An introduction to total parenteral nutrition. This was from a lecture given to medical students, internal medicine residents, and gastroenterology fellows

1. Ed McDonald
THE HITCHHIKER'S GUIDE TO
PARENTERAL NUTRITION (PN)

3. How Do You Determine if PN Is Needed?
How Do You Start PN?
What Do You Put In PN?
What Are Common Complications?
How Do You Monitor Patients On PN?

4. Harvey discovers circulation 1616
IV Glucose administration 1896
IV Saline administration 1831
A Brief History of Parenteral Nutrition
1968 Dudrick- Pt on PN for 6 mos.
1966 Dudrick- Beagles on PN alone
1961 IV Fat Emulsion
Dudrick SJ. Surg Clin North Am. 2011

5. PN as sole nutrition in Beagles
Dudrick SJ. Surg Clin North Am. 2011

7. Significance of Malnutrition
20–62% of hospitalized at risk
• Increased incidence of nosocomial
infections
• Higher rates of surgical complications
• Higher hospital costs
• Increased mortality
• Increased LOS
Malnutrition associations:
Kyle et al. Curr Opin Clin Nutr Metab Care 8:397–402.

8. One
Two
• 5% weight loss in one month
Three
• 10% weight loss in 6 months
Four
• 20% weight loss in 6 months is severe
Nutrition Screening: Quick Rules of Thumb
Alpers et al. Manual of Nutritional Therapeutics. 2008

9. When to Start PN? Nutritional Assessment
History
• Weight Change
• PO intake
• Symptoms
• Functional
Capacity
Physical
Exam
• Edema
• Muscle Wasting
• Fat Loss
Labs
• Acute Phase
Proteins
Screening
Tools:
-SGA
-MNA
-PINI
Mueller, Charles. JPEN J Parenter Enteral Nutr. 2011 Jan

10. Hepatic Proteins as Nutritional Markers
 Transferrin, Albumin,
Prealbumin
 May not reflect nutritional
status
 Albumin ½ life 18-22d
 Pre albumin ½ life 2-4d
 Transferrin ½ 7-10d
 Can be normal in marasmus
INCREASE DECREASE
Volume Depletion Volume Excess
Exogenous
Albumin
Protein Loss
Renal Failure Liver Disease
Iron Deficiency Pregnancy
Etoh Abuse
Malignancy
Trauma/
Inflammation
Furman. J Am Diet Assoc. 2004 Aug

11. Stress Induced Hypo-albuminemia
 FLI-0908-3DC-5N
Stress
Inflammation
↑TNF
↑Eicosenoids
Capillary
Leak
Extravascular
Space
Low Albumin
Furman. J Am Diet Assoc. 2004 Aug

12. Furman. J Am Diet Assoc. 2004 Aug
Stress Induced Hypo-albuminemia
Giltin JD. In: Pick E, Landy M, eds. Lymphokines. 1987.

13. Albumin Level is Still Important
 Meta-analysis (90 cohort studies; 291,433
patients)
 For each 0.1g/dL decline in serum albumin
 Mortality by ↑137%
 Morbidity by 89%,
 Prolonged intensive care unit stay 28%
 Hospital stay 71%
Vincent, JL, et al. Ann Surg. 2003 Mar;237(3):319-34

14. Recognize Intestinal Failure
O’keefe et al. CLINICAL GASTROENTEROLOGY AND HEPATOLOGY 2006;4:6–10
Inability to
maintain
protein energy,
fluid, electrolyte,
or micronutrient
balance
Absorption Loss
Congenital
Surgical Resection
Dysmotility
Obstruction

15. 0 10 20 30 40 50
Crohns
Ischemic Bowel
Motility Disorder
Congenital Bowel disease
Hyperemesis Gravidarum
Chronic Pancreatitis
Radiation Enteritis
Chronic Obstruction
Cystic Fibrosis
Neoplasm
AIDS
Neuromuscular Disease
Other
Registry of Diagnosis 1985-1992 (n= 5481)
The Oley Foundation. Annual Report. 1994

16. Recognize When Not to Start PN
 NFL-0028-2DA-5N
FUNCTIONAL
GUT
Anticipated
Duration
<5 days
End of Life
Inability to
obtain
Venous
Access
Risks> Benefit
PN
Contraindications

17. Impact of Timing of PN Initiation
 ESPEN- 2d after ICU admit
 ASPEN- 7d low cal feeding
 Caeser et al, NEJM
 No difference in mortality
 fewer ICU infections (22.8% vs.
26.2%, P = 0.008)
 lower incidence of cholestasis
(P<0.001)
 a mean cost reduction of $1,600
(P = 0.04).
Casear et al. N Engl J Med 2011;365:506-17.

18. NFL-0003-2DA-4N
Start
Immediately if
Malnourished
And
Unable to Feed
Enterally
Wait ~7 days if
adequately
nourished
NO BENEFIT
OF
1-2 Days
> 90 Days for
Home Medicare
Coverage
KEY POINTS
AND
CAVEATS

19. Weight
Fluid Status
Meds
-steroids
-Insulin
Allergies
-Egg Allergy
Labs
• Lytes
• Trig
• LFTs
• Glucose
Disease
• Cirrhosis
• Dialysis
• Severe
Burns
• Diabetes
Access
• Peripheral
• Central
• Location
How Do You Start PN?

20. Venous Access Devices
Avoid femoral lines
Use smallest caliber
Fewest lumens
Port or Tunneled for
Long-term Access
Vanek et al. Nutr Clin Pract 2002 17: 142

21. 0
10
20
30
40
50
60
70
80
90
100
%Malfunction
Catheter Tip Location above SVC/ RA
Junction (n=141)
Peterson et al. Am J Surg. 1999 Jul;178(1):38-41
Tip Location: SVC or RA for PN

22. Formulating PN
 JHO-0003-3DA-4N
Step 1: Energy and
protein requirements.
Step 2: Macronutrients.
Step 3: Fluid and electrolytes
Step 4: Micronutrients
and additives.

23. Calculating Basal Energy Expenditure: Harris
Benedict Equation
• Most Common method
• Use Dry Weight in Kg
• Use Adjusted Body Wt if Actual
Body Wt/Ideal Body Weight is
>130%
• See supplement for equations

24. Total Energy Expenditure (TEE)
 Varies with Activity and Stress
 Activity Factor
 1.1 Bed Rest
 1.2 Limited to Room
 1.3 Ambulatory
 Stress Factor
 1.1 Post Operative
 1.2 Uncomplicated infection
 1.25 Sepsis
 1.3 Abscess, fistulas, wounds
 Add the fraction of each category for TEE

25. Harris Benedict Limitations
 20% inaccuracy in the
obese/critically ill
 Fluid overload/ascites
 Based of 1919 data
Comparison of Wt, height, BMI: 1919 Harris
Benedict vs. 2002 US population
Women Men
Harris
Benedict
1919
2002
US
Harris
Benedict
1919
2002 US
Avg Ht 5’4’’ 5’4’’ 5’9’’ 5’9’’
Avg Wt
(lbs)
124 164 142 191
Avg BMI 21.5 28 21.7 28

26. Weight Based Energy Expenditure
Semrad et al. Gastrointest Endosc. 2009 Jun;69(7):1351-3

27. MoreAccurate: Indirect Calorimetry

28. Determining Protein Requirements
Protein g/kg/
day
0.8 - 1.0
Normal Adult
1.0 - 1.2
Catabolic
1.2 - 1.5
CKD + HD
1.5 - 2.0
Burns
• Severe Hepatic
Encephalopathy
• Severe Kidney Injury Without
HD
Consider
Protein
Restriction
Semrad et al. Gastrointest Endosc. 2009 Jun;69(7):1351-3

29. Dextrose
• 3.4 kcal/g
• 1.4 g/kg to avoid starvation
• Initial dose should not exceed 200g
Lipids
• 10 kcal/g
• Essential fatty acid deficiency < 2-4% of
total calories
• Do not exceed 1g/kg
Protein
• 4 kcal/g
 Calculate fat and AA cal
then give dex as remaining
 Common distribution
 70–85% as carbohydrate
 15–30% as fat.
Macronutrients
JPEN J Parenter Enteral Nutr. 2002 Jan-Feb;26(1 Suppl):1SA-138SA

30. Lipids: Intravenous Fat Emulsion (IVFE)
Soybean or Safflower oil in US
Pro-inflammatory omega-6 fatty acids
10%, 20%, 30% concentrations
250ml or 500ml bags
Hold if pt on propofol (1.1 kcal/ml)
Do not start if triglycerides >400
JPEN J Parenter Enteral Nutr. 2002 Jan-Feb;26(1 Suppl):1SA-138SA

31. Parenteral Nutrition Fluid
 Based on weight and fluid status.
 30 mL/kg per day if euvolemic
 Minimal of 1 to 1.2 L
 PN not for volume resuscitation
JPEN J Parenter Enteral Nutr. 2002 Jan-Feb;26(1 Suppl):
1SA-138SA

32. Electrolytes
 Try to approximate ¼, ½, 0.9
NS
 Correct deficits with IV
replacement, not PN
 Liver converts acetate to
HCO3
 Remove mag, phos, ca in
CVVH
Semrad et al. Gastrointest Endosc. 2009 Jun;69(7):1351-3

33. Micronutrients and Additives
 Based on 1975 NAG-AMA
guidelines
 Increase zinc in diarrhea or
high output fistulas
 Hold copper and manganese
in liver/biliary disease
 Recognize signs symptoms of
deficiency
Buchman et al. Gastroenterology 2009;137:S1-6

34. Parenteral Nutrition Rate
 Total Volume/24 hours
 Lipid Volume/24 hours in 2:1
solutions
 Cycling- increasing rate to
finish less than 24 hours
 Typically 10 – 12 hours
 PN volume/(cycle goal time –
1 hour)
 No more than 0.5g/kg of
dextrose per hour
Alpers et al. Manual of Nutritional Therapeutics. 2008

35. Formulating PN

36. Peripheral Parenteral Nutrition (PPN)
Risk of thrombophlebitis,
limit osmolarity to < 900
mOSM/L
Always run fat emulsion
w/ PPN
Good veins/ stable
peripheral access
Nutritional needs <1800
kcals per day
• Less than 10 to 14 days
of IV nutrition
• Fluid restriction is not
an issue
Belloni et al n engl j med 364;10

37. Medications compatible with PN
Regular insulin Heparin
Famotidine/
Ranitidine
Octreotide
Metoclopramide IV Dextran Solumedrol
Morphine
sulfate

38. PN IS NOT NATURAL

39. Monitoring Patients on PN
In Hospital
Electrolytes Daily until stable
LFTs Baseline, then
weekly
Accuchecks Every 6 hours
Triglycerides Baseline, then
weekly
Weight 2-3x weekly
Ins and Outs Daily
Adequacy of
nutrition
?
Home PN
CMP Weekly. Monthly,
Quarterly
CBC Monthly, Quarterly
INR Monthly
Trig Monthly
Iron, B12, Folate Q 6 months
Vitamins/minerals A,D,E, Se, Zn,
Mn, Cu,Cr yearly
Essential Fatty
Acid
If deficiency
Suspected
Bone Density Yearly
Semrad et al. Gastrointest Endosc. 2009 Jul;70(1):142-4

40. Catheter
Related Infectious
Metabolic
Parenteral Nutrition Complications

41. How to Discontinue PN
 Risk for hypoglycemia
 No consensus if weaning is needed
 Cut rate in ½ for 1 hour then stop
 Run at ½ rate for 2-4 hours if pt on insulin
 Repeat accuchecks 1 and 4 hours after stopping
 Consider transition with D5 or D10

42. Catheter Related Complications

43. Infectious Complications
 4x higher risk of line infection
compared to other IV fluids
 Infection rates of 0.9, 1.4, and 1.9
per 1000 catheter-days for
tunneled, nontunneled, and PICCs
respectively
 Follow CDC guidelines for CRBSI
Semrad et al. Gastrointest Endosc. 2009 Jun;69(7):1351-3

44. • Excess/ Deficiency1
• Re-feeding Syndrome2
• Metabolic Bone Disease3
• PN Associated Liver
Disease (PNALD)
4
Metabolic Complications

45. Essential Fatty Acid Deficiency
 Linoleic acid / α linolenic acid
 Platelet function, hair loss, poor
wound healing, and scaly skin
 2-4 weeks of fat free PN
 Triene:Tetraene ratio > 0.2 - 0.4
 Cutaneous Safflower oil or oral
MCT/corn oil

46. Parenteral Nutrition Associated Liver Disease
 1st reported in 1971
 Steatosis in adults,
cholestasis in children
 Mechanism, unknown
 Overfeeding
 Nutrient Deficiency (i.e. choline)
 Bacterial Overgrowth w/ altered
bile acid metabolism
Buchman et al. HEPATOLOGY, Vol. 43, No. 1, 2006

47. Buchman et al. HEPATOLOGY, Vol. 43, No. 1, 2006

48. PN Summary
 Use only if enteral nutrition is contraindicated
 Appropriate in pts with intestinal failure
 No benefit of 1-2 days of PN
 Start immediately if malnourished, after 7 days if not
 IV access with smaller lines and fewer lumens
 Catheter tip should be in distal SVC or RA
 Formulating PN entails calculating requirements and dividing
calories between dextrose, protein, and lipids
 Monitor for complications

49. Harris Benedict Equation
• Male = 66 + (13.7 x wt in Kg) +
(5 x ht in cm – (6.8 x age)
• Female = 655 + (9.6 x wt in kg)
+ (1.8 x ht in cm) – (4.7 x age)
Equation For Calculating Osmolarity
of PPN
Osmo = (g dex/L) x 5 + (g AA/L)x10
+ (g lipid/L) x 0.67 + (meq cation/L) x
2