EN Practice Questions - 1 Flashcards
The administration of 1 litre of 0.9% NaCl to a normonatremic patient will increase the intravascular and interstitial fluid compartments by how much? Why?
250 ml intravascular
750 ml interstitial
-0.9% solution is isotonic, thus does not contribute to an osmotic gradient.
-100% of isotonic solution will go to the ECF, where the ECF consists of the interstitial and intravascular spaces
The intravascular volume accounts for ___ of the ECF
25%
The interstitial volume accounts for ____ of the ECF
75%
What is the equation for calculating free water deficit?
FWD = TBW - (1-(140/Serum Sodium))
Assuming the same weight and serum sodium concentration, which of the following patients have the greatest free water deficit? A) 35-year old man B) 75 year old man C) 35-year old woman D) 75-year old man
A
When we calculate FWD knowing weight and serum sodium is the same, thus knowing that TBW increases as LBM increases and LBM is the highest in younger males we know that they would have the greatest TBW.
The percentage of TBW increases as the proportion of LBM to _____ increases
adipose tissue
When does TBW decrease? In what gender is it usually higher?
- Decreases with age
- Higher in males
A patient with severe intractable nausea and vomiting is at risk for what acid base disorder?
- Hypochloremic metabolic alkalosis
- Losing a lot of gastric fluids means that we lose a lot of Cl-, which means that we lose acid and are left with more alkali,
How many mEq of chloride is estimated to be contained per litre of gastric fluid?
130
Which of the following is an example of a patient condition anticipated to manifest with severe systemic inflammatory losses?
A) Anorexia nervosa with a BMI of 15
B) Major depression with compromised dietary intake and 5% loss of body weight
C) Homebound older adult with restricted access to food and 10% loss of body weight
D) Thermal burn injury of second and third degree burns covering 15% surface area
D
- Burns can sometimes double metabolic demands, and will be confirmed throughout the assessment
- Others are rather cases of starvation, thus do not indicate severe systemic inflammatory losses
A physician informs you that a patient has a serum albumin of 2.8 g/dL and prealbumin of 14 mg/dL and asks whether these findings are indicative of malnutrition. What is your impression?
- Consideration of medical history, clinical diagnosis and laboratory signs of the inflammatory response would help us further interpret these signs.
- Lack of specificity and sensitivity where these lab markers must be confirmed by past food intake history an presence of inflammation
Which of the following is one of the best validated screening for indicators of malnutrition risk?
A) Patient reports non-volitional weight loss
B) Patient reports following a low CHO-diet
C) Patient is 2-days S/P laparoscopic cholecystectomy
D) Patient report a recent febrile-flu like illness
A
A well validated indicator of malnutrition is involuntary weight-loss
According to the SGA, what severity of malnutrition best describes the a patient who presents with cirrhosis complicated by portal hypertension, ascites and edema? He has gained 10 lbs over the past two weeks, but reports eating <50% of normal intake with N/V. Severe muscle wasting is noted in the deltoids, triceps and chest. He is confined to bed/chair
SGA C - Severely malnourished As evidenced by: 1) Presence of GI symptoms >2 wks 2)Food intake <50% for 1 mo 3) Severe muscle wasting 4) Decreased functional capacity
(T/F) Cirrhosis is a serious condition but does not increase metabolic demands
F
What may be indicative of cirrhosis?
Ascites and lower extremity edema
What is the cause of weight-gain although a patient is severely malnourished?
Ascites and edema will falsely inflate weight
According to ASPEN and the Academy of Nutrition and Dietetics, what etiology and severity of malnutrition best describes a patient who is diagnosed with Anorexia Nervosa? This patient:
- 500 kcal/day, with excessive exercising
- PMHx of restrictive eating
- High CRP
- 97.9 lbs 4 weeks ago, now 92.6
- Severe SC fat loss and muscle loss
- Lanugo and dry mucus membranes
- Weight loss of 18.9 kg over 6 mo
- The etiology of this patients malnutrition is rooted in social/behavioural/environmental circumstances.
- Other etiology options would be acute illness/injury or chronic illness
- Her energy intake, muscle and fat wasting and significant weight loss without inflammation alongside PMHx also supports this
According to ASPEN and the Academy of Nutrition and Dietetics, what etiology and severity best describes a multiple trauma victim early in the course of recovery? The patient:
- Has muscle wasting, but fat loss hard to assess due to edema
- Has sub-optimal nutrition support as feeds were stopped to prioritize medical procedures
Acute/illness related and indicated by the inadequate nutrition intake and muscular wasting.
Many trauma patients are well-nourished at baseline, why are they at a severe risk of becoming malnourished?
Due to acute metabolic dysregulation and associated catabolism and compromised nutrient intake
Why will trauma patients show a negative nitrogen balance despite aggressive nutrition support?
Due to the marked pro-inflammatory response
According to ESPEN consensus, would an elderly patient who presents in a clinic with obesity and frailty be considered malnourished? This patients
- Is obese, 70 y/o
- Has knee pain and swelling
- Low-grade fever for the past week
- Low albumin, high CRP
- Complains of N/V, disinterest in food, early satiety, 4.5-9 kg loss over the past 6 months
- Difficulty ambulating
- Mild muscle loss observed, low fat-free mass of 12
The patient is malnourished based on her low FFM and weight loss.
ESPEN low-fat free mass women?
<15
ESPEN low-fat free mass men?
<17
ESPEN reduced BMI if <70 years?
<20
ESPEN reduced BMI if >70 years old
<22
What are the two characteristics that ESPEN screens for in combination with unintentional weight loss to diagnose malnutrition?
- Low BMI
- Low fat-free mass
Having one of these in combination with unintentional weight-loss will indicate a diagnosis of malnutrition
Explain the starvation adaptation of nutrient utilization
Glycogen quickly depleted, where we will use amino acids. Then, we switch to fat oxidation as REE decreases to spare LBM
Explain the stress response adaptation of nutrient utlization
Storm of hormones and cell mediators are driven to repair tissues, however will derive much energy for this process by breaking down skeletal and LBM. They use the amino acids in gluconeogenesis for energy.
Which of the following is a benefit of EN compared to PN or no nutrition?
A) Maintenance of normal gallbladder function
B) Reduced GI bacterial translocation
C) More efficient nutrient metabolism
D) All of the above
D
- Provides the release of CCK, helps maintain normal gallbladder function
- Luminal nutrients provide GI structure support and maintain gut mucosa integral to immune function
- More closely mimic oral feeding, undergo “first pass” metabolism
What is secreted within the GI tract which prevents bacterial translocation?
IgA
High protein hypocaloric EN feeding provides 65-70% of energy needs as determined by indirect calorimetry. This is recommended for what kind of ICU patient? A) Malnutrition B) Obesity C) Liver failure D) Acute Respiratory Disorder (ARD)
B
-Patients with malnutrition should receive more than 80% of their nutrient needs within 48-72 hours after intubation
What are the consequences of not beginning EN feeds of 80% within 48-72 hours in a malnourished, ICU patient?
Greater protein and energy deficits which may lead to higher infection and mortality rates
What EN feeding may obese patients benefit from within the context of ICU? Why?
Low-kcal high protein feeding to minimize metabolic complications while preserving LBM and mobilizing fat stores
In patients with ARDS, should they be receiving trophic or eucaloric feedings in the ICU context?
No difference
Risk factors for aspiration include all of the following except: A) Malnutrition B) Use of naso/oro feeding tube C) Bolus EN feeding D) Supine position
A
-Despite malnutrition being associated with generalized weakness and potential less ability to swallow, malnutrition is not recognized on it’s own.
What increases the risk of aspiration?
Things that interfere with the function of the LES, such as the presence of a feeding tube as it will increase the risk of reflux and thus, aspiration.
Why do bolus feedings increase risk of aspiration?
As it increases the contents of the stomach
Why does EN preserve a normal gallbladder?
Nutrients in the SI stimulate CCK, which stimulates gallbladder contraction. This reduces the risk of cholecystisis.
4 key benefits of EN
- Gallbladder, GI architecture
- Immune system (IGA release, mucosal barrier and preventing bacterial translocation)
- Less infection than PN
- Less expensive than PN
How do we know we have passed into the duodenum? The jejunum?
- Passing the pyloric sphincter means we are in the duodenum
- Passing the ligament of treitz means we are in the jejunum
(T/F) In refeeding syndrome, hypoglycemia is observed
F, hyperglycemia.
(T/F) Even though most EN formulas provide 100% RDA of thiamine, we should still add additional supplementation if refeeding syndrome is expected
T, especially for those at a risk of deficiency such as alcoholics
What does post-pyloric feeding reduce? What may it not reduce?
Risk of aspiration, risk of pneumonia
When is EN indicated in well nourished patients? Critically ill?
- 7 to 14 days of inadequate intake
- Within 24 to 48 hours of admission
When is continuous feeding preferred?
- ICU, mechanically ventilated
- At risk of refeeding
- Poor glycemic control
- Jejunostomy tube in place q
When is cyclic feeding preferred?
- When on step-down unit or LTC
- May be permissive for oral/day feedings
- Allows disconnect during day, feeds often at nights
When is intermittent feeding preferred?
-Patients with feeding tubes that terminate in the stomach as they can accomodate higher volumes within a shorter period
When is bolus feeding preferred? (Delivered through syringes)
- Most “normal” to oral feeds
- Freedom of movement
- Administered in convenient settings
- Cheapest option
EN protocol rate for non-critically ill patients starts at ____ and advances ____ ml every ___ hours to reach goal
50 ml
15 ml
4 hours
EN protocol rate for critically ill patients starts at ____ and advances ____ ml every ___ hours to reach goal
10-40 ml
10-20 ml
8-12 hours
When should the goal rate be met in the critically ill?
Ideally within 24 to 48 hours
What is volume–based feeding?
When EN is prescribed by goal volume per day, rather per hour. May be more used in critically-ill
Define hemodynamically unstable
Those with BP <50 mmHg (Normal is 120/80) or beginning vasopressor medications
What is the goal of EN in the malnourished patient in terms of goal rate?
EN should be advanced to the goal rate, as tolerated, within 24-48 hours, with the goal of providing >80% of energy needs within 48-72 hours.
What is hypocaloric feeding? Who may benefit?
60-75% of energy needs
Obese
Patient with sepsis EN protocol?
60-70% first week
Progress to 80% next week
Adequate ____ is more closely correlated to positive outcomes than adequate ____
protein
energy
What is trophic EN?
10-20 ml/h or up to 500 kcal/day
(T/F) patients with EN will use a different access device for medication delivery
F, all goes through the same tube
Why may GRVs not be checked?
- Increase tube occlusion
- Reduce total volume of EN delivered
- Increased nursing time
In addition to outputs, how else may a patient become dehydrated?
- Burns, high fever and extensive wounds
- EN if hyperosmolar
Why hyperglycemia, without diabetes in ICU?
- Cortisol
- Inflammation, causing insulin resistance
- Steroid medications
- Dextrose solution
A 55-year old man presents with acute renal failure following a trauma. He is on dialysis. What is the type of enteral formula which would most likely meet his needs?
-A formula restricted in fluid, but not restricted in protein or electrolytes.
In renal failure, when should electrolytes be restricted?
Only when serum levels are very high
When can we have a formula high in electrolytes and protein in renal failure?
Usually OK when patient is on dialysis, but we will still want to restrict fluids
A 60 y/o critically ill patient has been tolerating 1 kcal/ml feeds for 1 week but begins having loose stool and requires a rectal tube. What should be the next suggestion?
A) Change to peptide based formula
B) Determine cause of diarrhea
C) Add pre and pro-biotics to feeding regimen
D) Change to a fibre supplemented formula
B
- As she has been tolerating feeds for one week, unlikely that the formula is the cause of the diarrhea
- Rule out C.Diff
What should a clinician do when considering the use of enteral fomulas marketed for specific diseases?
-Evaluate studies which support the use of specialty formulas and apply clinical judgement to select this product
Explain why MCT is absorbed more efficiently
MCTs will bypass portal liver circulation, go directly into the bloodstream and do not need to be packed into chylomicrons. They do not require pancreatic enzymes of bile salts for absorption, and can be cleared rapidly by the mitochondrial membrane without carnitine, allowing oxidation for energy.
Enteral fat source?
LCT and MCT mix, usually soybean and corn oil
Enteral CHO source?
Corn syrup solids in polymeric
Maltodextrin or hydrolyzed cornstarch in hydrolyzed
Enteral fibre source?
Guar gum and soy fibre
(T/F) MCT meets EFA needs
F, thats why we need a mix of MCT and LCT
Enteral protein source?
Casein and soy protein isolates
The more energy dense a formula, the less _____ it contains
free water
(T/F) EN formulas are designed to meet all of the patients fluids needs
F
(T/F) Polymeric formulas have a lower osmolality than semi-elemental formulas
T
Why is the evaluation of disease specific EN often left up to the clinician?
Since FDA does not require rigorous pre-market research on medical foods, often much of the research may have been done by the company itself
Diabetes specific EN formula?
- Lower in CHO
- Higher in MUFA and PUFA
- More fibre than standard
Should diabetes specific En formula be used for diabetics in ICU?
Likely not, as research is limited
-Continuous insulin would more likely improve glycemia in a critically ill patient, not EN
Bottom line on disease specific formulas?
Not a lot of evidence of benefiting ICU patients, must conduct research
What is the main complication of liver disease?
Hepatic encephalopathy (build up of ammonia in liver)
What is the issues with the ratio of aromatic AA and branched-chain AA in hepatic ecephalophathy?
Have higher levels of AAA vs BCAA, more AAA will enter into the brain to produce neurotransmitters which contribute to the symptoms
Which key nutrients are found in immune-modulating formulas?
- Arginine
- Glutamine
- Omega 3 PUFA
- Nucleotides
- Antioxidants
When should IMFs be used ? What have recent systematic reviews indicated about IMFs
- Not in ICU or in Sepsis, but OK is postop elective Sx
- May have reduced risk for infections and mortality
In patients with resp. failure, is reducing CHO or energy more efficient?
Likely total energy restriction more important to underfeed rather than restricting CHO
Patients with CKD and on dialysis have increased ____ and may need ____ & _____ restrictions
- Protein
- Fluid, electrolytes
Patients with CKD and NOT on dialysis may slow the progression of CKD by limiting what?
Protein intake
Why is protein requirement increased for patients with dialysis?
Dialysis causes catabolism and protein wasting, thus protein requirement increases
What does ASPEN recommend for patients with acute resp. failure?
Concentrated formulas, as we don’t want fluid overload
In addition to arginine and glutamine supplementation for wasting conditions, what is another AA that may be recommended?
HMB, a metabolite of the BCAA leucine
Increases protein synthesis, inhibits ubiquitin proteasome pathway
Why may we promote weight-loss, while maintaining LBM in obese critically-ill patients?
May improve insulin sensitivity, and reduce co-morbidities
kcal req for critically-ill obese BMI 30-50?
11-14 kcal/kg
kcal req for critically-ill obese BMI >50?
22-25 kcal/kg
Protein req for critically ill-obese?
at least 2 g/kg
Caution with modulars?
May be hyperosmolar
If a nasoenteric feeding tube cannot be unclogged using water flushes, what is the next most reliable method for unclogging the tube before it is replaced?
-Pancreatic enzyme and bicarbonate solution mixture. Allow it to sit for 1-2 hours, then flush with warm water.
A patient reports that they have gained over 20 lbs on their home tube feeding. What is your impression?
The patient must come to clinic to rule out buried bumper syndrome
Why are we concerned with sig. weight loss or weight gain when pt on long-term EN feeds
Whenever a patient on EN loses/gains a sig. amount of weight, there is a risk that the tube does not fit properly anymore and could lead to buried bumper syndrome
What is buried bumper syndrome?
When weight change occurs, there may be abnormal internal pressure from the bolster or the balloon which can erode the gastric mucosa - the gastric mucosa will grow partially or completely over the internal bumper or increased pressure between the gastric mucosa and abdominal wall may occur. Infection and pain may occur.
An 18 Y/O F with cystic fibrosis has a standard profile, solid internal bolster, 20 Fr percutaneous endoscopic gastrostomy (PEG) placed one year ago. The tube is now stiff and is cracking, what do you recommend? The patient is active, and is concerned about the cosmetic appearance of the tube itself. She has family support.
A low profile, 20 Fr percutaneous G-tube with balloon internal bolster
Why is a low profile, 20 Fr percutaneous G-tube with balloon internal bolster ideal of a patient who is active, and is concerned about the cosmetic appearance of the tube itself?
- Low-profile are skin-level tubes and are more discrete and ideal for those who are active
- Balloon is preferred, as although bolster lasts longer the balloon can be changed at home which can be facilitated through family support
When do we gastric feed?
- Normal gastric emptying
- Low risk of gastric aspiration
When do we small bowel feed?
- Gastric outlet obstruction
- Gastroparesis
- Severely increased risk of aspiration
- Pancreatitis
When do we use G-J feeds? Why?
- Gastric outlet obstruction
- Gastroparesis
- GERD
- Early post-op feeding
- -> Will allow for simultaneous gastric decompression
35 y/o indicated to be on long term EN feeds, he has GERD. What kind of tube feeding?
PEG is ideal, with bolus feeds and solid internal bolster
Most closely mimics the physiological state
Cheaper, less tubes and more safe
Does a tube placed in the stomach increase risk of aspiration within the context of GERD?
Research conflicts, and ASPEN recommends feeding in the stomach as a first-line option independant of GERD. If not tolerated, then consider small bowel feeding
____ tubes have a larger internal diameter than silicone, where they may less likely to clot.
Polyurethane
What is the complication in a patient with PEG who develops pain after a tube change?
Dislodgement of abdominal feeding tube is likely - it may have been placed into the stoma tract instead of the gastric lumen, or has perforated the peritoneal space.
Which of the following actions is the most appropriate for enhancing gastric emptying during the administration of EN?
A) Keep the bed in Trendelenburg position
B) Decrease the rate of continuous feeding infusion, or change from bolus to continuous feeding
C) Switch to an EN formulation with a higher fat content
D) Switch to an enteral formulation with higher protein content
B)
Factors that decrease gastric emptying include large boluses, increased rates of infusion, increased fat and protein and infusions of solutions that are colder than room temp.
How can we change the patients position to enhance gastric emptying?
Elevating the head of the bed
Turning slightly on the right side
However, may be difficult in the hospital setting
Which of the following is the most appropriate initial action for the management of tube feeding-associated diarrhea?
A) Change to EN formula with fibre
B) Review patients medication administration record to determine if hyperosmolar agents were administered
C) Change to a peptide based EN formula
D) Use an antimotility agent
B
If no hyperosmolar agents are administered, potential for C.Diff
If no hyperosmolar agents and C.Diff is ruled out but diarrhea is persistant, what can be our next course of action?
Addition of fibre to EN formulation, if this fails in ceasing diarrhea, add auto-motility agent or change to a peptide-based formula. T
Which of the following methods is not recommended to minimize contamination from enteral feeding formula?
A) Washing hands and donning clean gloves before handling
B) Immediate use of EN from a newly open container
C) Infusing reconstituted powdered formulas or with added modular components in 1 bag for up to 8 hours
D) Changing an”open” feeding container every 24 hours
C
Should not be infused for more than 4 hours due to risk of infection
What may decrease gastrci emptying, causing nausea and vomiting?
- Anticholinergic medications
- Opiate medications
- Excesive infusion of formula
- Formula of cold temperature, or high fat/protein
- Stress
- Diabetic gastropathy
Patient with N/V on EN feeds, has low-fibre, low-fat, lower-protein, reduced continuous infusion with pro-kinetic agent and has discontinued all hyperosmolar meds, what could be considered?
Small bowel feeding
What may be a serious cause of abdominal distension?
GI ileus or bowel obstruction
What is maldigestion?
The impaired breakdown of nutrients into absorbable forms, which can lead to malabsorption
-Maldigestion can cause bloating, cramps and diarrhea
What is malabsorption?
The defective mucosal uptake and transport of nutrients from the SI
-Can cause nutrient deficiencies, unintentional weight loss, steatorrhea and diarrhea
Patients with severe malabsorption may require what?
PN
What is the most common side-effect of those receiving EN?
Diarrhea
What is diarrhea?
- > 500 ml stool output ever 24 hours
- 3 stools per day for at least 2 consecutive days
What may cause diarrhea, besides hypertonic medications
- Electrolyte supplementation
- Meds delivered in liquid form with magnesium or sorbitol as the vehicle (should be diluted, especially if in the small bowel to avoid dumping syndrome)
Main consequences of primary GI diseases?
- Malabsorption
- Secretory diarrhea
How should a nutrition support clinician select an enteral formula for a tube-fed patient who experiences diarrhea?
1) Rule-out hypertonic or sorbitol medications, and see if pro-kinetic agent has been added
2) Rule-out C.Diff by ordering a stool culture
3) Recommend an enteral formula high in fibre to assist controlling the patients diarrhea
Drugs which have a direct effect on the gut, and may cause diarrhea?
- Antibiotics
- Proton pump inhibitors
- Pro-kinetic medications
What should be recommended in terms of fibre and diarrhea for EN?
- Try adding a soluble- fibre based EN formula as long as patient is hemodynamically stable
- Do not use modulars, as it will risk clogging the feeding tube
Who may experience SIBO?
- After Roux-en-Y gastric bypass surgery
- Patients on prolonged antibiotics
How is constipation managed if the patient if there is a fluid restriction?
- Add stool softner
- Encourage ambulation
What is impaction?
- A variation of constipation
- Firm collection of stool in the distal colon
- May cause agitation and confusion in older adults
Risk of intestinal ischemia, such as non-occlusive bowel necrosis?
- Jejunal feedings
- Hyperosmolar formulas
- Hypotension
- Disordered peristalsis
Why are GRVS used?
Will suck out gastric fluids intermittently from enteral access device, as GRVs will predict vomiting, reflux or aspiration. Therefore, if GRV is considered too high, we will hold feeds.
Is there a reliable and standard bedside method to determine gastric emptying?
No
What is a general protocol for those with elevated GRVs and critically ill?
- HOB at 30-45 degrees
- GRV checks every hours
- Prokinetic agent
When GRVs >200ml after prokinetic administration, what is the protocol?
Change to small bowel feeding
What is ASPENs bottomline guideline on GRVs?
- Not to be used in ICU
- If still used, avoid holding feeds for GRVs with <500 ml and no other intolerances noted
How could displacement of a tube be indicated? (i.e. from SI to stomach)
Changes in volume aspirate and/or pH
Patients at higher risk for refeeding syndrome?
- Diarrhea
- High-output fistula
- Vomiting
Can re-feeding syndrome only occur with the administration of EN feeding?
No, can also occur when patients are resuscitated with standard IV solutions containing dextrose
ASPEN recommends that EN for patients with refeeding syndrome should be provided with only ___ of energy goal on Day 1
25%
Absorption of glucose from _____ is more affected by the rate of CHO delivery than the Glycemic Index
Continuous feeds
-Glycemic index is in terms of bolus feeds
Why are older adults at a greater risk of dehydration?
- Lower LBM, therefore less reserves
- Less thirst mechanism
- Less access to water
- Dysphagia, cognitive issues
For patient with fever, how should fluid req. be adjusted?
Increase fluid intake by 12% per degree above 37.8
