1. Basic Concepts in Clinical Nutrition
Özlem Korkmaz Dilmen
Associate Professor of Anesthesiology and Intensive Care
Cerrahpasa School of Medicine

2. Green CJ. Clin Nutr 1999;18(s):3-28
Types of Malnutrition
Marasmus
Kwashiorkor
Mixed
Because this is a disease with multiple etiologies, the
best terminology would probably be polydeficient
malnutrition.
There are three types of malnutrition.
Chronic malnutrition is a consequence of reducing nutrient intake over an extended period of time. The body undergoes progressive adaptation with a consequent decrease in metabolism in order to protect energy and protein stores. It is a condition known as Marasmus.
Acute malnutrition is generally a consequence of trauma or acute injury. An example is surgery. Energy and protein needs increase rapidly and are independent of the nutritional state. Stress hormones increase, which produces a hypermetabolic state. It is a condition known as Kwashiorkor.
Mixed malnutrition is represented by the patient who has symptoms of chronic malnutrition which are aggravated by a stress event.
Because this is a disease with multiple etiologies, the best terminology would probably be polydeficient malnutrition.
Green CJ. Existence, causes and consequences of disease-related malnutrition in the hospital and the community, and clinical and financial benefits of nutritional intervention. Clin Nutr 1999; 18(s): 3-28.
Green CJ. Clin Nutr 1999;18(s):3-28

3. 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
Malnutrition is clearly recognized as a problem during periods of famine, natural disasters, and wars. It is also frequently seen in underdeveloped nations where food is scarce.
Until the landmark publication of Dr. Charles Butterworth’s 1974 article, it was not generally known that malnutrition could also be found in many modern hospitals in developed countries, where the food supply is not typically limited.
In his report entitled, “The Skeleton in the Hospital Closet,” Dr. Butterworth stated that important parameters such as height and weight were not even recorded in many cases; and weight loss, low serum albumin levels, and neglect of nutritional supplementation, were alarmingly common.
Butterworth CE. Nutr Today 1974; Mar/Apr: 4-8.
“I am convinced that iatrogenic malnutrition has become a significant factor in determining disease outcomes in many patients.”
Butterworth CE. Nutr Today 1974

4. 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.
Since the publication of Dr. Butterworth’s report, other studies have been conducted, with some using the same parameters and others using more complex and sensitive measurements, to assess the degree, prevalence, and risk of malnutrition.
More than 150 studies of hospital malnutrition have been conducted since Though the parameters used in these studies to assess nutritional status differ substantially, the results strongly indicate that between 30% and 50% of hospitalized patients show some evidence of malnutrition, and that nutritional state worsens with length of hospitalization.
Coats KG et al. J Am Diet Assoc 1993;
Coats KG et al. J Am Diet Assoc 1993

5. 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
Despite the high prevalence of malnutrition and its associated complications, physicians may not recognize its existence and the impact it has on patient outcomes.
Roubenoff and colleagues (1987) reported that, prior to nutritional assessment training, only 12.5% of malnourished patients were identified.
After four hours of training, physicians were able to identify 100% of malnourished patients.
Roubenoff R et al. Arch Intern Med 1987; 147:
Roubenoff et al. Arch Intern Med 1987

6. 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
European health providers have studied malnutrition in their patients in This British study assessed nutritional status at hospital admission. The data demonstrate a significant number of patients with malnutrition at the time of admission to the hospital.
McWhirter JP, Pennington CR. Br Med J 1994; 308:
McWhirter et al. Br Med J 1994

7. Prevalence of Malnutrition in Hospitalized Patients
10% Severely Malnourished
21% Moderately
Malnourished
69% Adequate Nutritional State
In 1987, Detsky published a study of 202 patients hospitalized for major gastrointestinal tract surgery. Thirty-one percent of these patients had some degree of malnutrition, and 10% suffered from severe malnutrition.
This suggests that despite medical and technological progress, the prevalence of malnutrition among hospitalized patients is still consistently and significantly present.
These data may be old (1987) but the situation continues to be consistent throughout the world.
Detsky AS et al. JPEN J Parenter Enteral Nutr 1987;
Detsky et al. JPEN 1987

8. Malnutrition and its Consequences
Changes in intestinal barrier
Reduction in glomerular filtration
Alterations in cardiac function
Altered drug pharmacokinetics
Malnutrition interferes with practically all organs.
The intestine is one of the most affected as the intestinal barrier and absorptive, digestive, and immune functions are altered. The colon is also affected by fasting due to the decrease in the ability to absorb water and electrolytes associated with an increase in secretory function. This is one of the possible explanations for diarrhea in severely malnourished patients.
The kidneys of the malnourished patient show a decrease in glomerular filtration.
Cardiac function also decreases in malnourished patients. Malnourished children exhibit delayed growth.
The pharmacokinetics of some drugs, such as gentamycin, are altered because oxidative liver metabolism is decreased in malnourished patients. Malnutrition is also associated with an increase in morbidity and mortality, as we will examine later.
Roediger 1994; Green 1999; Zarowitz 1990
Roediger 1994; Green 1999; Zarowitz 1990

9. 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 is associated with complications, particularly in patients suffering metabolic stress. Their protein requirements are higher than for those without stress. If a patient with metabolic stress is not given adequate nutrition therapy, the body will use its protein stores to supply energy requirements. This will cause a decrease in body mass, a delay in wound healing, compromise in immune function, and increase in mortality.

10. 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.
Studies by Buzby, Hickman, and Klidjian, have shown that malnourished patients may suffer complications 2 to 20 times more frequently than comparable but well-nourished patients.
Buzby et al. Am J Surg 1980; 139: Hickman et al. JPEN J Parenter Enteral Nutr 1980; 4(3): Klidjian et al. JPEN J Parenter Enteral Nutr 1982; 6(2):
Buzby et al. Am J Surg 1980 Hickman et al. JPEN 1980 Klidjian et al. JPEN 1982

11. Malnutrition and Slow Wound Healing
Foot Amputation
86% of well-nourished patients healed without problems
Only 20% of malnourished patients healed successfully
Clinical studies have shown that malnourished patients are more likely to suffer significant physiological problems compared to well-nourished patients.
For example, a study by Dickhaut et al found malnutrition to be associated with delayed wound healing. During postoperative follow-up of foot amputation patients, 86% of those adequately nourished healed successfully while only 20% of the malnourished patients healed well.
Dickhaut SC et al. J Bone Joint Surg Am 1984; 66-A(1):
Dickhaut SC et al. J Bone Joint Surg Am 1984

12. 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 found a similar link between malnutrition and complications. In this study of surgical patients, 42% of those severely malnourished and 9% of those moderately malnourished suffered major complications. Severely malnourished patients are four times more likely to suffer postoperative complications than well-nourished patients
Detsky AS et al. JAMA 1994; 271(1):
Detsky et al. JAMA 1994

13. Risk of Malnutrition – Hospital Costs
(US dollars)
Cost per Patient
With the risk of complications much greater in those with a high likelihood of malnutrition compared to those with a low likelihood, Reilly evaluated whether health care costs were influenced.
Reilly found that the cost of treating pneumonia, bowel surgery, and all complications was significantly higher in those with a high likelihood of malnutrition.
This suggests that, compared to those who are well-nourished, patients with a high likelihood of malnutrition have greater and more costly complications.
Reilly J et al. JPEN J Parenter Enteral Nutr 1988; 12(4):
Pneumonia Intestinal Surgery Complications
Reilly J et al. JPEN 1988

14. 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, on the other hand, is the process of collecting and assessing data about clinical conditions, diet, body composition, and biochemical data, in order to identify patients with poor nutritional status and develop an appropriate nutrition therapy plan.

15. Nutritional Assessment
The diagnosis of nutritional status cannot be made on observation alone. This slide reveals a patient with chronic malnutrition due to the obvious loss of subcutaneous fat and muscle mass. Even with evidence such as this, it is important to conduct the clinical interview and physical exam to make an accurate nutritional diagnosis. A variety of methods can be used to assess nutritional status: clinical assessment, body composition tests, and biochemical data.

16. Nutritional Assessment
Although this patient does not appear to be malnourished, based on the clinical history and clinical data obtained, he was diagnosed with severe malnutrition.
Thus, observation alone is insufficient in performing an accurate nutritional assessment.

17. 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
The first step in the process is to screen patients according to their nutritional risk. Screening tools can be quite simple and quick to administer.
This slide gives an example of nutritional information that the patient can provide, such as body weight changes within a given time frame and amount of oral intake.
Barrocas et al. J Am Diet Assoc 1995;95:
Barrocas et al. J Am Diet Assoc 1995;95:

18. 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
Body composition parameters in nutritional assessment are often measured by anthropometric techniques. Among the most common are:
Weight and height, which can generally be expressed as Body Mass Index (BMI).
Triceps or subscapular skin fold thickness, which is used to measure fat mass.
Mid-arm muscle circumference (MAMC) and mid-arm muscle area (MAMA), used to measure muscle mass.
Some institutions have the technical resources and trained staff to take other measurements, such as bioelectric impedance, underwater weighing, tomography, total-body potassium, and ultrasound.

19. Nutritional Assessment: Biochemical Parameters
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
Several biochemical parameters should be assessed:
Serum albumin, which has a long half-life of 21 days. Values below 3.5 g/dL indicate risk of malnutrition.
Total lymphocyte count. Less than 1,500 cells per cubic millimeter indicates risk of malnutrition.
Serum transferrin, which has a half-life of 7 days. Any patient whose numbers are below 140 mg/dL is at risk.
Serum pre-albumin (transthyretin), with a half-life of 3 days. Numbers below 17 mg/dL indicate risk of malnutrition.
Total iron-binding capacity is normally between 250 and 450 mcg/dL.
Serum cholesterol levels less than 150 mg/dL indicate increased risk.
Heymsfield SB, et al. Nutritional assessment by anthropometric and biochemical methods. In: Modern Nutrition in Health and Disease. Philadelphia, PA: Lea & Febiger; 1994:
Heymsfield SB, et al. In: Modern Nutrition in Health and Disease. Philadelphia, PA: Lea & Febiger;1994:

20. Identification of malnutrition (biochemical parameters)
Serum Proteins
Serum albumine – 19 days
Serum transferrine days
Serum prealbumine days
Ferritin binding protein days
IgA & IgM – 6 days
Serum cholesterol < 150
Total lymphocytes count < mm3

21. Subjective Global Assessment (SGA)
1. Weight changes
2 Changes in dietary intake
3. Gastrointestinal symptoms
4. Functional capacity
5. Link between disease and nutritional requirements
6. Physical exam focused on nutritional aspects
As a clinical assessment tool, the Subjective Global Assessment (SGA) is simple to administer as long as personnel are appropriately trained. Also, clinicians have found the nutritional diagnosis it provides to be an accurate predictor of which patients are at increased risk for developing complications such as infection or poor wound healing.
The SGA elicits information on:
Weight change
Changes in dietary intake
Gastrointestinal symptoms
Functional capacity
Link between illness/disease and nutritional requirements
Physical exam focused on symptoms of nutritional deficiency
Detsky AS et al. JPEN 1987;11:8-15
Detsky AS, et al. JPEN 1987;11:8-15.

22. 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
(+) (-)

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

24. 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
Weight loss questions have less than ideal accuracy in studies. Same story with skin fold thickness or muscle circumference techniques, shown to have 20-30% false positives. Albumin falls too slowly for too many reasons (cirrhosis, nephrosis, burns, infections) and is too prone to shifts between compartments to rely on to detect early malnutrition and levels do not rise until physiologic stressors remit despite nutritional support. Prealbumin is a transport protein for thyroid hormones. It has a 2-3 day half-life. However, it too drops due to infections, cytokines, stress hormones, liver failure etc. It is catabolized in the kidney and rises with renal failure.

25. Nutrients necessary for cell metabolism
Macronutrients
carbohydrate 4 kcal/g
protein 4 kcal/g
fat kcal/g
Micronutrients
Vitamins, minerals
trace elements, water

26. Body Composition

27. Body Mass Index (BW/h2)
14-15 kg/m2 mortality  < > kg/m2 N >30 kg/m2 mortality 

28. Nutritional Deficiency
decrease of food intake
increase of metabolic requirements

29. Nutritional Deficiency
decrease of food intake
oral feeding is restricted/limited
malabsorption
neurogenic & psychogenic disorders

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

31. 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)

32. Total nutritional therapy
Caloric provision (30 kcal/kg)
Carbohydrate %  15 kcal/kg (sol %)
- Protein %  6 kcal/kg (sol %)
Lipid %  9 kcal/kg (sol %)

33. 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
1.20 – 1.40
1.20 – 2.00
1.10 –

34. Metabolic Response to Injury
“Flow” Phase
 Catecholamins
 glucocorticoids
 glucagon
Cytokin release
Release of lipid mediators,
Production of acute phase proteins
“Ebb” Phase (24-48 h)
Aims to maintain Homeostasis
 Cardiac output
 VO2
 blood pressure
 Tissue perfusion
 Body T°
 metabolic rate

35. Metabolic response to Injury/Starvation
injury/illness
Metabolic rate  
Body fuels
conserved
vasted
Body proteins
Urinary Nitrogen
Weight loss
slow
rapid

36. Route of Administration
Enteral
Parenteral
Combined; enteral & parenteral
liver usually retains 75% of aa’s from the gut for gluconeogenesis, protein synth and passes 25% to systemic circulation.
TPN an be life-saving, but it’s hard to know who’ll benefit from TPN, b/c we don’t know exactly when the clinical harm of semi-starvation outweighs the risks of TPN.

37. 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
liver usually retains 75% of aa’s from the gut for gluconeogenesis, protein synth and passes 25% to systemic circulation.
TPN an be life-saving, but it’s hard to know who’ll benefit from TPN, b/c we don’t know exactly when the clinical harm of semi-starvation outweighs the risks of TPN.

38. 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
liver usually retains 75% of aa’s from the gut for gluconeogenesis, protein synth and passes 25% to systemic circulation.
TPN an be life-saving, but it’s hard to know who’ll benefit from TPN, b/c we don’t know exactly when the clinical harm of semi-starvation outweighs the risks of TPN.

39. if the GUT
works
Use it