Basic Concepts in Clinical Nutrition

Özlem Korkmaz Dilmen

Associate Professor of Anesthesiology and Intensive Care

Cerrahpasa School of Medicine

Types of Malnutrition

•Marasmus•Kwashiorkor•Mixed

Because this is a disease with multiple etiologies, the best terminology would probably be polydeficient malnutrition.

Green CJ. Clin Nutr 1999;18(s):3-28

Hospital Malnutrition: Critical Evidence

The Skeleton in the Hospital Closet

• Height not recorded in 56% of cases• Body weight not recorded in 23% of cases• 61% of those whose weight was recorded lost > 6 kg• 37% had albumin < 3.0 g/dL

Butterworth CE. Nutr Today 1974

“I am convinced that iatrogenic malnutrition has become a significant factor in determining disease outcomes in many patients.”

Hospital Malnutrition: Prevalence

Numerous studies on hospital malnutrition have been published.

Prevalence of malnutrition in U.S. hospitals today ranges from 30% to 50%.

Patient’s nutritional status declines with extended hospital stay.

Coats KG et al. J Am Diet Assoc 1993

Malnutrition Among Hospitalized Patients:A Problem of Physician Awareness Up to 50% of hospitalized patients may be malnourished

on admission Before nutritional assessment training:

– Only 12.5% of malnourished patients are identified

After 4 hours of training:– 100% of patients are identified

Roubenoff et al. Arch Intern Med 1987

Prevalence of Malnutrition in Hospitalized Patients

In a published British study: 46% of general medicine patients 45% of patients with respiratory problems 27% of surgical patients 43% of elderly patients

Percentage of malnourished patients at time of admission

McWhirter et al. Br Med J 1994

Prevalence of Malnutrition inHospitalized Patients

69% Adequate Nutritional State

21% ModeratelyMalnourished

10% Severely Malnourished

Detsky et al. JPEN 1987

Malnutrition and its Consequences

Changes in intestinal barrier Reduction in glomerular filtration Alterations in cardiac function Altered drug pharmacokinetics

Roediger 1994; Green 1999; Zarowitz 1990

Malnutrition and its Consequences Loss of weight Slow wound healing Impaired immunity Increase in length of hospital stays Increased treatment costs Increase in mortality

Malnutrition and Increased Complications

Many studies have shown that complications are 2 to 20 times more frequent in malnourished patients than in well-nourished patients.

Buzby et al. Am J Surg 1980Hickman et al. JPEN 1980

Klidjian et al. JPEN 1982

Malnutrition and Slow Wound Healing

Foot Amputation

86% of well-nourished patients healed without problems Only 20% of malnourished patients healed successfully

Dickhaut SC et al. J Bone Joint Surg Am 1984

Malnutrition and Increased Complications

42% of severely malnourished patients suffer major complications

9% of moderately malnourished patients suffer major complications

Severely malnourished patients are four times more likely to suffer postoperative complications than well-nourished patients

Detsky et al. JAMA 1994

Risk of Malnutrition – Hospital Costs

Cost

per

Pati

ent

(US

dolla

rs)

Pneumonia Intestinal Surgery Complications

Reilly J et al. JPEN 1988

Nutritional Assessment

• Collect and evaluate clinical conditions, diet, body composition and biochemical data, among others

• Classify patients by nutritional state: well-nourished or malnourished

Nutritional Assessment

Nutritional Assessment

Nutritional Screening

• Involuntary increase or decrease in weight > 10% of usual weight over 6 months or > 5% of usual weight over 1 month

• Inadequate oral intake

Barrocas et al. J Am Diet Assoc 1995;95:647-648.

Nutritional Assessment: Body Composition Parameters

• Weight and height• BMI = weight / height2

• Triceps or subscapular thickness of skin fold • Mid-arm muscle circumference and mid-arm muscle area

Nutritional Assessment:Biochemical Parameters

Heymsfield SB, et al. In: Modern Nutrition in Health and Disease. Philadelphia, PA: Lea & Febiger;1994:812-841.

At Risk Level• Serum albumin < 3.5 g/dL• Total lymphocyte count < 1500 cell/mm3

• Serum transferrin <140 mg/dL• Serum pre-albumin < 17 mg/dL• Total iron-binding capacity < 250 mcg/dL• Serum cholesterol < 150 mg/dL

Identification of malnutrition(biochemical parameters)

Serum Proteins

Serum albumine 13 – 19 days

Serum transferrine 7.5 days

Serum prealbumine 1.9 days

Ferritin binding protein 2.1 days

IgA & IgM 5 – 6 days

Serum cholesterol < 150

Total lymphocytes count < 1500 mm3

Subjective Global Assessment (SGA)

Detsky AS, et al. JPEN 1987;11:8-15.

1. Weight changes2 Changes in dietary intake3. Gastrointestinal symptoms4. Functional capacity5. Link between disease and nutritional requirements6. Physical exam focused on nutritional aspects

Nitrogen excretion and balance

Urine (urea, amonium, creatinine)

Stool (nonabsorbable proteins)

Dermis (absorbable proteins)

Nasal secr., hair loss, menstruation

N balance = N intake – N loss

(+) (-)

Nutritional Assessment

Every patient should prompt three questions• Does malnutrition exist?• Is malnutrition likely to occur?• When and how to correct the situation?

Does malnutrition exist?

anthropometric changes• loss of SQ fat, muscle wasting, BMI < 14

functional changes• muscle weakness, respiratory effort

lab studies• albumin, transferrin, prealbumin, RBP,

cholesterol, immune function

Nutrients necessary for cell metabolism

Macronutrientscarbohydrate 4 kcal/gprotein 4 kcal/gfat 9 kcal/g

MicronutrientsVitamins, minerals 0 trace elements, water 0

Body Composition

water61%

fat14%

protein17%

mineral7%

carbohydrate1%

Body Mass Index (BW/h2)

14-15 kg/m2 mortality

<18.5 - 25> kg/m2 N

>30 kg/m2 mortality

Nutritional Deficiency

decrease of food intake increase of metabolic requirements

Nutritional Deficiency

decrease of food intake• oral feeding is restricted/limited• malabsorption• neurogenic & psychogenic disorders

Nutritional Deficiency

increase of metabolic requirements - infection, sepsis, critical illness - major trauma - surgery & postoperative period - cancer patients - painful stimuli - elevated body temperature - burns

Methods for determining caloric needs

Resting energy expenditure (REE) (BEE) (Harris-Benedict, Aub-Dubois, Schoefield) kcal x stress factor

Indirect calorimetry (VO2 ; VCO2)

25 – 35 kcal/kg body weight

Diet induced thermogenesis (DEE) fat carbohydrate protein

Activity induced energy expenditure (AEE)

Total nutritional therapy

Caloric provision (30 kcal/kg)

Carbohydrate 50 % 15 kcal/kg (sol. 5 - 50 %)

- Protein 20 % 6 kcal/kg (sol. 3 - 10 %)

Lipid 30 % 9 kcal/kg (sol. 3 - 10 %)

Nutritional requirements

Injury Minor surgery Long bone fracture Cancer Peritonitis / sepsis Severe infect /

trauma MOF syndrome Burns Temperature +1

C°

Stress factor

1.00 – 1.1 1.15 – 1.30 1.10 – 1.30 1.10 – 1.30 1.20 – 1.40 1.20 – 1.40 1.20 – 2.00 1.10 –

Metabolic Response to Injury

“Ebb” Phase (24-48 h)Aims to maintain Homeostasis

• Cardiac output

• VO2

• blood pressure

• Tissue perfusion

• Body T°

• metabolic rate

“Flow” Phase

• Catecholamins

• glucocorticoids

• glucagon

• Cytokin release

• Release of lipid mediators,

• Production of acute phase proteins

Metabolic response to Injury/Starvation

starvation injury/illness

Metabolic rate

Body fuels conserved vasted

Body proteins conserved vasted

Urinary Nitrogen

Weight loss slow rapid

Route of Administration

EnteralParenteralCombined; enteral & parenteral

Route of Administration

Enteral• more physiologic (doesn’t bypass gut mucosa

and liver)• less complicated (supplements, NG tube,

PEG, DHT, naso-jejunal tube)• less costly (especially cyclic, intermittent, or

bolus feeding)• fewer infectious and other complications• better at preserving gut mucosal integrity

and preventing microbial translocation

Route of Administration

Parenteral• use only if you cannot use the gut

bowel surgery bowel obstruction ileus not enough bowel / severe malabsorption no gut access

Use it

if the GUT works