RD Exam - EN & PN

How is osmolarity calculated?

(dextrose g/L x 5) + (amino acid g/L x 10) + (300-400 for vitamins and minerals) Remember, lipids don't contribute to osmolarity

define Percutaneous endoscopic gastrostomy(PEG) & percutaneous endoscopic jejunostomy (PEJ)

lighted endoscope fed through the mouth down into the stomach(or jejunum) to guide where the abdominal incision is made and to guide placement of the G-tube or J-tube once inserted in the incision. PEG/PEJ tubes can last months or years.

Define aspiration

when regurgitated fluids enter the lungs, leading to infection or aspiration pneumonia

define Nasoduodenal (ND) and Nasojejunal (NJ)

Flexible tube is fed through the nose, down the back of the throat, and terminates in the small intestine. OK to use for a few weeks

define peripheral access in relation to PN

achieved via a short IV cannula in the hand or arm and shouldn't be used for more than 10 -14 days. used when central access is contraindicated or for short term PN

define parenteral nutrition (PN)

an alternative to oral or enteral nutrition when patients have intestinal failure

how do we calculate GIR?

convert grams to milligrams, divide by body weight (kg), and divide by minutes per day (or per infusion duration) Note: There are 1,440 minutes in a day and we try to keep GIR to 3-5 mg/kg/min

Define gastroparesis

delayed gastric emptying. when the stomach isn't moving food through the stomach and into the duodenum

when does a "well-nourished stable patient who is unable to meet at least 50% of nutritional needs PO or via enteral nutrition" need PN?

initiate PN after 7 days

when does a "Moderately or severely malnourished patient in which oral intake or EN is not possible" need PN?

initiate PN as soon as possible

when does a "Metabolically unstable patient" need PN?

initiate PN until condition is improved

when does a "Nutritionally-at-risk patient unlikely to achieve sufficient oral or EN intake" need PN?

initiate PN within 3-5 days

How is dysphagia diagnosed?

patient history signs and symptoms videofluoroscopy / swallow test

define Gastrostomy and jejunostomy

surgically placed directly into stomach or jejunum. By making an incision in the abdominal wall (stoma) and is usually done during another pre-planned surgery. Used if EN needed for more than a few weeks, cannot have a tube through the mouth or throat, or vomit frequently (which would displace NG, ND, or NJ tubes).

what are 3 steps to take to prevent dumping syndrome with EN patients?

tapering up infusion rates, using continuous instead of bolus feeds, and using isotonic formula

why can hypertonic solution be provided via central access

the large vena cava dilutes parenteral nutrition via its large blood volume and high blood flow rate

what is the goal for amino acids in a PN solution?

to be used for protein synthesis, not calorie requirements. We want to provide sufficient calories from other sources so that the body can use amino acids for protein synthesis

why are lipid emulsions not administered daily in PN patients?

to prevent hyperlipidemia If we provided continuous lipid infusions, the body wouldn't have time to clear the lipids from the blood

define combination feeds in relation to EN feedings

use bolus feeds during the day and continuous feeds at night

When would we transition someone from a nasal tube to a G-tube?

when it is decided that EN will be long term

Calculate the following (in kcal and grams) 100 mL, 10% emulsion 250 mL, 10% emulsion 200 mL, 20% emulsion 500 mL, 20% emulsion

110 kcal, 11g 275 kcal, 27.5g 400 kcal, 40g 1000 kcal, 100g

what percentage of amino acids are nitrogen?

16%

what is the maximum lipid dose in PN?

2.5 g/kg/day

how many kcal per gram of dextrose in a PN formula?

3.4 kcal/g

How many grams of amino acids would be in 1.5 L of 3.5% AA solution? 0.75 L of 8.5%?

52.5g, 64g

Why do we calculate dextrose infusion rate?

The body can only oxidize glucose at a certain rate (0.36 g/kg/hr) and if we provide excess dextrose,we increase their risk of fatty liver.

define post-pyloric access

When the tube terminates beyond the stomach -beyond the pylorus

define trophic feeds

a small volume of balanced enteral nutrition insufficient for the patient's nutritional needs but producing some positive gastrointestinal or systemic benefit

why is GIR important to control?

because a rate in excess of 0.36 g dextrose per kg body weight per hour can lead to hyperglycemia, fatty liver, and respiratory issues because glucose is oxidized at a maximum rate of 0.36 g/kg/hour in our body

when is it important to check residuals? what does a high residual mean?

before bolus feeds and every 3-5 hours with continuous feeds. A residual of 100 -150 mL may indicate an obstruction or poor motility

define continuous drip in terms of EN

given at a steady flow rate for as many hours is required to administer the nutrients for the day. We often calculate the flow rate assuming a 24-hour duration.Continuous drip requires that the patient is tethered to an IV pole or pump

define Bolus feeds or intermittent feedings in terms of EN

given several times throughout the day, often at meal times. Patients often transition from continuous drip in the hospital to bolus feeds when they leave in order to have more mobility during the day. However, bolus feeds may be difficult to tolerate,especially with post-pyloric access

Specialty formulas with glutamine can improve _________________ metabolism and prevent ________________ atrophy

glucose and protein; GI

what happens if the gut is not used for 2+ weeks?

gut atrophy

define glucose infusion rate

how quickly the parenteral nutrition formula enters the bloodstream

what are the 2 parts of the EN tube types?

where the tube goes and where the tube ends

name some contraindications for EN

1.Intestinal obstruction, ileus, or hypomotility 2.Severe diarrhea or vomiting 3.Severe hemodynamic instability 4.Major upper GI bleeding 5.Prognosis doesn't warrant aggressive nutrition support 6.High output enterocutaneous fistula

what are the 5 main indications for enteral nutrition?

1.Protein-energy malnutrition and inadequate oral nutrient intake for ≥ 5 days 2.Meeting < 50% of nutrient needs for 5 -7 days 3.Severe dysphagia 4.Coma 5.Low output enterocutaneous fistula

what % do standard amino acid concentrations range?

3-10%

how much of the total calorie needs should be from PN lipids? Why?

At least 4% of calories should come from lipids to avoid essential fatty acid deficiency

what are the typical % lipid emulsions and their kcal per mL?

10% - 1.1 kcal/mL 20% - 2.0 kcal/mL

How many grams of amino acids would be in 500 mL of a 3% AA solution? 7% AA solution?

15g, 35g

In grams, what is a 3% solution of amino acids per 100mL? what about 10%? 7%?

3g, 10g, 7g

how many kcal per gram of amino acids in a PN formula?

4 kcal/g

what do... D50W D5W D30W mean?

50% dextrose in water or 50g per 100mL 5% dextrose in water or 5g per 100mL 30% dextrose in water or 30g per 100mL

what is the "normal" GIR for adults?

3-5 mg/kg/min

what broken down macros contribute the the hypertonicity of PN formula?

dextrose and amino acids. fat does not

define dysphasia

difficulty swallowing

Define ileus

occurs when there is a non-mechanical decrease or stoppage of the flow of intestinal contents

The 5 indications for parenteral nutrition answer the "why" question -why a patient can't use oral or enteral nutrition, and why we can't use the gut.

1.Inability to achieve or maintain enteral access 2.Impaired absorption or loss of nutrients 3.Mechanical bowel obstruction 4.Need for bowel rest 5.Motility disorders

With PPN, it's important to maintain formula osmolarity below _________.

900-1100 mOsm/L

what are the signs and symptoms of shock

Low blood pressure. Altered mental state, including reduced alertness and awareness, confusion, and sleepiness. Cold, moist skin. Hands and feet may be blue or pale. Weak or rapid pulse. Rapid breathing and hyperventilation. Decreased urine output.

how can you prevent regurgitation in a hospital patient?

Raising the patient's bed to at least 30 degrees

is hydrolyzed formula hyper/hypo/isotonic?

hypotonic which can lead to excess fluid in the GI tract causing cramping, nausea, vomiting, and diarrhea

what can cause diarrhea after tube feeding?

infection (gastroenteritis), antibiotics, medications with sorbitol, malabsorption,and formula intolerance It can also be due to a rapid infusion of solution or bolus feeds (instead of continuous) but will manifest later than dumping syndrome If a question asks about the cause of diarrhea following enteral feeds, think about the timing of onset

Glutamine is a key transporter of nitrogen, carbon, or ATP?

nitrogen

Define dumping syndrome

occurs when hypertonic contents enter the small intestine, causing an influx of fluid into the lumen. This leads to epigastric fullness, weakness, dizziness, vertigo, diaphoresis, tachycardia, and/or abdominal cramping

When does dumping syndrome occur?

occurs within 1 hour of eating or EN administration

define PEG-J tube

one where the tube enters the stomach and is fed through to the jejunum, rather than entering the body directly at the level of the jejunum

what does PPN stand for?

peripheral parenteral nutrition

define hydrolyzed formula

pre-digested, monomeric formula. Fat is in the form of MCTs (can be absorbed without transforming back into TGs) Used with jejunal access, short bowel syndrome, patients with impaired ability to digest nutrient

Soluble fiber is converted to ______________ which is used by gut bacteria for food. Helps maintain a healthy gut

short chain fatty acids

Glutamine requirements are increased during ______________

stress

define central access in relation to PN

venous access delivered to the superior vena cava or right atrium. achieved by a catheter into the chest or PICC line, which is peripherally inserted (arm) and threaded up to the chest

Low CHO/high fat formulas can facilitate _____________ weaning because excess CHO is converted to ________________, releasing CO2 (which is difficult to clear with impaired respiratory function)

ventilator; fat

define enteral nutrition (EN)

when nutrition is provided to the gut when a person cannot consume sufficient (or any) nutrition on their own

what is the maximum hourly lipid infusion rate in PN?

0.11 g/kg/hr

how can we calculate the maximum grams of dextrose to give a patient

0.36 g x body weight x 24 hours

Why do we taper up PN infusion rates?

By starting infusion rates slowly, we allow the body to adjust to the glucose load, the hyperosmolarity of the solution, and reduce the risk of fluid overload. We often start with 1 L of the solution for 24 hours, and increase by 1 L a day until we get to goal volume. It's important to monitor blood glucose and electrolytes. If the pump is turned off, don't try to "catch-up

how are dextrose concentrations abbreviated? what does this abbreviation mean?

D(%)W tells you the % dextrose (D) in water (W)

define nasogastric (NG)

Flexible tube is fed through the nose, down the back of throat,and terminates in the stomach. OK to use for a few week

another term for PN is ______

IV nutrition

which tubes are used for short term EN and which tubes are used for long term EN?

Nasal and oral tube feeding access is for short term only. If the patient needs long term enteral nutrition support, we would switch to G-tube, J-tube, PEG, PEG-J, or PEJ tube.

with which EN tube is aspiration an issue?

PEG tube

does PEG or PEJ tube have higher chance for diarrhea?

PEJ

Patient was admitted to the ICU after bowel surgery. She is 80% of her ideal body weight and will remain NPO for 7 days. Would you consider starting her on PN, and if so, when?

Patient is nutritionally at risk and unlikely to achieve desired oral intake or EN within 3-5 days -initiate PN immediately

Is PPN supplemental or total nutrition? Why?

Supplemental because large amounts of nutrients can't be provided through small peripheral veins, and small veins cannot tolerate hypertonic solution, because they result in a large fluid shift into vascular compartments leading to phlebitis (inflammation of the walls of a vein) or thrombosis (when blood clots block veins or arteries)

define gut atrophy

This condition is characterized by inflamed intestinal cells, blunt or malformed villi, leaky channels between intestinal cells, translocation of lumen contents into the bloodstream

why would an RD choose post-pyloric access with an EN feed?

To avoid stimulating the pancreas Due to recent esophageal or gastric surgery Due to severe gastroparesis

how do you calculate non-protein calorie: nitrogen (NPC:N) ratio?

To calculate NPC:N ratio, divide total NPC by grams of N. To convert protein (g) to nitrogen (g) divide by 6.25 or multiply by 0.16 (16%)

How do we verify that a tube is actually terminating in the jejunum?

camera with a light at the end

80:1 (NPC:N) for critically ill patients 100:1 (NPC:N) for patients with difficulty maintaining muscle mass 150:1 (NPC:N) for unstressed and stable patients rationalize why these ratios make sense

critically ill patients are in protein catabolism, therefore they need more g of protein, lowering the ratio # versus stable patients are neutral

define cyclic feeds in terms of EN

given at a faster rate over a shorter period of time, and thus a faster flow rate must be tolerated. It's often used overnight so the patient can freely move around during the day, or if a patient has a treatment schedule during the day (like chemotherapy) that precludes daytime feedings