Parenteral Nutrition

What are the three macronutrients?

Proteins, carbohydrates, and lipids

Includes electrolytes, trace elements, fat-soluble vitamins (A, D, E, K) and water-soluble vitamins (B-complex, C)

Micronutrients

Goals are to maintain or gain weight, preserve lean body mass, and maintain a positive nitrogen balance until oral intake resumes

Parenteral nutrition

Ideal for anabolism/tissue building; protein intake > protein breakdown

Positive nitrogen balance

Nutrition assessment tries to _______ complications before they occur

Prevent

Nutrition assessments ________ decreased intake, increased nutrient losses (fistulas, Short Bowel Syndrome), increased needs (growth, critical illness)

Identify

Validated clinical tool using subjective data (history + physical exam), not just labs

Subjective global assessment

When looking at weight loss the ______ and ______ are more important than the absolute amount

Pattern and velocity

A patient experiencing >____ weight-loss if at high risk for nutritional deficiency

10%

_______ change is an unreliable measurement when dealing with edema/ascites (fluid masks true tissue loss)

Weight

Malnutrition is likely if dietary intake is significantly decreased for over ___ ________

2 weeks

Edema/ascites in malnutrition is caused by a decrease in this type of pressure due to low albumin/protein

Capillary oncotic pressure

No weight loss or <1 kg; normal dietary intake; GI symptoms <2 days

Normally nourished

5-10% weight loss over 6 months; abnormal dietary intake for 1 month; short-term/intermittent GI symptoms

Moderate malnutrition

>10% weight loss if <6 months; inadequate intake for >1 month; GI symptoms for >1 month

Severe malnutrition

A greater than _____ loss in usual body weight indicates significant nutritional risk

10%

Use growth charts to determine malnutrition risk; falling off the chart is the primary concern

Pediatrics

_______ _______ is better than ideal body weight as a clinical indicator since it reflects patient’s own baseline

Usual weight

Anthropometric measurement indicating lean body mass (somatic protein)

Midarm circumference

Anthropometric measurement indicating fat reserves (subcutaneous fat)

Triceps skinfold

Serum _______ reflect the liver’s synthetic capacity, though they are heavily influenced by hydration and inflammation

Proteins

Half-life is ~20 days; indicates long-term status; good prognosis marker; slow to change

Albumin

Half-life is 8-10 days; mid-range marker; smaller body pool

Transferrin

Half-life is 2-3 days; best marker for acute monitoring; reflects recent intake and response to therapy

Pre-albumin

When you start nutrition, you will see a change in ________ first

Prealbumin

_________ can falsely elevate albumin, transferrin, and prealbumin

Dehydration

Malnutrition can lead to suppressed _______ function

Immune

A total lymphocyte count less than _______/mm³ indicates nutritional risk

1500

No reaction to cutaneous hypersensitivity test can indicate ________

Malnutrition

Malnutrition; often evident in quadriceps, deltoids, and temporal muscles

Muscle wasting

Malnutrition; often present in triceps area, orbital (sunken eyes)

Fat loss

______ can mask weight loss

Edema

Malnutrition can prevent as _______ dermatitis and poor wound healing

Flaky

Severe acute malnutrition due to low protein but adequate calories; presents as edema (decreased plasma oncotic pressure)

Kwashiorkor

Baby appears normal/plump weight due to fluid with thin limbs, fatty liver, and skin lesions; has high mortality, hard to treat

Kwashiorkor

Severe acute malnutrition with low protein and calories (starvation); presents as generalized wasting

Marasmus

Severe acute malnutrition with no edema and loose, hanging skin; better survival if treated

Marasmus

In __________, there is low albumin leading to low oncotic pressure and fluid leaking into the interstitium

Kwashiorkor

Minimum energy to maintain life (HR, breathing, temp); measured at full rest, immediately upon waking; accounts for 50-60% of total energy

Basal energy expenditure

Basal energy expenditure + 10%; includes thermic effect of food and energy while awake/sitting

Resting energy expenditure

Basal energy expenditure x stress factor

Total energy expenditure

Burns/trauma have the highest caloric demands due to _________ stress response

Hypermetabolic

If the gut works, use it - always prefer ________ nutrition

Enteral

Route is GI tract; preferred method; maintains gut mucosal integrity, cheaper, safer

Enteral nutrition

Route is IV (peripheral or central); used only when GI non-functional; provides complete nutrition while bypassing GI

Parenteral nutrition

_______ feeding maintains tight junctions of the gut epithelium, stimulates IgA secretion, and prevents bacterial translocation

Enteral

Parenteral nutrition is indicated if EN/oral is not feasible for over ___ days

7

Parenteral nutrition is indicated if complete ______ ______ is clinically indicated

Bowel rest

Parenteral nutrition is indicated if moderate-to-severe ________ is present preoperatively

Malnutrition

Parenteral nutrition is indicated due to bowel obstruction or ______

Ileus

PN is needed due to small bowel syndrome is less than _____ cm of small bowel remain (no colon)

100

PN is needed for short bowel syndrome if less than ____ cm remain (with colon)

50

Enteral nutrition can’t be delivered above or below the GI _______

Fistula

PN is indicated in diffuse peritonitis, severe ________, and intractable vomiting or diarrhea

Pancreatitis

When GI function returns, always return back to _______ nutrition ASAP to avoid CRBSI and PN-associated liver dysfunction

Enteral

Given via small peripheral veins (cephalic, basilic); short-term duration (<7 days); low nutrient density and high volume

PPN

Given via large central veins (subclavian, internal jugular); long-term (>7 days); high nutrient density in lower volume

TPN

What is the max osmolarity for PPN?

900 mOsm/L

What is the max osmolarity for TPN?

1500 mOsm/L

What is the amino acid max concentration for PPN?

25 g/L

What is the amino acid max concentration for TPN?

60 g/L

What is the dextrose max for PPN?

10%

What is the dextrose max for TPN?

25%

Parenteral nutrition associated with phlebitis

PPN

Parenteral nutrition associated with insertion complications and CRBSI

TPN

If a patient needs parenteral nutrition >7 days OR has high caloric needs in a fluid-restricted state, _____ is the ONLY option

TPN

High osmolarity can be _______ to small veins

Caustic

Vein inflammation

Phlebitis

________ veins have high blood flow and rapid dilution of hypertonic solution so no irritation

Central

Risk factors for ________ are high osmolarity, extreme pH, rapid infusion rate, and poor vein condition

Phlebitis

Can be given via standard IV catheter or midline catheter

Peripheral

Devices include PICC line, Non-tunneled CVC, tunneled catheter, and implanted port

Central

Central; inserted in arm and tip goes to central vein; best for intermediate-term

PICC line

Central; fully under skin, long-term/permanent; lowest infection risk

Implanted port

______ access can cause pneumothorax, air embolism, brachial plexus injury, venous thrombosis, CRBSI, and chylothorax

Central

Catheter-related bloodstream infection; most common serious complication of TPN/central access

CRBSI

Prevention includes strict sterile technique, daily line assessment, and removing the line ASAP when no longer needed

CRBSI

Bag contains Dextrose and Amino Acids; lipids given separately, requires 0.22 micron filter (catches bacteria/fungi)

2-in-1

What is the size filter for 2-in-1?

0.22 micron

Bag contains dextrose, amino acids, and lipids all together; filter is 1.2 micron (must be larger to allow lipid particles through)

3-in-1

Has less nursing/pharmacy labor; better for home use; less chemically stable; milky/white so can’t see precipitates

3-in-1

Uses 1.2 micron filter (less effective vs. pathogens); higher infection risk; low EFAD risk; potentially lower risk of contamination due to fewer connections

3-in-1

More complex; higher labor cost; more stable; more meds compatible; mxiture is clear so there is easy visual inspection

2-in-1

Requires a 0.22 micron filter (superior for bacteria); lower infection risk; higher EFAD risk; more connections are needed

2-in-1

Occurs within 2-4 weeks without fat intake - manifests as dermatitis, alopecia, poor wound healing; prevented by giving IV lipids at least 2-3x/week minimum

EFAD

What percentage of calories should be from amino acids?

10-20%

What percentage of calories should be from dextrose?

50-60%

What percentage of calories should be from lipids?

20-30%

What are the five trace elements?

Zn, Cu, Se, Cr, Mn

Additive to parenteral nutrition to prevent catheter-related thrombosis

Heparin

Additive to parenteral nutrition for stress ulcer prophylaxis

H2RAs

Additive to parenteral nutrition to manage hyperglycemia (most common PN complication)

Insulin

This is for nutrition only; NOT for fixing acute fluid/electrolyte crises

Parenteral nutrition

Daily fluid maintenance for <10 kg

100 mL/kg

Daily fluid maintenance for 11-20 kg

1000 mL +50 mL/kg over 10

Daily fluid maintenance for >20 kg

1500 mL + 20 mL/kg over 20

Purpose is to preserve lean body mass, wound healing, and anabolism

Amino acids

What is the caloric density for amino acids?

4 kcal/g

Stock solutions for amino acids are available as _____ or ______

10% or 15%

To dose amino acids, ______ ______ ______ is typically used

Ideal body weight