the hitchhiker’s guide to tpn

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



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


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


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


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


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


•  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

the hitchhiker’s guide to tpn

Health & Medicine

pn nfl

weight loss

parenteral nutrition

pn initiation espen

formulating pn jho

protein energy

dry weight

n step