IC7 Palliative Care (Nutritional Support)

Question 1

What are the functions of GIT?

Answer 1

1. Digestion, absorption and excretion
2. Secretion of fluids and enzymes

• This amt of fluid can amount to 1-2L per day and this fluids have enzymes for digestion, gastric acid which helps denature proteins and fend off against bacterial infections, there are electrolytes too
• If patient has high vomitus/vomit alot, apart from dehydration, patients might have electrolyte derangements

1. Gut hormones e.g. cholecystokinin
2. Immune function
3. reservoir

• it acts as a reservoir. Food is stored in the stomach for a period of time and mixed with the digestive juices before passing fown to the duodenum.
• If dont have stomach as the reservoir, all these will go straight to the intestine which have no storage capabilities → thus patients might have abdominal cramps, nausea or diarrhoea since every thing just flows through so it’s called dumping syndrome

Question 2

What are the accessory organs of the GIT?

Answer 2

Accessory organs: liver, gallbladder, pancreas

Question 3

Where is the absorption of vitamine B12?

Answer 3

Terminal Ileum → site of vit B12 (cobalamin) absorption

• For patients with resected terminal ileum they need to be on long term vit B12 supplementation via injection

Question 4

What factor is needed to ensure god vit B12 absorption?
Where is this factor released?

Answer 4

Intrinsic factor released in the stomach for B12 absorption

Question 5

Where is the cholecystokinin (CCK) produced?
What triggers it to be produced?
What is the functions of CCK?

Answer 5

GI also have gut hormones, mainly peptide hormones e.g. cholecystokinin (CCK), produced in the duodenum in response to the food passage from the stomach into the duodenum

• CCK helps to stimulate pancreatic contraction to release pancreatic enzymes into the intestine and stimulate liver to produce bile and stimulate gallbladder to contract to release these bile into the intestines too
• Without food, intestines will not produce CCK, so the other organs will not function properly
• Gall bladder contraction will be impaired, in turn impair biliary flow and this will cause cholestasis, bile doesn’t flow just stuck there and accumulates and cause jaundice

Question 6

What is the immune parts of the GIT?

Answer 6

GI also have immune function
GALT → gut associated lymphoid tissue, it’s the largest immune organ in the body, immune cells there to protect us from infections

Question 7

What does the gall bladder secretes?
What is the substance for?

Answer 7

Gall bladder will secrete bile for fat digestion, so patient without gallbladder potentially need to be on low fat meals

Question 8

What are the causes of malnutrition?

Answer 8

Causes:

1. Reduced Intake Absorption
2. Increased Expenditure Losses (increase use of energy)

Medical conditions lead to malnutrition, how they are associated.

• E.g. cancer, chemo is well known to cause N&V, taste alteration → this will reduce oral intakes for prolong periods of time and for pts with advanced abdominal cancer, they might have this condition ascites where fluids accumulate in the 3rd spacing in the abdominal space and if too much and press on GIT will cause early satiety, stomach can’t expand as much as it usually does, so patient tend to feel full earlier and reduce intake (eat less)

Conditions that lead to malabsorption

• e.g. patients after surgery, resect too much of the intestines thus will cause malabsorption since there is where nutrients absorption take place
• If body is under stress e.g. surgery, burns, trauma, sepsis, these might increase the body energy expenditure/consumption so as to promote wound healing so as to help body fight pathogens
• Conditions that increase nutrient losses e.g. in renal patients if go through dialysis might have nutrients lost through dialysis process

Question 9

What are the effects of malnutrition?

Answer 9

Effects:

1. Increased complications

• E.g. pts undergo surgery need nutrients for wound recovery
  So if patients are malnourished before the op and during the op, patient may have poor wound healing, wound might break down and thus patient might need multiple surgery and thus increase length of stay

2. Poor wound healing
3. Compromised immune status
4. Impairment of organ functions

• Organs need energy so in order to pump heart, it needs energy, in order to think, neuro cells need energy to transmit electrical impulsion
  So if not enough energy then can’t function properly

5. Increased mortality

• indirectly
• Not really direct effect in developed countries but it predisposes patients to succumb to their underlying conditions e.g. surgery if the wound breaks down, e.g. GIT surgery if the wound breaks down, the enteric contents will flow into the abdominal space which is meant to be sterile and this can cause sepsis and patient can die from that

6. Increased use of healthcare resources

Question 10

How to prevent malnutrition from happening to patients in the hospital (in general)? (what are the steps)

Answer 10

1. Nutritional screening

• To quickly identify individuals at nutrition risk
• Should be easy to implement, simple and everyone can do
• In hospital every patient who is admitted everyone needs to be screened either by nurses or patient service associates
• If at risk then referred

2. Refer to dietitian / nutritional specialist
3. Nutritional assessment

• An in-depth, systematic process that integrates and interpret patient data to identify nutrition-related problems
• If at risk, then referred for more in-dept nutritional assessment e.g. ABCDs
• Anthropometric data e.g. height and weight (measureements and proportion of the human body)
• Biochemical data e.g. electrolytes, sometimes look at serum albumin
  Albumin produced by liver, if malnourished not enough protein levels, the production of albumin by liver will also drop but serum albumin is not an accurate indicator of nutritional status. Affected by other things such as inflammation and fluid overload
• Clinical data e.g. patients medical hx, medication hx, physical examination to check muscular or fat store or presence of edema
• Diet hx

4. Formulation of nutritional regime

• To ensure patients get sufficient nutrients

Question 11

What are the nutritional screening tools available for local use?

Answer 11

1. 3 min NS (Nutritional Screening) score

• Developed by local specialist and validated among asian populations so widely adopted in local hospital settings
• Look at whether patient has weight loss, nutritional intake, muscle from temple and how obvious your clavicle bone is
• If patients deemed at risk then referred to nutrition specialist for assessment
• Moderate malnutrition: 3-4
  Severe malnutrition: 5-9

2. Seven-Point Subjective Global Assessment (SGA)

• Tool that nutrition specialist will use
  ABCDs are incorporated into this too
  (1) Weight trend/how much weight loss
  (2) dietary intake,
  (3) any sx of N/V/D, becos whatever is going in is coming out
  (4) Disease states that will affect the metabolic demands of the body / nutritional requirements
  Physical examination – (5) Muscle waste, (6) fat wastage, (7) presence of edema
• Each point pt is given a score then the specialist will give an overall score at the end
• Give us what the pt baseline nutritional status is, tell us how urgent to start nutrition for the patients
• For v well nourished patient, can’t eat for a couple of days after surgery, we wouldn’t start nutritional support immediately, BUT for a very malnourished patient, we want to consider starting earlier

Question 12

What is total energy expenditure dependent on?

Answer 12

Total energy expenditure dependent on resting/basal metabolic rate, physical activity, stress factor

• Meaning energy expenditure when we rest coupled with (physical activity) how much exercise you do and (stress factor) kind of medical conditions you have

Question 13

What are the modes of measurement for energy requirement?
What units is used for energy requirement?

Answer 13

Modes of measurement

1. Indirect calorimetry

• Measurement of gas exchange during consumption of substrates to produce required energy
• Gold standard
• Most accurate form of measurement but is seldom applied in real life because the process is tedious, must ensure the amt of gas collected is accurate which is difficult
• So the test will collect the amount of CO2 from the patient and will calculate, from this equation, how much energy is being produced which is equivalent to how much energy the body needs

Substrate + Oxygen → Heat/Energy + CO2 + water
C6H12O6 + 6O2 → ATP + 6CO2 + 6H2O

2. Weight based - 25-35 kcal/kg for general hospitalised patients (ESPEN)

• Simple range
• Consider the age of patient, physical activity and stress factor

3. Predictive equations

• Only estimates basal metabolic rate – so need to adjust for physical activity and stress factor
• Lower accuracy than calorimetry
• A lot of equations just listing here as examples
• Consider the weight, age, height so less accurate than the indirect calorimetry but is the most used by institutions

1. Schofield equation
2. Harris-Benedict equation
   Men:
   66.5 + (13.75 x weight in kg) + (5.003 x height in cm) – (6.755 x age in years)
   Women:
   655.1 + (9.563 x weight in kg) + (1.850 x height in cm) – (4.676 x age in years)

kcal

Question 14

What is the protein requirement calculation dependent on?
What units is used for protein requirement?

Answer 14

Usually measured in g
Dependent on underlying medical conditions

• For normal adult, not those who does gym – Is 0.8g/kg/day
• Trauma/ surgery / burn 1.5 – 2 g/kg/day (due to wound healing)
• Sepsis / critical illness 1.5 – 2, up to 2.5 g/kg/day (build up immunity to fight off infection)
• For CKD, not on dialysis 0.6 – 0.8 g/kg/day (lower proteins)
• For CKD, on dialysis 1.2 g/kg/day (higher amts since protein is lost through dialysis)
• For CRRT, Up to 2 g/kg/day

For HD, it’s conducted over a few hours, patients might experience hypotension. Thus patient who cant tolerate dialysis well then put patients on CRRT or SLED (sustained low efficiency dialysis) which is a prolonged dialysis session. Since it involves removing fluids at a slower rate so it’s better tolerated, and this tends to be used in ICU side

Question 15

What is enteral nutrition?

Answer 15

“Nutrition provided through the gastrointestinal tract via a tube, catheter, or stoma that delivers nutrients distal to the oral cavity.” - ASPEN

• Going through the GIT but bypassing the mouth and oesophagus
• Insert tube and go to the stomach or anything below

For patients who are unable to receive/tolerate adequate nutrition by the oral route

Examples:

• Swallowing impairment (esp after stroke)
• Mechanical ventilation (have a tube for breathing so can’t take anything orally, so need another tube for feeding)
• Altered mental status (more for those who have brain injury and lose consciousness, so cant even have oral intake)
• Motility disorders (e.g. diabetic patients prone to gastroparesis (delayed gastric emptying), motility of the stomach, things don’t flowdown, so need a tube to bypass the segment of immotility and feed to the distal gut)

Question 16

What are the 2 main categories enteral access devices?

Answer 16

1. Pre-pyloric (NasoGastric, PEG) [before pyloric sphincter]
   PEG → percutaneous endoscopic gastrostomy
2. Post-pyloric (NasoJejunal, PEJ)
   [bypass the stomach, go straight into the intestines, either duodenum or jejunum]

Question 17

What are the pros and cons of the 2 different types of enteral access devices?

Answer 17

(A) Pre-pyloric

Pros:

1. More physiologic

• So bypass less of the GIT so can maximise the potential or functions of what your GIT can do, so more preferred route
• Becos of the reservoir function of the stomach

2. Higher tolerance to bolus feeding

• 1 big meal over small little meals

3. Higher tolerance to a wide range of enteral products

• Especially for enteral products with higher osmolarity
• Usually iso-osmolar products which are products that have similar osmolarity as physiologic conditions about 300 osmol/L, this is the most tolerated one but in the stomach have more leeway. If have high osmolarity enteral products and feed to the stomach, patients tend to have higher tolerance than feeding to the intestines
• If hyperosmolar, it tends to draw water into the intestinal lumen and thus flush the feeds through and thus patients might have diarrhoea, compared to stomach already have a lot of fluids floating around in there already

4. May be used for venting

• Used to aspirate, meaning remove gastric fluids
• Stomach produces 1-2L of fluids a day but if gastric outlet is obstructed, it will just accumulate in stomach and pts will start to vomit, this leads to aspiration pneumonia. Thus dr will insert a nasogastric tube to facilitate the removal of excessive fluids in the stomach

Cons:

1. Not to be used for feeding in patients with delayed gastric emptying (increase risk of aspiration)

(B) Post-pyloric

Pros:

1. Smaller bore, less discomfort

• Since need to go through pyloric sphincter which is a smaller passage, (bore) the internal diameter is smaller. Thus goes through the nose, it will cause less discomfort for the patients

2. May be used in conditions that result in dysfunctionality in proximal GIT (GIT parts nearer to the centre of the body)
3. Minimise aspiration risk

• Since bypass the stomach, thus lower risk of aspiration when we feed

Cons:

1. Higher risk of tube clogging

• Becos of the smaller diameter

Question 18

What are the benefits of using nasal vs stomy tubes?

Answer 18

Benefits of nasal vs stomy tubes?

• Anything that has -stomy/-stoma → it’s an opening in the abdomen

Stomy (summarised):

1. for those using it lifelong + aesthetically pleasing
2. surgery, difficult to insert and remove + more long term complications

Stomy cons:

• Stomy tube → Small surgical procedure, so unlike nasal tubes which can just insert at bedside, the stomy tube usually requires surgery, so more difficult to insert and remove. Patients after removing gastrostomy tubes, the wound doesn’t heal and thus have long term complications.

Stomy pros:

• But if patients need it lifelong, then stomy tube is the way to go, becos if have nasotube, it’s not comfortable and aesthetically wise it’s not pleasing to the eyes e.g. someone who is active and walking around, wouldn’t want to have the nasotube

Question 19

What are the modes of administration of enteral feeds?

Answer 19

1. Bolus

• Usually by gravity - Mimics oral intake
• More physiologic
• No pump required
• Greater freedom for ambulation
• 1 main meal instead of 3

2. Continuous

• Pump assisted delivery at a constant rate
• Better tolerated
  3 main meals, but split into smaller meals so less bloating and abdominal discomfort
• Lower risk of aspiration

Question 20

What are the types of enteral feeds?

Answer 20

1. Modular

• Contains single nutrient
• Used as fortifier (added to food or enteral products) to enhance a specific nutritional component / augment oral diet
• Not meant to be a meal replacement

2. Semi-elemental

• Contains partially/ completely hydrolyzed nutrients
• For patients with impaired GI function, impaired tolerance to standard feeds
• If patient have reduced absorption then try to digest down the nutrients first then reduce reliance on GI function
• Usually quite high in osmolarity, so sometimes can cause diarrhoea, so counterproductive, because we say it’s better tolerated but then still have diarrhea

3. Polymeric

• Contains intact macronutrients/ complex sugars
• Requires sufficiently functional GIT in order to digest it down to simplest form

4. Immune-modulating/ disease-specific

• Contains additions / restrictions of specific nutrients to meet needs for disease management
• E.g. renal
• May or may not meet individual’s full nutritional needs

Question 21

What are the examples of the different types of enteral feeds?

Answer 21

1. (modular) Myotein - protein powder
2. (modular) MCT Oil

• Diff types of triglycerides, long chain and medium chain triglycerides (LCT, MCT)
• Long chain will be absorbed in lymphatic system before going back into bloodstream
• For medium chain will go straight into the bloodstream and bypass the lymphatic system
• For patients with neck surgery, have injured lymphatic vessels, so have Chyle leak. To control the leakage, they will put patients on fat free diet, but some point need fats, so will give the MCT oil instead to eliminate the LCT component that goes through the lymphatic system

3. (semi-elemental) Peptamen

• Complete nutrition (MCT, sugar), only the protein part that is partially hydrolysed into peptides
• So can be used as a meal replacement

4. Polymeric

• Boost isocal
  iso-osmolar feed, when patients are first started on enteral nutrition, they will use this
• Fat free feeds e.g. resource food
  Clear feeds means don’t have fats
  When started on diets, have clear feed or full feeds. Clear feeds are more easily digested so start with clear feeds first

Question 22

What are the disease-specific enteral formula?
What are the components in each of them?

Answer 22

All these feeds can be used beyong what they are indicated for

1. Glucerna

• 1kcal/mL
• low glycemic index
• Ind: diabetes

2. Fresubin protein energy

• 1.5kcal/mL
• high protein, 20g/serving

3. Nepro HP (high protein)

• 1.8kcal/mL
• High protein 18g/serving
• Ind: dialysis
• could also be used for HF that has undergone surgery where they need low fluids but high protein

4. Nepro LP (low protein)

• 1.8kcal/mL
• low protein, K, phosphate
• Ind: Not on dialysis

5. NutriFriend

• 1kcal/mL
• contains omega 3 fatty acids, EPA/DHA

Question 23

What are the drug nutrient interaction?
How to prevent and mitigate such interactions?

Answer 23

Usually not an issue with bolus / intermittent feeding (more for continuous feeding)

• Intermittent feeding is in between bolus and continuous feeding. Some Patients do night feeding so before they sleep they do the feeding

Administration of incompatible drugs may cause

1. Precipitation
2. Curdling, clumping of protein (esp when in contact with acids)
   E.g. some syrups are acidic fecal, so need to check if compatible
   Or sometimes our gastric acid, if have reflux into the tube and nurses don’t flush properly then can have curdling
3. Alteration of dosage form (e.g. sustained/modified release/enteric coated)
   So if crush and put into tube then it will lose the function of the coats
4. Some drugs are known to interact with feeds directly
   E.g. fluoroquinolones → Ciprofloxacin chelate with cations e.g. calcium, so space apart

Prevention and mitigation

• When gonna give meds, stop feeding, flush access device before and after drug administration so that things don’t accumulate in the tube
• Use therapeutic alternatives available in appropriate dosage form
  e.g. previously on enteric coating or sustain release drug then need to convert to something appropriate that is immediately release and suitable for crushing

Question 24

What are the common complications of enteral feeding?

Answer 24

1. Occlusion of feeding tube (blocked)

• Jejunal > gastric tube (since smaller diameter)
• Medication administration
• Formula – concentrated/high protein/fibre-enriched (adhere to walls of tube, so need to flush the tube)

2. Tube migration
   e.g. tube that is meant to exit jejunal site, if patient cough too much, it might migrate to duodenum or up to the stomach
3. Infections secondary to microbial contamination
   Apart from feeding enteral feeds through the tube, patient also need fluids e.g. water. Some people think can feed together but no, if they need extra fluids, then should increase amt of water flushes instead of adding water to nutritional feeds (give separately). This is becos the microbial load in nutritional feed is kept under control. May hand the bag for 4 hours, if you add water in, it promotes bacterial growth. So don’t dilute down the nutritional feeds
4. Aspiration
5. Nausea/vomiting
6. Diarrhea/Constipation
   Hyperosmalar feeds tend to cause more diarrhoea
7. Refeeding syndrome (impt)

Question 25

What are the strategies to maximize tolerance to EN?

Answer 25

If cant tolerate, doesn’t mean that we should straight away switch to parenteral but need to try other things first

1. Continuous instead of bolus
2. Use of prokinetic agents (e.g. metoclopramide, domperidone, IV erythromycin)
   For N&V
   Erythromycin in IV form does not have much antimicrobial properties so use it as a prokinetic agent
3. Post-pyloric feeding if intolerant to gastric feeding (gastric tube) where gastroparesis is the issue
4. Use of isotonic formula (e.g. boost isocal)
5. Semi-elemental/elemental feeds for patients with malabsorptive issue (e.g. short bowel syndrome –> not enough gut to break down food)
   Benefits are not clear as it may cause diarrhoea since it is usually hyperosmolar

Question 26

What are the pros of enteral feeding compared to parenteral feeding?

Answer 26

1. Usually try to go via the physiologic way of feeding as much as possible
   Maintain functional integrity of the gut
   Feeding the cells, the immune cells that are present in the gut
2. Undergo first-pass metabolism, promote efficient nutrient utilization
3. Maintains normal gallbladder function
4. Maintain gut-associated and mucosal-associated lymphoid tissues
5. Less complications than PN – e.g. line related sepsis, IFALD (intestinal failure-associated liver disease)
6. Less expensive

Question 27

What is parenteral nutrition?
When is parenteral nutrition considered?

Answer 27

“Intravenous administration of nutrients.” - ASPEN

For patients who are unable to receive or tolerate adequate nutrition by the oral/enteral route

Examples:

1. Paralytic ileus (dysmotility of intestines)
   After surgery/trauma, may take some time recover functions, so might need parenteral nutrition
2. Small bowel obstruction
   E.g. tumour might obstruct the lumen of gut, so nothing flows through
   While waiting for surgery, some might be on this to boost up the nutrition
3. High output / proximal fistula
   Fistula is an opening from one space to another e.g. if have fistula in GIT, the contents might flow out into the abdominal space
   E.g. have pyeloduodeno fistula, an opening that links bladder to intestines
4. Mesenteric ischemia (mesentery is the folds of membrane that holds the organs together)
   Mesenteric Artery is the vessels that supply blood to intestine, blood flow to intestine is compromised (GIT can’t work)
   If feed through GIT, in order for the GIT to function it needs energy and blood flow. So need to avoid if in this situation, where there is lack of oxygen, as feeding will increase demand which may push the gut towards necrosis

Question 28

What are the 2 parenteral access devices?
What are the pros and cons of each peripheral access?

Answer 28

1. Peripheral

• Peripheral veins on the hands
• Tip position is located outside of central vessels
• Requires frequent re-site
  Since the vessels are quite small, standard is 72 hours have to change the site
• Nutrient delivery limited by osmolarity and concentration
  If too high, will burn the veins (phlebitis), patients will complain of pain and swelling
  Cut of is 900 milliosmol

2. Central

• Position of catheter tip is in large bore blood vessel e.g. distal superior vena cava, inferior vena cava, right atrium
• High blood flow → even if nutrition bag has high osmolarity, it gets diluted quickly the moment it reaches the blood vessels so patients won’t feel the pain
  Thus can give more nutrients in a smaller volume
• Can be used for longer term care since don’t have to re-site frequently

Question 29

What are the 4 types of central parenteral access?

Answer 29

1. Non-tunnelled central venous catheter

• Goes Into large vessel directly and the other side comes out from the chest
• Short lived
• Usually don’t use more than 2 weeks
• So short thus highest risk of infection

2. Tunnelled central venous catheter

• Similar to the first one but it tunnels under the skin for a certain distance
• Infection risk is lower

3. Peripherally inserted central catheter (PICC)

• Commonly used
• Starting point is on your arm and tunnels through all the way in the large blood vessel

4. Port-a-cath

• Usually used for cancer patients, receiving chemotherapy maybe once every few week, so don’t need the access on a daily basis
• Implantable port that is inserted somewhere near your clavicle bone
  thus when we assess it, the nurse need to insert a needle, but becos implantable under the skin, so don’t see a line dangling from the arm. So aesthetically better

Question 30

What is the composition of parenteral feeds?

Answer 30

Nutrition in its simplest, most elemental form

• Instead of complex sugars have dextrose, instead of proteins have amino acids, instead of fats have triglycerides
• Doesn’t require digestion

Admixture of multiple components

• Like adding 10 meds in the same bag so need to check:
• Stability and compatibility are major concerns
• E.g. electrolytes → calcium and phosphate → known to cause ppt. When adding to bag need to calculate the concentration to avoid ppt
• Lipid emulsion are unstable system, affected by a lot of things e.g. pH. Dextrose solution is acidic, pH is about 2-3. If add dextrose and lipid emulsion in the same bag, the lipid emulsion is not stable, it will crack. So the amt of dextrose added into the lipids must be kept under a certain concentration

Commercial product vs customised formulas by compounding facility

• The one below is a commercial bag
  have a standard formula, fixed amt of each component – dextrose, amino, fats, calcium, phosphates, magnesium, potassium, sodium
• Can’t adjust the macronutrients part, but the electrolytes we can make adjustments by adding more
• Do in the compounding facility, within the clean rooms

Customised bags

• For patients who can’t tolerate the macronutrients part/amount
• Prepare bag from scratch

Question 31

What are the drug-nutrient interactions for parenteral feeds?

Answer 31

Usually not a problem if administering via separate lumens of same access device

• Will be completely separated until reach the blood vessels

Admixture vs Y-site compatibility

• This is different from the number of lumens in 1 line
• When enquirer asks if they are compatible, need to ask what the patient has
• Y site compatibility means has a single lumen, but have a Y connection at the end of this single lumen
• There is no interaction between meds and TPN when running through the y site but there will be interaction when it reaches the single lumen
• So if they are asking for y site compatibility, then need to check all the references e.g. trissels, king’s guide, micromedex → must check what you are checking against, is it TPN or TNA

Total parenteral nutrition (TPN) vs Total nutrition admixture (TNA)

• TPN refers to nutrition bags without fats
• TNA is 3 in 1 TPN, so it means every component inside. Becos lipid emulsions are very unstable, so with lipids inside it is incompatible with a lot more drugs

Administration of incompatible drugs may cause

1. Precipitation
2. Loss of drug activity
3. Phase separation of lipid emulsions / cracking
4. Toxicity

Question 32

What are the prevention and mitigation steps to avoid drug-nutrient interactions for parenteral feeds?

Answer 32

1. Administer via separate peripheral IV cannula (2 different lines/2 different tubes?)

• just set a plug and administer the drug
• We advise the nurse
• If needed, pause PN administration, flush access device before and after drug administration before resuming PN infusion
• But some patients have very poor venous access, some are poked 3-4 times are still can’t insert a plug. So need to share the line – if only have 1 line to run both TPN and medications, need to pause the TPN, flush tube, admin. Med, flush again to clear any drug residuals before resuming the TPN
• During the pause, need to ensure, if e.g. run the meds over long period of time 2-4hrs, need to check patients blood sugar levels, ensure they don’t become hypoglycemia, since they are not eating at all, they are just getting nutrients from the bag

Question 33

What are some parenteral access device related complications?

Answer 33

1. Occlusion in IV catheter, can be caused by a lot of things

(A) Thrombosis / clotting

• Inserting foreign object into body so this is a natural response
• In the pic below, there are 4 diff types of thrombosis
• Top left → fibrin flap → when infuse, the flap will be pushed open, so can still infuse meds, but if try to draw blood, the flap will be drawn in, and cause a blockage. Thus depending on how urgent you need the line and whether can get another appointment to change the line, they might just continue to use, but there is already occlusion just considered as a partial occlusion, so want to get rid of it before it gets fully occluded.
• For this, can do a heparin lock, admin. Heparin in the catheter and let it dwell, hopefully it can clear the clotting

(B) Inappropriate flushing techniques

• Flush with normal saline
• Push and pause technique → creates turbulence to clear the residuals stuck on the walls of the catheter

(C) Precipitates as a result of drug incompatibilities, crystallisation

• If give calcium/phosphates at a high concentration

(D) Lipid residues

• Before connecting the nutrition bag back to the catheter, need an administration set. For lipid, if infusion contains lipids, advise to change the administration set every 24 hours becos don’t want to have accumulation of the lipid residues as it increases the risk of infections (and occlusion)

2. Mal-positioning

• E.g. PICC line, it’s just hanging there, patients can pull out sometimes or not in correct position, will have pain since not in the large blood vessels

3. Catheter-related bloodstream infection (CRBSI)

• These Catheters go straight into a major blood vessel
• Every port you have is an entry point for bacteria
• And when giving nutrition bag, it’s not just for the human but for the bacteria too
• So want to try to handle it with aseptic techniques e.g. disinfection when administer the bag, nurse need to alcohol swab the entry points and rubber bang where they spike the bag before they administer

Question 35

What are the metabolic complications of using parenteral feeds?

Answer 35

1. Refeeding syndrome
2. Hyper/hypoglycemia

• Becos administer directly into bloodstream

3. Fluid overload

• Giving directly into bloodstream without the gut sieving through all the unnecessary stuff

4. Intestinal failure associated liver disease (IFALD)

• Associated with nil by mouth, don’t eat for a prolonged period of time
• Lack of CCK → CCK stimulates gallbladder contraction, so if don’t feed patient, will have impaired bile flow and cause cholestasis → This is one type of IFALD
• fatty liver, if overfeed the patient, too much fats or dextrose may accumulate in the liver → not good
• Type of triglycerides we are administering, in the market have a few lipid emulsion products, the main one we have is the MCT/LCT oil becos this is where we have the essential fatty acids
• We have 2 essential fatty acids
• LCT is known to be proinflammatory, precursor of inflammatory markers
• So if give pure MCT/LCT oil, over a long period of time it may cause liver damage
• There are newer lipid emulsion products in the market e.g. SMOF → soybean (LCT), M(MCT), Olive oil, Fish oil
  Fish oil is anti inflammatory, meant to balance out the proinflammatory effects of the LCT component → help with IFALD
• Have pure fish oil in the market, but does not provide essential fatty acid so don’t use pure fish oil as the source of lipids

5. Metabolic bone disease

• Patho is unclear
• Patients are dependent solely on parenteral nutrition often have osteomalacia or osteoporosis in the long term

Question 36

What is the pathophysiology of refeeding syndrome?

Answer 36

Disrupts electrochemical membrane potential

Prolonged duration of Starvation / malnutrition
→ glycogenolysis, gluconeogenesis and protein catabolism
→ protein, fat, mineral, electrolyte and vitamin depletion – salt and water intolerance (since only high salt conc and water left in the blood)
→ serum electrolytes may appear normal as body draws from intracellular stores (result in overall depletion) and reduces renal excretion
→ refeeding (switch to anaboilsm)
→ fluid, salt, nutrients (CHO major energy source)
→ insulin excretion
→ increase protein and glycogen synthesis → increase glucose uptake, utilization of thiamine, uptake of K+, MG2+ & PO42- →
Hypokalaemia
Hypomagnesaemia
Hypophosphatemia
Thiamine (vit B1) deficiency
Salt and water
Retention – oedema
→ all these can lead to refeeding syndrome

• high blood pressure, difficulty breathing, fatigue, weakness, confusion, and irregular heartbeat→ sudden cardiac arrest, arrhythmia, cardiac failure, neuromuscular complications, seizures

Explanation: Prolonged duration of Starvation / malnutrition → (body will start drawing nutrients from your own stores, muscles are protein stores and fat stores, intracellular electrolytes – K, MG, PO42-). But when reinitiating feeding, it will stimulate insulin secretion, in turn lead to glucose uptake, cell will take in nutrients and produce energy, then use thiamine as it is a cofactor for energy metabolism, take back whatever it has been contributing to the body. Thus will see a drastic drops in all these electrolytes. ATP (adenosine triphosphate), every ATP molecule used, 3 millimoles of PO42- will be used.
Hallmark of this refeeding syndrome is hypophosphatemia
0.75-1.45 is the usual range of phosphates → some patients can drop to 0.3
Thus need to be mindful that all these electrolytes maintain our membrane potential thus it may be fatal
Potentially Fatal – arrhythmia, cardiac failure, neuromuscular complications

Question 36

What type of nutritional therapy / calorie provision can cause refeeding syndrome?

Answer 36

Can occur with any form of calorie provision - oral, EN, PN, IV dextrose
Any form of caloric provision can be oral, oral supplements, oral feeds, enteral nutrition, parenteral nutrition, dextrose infusion
Sometimes specialist would say to just start with dextrose drip but it can also lead to refeeding syndrome

Question 37

What are the management startegies of refeeding syndrome?

Answer 37

1. Identify high risk patients
2. Check serum electrolytes at baseline

• If low then need to replete before starting
• Correct deficiencies prior to feeding, defer feeding if electrolytes are critically low
• Might even supra correct before starting nutrition therapy
• E.g. start phosphate of more than 1

3. Administer thiamine (Vit B1) supplement

• Then replete thiamine since it’s a cofactor
• Don’t routinely check vit B1 levels in the blood, just give as a preemptive measure

4. Initiate feeding slowly and gradually increase over next few days to meet nutritional requirements (Start low and go slow!)

• Starting low at 40-50% of the energy requirements then slowly grade up over the next few days to meet the requirements so that body can adjust

5. Continue to monitor electrolytes as feeding progresses, adjust amount of replacements as needed

• General guide: 10 millimoles of KCL replacement will increase blood serum K by 0.1 millimoles/L
• But for those undergoing refeeding syndrome, can give them 100 millimoles of KCL and their serum K might not move, but by the time the cells/ intracellular stores get replete will start to see sharp increase in K, so need to cut down on electrolyte replacement. So need to be careful and recheck the electrolyte levels more closely

Question 38

What are the criteria of high refeeding syndrome risk patients?

Answer 38

Criteria of the National Institute for Health Care and Excellence (NICE) for the identification of patients at high risk for development of refeeding syndrome

Patient has one of the following:

1. Body mass index (BMI) < 16 kg/m2
2. Unintentional weight loss > 15% in past 3-6 months
3. Little or no nutritional intake > 10 days
4. Low levels of K, Mg, Phosphate before feeding
   (if refeed may drop even further)

OR

Patient has ≥2 of the following:

1. BMI < 18.5 kg/m2
2. Unintentional weight loss > 10% in past 3-6 months
3. Little or no nutritional intake > 5 days
4. History of alcohol misuse or drugs, including insulin, chemotherapy, antacids, or diuretics

Question 39

A patient with leukemia was referred for oral nutritional support due to poor appetite and taste changes. Which of the following type of nutritional formula would be the most appropriate to initiate for the patient?

A) Polymeric
B) Monomeric
C) Elemental
D) Semi-elemental

Answer 39

Ans: A

• Modular, semi-elemental, polymeric
• Answer is polymeric because patient needs nutritional support due to poor appetite and taste changes
• Does not have impaired GI function, not requiring modular single nutrition type of enteral formula

Question 40

A 42-year-old woman had recently undergone a bariatric sleeve gastrectomy (partial removal of stomach) and is currently admitted for vomiting, severe electrolyte imbalances and malnutrition. A barium swallow and meal test shows that there is narrowing of passage at the anastomosis (surgical connection between two resected points), but transit time to small and large intestines are within normal limits. Which of the following route would be the first choice for nutritional support?

A) Nasojejunal
B) Nasogastric
C) Parenteral
D) Oral

Answer 40

Ans: A

• Anastomosis: Stomach cut 2 parts and take 1 part out then join, so there’s an issue there
• Nasojejunal because issue w stomach (gastrectomy), so should have a tube to bypass the stomach. Nasojejunal go straight to the jejunum
• You know the different routes, when there are surgeries must know how to bypass
• Parenteral: overkill. If gut works, use it!

Question 41

The patient in Question 8 is assessed to be at high risk of refeeding syndrome. Which of the following is the most appropriate in the prevention of refeeding syndrome when initiating nutritional support for the patient?

A) Replace electrolyte deficits prior to initiation
B) Provide as much calories as possible to meet patient’s requirements on day 1 to make up for past nutritional deficits
C) Provide vitamin B12 supplementation
D) Ensure blood sugar levels are within range prior to initiation

Answer 41

Ans: A

• Check and replace electrolyte deficits: P, Mg, K, make sure well replenished if not it will be detrimental to patient
• Thiamine: Vit B1, not B12 (cobalamin)

Question 42

Which of the following electrolytes are commonly involved in refeeding syndrome? (Select all that apply)

A) Magnesium
B) Phosphate
C) Potassium
D) Calcium

Answer 42

Ans: A, B, C
NEED to know, key concept