Download Parenteral Nutrition

Parenteral Nutrition:
Assessment & Management
Techniques
Kris M. Mogensen, MS, RD, LDN, CNSC
Team Leader Dietitian
Department of Nutrition
Brigham and Women’s Hospital
December 8, 2014
Overview
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Deciding who needs parenteral nutrition
Peripheral vs. central parenteral nutrition
Nutrition assessment
Protein
Carbohydrate
Fat
Fluid requirements
Additives
Calculating the PN prescription
Monitoring/complications
Overview
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Deciding who needs parenteral nutrition
Peripheral vs. central parenteral nutrition
Nutrition assessment
Protein
Carbohydrate
Fat
Fluid requirements
Additives
Calculating the PN prescription
Monitoring/complications
Who needs PN?
• PN carries a fair amount of risk
– Inserting a central line, infections,
metabolic complications…
• If the gut works, and can be used
safely, use it!
Typical Indications for PN
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Diffuse peritonitis
Intestinal ischemia
Intestinal obstruction
Paralytic ileus
Severe diarrhea (> 1 liter/day)
Severe malabsorption
Intestinal failure
Other Indications
• Failed enteral trial or inability to
obtain enteral access
– Severe pancreatitis
– Prolonged severe mucositis
– Multi-organ system failure
A.S.P.E.N. Board of Directors and The Clinical Guidelines Task Force. Guidelines for the
use of parenteral and enteral nutrition in adult and pediatric patients. JPEN 2002
BWH Algorithm for Determining Route of
Nutrition Support
Consider nutritional support if any of the following conditions are present:
• Patient has been without nutrition for 5-7 days
• Expected duration of illness > 10 days
• Patient is malnourished (weight loss > 10% of usual weight)
Initiate nutritional support only if tissue perfusion is adequate
and electrolytes and acid-base balance are near normal
Is GI output > 600 ml/24 hr, massive GI hemorrhage, prolonged
ileus or other contraindication to enteral feeding?
NO
YES
Administer
Parenteral Nutrition
Initiate Enteral
Feedings
Enteral Feeding
Tolerated
Enteral feeding
not tolerated
Initiate
CPN
Initiate
PPN
Reassess PN need
Overview
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•
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•
•
•
•
•
•
•
Deciding who needs parenteral nutrition
Peripheral vs. central parenteral nutrition
Nutrition assessment
Protein
Carbohydrate
Fat
Fluid requirements
Additives
Calculating the PN prescription
Monitoring/complications
Peripheral vs. Central PN
• Decision process
– Duration of therapy
– Type of venous access
– Status of peripheral veins
– Energy and protein needs
– Volume required
Peripheral PN Safety Point
Boullata JI et al. A.S.P.E.N. clinical guidelines: parenteral nutrition ordering, order
review, compounding, labeling, and dispensing. JPEN 2014
Peripheral PN
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Safety concern: thrombophlebitis
High osmolarity increases risk
Need good peripheral access
Amino acid and dextrose concentrations are low
to keep osmolarity ≤ 900 mOsm/L
• This typically means a solution that is < 10%
dextrose and < 5% amino acids, with most of the
energy delivery from fat
• Need large volume (up to 2-3 L/day)
Peripheral PN
• Practical safety concern:
– If large volume is required to provide a
substantial amount of energy and
protein, are there patients who should
not be peripheral PN candidates?
Central PN
• Hyperosmolar solution, > 900 mOsm/L
• Can meet energy and protein needs in a
concentrated volume
• Requires central venous access
• Tip of the catheter must be in the
superior vena cava
Mirtallo J et al. Safe practices for parenteral nutrition. JPEN. 2004
Preferred
catheter
tip
location
for PN
From Nelms, Nutrition Therapy and Pathophysiology, 2nd ed, 2011.
Overview
•
•
•
•
•
•
•
•
•
•
Deciding who needs parenteral nutrition
Peripheral vs. central parenteral nutrition
Nutrition assessment
Protein
Carbohydrate
Fat
Fluid requirements
Additives
Calculating the PN prescription
Monitoring/complications
Nutrition Assessment
• Your PN prescription is driven by
your nutritional assessment
– Is the patient malnourished?
– Is there risk of the refeeding syndrome?
– What are the patient’s energy, protein,
and fluid requirements?
– Does the patient need specialized
nutrients or additives to the PN?
Energy Requirements
• In the good old days, PN was referred to
“hyperalimentation”
– This is a misnomer; the current practice is to
avoid overfeeding
– Provide what your patient needs to prevent
complications such as hyperglycemia &
fatty liver
• Bottom line:
– Estimate energy requirements carefully or
measure when you can
– Avoid overfeeding!
Mirtallo J et al. Safe practices for parenteral nutrition. JPEN. 2004
Overview
•
•
•
•
•
•
•
•
•
•
Deciding who needs parenteral nutrition
Peripheral vs. central parenteral nutrition
Nutrition assessment
Protein
Carbohydrate
Fat
Fluid requirements
Additives
Calculating the PN prescription
Monitoring/complications
Protein
• Protein in PN is provided as crystalline
amino acids
• Parenteral amino acids provide 4 kcal/g
• Various concentrations are available
– 8.5% up to 20% as a base solution
• Total amino acid delivery depends on your
assessment of protein requirements
Protein
(continued)
• Safety point:
– For a total nutrient admixture (3-in-1):
• At least ≥ 4% amino acid concentration for
appropriate stability
– However, lots of considerations for
stability, so it’s important to work with
your pharmacist on this!
Boullata JI et al. A.S.P.E.N. clinical guidelines: parenteral nutrition ordering, order
review, compounding, labeling, and dispensing. JPEN 2014
Overview
•
•
•
•
•
•
•
•
•
•
Deciding who needs parenteral nutrition
Peripheral vs. central parenteral nutrition
Nutrition assessment
Protein
Carbohydrate
Fat
Fluid requirements
Additives
Calculating the PN prescription
Monitoring/complications
Carbohydrate
• Parenteral CHO is dextrose
• Provides 3.4 kcal/g
• Total dextrose delivery depends on energy
requirements
– 50-60% kcals from dextrose for CPN
– ~ 30% kcals from dextrose for PPN
• Base solutions range from 50-70% dextrose
• Final dextrose concentration depends on
– Peripheral vs. central infusion
– Volume requirements
• Concentrated PN = higher dextrose concentration
• Safety point: for a 3-in-1 PN, dextrose concentration
should be ≥ 10%
Boullata JI et al. A.S.P.E.N. clinical guidelines: parenteral nutrition ordering, order review, compounding,
labeling, and dispensing. JPEN 2014
Carbohydrate
(continued)
• CHO safety point: avoid overfeeding!
• Maximum oxidative rate:
– 5 mg/kg/minute
• Example calculation:
– 70 kg pt x 5 mg x 1440 minutes/day =
504,000 mg dextrose = 504 grams
Mirtallo J et al. Safe practices for parenteral nutrition. JPEN. 2004
Carbohydrate
(continued)
• Consequences of short-term overfeeding:
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Hyperglycemia
CO2 retention
Increased respiratory drive
Respiratory distress
• Long-term overfeeding of dextrose can
lead to fatty liver
– Overfeeding total calories from all
macronutrients can lead to a fatty liver!
Overview
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Deciding who needs parenteral nutrition
IV access
Peripheral vs. central parenteral nutrition
Nutrition assessment
Protein
Carbohydrate
Fat
Fluid requirements
Additives
Calculating the PN prescription
Monitoring/complications
Fat
• IV fat emulsion (IVFE) is an important
source of calories and essential fatty
acids
• IVFE is comprised of:
– Soybean oil or a blend of soybean &
safflower oil
– Also includes phospholipids and glycerol
Fat
(continued)
• Safety points:
– For a 3-in-1 PN, lipid concentration should be ≥ 2%
– Provide enough fat to meet essential fatty acid
requirements
• 4% - 6% of total calories
– Avoid too much fat
• Generally restrict to ~ 1 g/kg
• Some give 20% - 30% of total calories as fat
• Maximum 2.5 g/kg
Boullata JI et al. A.S.P.E.N. clinical guidelines: parenteral nutrition ordering, order review, compounding, labeling,
and dispensing. JPEN 2014
Mirtallo J et al. Safe practices for parenteral nutrition. JPEN. 2004
Comparison of IV Fat Emulsions
Concentration
10%
20%
30%
kcal/mL
Fat g/L (9.3 kcal/g)
Phospholipid g/L (6 kcal/g)
1.1
100
12
2
200
12
2.9
300
12
Glycerol g/L (4.2 kcal/g)
22.5
22.5
17
Example:
250 mL 20% IVFE = 500 kcals, 50 g fat, 3 g phospholipid, 5.625 g
glycerol
Parenteral fat does NOT provide 10 kcal/gram!!!!
Fat
(continued)
• Monitor triglycerides to assess lipid
clearance
– Pancreatitis may occur with TG > 500 mg/dL
– Hold IVFE if TG > 400 mg/dL
• Other possible complications
– Hypersensitivity reaction
• Fever, chills, chest or back pain, dyspnea,
cyanosis
– True allergic reaction
• Hives, anaphylaxis
Overview
•
•
•
•
•
•
•
•
•
•
Deciding who needs parenteral nutrition
Peripheral vs. central parenteral nutrition
Nutrition assessment
Protein
Carbohydrate
Fat
Fluid requirements
Additives
Calculating the PN prescription
Monitoring/complications
Fluid
• There are many ways to estimate
maintenance fluid needs:
– 1500 mL for the 1st 20 kg, then 20 mL/kg
• For > 65 y.o., decrease to 15 mL/kg
– 1500 mL/m2
– 30-40 mL/kg for an average sized adult
– 30-40 mL/kg age 18-64
– 30 mL/kg age 55-65
– 25 mL/kg > age 65
– RDA = 1 mL/kcal
Fluid
Safety point: too much or too little fluid may
harm your patient!
• Risk of dehydration:
– Severe diarrhea
– Fistula
– Gastrostomy tube for
obstructed patients
– Vomiting
• Risk of volume overload
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CHF
ESRD
ESLD/ascites
Anasarca
Monitoring Fluid Status
• In the hospital:
– Input/output
– Weight
– Blood pressure
– Orthostatics
• Check BP supine, seated, standing
– Physical exam
– Labs: sodium, BUN:creatinine ratio
Monitoring Fluid Status
• At home:
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Frequency of urination, color of urine
Output from ostomy, fistula, or tubes
Presence/absence of thirst, perspiration
Fevers?
Ask about orthostatics
• “Are you dizzy when you stand up?”
– Weight trend
– Virtual physical exam
• “Are your ankles puffy?”
– Labs: sodium, BUN:creatinine ratio
Pitting edema
From: http://medicine.ucsd.edu/Clinicalimg/extremities-massive-edema.html, accessed 4/30/07
Assessing skin turgor
From: http://www.nlm.nih.gov/medlineplus/ency/imagepages/17223.htm, accessed 4/30/07
Overview
•
•
•
•
•
•
•
•
•
•
Deciding who needs parenteral nutrition
Peripheral vs. central parenteral nutrition
Nutrition assessment
Protein
Carbohydrate
Fat
Fluid requirements
Additives
Calculating the PN prescription
Monitoring/complications
PN Additives
• Electrolytes
• 10 mL MVI-13 daily
– Can add additional vitamins separately if
necessary
• Trace elements
– Can add additional trace elements
separately if necessary
• Carnitine
• Medications
Electrolytes in PN
Mirtallo J et al. Safe practices for parenteral nutrition. JPEN. 2004
Electrolytes in PN
Additive
Usual
Amt
Modified
Amount
Condition
Na (mEq/L)
60-80
30-40
120-140
Renal or liver failure
Na deficit (diarrhea)
K (mEq/L)
40-60
0-20
Renal failure,
hyperkalemia
Excess losses or
increased needs
60-120
Chloride*
(mEq/L)
60-80
30-40
120-140
Metabolic alkalosis
Cl deficit (gastric)
Acetate*
(mEq/L)
20-40
100-120
Metabolic acidosis,
chronic diarrhea
*Adjust to maintain acid/base balance
Electrolytes in PN
Additive
Phosphate
(mMol/L)
Usual
Modified Condition
Amount Amount
10-20
0-5
Renal failure
30-40
Malnutrition
Magnesium 8-16
(mEq/L)
0-8
24-32
Renal failure
Excess losses
(diarrhea)
Calcium
(mEq/L)
0
12.5-15
Hypercalcemia
Low iCa;
osteoporosis
5-10
What forms of electrolytes do we use?
• Sodium chloride
• Sodium acetate
• Sodium phosphate
– Each 3 mMol NaPhos=3 mMol phos & 4 mEq Na
• Potassium chloride
• Potassium acetate
• Potassium phosphate
– Each 3 mMol KPhos=3 mMol phos & 4.4 mEq K
• Magnesium sulfate
• Calcium gluconate
Ordering Electrolytes in PN
Ayers P et al. A.S.P.E.N. Parenteral Nutrition Safety Consensus Recommendations. JPEN 2014
Order Snapshot
Ayers P et al. A.S.P.E.N. Parenteral Nutrition Safety Consensus Recommendations. JPEN 2014
Electrolytes in PN
• Not all institutions follow this process yet
– Order “per bag/day” vs. “per liter”
– Order single electrolytes vs. salts
• There will be a learning curve depending
on the current institution’s practice
– Ordering based on salts vs. individual electrolytes
– Improved knowledge of compatibilities
• Working with the nutrition support pharmacist is
essential to do this safely!
Parenteral Vitamins
Mirtallo J et al. Safe practices for parenteral nutrition. JPEN. 2004
Parenteral Trace Elements
Mirtallo J et al. Safe practices for parenteral nutrition. JPEN. 2004
Vitamin/Mineral Monitoring
• For long-term PN patients, check every 6
months
• Copper and manganese are of particular
concern for toxicity
• Zinc deficiency can be an issue for patients
with excessive losses
• Watch iron levels - may need separate iron
repletion
• Yearly DEXA in long-term patients
Other Additives
• Carnitine
– Essential for fat metabolism
– Long-term PN patients are at risk for
deficiency
• Medications
– Insulin
– H2 blockers
– Heparin
– Steroids (hydrocortisone)
Rarely added
Importance of Glucose Control
Blood Sugar
> 200 mg/dL
Impaired leukocyte
phagocytic function
Increased risk
for infection
Target Blood Glucose
• A.S.P.E.N. Clinical Guidelines
A.S.P.E.N. Clinical Guidelines: Nutrition Support of
Adult Patients with Hyperglycemia
McMahon MM et al. JPEN 2013
How to Achieve Glucose Control?
• In the ICU setting
– Often continuous insulin infusion
• Non-ICU
– Generally start with a regular insulin sliding
scale, checking BGs every 6 hours
– Add half to two-thirds of prior day’s insulin to
the PN solution
– Patients with known DM often need insulin
added to PN on day one
– Work with your nutrition support pharmacist or
endocrinologist to determine best way to
achieve glucose control
Glucose Control for Home
• Balance good glucose control with
avoiding hypoglycemia!
• It’s important to think about what is
safe for the patient and work with the
nutrition support pharmacist and
physician to optimize glucose
control
Overview
•
•
•
•
•
•
•
•
•
•
Deciding who needs parenteral nutrition
Peripheral vs. central parenteral nutrition
Nutrition assessment
Protein
Carbohydrate
Fat
Fluid requirements
Additives
Calculating the PN prescription
Monitoring/complications
Putting It All Together…
You need to
figure out how to
fit all of these
components into
your patient’s PN
solution!
Sterile Water
Additives
IVFE
Amino Acids
Dextrose
Writing the PN Prescription
• Now, the fun part!
• This is basically a lot of calculations, so
it’s best done through a case study:
– 55 year old woman with a bowel obstruction
from ovarian cancer
– Plan is for conservative management
– She has a G-tube for decompression & plan is
for nutrition support via PN
Writing the PN Prescription
• Anthropometric:
– Height 66” Weight 52 kg
– IBW 59 kg 88% IBW
• Needs:
– 1600 kcals (~ 31 kcal/kg)
– 80g protein (~ 1.5 g/kg)
– 1800 mL Fluid (35 mL/kg)
UBW 58 kg
~ 90% UBW
Do the Math!
1. Your protein is a known, so calculate
calories from protein:
•
80 grams/day x 4 kcal/gram = 320 kcals
Do the Math!
2. Determine amount of fat you will provide
the patient:
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Let’s give 25% of calories from fat:
1600 kcals x 0.25 = 400 kcals
If we use 20% IVFE, this will give us 40 grams
of fat
400 kcals ÷ 2 kcal/mL = 200 mL
200 mL x 0.2 = 40 grams
Cross check for safety—grams of fat/kg?
40g ÷ 52 kg = 0.77 g/kg so we are ok!
Do the Math!
3. Add up kcals from protein and fat:
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320 + 400 = 720 kcals from protein & fat
So make up the rest of the kcals from dextrose:
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1600 kcals – 720 = 880 kcals for dextrose
880 kcals ÷ 3.4 kcal/g = ~ 260 grams dextrose
Does this exceed her maximum?
Let’s find out by calculating the glucose infusion
rate:
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260 g x 1000 = 260,000 mg
260,000 mg/52 kg/1440 min = ~ 3.5 mg/kg/min
Do the Math!
•
Sometimes I calculate the maximum
glucose infusion rate, so I know what
my maximum is:
– 5 mg x 52 kg x 1440 minutes/day = 374,400
mg dextrose = 374.4 grams
– Ok to round to 374 grams!
The calculations are
done…now what?
• We need to come up with an order
• Let’s look at that snapshot of an
order again
Order Snapshot
Our PN:
AA 80g
Dextrose 260g
IVFE 40g
Volume 1.8 L
Safety check:
80g AA ÷ 1.8L = ~ 44g/L = 4.4 g/dL
260g dex ÷ 1.8L = ~ 144 g/L = 14.4 g/dL
40g fat ÷ 1.8L = ~ 22g/L = 2.2 g/dL
Ayers P et al. A.S.P.E.N. Parenteral Nutrition Safety Consensus Recommendations. JPEN 2014
But…what about the additives?
• Depending on where you work, the RDs may
or may not make the final recommendations
for all of the electrolytes.
• This often depends on experience with
making electrolyte adjustments in TPN.
• Do not hesitate to consult the pharmacy
and/or the medical/surgical team for
assistance!
• But here’s what I’d do in this case:
First, I’d review the labs:
Lab
Value
Normal Range
Na
138
136-142 mMol/L
K
3.6
3.5-5 mMol/L
Cl
95
98-108 mMol/L
CO2
32
23-32 mMol/L
BUN
18
9-25 mg/dL
Creatinine
0.6
0.7-1.3 mg/dL
BUN:Cr
30
< 20
Random Glucose
98
54-118 mg/dL
Calcium
9.0
8.8-10.5 mg/dL
Magnesium
1.8
1.8-2.5 mEq/L
Phosphorus
2.7
2.5-4.5 mg/dL
Triglycerides
77
35-150 mg/dL
Then I’d come up with a “starter” order
Amino Acids
Dextrose
IVFE
40g
100 g
20g
Sodium phosphate
20 mMol
Sodium chloride
60 mEq
Sodium acetate
0 mEq
Potassium phosphate
0 mEq
Potassium chloride
40 mEq
Potassium acetate
0 mEq
Magnesium sulfate
10 mEq
Calcium gluconate
10 mEq
Total volume
•Start with the
lower end of the
normal range for
additives
•Add more chloride
than acetate to
offset losses
•Give high end of
magnesium and
phos
1 liter
Daily additives: 10 mL MVI-13, 1 mL MTE-5
How would I initiate & advance the
PN?
• I typically take 3 days to get to the goal,
depending on the patient and the amount of
dextrose in the solution
– Day 1: start with 1 liter of the solution
– Day 2: increase to 1.4 liters and adjust
macronutrients to get 2/3 of the way to goal
– Day 3: increase to the goal
– Start with no more than 100-150 g dextrose in the
first day, but could start with more dextrose
depending on prior IVF
What if the patient is getting ready to
go home? How do I “cycle” the PN?
• First, what’s cycling?
– Infusing only part of the day (typically over night)
to allow the patient time off of the pump
– Important for quality of life!
• Depending on blood glucoses, I might do this
over 2-3 nights:
• Cycle day 1: infuse over 18 hours
• Cycle day 2: infuse over 16 hours
• Cycle day 3: infuse over 12 hours
– Check a finger-stick blood glucose at the midpoint
of the cycle to assess for hyperglycemia
– The PN requires a “ramp-up” and a “ramp-down”
to avoid help avoid hyper/hypoglycemia
EVERYBODY PRACTICE!
Practice Case
• Calculate a goal PN prescription for
this patient:
– 85 kg patient
– Needs 2500 kcals and 128g protein
– You will give 30 mL/kg, which is about
2500 mL/day
Overview
•
•
•
•
•
•
•
•
•
•
Deciding who needs parenteral nutrition
Peripheral vs. central parenteral nutrition
Nutrition assessment
Protein
Carbohydrate
Fat
Fluid requirements
Additives
Calculating the PN prescription
Monitoring/complications
Hospital Monitoring
• Prior to initiating PN, electrolyte imbalances
should be corrected
• Check daily:
– Na, K, Cl, CO2, BUN, Cr, BG, Ca, Mg, Phos
• Check prior to therapy, then weekly
– CBC, LFTs (but in reality, CBC is often daily)
• Monitor TG twice/wk to assess lipid clearance
• Daily weights, strict I/O to monitor fluid balance
• Readiness to transition to enteral or oral diet
Mirtallo J et al. Safe practices for parenteral nutrition. JPEN. 2004
Home Monitoring
• Check weekly:
– Na, K, Cl, CO2, BUN, Cr, BG, Ca, Mg, Phos, LFTs,
triglycerides, CBC with differential
– As the patient stabilizes, transition to every other
week labs, then monthly labs
• Daily weights
• Weekly nursing visit
• Weekly phone call from RD to assess
hydration, overall patient status
– Can decrease RD follow-up calls if pt is very stable
• Vitamin/mineral panel every 6 months
• DEXA scan yearly
Complications Associated with PN
• Metabolic
– Electrolyte imbalance
• Hyper/hypokalemia
• Hyper/hypomagnesemia
• Hyper/hypophosphatemia
– Hyper/hypoglycemia
– Metabolic bone disease
• Gastrointestinal
– Cholestasis
– Fatty liver
– GI atrophy
Complications Associated with PN
(continued)
• Infectious
– Central line associated bloodstream infection
– Central line insertion site infections
• Mechanical
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Arterial laceration
Pneumothorax
Hydrothorax
Air embolism
Nerve injury
Phlebitis (especially if using a PICC)
Venous thrombosis
Venous sclerosis
Conclusions
• PN is a complex therapy
• Reserve for patients with intestinal dysfunction
• Be aware of the complications associated with
PN and be proactive in preventing what you can
• Work closely with your nutrition support
pharmacist to develop a safe PN ordering
process for your institution and individual
patients
• The team approach is an important part of safe
management of PN
Thank you!