TPN (Total Parenteral Nutrition) Tips

In case you don’t know who Guenther is. That’s Guenther.

Preparing TPN

Parenteral nutrition is given via central lines e.g. via a Hickman (aka Pacman) in my case. Hence, the nutrition is broken into the smallest compounds such that the blood stream can transport them without the involvement of the GI tract. There are many different TPN bags depending on the patient’s needs (calories, amount of fluids, lipids/glucose/amino acids, further compounds such as vitamins and minerals,…). If needed (for example for glucose intolerances or liver problems one can individually produce those bags called compounding), here is an example of an Olimel 4,4% 1000ml bag that is added with vitamins and minerals.

That’s how I find it the easiest, from left to right: Empty syringes, (shower plaster), disinfection, compresses, cannulae, additional compounds minerals, NaCl, vitamins, antimicrobial solution, stoppers. Below the table I store the nutrition bags and a bin for the plastic accumulation and papers. At the side I have a bin for the cannulae and glass which makes it safer. Then, I also have a big box with the drapes, connecting sets, filled NaCl syringes (for flushing), emergency gear (sets if the pump shouldn’t work where you can manually use them), gear for plaster change including new bionectors (that are put on the Hickman catheter).

Please also follow the ‘bewares’ below. I don’t want to write ‘Disinfect’ every second sentence in the following.

1. Wash your hands (according to the WHO). Disinfect them. Put on medical gloves and a mask.
2. Prepare a sterile drape (with the ‘dry’ side towards you).
3. Prepare the syringes i.e. put the cannulae on the empty syringes. Put aside the minerals, NaCl and vitamins as well as (if you use it) the antimicrobial solution*. Put aside the set you connect between the central line and nutrition bag.

4. Draw out the liquids. Usually, all of it. For the antimicrobial solution I have to split 6ml into two parts and put them in the fridge as it has to be cooled until it is used.

It is difficult to describe how to prepare them, so here is a video (breaking ampoule, plastic ampoule such as the minerals, glass ampoule with powder, respectively). I guess it needs some practice, but it will get easy.

5. Now prepare the vitamins which is a powder in the glass that you need to dissolve with the withdrawn NaCl syringe.

6. Now take the nutrition bag and mix the three main compounds by ‘kneading’ it. Some bags have an oxygen indicator, check it’s colour before opening.

7. Now add the withdrawn components into the nutrition bag. Depending on the bag you might need to remove a stopper. Only inject it into the opening it is supposed to get into.

8. Knead it again and connect the set (belonging to the pump you have) into the other opening. I always closed since I don’t want to have the solution all over the floor.

9. Now the bag is ready to go to the iv pole. Vent the set i.e. open it and move it up and down until the solution has reached its end, close it again. Gravity will help you. There is a filter the solution needs to go through to eliminate air bubbles.

Stay with me. Preparing dinner lasts at least equally long.

10. You can insert the set into the pump (have a look at its instruction as it really depends on the pump you using). You can then turn it on and set it according to the amount of the bag and the duration it runs through (or equivalently the speed it should run).

11. You are ready to eat. Wash your hands again, disinfect and flush your line with NaCl (the prepared syringes). Disinfect again and connect to the set. Play start and make sure that it is running.

Make sure to vent the syringe prior. And flush discontinuously to ‘rub’ the line. Stop and Go, Stop and Go.

yumyum

If you have eaten, you can disconnect again. Wash your handy, disinfect, flush again. Inject the locking solution (remember to get it out of the fridge beforehand) and put a cap*** on. Close the set with a stopper (I always use the stopper of the syringe) and take it out of the pump.

Beware (before and during preparation):

• Disinfect always. Your hands. When withdrawing or injecting, all openings. 
• Always vent before injecting or flushing.
• Always change the cannula when you have drawn something (i.e. if there was one contact with the cannula and something else.
• Use the components as indicated (e.g. store them in the dark etc), use the bags max. 24h and don’t let them stay in the heat or cold i.e. don’t put them in the sunlight. Some bags need to be cooled, you have to warm them up sufficiently long, only place them outside and don’t warm them actively up. 
• Make sure that all connections are closed if needed.
• Take care of the tube line in the household (e.g. when animals are present). I always wrap the line around the iv pole again to make sure that I don’t roll over it/ put most of the line inside my backpack. 
• Only use sterile equipment.
• Read the package leaflet to make sure that you are not allergic to any substances.
• Use a sterile room to prepare the nutrition.
• Set the right speed. 
• Make sure that all components are available i.e. tell social services/the pharmacy about any shortages early on and keep some emergency stores.
• Be careful with the line, especially a Hickman line. Don’t pull it.****

TPN Tips

• Have good doctors and a dietitian who control the start of your feeding (first as in inpatient regarding refeeding syndrome, reactions…). If stable and discharged, have good social services that continue TPN prep or show you how to do it. 
• Have doctors that follow up on you.
• Have weekly, then monthly blood draws.
• Establish a routine (if it is possible). Some people can’t have night feeds due to nausea or being unwell, others prefer having the feeds over night such that they can move more freely during the day. 
• Press the NaCl syringes at first together to pop it, when venting it won’t go up to the ceiling.
• I usually load the batteries of the pump in the hours I am not connected such that I am free when I am connected. 
• Get a backpack. It is heavy, but makes things a lot easier. Whether you need to go to the doctors or want to go a bit outside.
• During prep, draw the empty syringes up to the ml level you will fill them. Open the cannulae packets such that you can put them on the syringes immediately after taking off the used ones.
• Prepare everything in order, it will be faster.
• Do it together with someone from your household. Make sure they know how to do it. If I feel too unwell, my mum prepares the nutrition.
• Use the big package of the drap for the garbage, then you have a nice little packet for the bin.
• Use a connection (Bionector) that has a check valve. Then you don’t need to close the line to prevent blood outflow. That increases the life duration of the Hickman line.
• Always have syringes for flushing with you.
• Wear something with buttons or zippers that you can take on and off without the need of disconnecting.

Bo, Franklin and me

Components

If you are interested in the components added, here are some examples.

TPN bags normally have

• 25%-30% lipids
• 40%-70% glucose
• rest amino acid solution (patients need up to 1.5gm/kg/day)

of the calories. Depending whether the patient is able to drink the bags contain more or less fluid (or additional iv fluids with electrolytes are needed e.g. in Pots patients). There are also some of the most important electrolytes inside the prepared bag (magnesium, potassium, sodium).

Trace elements including

• zinc (as co-factor of many necessary enzymes, helps wound-healing)
• copper (important in iron processes, blood cell formation,
• manganese (activates important enzymes in your liver and gallbladder)
• iron (blood cell formation, metabolic processes)
• selenium (cell metabolism)
• chromium (glucose metabolism, peripheral nerve function)

and vitamins

are added. If you cannot get them orally (either as you cannot eat or your intestines don’t absorb them), this can be a life-improver or -saver. I would recommend getting micro nutrition blood tests every few months.

We got informed that due to the vaccinations for COVID the companies weren’t able to produce sufficient vitamins. Hence, vitamin injections will reduce. I find it quite concerning that you are so dependent on those production processes.

TPN – a curse or a blessing?

Total parenteral nutrition is the last possibility to give a patient nutrition via a central vein. Only if patients’ nutritional intake cannot be ensured via the oral (by mouth) or enteral (tube feeding e.g. to the stomach via an NG tube or to the duodenum via an NJ tube which are both inserted through the nose or via a PEG/J that is inserted through the abdominal wall into the stomach or jejunum, respectively) way, a central line is inserted in order to slowly inject the nutrition that is already broken down into smallest compounds into the bloodstream such that the way through the GI tract is completely circumvented. 

Patients that suffer from severe dysmotility, that have lost large parts of the GI tract (e.g. that suffer from short bowel syndrome) or have other GI issues that prevent absorption/resorption such as severe CEDs or MCAS, are put on parenteral nutrition. This can either be in addition to a reduced oral or enteral intake or the patient is exclusively fed via the vein.

For those that cannot survive without it, it is a blessing. I am very grateful for the possibility of parenteral nutrition. Otherwise I would slowly die from malnutrition and experience the symptoms I had back then when I wasn’t able to eat and didn’t have any other way of feeding – symptoms of hungering and malnutrition (see also cachexia)

• Fainting
• Too weak to do anything
• Reduced cognitive ability 
• Metabolism stops that can lead to 
• Organ damages/failure
• Reduced immune response, infections
• Reduced wound healing
• Being cold (always)
• Reduced ability to breathe on your own
• Glucose level too low (hypoglycemia): sweating, tachycardia, shivering, tremors, epileptic flare-ups, breathing difficulties, unconsciousness etc 
• If no resources are left, it can lead to death

Nonetheless, it can become a serious relationship. If your life depends on a central line through which you give the nutrition, it better should work without complications. However, this isn’t the case. Long-term TPN includes the risks of 

• Sepsis due to central line infections (hygiene!)
• (In the beginning after severe weight loss or long periods of fasting) refeeding syndrome
• Thrombosis (up to the impossibility of inserting central lines due to lack and loss of vascular access)
• Electrolyte imbalances (frequent blood draws!)
• Still deficiencies in minerals and vitamins (check micronutrients!)
• Liver failure (long-term!)
• Glucose imbalances (too high or low levels with respective symptoms)
• Complications during the surgery where central lines are inserted 

That’s why patients, their carers and clinic staff have to be well educated and always take care when preparing, applying and observing the patient during TPN. See above tips.

The nutrition goes directly into the bloodstream, through one of the main veins in the body. Thus, the risk of catheter-related infection is high and its consequences can be life-threatening. 

Hepatic dysfunction***** (liver cannot come up with the metabolism anymore) and loss of venous access (due to infection or thrombosis only a certain number of new catheters can be inserted) are the main concerns that lead to intestinal failure and the need for an intestinal transplant since TPN and oral intake aren’t possible anymore. 

What to expect:

Sometimes one also has to adapt TPN to the individual patient (compounding) or additional supplements are needed e.g. potassium or iron infusions. Especially, if the patient has low weight or a past phase of extreme weight loss, the calories and the speed of injection have to be rather low i.e. one is connected to the pump for most of the day. When starting TPN the patient should be in hospital such that frequent blood draws are possible and the TPN bags can be adjusted. This also means you have to carry the iv pole or a heavy backpack (which I do recommend e.g. for doctor visits, more flexibility in- and around the house) with you almost all day long. Some don’t necessarily like it to be connected overnight, you wouldn’t eat during sleep as well. However, the body gets used to it. The pump is too loud or the cables are annoying. But one gets used to it soon (you have to). After the surgery the insertion/puncture side might hurt. TPN prep, changing the plaster (and if you have a port catheter, its access) all take a lot of time and attention. 

The risk factors mentioned above have to be prevented as best as possible or if present, treated accordingly e.g. glucose measurements etc. TPN can also cause diarrhoea, nausea or other GI issues – usually only at the start when the body gets used to it.  

I cannot take a bath, swim or shower properly (my autonomic neuropathy symptoms wouldn’t allow it anyway) due to my hickman line (if you have a port catheter, you can do so, when it isn’t accessed). There are also special water-proof plasters that decrease the risk of water (and bacteria) entering the puncture side.

Increased urination (also during the night), chills, muscle sores and more are possible side effects. 

My face and legs swell every now and then because of the oedema. Although my weight doesn’t seem to increase above a certain level (hence, I am still severely underweight, even cachexic) I am very grateful for TPN. Without it my weight would drop dangerously low again and I wouldn’t be alive. Patients’ weights react very differently to TPN, it might increase a lot or stabilise or continue decreasing (in this case, severe further illness/inflammation is going on where the body needs extra energy). Rapid weight gain and loss are common effects of TPN.

And the list goes on. But, to be honest, those are all only little annoying things. The gratefulness that it keeps me alive is much greater.

Cachexia

Cachexia is characterised by involuntary severe weight loss as well as muscle wasting due to other (often extreme) diseases such as cancer or GI issues such as dysmotility. The body uses all its reserves (mainly the fats around the organs) to combat the illness and/or cannot absorb sufficient nutrition that it could turn into these resources. When the body’s immune system is overactive as in cancer or severe pain episodes, an excess in calories is needed. 

Patients are usually very thin (BMI of below 18.5, often far below that), weak, fragile and skeletal. However, it is far more than this, cachexia comes with many (severe and long-term) side effects and can lead to serious complications: 

• Bad wound healing, open wounds, (inner) bleeding leading to
• Prolonged and severe complications after surgeries 
• Inflammations
• Nerve damages 
• Difficulty to move because of the lack of energy 
• Severe fatigue, weakness, inability to conduct even small exercises 
• Circulating problems up to fainting
• Swelling due to fluid accumulation in the tissue (due to the lack of protein)
• Reduced immunity, frequent infections
• Impairment, reduced functional ability
• Osteoporosis, long-term issues with bone fragility
• Ultimately, death

The body literally wastes away.

If food intake is related to an increase in symptoms, patients may also develop a loss of appetite or anorexia. Also, one should always have in mind that the ratio of weight loss in a specific time and the onset weight are important in evaluation. Patients that were obese and lost weight to a normal level are still hungering and need treatment. 

Obviously, it is quite complex to battle cachexia if you cannot treat the underlying condition. There is the possibility to support enteral feeding by diet changes, high calorie drinks, NG/NJ feeding and also parenteral nutrition if otherwise it is not possible. Often this isn’t sufficient as the underlying condition is continuously working against it. 

In fact, due to the pain, metabolic imbalances or the underlying conditions resting calorie expenditure is often higher than the reference values. However, increasing the calories doesn’t always equal weight gain as the body cannot process them. 

Cachexia has immediate and long-term effects, it decreases the quality of life even more and makes work or daily activities impossible. Patients lose their independence and most of their energy.

Plaster Change

in progress

NG Tube Tips

in progress

*Those reduce the risk of catheter related infections. Here you can see how microorganisms can get through the catheter otherwise. It basically ‘locks’ the catheter. It can stay in the catheter for weeks. I insert it for the 8-hour breaks between feeds. There are also agents with an additional anticoagulant solution to reduce the risk of thrombosis (unfortunately, those aren’t covered by insurance). Here you might need to use a glass breaking ampoule. Break the top with a compress and draw out the liquid as usual. I used to inject it into my catheter. However, it only makes sense when there is a pause of 4h or more between the catheter is used. Since I have an iv pain pump 24h, I don’t use it anymore.

**Normally, you should (if the catheter is locked) aspirate it first i.e. aspirate blood with the solution. Because of the fragility of my vessels I always flush the catheter immediately (it isn’t toxic).

***There are caps that contain a disinfectant.

****You can use additional plasters with a hook and loop connection that circumvent forces.

*****There is TPN associated liver dysfunction and failure both of which can be reversible or irreversible. Stats show that liver dysfunction can follow even after only 14 days of TPN. A proper amd frequent analysis of liver levels (APT, GGT etc) and further diagnostics regarding the patient’s liver function (US, symptomy, further co-conditions e.g. gallstones, yellow skin…) as well as adapting TPN administration (speed, calories, percentage of fats, quality of fats…) can prevent or reduce it. For example, Steatosis (accumulation of fat inside the liver, may not be that severe, but can progress to fibrosis later on) is common in overfeeding which presents in increased APT, AP and total bilirubin. Soybean oil fat emulsions are known to cause liver dysfunction in some patients due to inflammatory responses of certain fatty acids.

Further liver damaging substances (e.g. NSAIDs, alcohol…) should be avoided as much as possible. As mentioned above, the right balance between calories and introducing and maximising of enteral or oral feeding (if possible) both reduce the risk of hepatic damage.

Along with liver dysfunction the PN cannot be properly absorbed and the patient might lose weight/doesn’t gain any weight. Intestinal dysmotility or resection and intestinal failure lead to damage of the enterohepatic circulation and, hence, to malabsorption (also of drugs) and further liver damage. SIBO (which often occurs in dysmotility) produces anaerobic bacteria that themselves produce toxins that also damage the liver. Etc. You see, there are many factors in dysmotility or other GI issues that catalyse each other and ultimately lead to hepatic damage or even failure.