. Margaret Lie: So a standard formula specifically contains whole intact proteins which means the patient’s digestive system needs to do the work and break down those amino acid chains. These formulas can be oral or given via a tube. Some examples are Nutren and Isosource. 

Dr. Hina Mehta: But sometimes I see a number after the standard formulas like Nutren 1.0 or Isosource 1.2. So is 1.2 just an updated version of a 1.0?

Dr. Shreya Trivedi: I though that for a while, too!

Cindy Hwang, RD: A standard formula would have one to 1.2 calories per milliliter. There’s a little bit more dense would be 1.5. You see that number a lot in the formulas on the market, 1.5. 

Dr. Shreya Trivedi: Oh my goodness! So good to know that the number behind a name of a formula actually means how many calories are in a mL of formula. So if we put that into context and close the loop, let’s do some quick math. If a patient gets 1 L of Nutren 1.0, 1 L is 1000 ml and if there’s 1 cal in each ml and so we are giving our patient 1,000 calories.

Dr. Hina Mehta: And did you know that about 70-85% of tube feeds is actually water? So if a patient is fluid sensitive, then knowing if the tube feed is 1.0 vs. 1.5  can make a big difference.

Dr. Shreya Trivedi: That makes sense! So for a patient needing fluid restriction, we would choose a more caloric dense tube feed in the same amount of fluid. So a formula like Nutren 1.5 or something – if there is 1.5 cal, I only give about 660 mls Nutren 1.5 to get to 1,000 calories.

Dr. Hina Mehta: So is it always better to choose a denser formula?

Dr. Margaret Lie: WELL, everything has its pros and cons. You see, denser formulas have higher osmolality.  So hypertonic formulas like isosource 1.5 can increase the risk for osmotically induced diarrhea when compared to its less calorically dense counterparts!

Dr. Shreya Trivedi: That is no fun, but good to be aware of! Okay! What are other different types formulas we might see out there?

Cindy Hwang, RD: The name kind of give you a little bit of an idea of the patient type of tailored towards most common institutions will have a low carbohydrate formula because that’s often needed right. By patients. Glucerna and then Diabetisource. There are also there are also specialized formulas for patients that need low electrolytes and lower protein for renal disease. There’s another option for renal disease patients, low electrolytes, but high protein for those that are on dialysis. Because for dialysis, you lose protein through that process and your protein needs are actually higher now that you are getting dialysis and your kidneys aren’t worried about the high protein, you actually need more. So it will help with lowering electrolytes.

Dr. Margaret Lie: One example of a low electrolyte, low protein formula in patients with CKD is Suplena and then for patients on dialysis where you want to reach for low electrolyte, but high protein formula, you might choose Nepro. 

Dr. Shreya Trivedi: That’s really helpful, but I’m wondering about my patients who can’t digest a typical standard formula and break down whole proteins? I am thinking about the patients who may have an abnormal digestive tract?

Dr. Amelie Therrien: If you have some abnormal digestion either with the pancreas, if the patient has had a whipple, then you go for semi elemental.

Dr. Margaret Lie: That is Dr. Amelie Therrien, a GI Attending at BIDMC with an interest in clinical GI nutrition. She is referring to a semi elemental formula which consists of partially pre-digested but not fully pre-digested peptides, polymers, and medium chain triglycerides.  

Dr. Hina Mehta: An example of a common semi elemental formula is Peptamen AF, which I remember all the time because my student used call it “Peptamen As F” 

Dr. Shreya Trivedi: Yikes! 

Dr. Hina Mehta: But its not what you think it means, AF actually means advanced formula.

Dr. Shreya Trivedi: Oh, okay! Alright! So know that I know what semi elemental is, I am guessing if a patient needs EVEN MORE assistance with digestion, we can move from semi elemental to just elemental formula, which I imagine is just the simplest peptide and sugars.

Dr. Margaret Lie: Yep, elemental formulas require minimal digestive tract effort.

Dr. Amelie Therrien: If you have someone that has a very severe enteropathy that has celiac disease, autoimmune enteropathy, then you try the elemental formula because what you have on top of your villa in your intestine are brush border enzymes. You need the brush border enzymes at the tip of your villi to continue the digestion to go from the disaccharide to regular glucose and to get from little chains of peptides to amino acid. So if you have a severe enteropathy, you’re not having those enzyme and then you need to have an elemental formula.

Dr. Margaret Lie: Aww man… when those brush border enzymes are MIA, you have to go for an elemental formula.  

Dr. Hina Mehta: Unfortunately, Vivonex is the only elemental formula we usually have and that’s super expensive!

Dr. Amelie Therrien: The problem with Vivonex is that it lacks essential fatty acids and so its only medium chain triglycerides. So there’s not omega-3, omega-6, omega-9. So people have to kind of supplement. 

Dr. Margaret Lie: And supplementing is a whole other bag of worms that we will leave to our dietician colleagues.

Dr. Shreya Trivedi: So if I were to summarize choosing tube feeds, it seems like the first thing about is the patients gut. Will they will tolerate a standard formula of whole proteins that their gut needs to digest? Or if they have some enteropathy or abnormality with their pancreas in not producing some enzymes the patient needs? And they may benefit from a semi-elemental or elemental formula. 

Dr. Margaret Lie: Then we can pay attention to the # after the name of a tube feed which stands for how many calories per ml is in that formula. For patients who may be fluid sensitive, we reach for more calorie dense formulas like 1.5 instead of 1.0. 

Pearl 4: Tube Feed Complications

Dr. Shreya Trivedi: Alright! So after we start tube feeds, I do a little prayer that I don’t get a page that there is a complication with the tube feeds, because I honestly, not my area of expertise.

Dr. Hina Mehta: Yeah same, from “oh your patient is hypoxic” and I think crap are they aspirating? Or oh your patient is now having diarrhea to calls about what to do about residuals!

Dr. Shreya Trivedi: Yeah so much good ground to cover! Let’s start with diving into aspiration. And we all know the typical teaching that we get about preventing aspiration.

Cindy Hwang: It’s a risk when you start tube feeding, it’s aspiration. So any patient that is gastric fed should be at an angle of minimum of 30 degrees. Some places say 45. It depends on the policy. And if it’s on cyclic feeding or gravity feeding, having patients sit up for at least 30 to 45 minutes after you’re done, kind of letting it go past your gut, not sitting in the gut or in the stomach to prevent any risk of aspiration. 

Dr. Shreya Trivedi: But is sitting up 30 to 45 degree for 30 to 45 mins after eating enough?

Dr. Maria Romanova: We know we are aware of aspiration risk. The real problem is there is no evidence that anything we do helps like position in the patient. We do it, but there is no good evidence. In reality there is a thought that aspiration is actually caused by aspirating oral secretion and not necessarily the tube feeds, which is even harder to prevent. 

Dr. Shreya Trivedi: Oh god. I feel like you’re going to tell me next that post pyloric tubes don’t actually help aspiration either!

Dr. Brian Li: One of the questions that comes up often is whether feeding in the stomach versus the small bowel has an increased risk of aspiration and aspiration pneumonia. And there’s not a huge amount of data, but I would say that most of the data suggests that there’s not really any significant benefit to post pylori feeding with regards to reducing aspiration pneumonia as compared to gastric feeding. The thought being that typically aspiration pneumonia in these circumstances is more related to oral secretions and oropharyngeal aspiration, oropharyngeal dysphagia, or difficulty with oral secretions rather than with frank vomiting from the stomach.

Dr. Shreya Trivedi: But with that being said, I guess it is empowering to know where the real risk of aspiration really comes, the oral sections, and focus on ways to stay on top of that if possible.

Dr. Margaret Lie: And I feel like this should be said explicitly, even though there hasn’t been a definite proven benefit yet. I am still going to advocate raising the head of bed and staying upright after feeds because that’s the best practice we have. And honestly it at least helps me sleep at night!

Dr. Hina Mehta: Yeah, and at least it’s free.  

Dr. Shreya Trivedi: Yeah, you’re right, it is free to raise the head above the head! Let’s move onto the next complication we might get pages about. Your patient is having diarrhea after starting tube feeds!

Cindy Hwang, RD: Most common I think just intolerance, whether that’s diarrhea or some people have some nausea or discomfort, cramping, that type of reaction, it can be hard to discern whether it’s the tube feed or whether it’s just introducing something into their gut when they haven’t had anything in their gut for a little bit. A lot of times the reason why we have them have a tube is because they haven’t been eating. So even in that amount of time, your gut starts atrophying if you’re not giving it anything. So it does take a little bit of time for your gut to recover and rebuild and have enough to do its job.

Dr. Margaret Lie: And so one big misconception that we’ve all had is attributing the diarrhea to the formula and unfortunately stopping the tube feeds, but that’s probably not what’s best for the gut.

Cindy Hwang, RD: It was caused by the introduction of formula. Yes, but it’s probably not just the formula because for patients that have had not much in their gut for a while, the gut starts atrophying, it’s going to take time for it to respond.

Dr. Maria Romanova: Whenever we encounter this we always need to rule out other reasons for diarrhea. For example, C. diff colitis. It’s not that common that enteral feeds cause diarrhea, but sometimes we need to change one formulation to another as standard tube feeds to let’s say semi elemental or elemental formula.

Dr. Shreya Trivedi: Most of the time the answer is not to stop tube feeds, especially if the tube feeds was just started at a low rate like 10-20cc/hr. Just give the gut some time to acclimate. 

Dr. Hina Mehta: And most importantly, think of the other things that can cause diarrhea. Even look at that med list and discontinue bowel regimens they are on! 

Dr. Margaret Lie: You can also try a bulking agent like Benefiber or psyllium husk! But sure, if they continue to have a lot of intolerance, nausea or cramping, try switching the formula.

Dr. Shreya Trivedi: Okay and last but not least, residuals! When I was in residency, which feels like eons ago, we monitored residuals. This seems so outdated now. 

Dr. Maria Romanova: What gastric residual volume is when nurse uses a syringe to remove gastric content, she measures the volume and in most cases she returns them into the stomach. It has been studied excessively and it turned out that routine measurement of gastric residual volumes poorly correlates with aspiration pneumonias or even with gastric empty or even with nausea and vomiting. But what it correlates with is with suboptimal nutrition delivery. So it’s not recommended anymore to do it routinely. 

Dr. Hina Mehta: What should I do when a nurse still calls about gastric residual volumes?  That still happens from time to time!

Dr. Maria Romanova: It’s only if GRV is over 500. We do recommend to hold it for an hour and then resume tube feeds. Maybe check it a little later. Basically the common practice now is not to measure it, but to monitor for patient’s symptoms. If you see that gastric residual volume is consistently elevated or if patient shows other signs of feeding intolerance, you can consider giving them a prokinetic agent metoclopramide 5 to 10 milligram four times a day or erythromycin four times a day. They can be used individually or in combination.

Dr. Margaret Lie: So it sounds like routine measuring of gastric residual volume is outdated and the focus is more on symptom monitoring. If it does get checked and its over 500 or so, we can hold it for an hour then resume tube feeds, and as a last resort start a prokinetic agent if needed. 

Dr. Shreya Trivedi: Yep, and then why don’t we summarize our takeaways about the other common complications with tube feeds we covered. The big teaching point with aspiration is that aspiration is actually caused by oral secretions rather than the tube feeds itself. And despite us doing this all the time, evidence for patient positioning to prevent aspiration has yet to show much of benefit.

Dr. Hina Mehta: With diarrhea in tube-fed patients, the diarrhea is usually not from the tube feeds itself, but from gut atrophy since these patients may not have eaten much for a long time. Next time I get this call about diarrhea, I’ll try giving the gut more time and put the tube feeds at a slower rate, and think of other things that can be causing diarrhea. And lastly, if its not getting better, talk to the dietician about adding a bulking agent or possibly changing up the formula.

Pearl 5: Tube Feeds Schedule & Meds

Dr. Shreya Trivedi: Now let’s round out things with what kind of tube feed schedule we are progressing patients to, especially as they approach discharge, and what counseling and nuances we should give around medications.

Cindy Hwang, RD: Most of the patients will start on continuous tube feeding in general, especially in the inpatient setting. We have that freedom to start them there, to also get them acclimated and to increase tolerance for it. If they’re going home with tube feeds, most people will transition to bolus or gravity. Technically bolus feeding in our dietetic world is really where you’re using a syringe and pushing through the formula in a bolus, a true bolus, if that makes sense. And then gravity drip is technically a bolus too. So it does take longer than bolus, but it’s gravity dripping, it’s intermittent feeding, it’s mimicking meals, similar to what bolus would be. So they’re a little bit different, but they’re kind of similar in terms of timing. And they don’t have to be attached to the pump continuously for 24 hours a day. And so most people will switch over to that. But of course we also have to test their tolerance with that, especially transitioning from the continuous feeding to a gravity or bolus feeding.

Dr. Hina Mehta: So we are progressing patients from continuous 24 hour tube feeds to cycled feeds.

Dr. Shreya Trivedi: So cycled is a scheduled regimen that is continuous, but less than and often we see it done at night time.

Dr. Hina Mehta: And from there we progress patients either gravity or bolus feeds.

Dr. Margaret Lie: I’ve definitely made that mistake of saying someone is ready to go home and the RN looks at me on case management rounds and reminds me, they are still on continuous tube feeds.

Dr. Shreya Trivedi: We’ve all been there, Margaret. So it sounds like gravity or bolus feed is the way to go especially if they are planning on going home or we just want to give them more freedom in the day to move around. And also we’re done with cycle feeds, as well. But are there any contraindications to bolus or gravity and situations where we should stick to cycled feeds at night or continuous? 

Cindy Hwang, RD: Of course, if you can’t tolerate having a larger volume of formula in one sitting, then you will have to do it more like a continuous or cyclic feeding, kind of spreading out the volume you’re getting over a course of time. So someone maybe with delayed gastric emptying, probably not a great idea to bolus or gravity feed, or if they’ve had any type of changes anatomically to their gut, that might be something to consider.

Dr. Margaret Lie: And maybe the biggest oversight that precludes patients from getting bolus feeds is if their tube does not terminate in the stomach. You see our stomach is a nice reservoir to support a bolus of tube feeds. 

Dr. Shreya Trivedi: That makes sense we can’t bolus into the jejunum. The jejunum is not really a reservoir at all since it doesn’t expand like the stomach. 

Dr. Margaret Lie: So if someone has a GJ or J tube, you’d likely want to progress them to cycled or nocturnal feeds.

Dr. Hina Mehta: And then what other things should we be educating patients on about tube feeds? Like how do we set up our patients for success when they go home? 

Dr. Margaret Lie: Another thing I learned is that with tubes feeds, whether they are continuous or a bolus, we of course start free water flushes, but that doesn’t just serve the purpose of hydration!

Dr. Brian Li: I think one thing that sometimes patients forget to do is to flush the tube after they feed. So particularly patients that are on bolus or recycled and so there’s times where patients come in, they have an endoscopically placed NJ tube, everything’s great, they’re discharged home, and then it clogs the next day because they don’t flush it and they come back and we scope them again. And so that’s one of the key things is to make sure they flush their tube when they’re done with their feed and to flush it immediately, not to like, oh, my last cycle finished a while ago, I’m going to go around and do some other stuff and then I’m going to flush it later. Then it’s too late already.

Dr. Shreya Trivedi: I really appreciate that. I didn’t know how time sensitive flushing was.

Dr. Margaret Lie: Another good rule of thumb with free water flushes is to increase the flushes if its a more concentrated formula.

Dr. Shreya Trivedi: That makes sense! I remember Hina telling us that most of the tube feeds is 70-85% water and so probably less if it’s more concentrated. That’s good to know! The other thing I did not appreciate until talking to our discussants is the impact of everyday medications on the tube feeds. For example, something that most patients reflexively when they are admitted – polyethylene glycol.

Dr. Amelie Therrien: MiraLax is kind of like an osmolar solution that will make the water or the liquid with it not being absorbed. So if you’re giving the MiraLax with tube feed, then your tube feeds will not be fully absorbed. And the same goes for cholestyramine.

Dr. Shreya Trivedi: And now that Dr. Therian says that, it makes a lot of sense of something like polyethylene glycol would impact absorption of the tube feeds.

Dr. Hina Mehta: Yeah, that’s good to know. Is there any other counseling we should be give for patients’ regarding their medication timings and their tube feeds?

Dr. Maria Romanova: There are only four medications where enteric feeding has been shown to affect absorption and for those four medications you need to hold tube feeds for a couple of hours before and a couple of hours after. So those four medications are phenytoin, carbamazepine, warfarin and fluoroquinolone antibiotics. So at least for antibiotics we can switch them to IV route if it’s reasonable.

Dr. Shreya Trivedi: One way to keep this all straight is maybe a mneumonic about the 3 a’s. A for antiepileptics, phenytoin and carbamazepine. A for anticoagulation with warfarin. And A for antibiotics with fluoroquinolones. Rule of thumb is you want to hold tube feeds usually an hour, some resources say 30 minutes or so, before and after giving those meds.

Dr. Margaret Lie: I did a lot of reading about it. There is a small caveat for the anti-epileptics, newer guidelines from 2021 say we don’t have to hold TF for antiepileptics, but there are still mixed practices and the interaction is real.

Dr. Hina Mehta: Good to know! The other thing to keep in mind about medications is that is it extended release? I’ll often get a page after ordering diltiazem extended release or even paxlovid that it can’t be crushed.

Dr. Margaret Lie: Thankfully some of these medications, like diltiazem, you can switch to its immediate release form.

Cindy Hwang, RD: There’s also alternatives. You can always do a liquid formulation, but then it’s being considerate of how the liquid formulation is made. Does it contain sorbitol, which is something that can increase the risk of diarrhea. And you’re thinking, oh gosh, is it the tube feeds? Oh no, maybe it’s the sorbitol. So something to check as well. And dieticians should be aware of that. They can look through their medications.

Dr. Margaret Lie: One common example of a liquid medication that has sorbitol is actually liquid tylenol! 

Dr. Shreya Trivedi: Something we use all the time! Okay we’ve covered a ton of good ground for preparing patients for discharge and counseling. Summarizing, ideally we would transition them to bolus or gravity feeds, but if they have a J tube or GJ where you are feeding into a smaller space, you generally can’t bolus into the small bowel.

Dr. Hina Mehta: I also learned to counsel patients to not keep tube feeds out for more than 4 hours, especially because most have milk in it. And to flush right away after feeds to prevent ER visits for clogging.

Dr. Margaret Lie: And lastly, we need to advise to hold tube feeds at least an hour or so before and after giving 3 A’s – the anticoagulant warfarin, the antibiotics class fluoroquinolones, and oftentimes antiepileptics like phenytoin and carbamazepine.

Dr. Shreya Trivedi: And that is a wrap for today! If you wanna learn more on tube feeds, check out our youtube channel where we linked to some of the original interviews.

Dr. Margaret Lie: If you found this episode helpful, please share with your team and colleagues and give it a rating on Apple podcasts or whatever podcast app you use! It really does help people find us! 

Dr. Shreya Trivedi: Thank you Dr. Vorada Sakulsaengprapha for the accompanying graphic. To Daksh Bhatia for the audio editing. Thank you to our reviewers Shaina Shape RD, LDN, CNSC, Danielle Hom MS, RDN, LDN, CNSC, as well as, Dr. Elliot Tapper and Dr. Chethan Ramprasad. Opinions expressed are our own and do not represent the opinions of any affiliated institutions.


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