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Ed McDonald THE HITCHHIKER'S GUIDE TO PARENTERAL NUTRITION (PN)
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?
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
PN as sole nutrition in Beagles
Dudrick SJ. Surg Clin North Am. 2011
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.
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
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
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
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
Furman. J Am Diet Assoc. 2004 Aug
Stress Induced Hypo-albuminemia
Giltin JD. In: Pick E, Landy M, eds. Lymphokines. 1987.
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
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
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
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
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.
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
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?
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
0 10 20 30 40 50 60 70 80 90
100
% M
alfu
nctio
n
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
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.
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
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
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
Weight Based Energy Expenditure
Semrad et al. Gastrointest Endosc. 2009 Jun;69(7):1351-3
More Accurate: Indirect Calorimetry
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
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
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
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
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
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
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
Formulating PN
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
Medications compatible with PN
Regular insulin Heparin Famotidine/ Ranitidine Octreotide
Metoclopramide IV Dextran Solumedrol Morphine sulfate
PN IS NOT NATURAL
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
Catheter Related Infectious
Metabolic
Parenteral Nutrition Complications
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
Catheter Related Complications
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
• Excess/ Deficiency 1
• Re-feeding Syndrome 2
• Metabolic Bone Disease 3
• PN Associated Liver Disease (PNALD) 4
Metabolic Complications
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
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
Buchman et al. HEPATOLOGY, Vol. 43, No. 1, 2006
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
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