35 Nutritional Assessment and Undernutrition

Question 1

Malnutrition

• Malnutrition
• optimized nutrition

Answer 1

• Malnutrition
  
  • includes extremes of both underweight and overweight states.
  • affects > 50% of hospitalized patients (frequently with coexistent chronic illnesses)
  • contributes to significantly longer hospital stays, higher morbidity, and higher mortality rates among both medical and surgical patients
• optimized nutrition
  
  • leads to improved clinical outcomes in patients with both medically- and surgically-treated conditions

Question 2

Protein-energy malnutrition (PEM)

• Protein-energy malnutrition (PEM)
• Other terms used interchangeably with PEM
• (PEM) and PCM are somewhat misleading terms implying that/
• malnutrition is a more general term that encompass

Answer 2

• Protein-energy malnutrition (PEM)
  
  • a form of malnutrition resulting from inadequate and/or inefficient nutrient availability in relation to tissue needs.
• Other terms used interchangeably with PEM are protein-calorie malnutrition (PCM), undernutrition, or simply, malnutrition.
• (PEM) and PCM are somewhat misleading terms implying that the clinical signs and symptoms of malnutrition are due only to energy (calories) and protein deficiencies.
  
  • deficiencies of vitamins, minerals and trace elements are equally important and often occur concurrently with macronutrient deficiencies (rarely with macronutrient excess).
• malnutrition is a more general term that encompass a mismatch of both macro- and/or micronutrient stores compared to physiological needs.

Question 3

Primary vs. Secondary Malnutrition

• Primary malnutrition:
• Secondary malnutrition:

Answer 3

• Primary malnutrition:
  
  • exists when the caloric, vitamin, or mineral content of ingested food is not sufficient to meet the minimum daily need as defined by the Recommended Daily Allowance (RDA).
• Secondary malnutrition:
  
  • occurs when an adequate diet is available and consumed, but the nutrients of the diet are unable to be digested, absorbed or assimilated because of illness.
  • can occur in the context of illnesses that markedly increase nutrient requirements such that even “normal” intake becomes insufficient to meet needs.
  • most common form in the United States, especially in acutely ill, hospitalized patients.

Question 4

Two major patterns of severe malnutrition

• Unstressed starvation
• Stressed starvation

Answer 4

• Unstressed starvation
  
  • generalized primary malnutrition resulting from slow, chronic semi-starvation (ingesting fewer nutrients than is required to meet daily needs) resulting in a severe total caloric deficiency that drives marked loss of body fat and protein stores.
• Stressed starvation
  
  • an acquired, maladaptive state with primary protein deficiency typically seen during severe metabolic stress.
  • common in patients with both acute and chronic illnesses and leads to rapid muscle wasting, micronutrient deficiencies, decubitus ulcers, and life-threatening infections.

Question 5

Common Etiologies of Malnutrition

• Primary malnutrition
• Common causes of secondary undernutrition
  
  • Digestion
  • Absorption
  • Metabolism
  • excretion
  • nutritional requirements

Answer 5

• Primary malnutrition
  
  • the most common form of malnutrition worldwide.
  • common in impoverished children in Third World countries where the increased nutrient needs during growth and development often exceed supply.
  • Other contributors to primary malnutrition include political unrest and displacement, famine, poverty, neglect, and lack of sanitation and infection.
  • also occurs in the United States, often in the context of individuals with ongoing gastrointestinal symptoms (e.g. gastroparesis, dysphagia), impaired deglutition (gingivitis, poor dentition, stroke), cancer-induced anorexia, alcoholism/drug abuse, eating disorders, and those with severe mental illness or dementia
• _Common causes of secondary undernutrition (i.e. malnutrition that occurs despite adequate oral intake) _
  
  • Digestion (cholestasis, disaccharidase deficiency, small bowel bacterial overgrowth, pancreatic insufficiency, cystic fibrosis, radiation enteritis, short bowel syndrome, AIDS, celiac disease, intestinal lymphoma)
  • Absorption (enteritis, short bowel syndrome, tropical sprue, celiac, Whipple’s disease)
  • Metabolism (AIDS, cancer, liver disease, renal disease, corticosteroid use, inborn errors of metabolism)
  • Increased nutrient excretion (diarrhea, protein losing enteropathy)
  • Increased nutritional requirements (burns, chronic infection, chronic lung disease, hyperthyroidism, major surgery, sepsis or trauma).

Question 6

Subjective Nutritional Assessment

Answer 6

• Typical diet, with attention to any medical restriction or self-imposed limits (i.e. low sodium, diabetic diet, vegan, Atkins, Kosher, lactose intolerance, etc.)
• Food allergies
• Use of vitamins/minerals and over-the-counter supplements
• Appetite changes
• Difficulties/barriers to normal intake (i.e. poor fitting dentures, tooth pain, etc.)
• Gastrointestinal symptoms such as dysphagia, abdominal pain, bloating, early satiety, nausea, vomiting or diarrhea
• Living situation / activities of daily living
  
  • elderly patients living alone are at high risk for malnutrition due to loss of independence with restricted mobility, driving, or access to shopping.
  • Nursing home residents with dementia or mental retardation may not be able to communicate or recognize hunger or thirst.

Question 7

Objective Nutritional Assessment

• In the clinical nutritional assessment,
  
  • important to identify/
  • undernutrition can be expected if a patient develops/
• nutritional risk

Answer 7

• In the clinical nutritional assessment,
  
  • important to identify recent changes in dietary intake and/or body weight, new or chronic gastrointestinal symptoms, levels of functional activity and diseases that may affect nutritional status.
  • undernutrition can be expected if a patient develops an unintentional weight loss of > 10% IBW (ideal body weight) within the preceding 3 months, if the patient’s body weight is < 90% of IBW or if the body mass index (BMI = Weight (kilograms) / Height (meters squared)) is < 18.5.
• patients can be placed at high, moderate or low nutritional risk based on either the current % of ideal body weight (IBW), or by using the body mass index (BMI).

Question 8

Objective Nutritional Assessment

• In clinical practice,
  
  • ideal body weight
  • Women
  • Men
• Undernutrition: Severity
  
  • Low
  • Moderate
  • High
  • Incompatible with life
• Weight Categories
  
  • Underweight
  • Normal
  • Overweight
  • Class I obese
  • Class II obese
  • Class III obese

Answer 8

• In clinical practice,
  
  • ideal body weight of an adult is often estimated using a simple calculation that considers only a person’s height and gender:
  • Women: 100 lbs + (# of inches greater than 5 feet in height) x 5 lbs = IBW
  • Men: 110 lbs + (# of inches greater than 5 feet in height) x 6 lbs = IBW
• Undernutrition: Severity
  
  • Low: BW< 90% IBW for HT
  • Moderate: BW< 85% IBW for HT
  • High: BW< 70% IBW for HT
  • Incompatible with life: BW< 60% IBW for HT
• Weight Categories
  
  • Underweight: BMI< 18.5 kg/m²
  • Normal: BMI 18.5 – 24.9 kg/m²
  • Overweight: BMI 25 – 29.9 kg/m²
  • Class I obese: BMI 30 – 34.9 kg/m²
  • Class II obese: BMI 35 – 39.9 kg/m²
  • Class III obese: BMI ≥40 kg/m²

Question 9

Objective Nutritional Assessment (p.5-7+24)

• Physical signs of malnutrition include:
  
  • General
  • Mouth
  • Head/neck
  • Hands
  • Abdomen
  • Skin
• Classic signs of micronutrient deficiency:
  
  • Glossitis
  • Cheilosis/Angular Stomatitis
  • Pellagra (Dermatitis)
  • Koilonychia (Spoon Nails)

Answer 9

• Physical signs of malnutrition include:
  
  • General: obesity (with attention to distribution to thighs/buttocks vs. abdominal), cachexia, or anasarca
  • Mouth: condition of teeth, lips, gums, tongue
  • Head/neck: temporal wasting, visible bony prominences, hair changes
  • Hands: interosseus/thenar/hypothenar muscle wasting, nail bed deformities
  • Abdomen: ascites, adiposity, presence of a gastrostomy/jejunostomy tube
  • Skin: xanthomas, rash, edema
• Classic signs of micronutrient deficiency:
  
  • Glossitis – Thiamine, Niacin, or B12 Deficiency
  • Cheilosis/Angular Stomatitis – Riboflavin and/or Folic Acid Deficiency
  • Pellagra (Dermatitis) - Niacin Deficiency
  • Koilonychia (Spoon Nails) –Severe Iron Deficiency

Question 10

Laboratory data

• Measurement of plasma proteins levels
• The measurement of visceral proteins needs to be taken in a physiological context.
  
  • In a steady state
  • systemic inflammatory states
  • during states of acute systemic inflammatory illness

Answer 10

• Measurement of plasma proteins levels
  
  • an objective method of nutritional assessment of macronutrient status.
  • Serum albumin, prealbumin, transferrin, and retinol binding protein are the most commonly used “visceral” proteins used in nutritional assessment.
  • equally important to assess the status of micronutrients when suspected by the history and/or physical examination.
• The measurement of visceral proteins needs to be taken in a physiological context.
  
  • In a steady state (without significantly active systemic disease), the levels of these proteins can be a useful readout of actual nutritional status.
  • systemic inflammatory states associated with acute illness or trauma rapidly reorient the hepatic synthesis of core visceral proteins due to the impact of circulating inflammatory cytokines.
    
    • Although true malnutrition clearly can occur simultaneously with acute illness, it becomes more difficult to use the absolute value of any one of the circulating visceral proteins as a direct measure of current nutritional state during systemic inflammatory states.
    • measurement of C-reactive protein (CRP) levels is typically integrated into the nutritional assessment as a measure of systemic inflammation.
  • during states of acute systemic inflammatory illness, there is a significant inverse correlation between albumin/prealbumin and CRP levels.
    
    • The trend of these measurements serves as an invaluable tool in assessing both the progression of clinical disease and the underlying nutritional state.

Question 11

Visceral Proteins in Nutritional Assessment:
For each: normal values, half-life, increased in, and decreased in

• Albumin
• Prealbumin (transthyretin)
• Retinol Binding Protein
• Transferrin

Answer 11

• Albumin
  
  • Normal values: 3.5-5.2 g/dl
  • Half-life: 3 weeks
  • Increased: Dehydration
  • Decreased: Chronic malnutrition, Nephrotic syndrome, Severe liver disease, Inflammation/Malignancy, Fluid overload, Pregnancy
• Prealbumin (transthyretin)
  
  • Normal values: 19-43 mg/dl
  • Half-life: 3 days
  • Increased: Dehydration, Renal failure
  • Decreased: Acute and chronic malnutrition, Cancer/Inflammatory response, Fluid overload, Hyperthyroidism, Severe liver injury, Pregnancy
• Retinol Binding Protein
  
  • Normal values: 2.1-6.4 mg/dl
  • Half-life: 12 hours
  • Increased: Renal Failure, Alcoholism
  • Decreased: Acute and Chronic malnutrition, Chronic Liver disorders, Hyperthyroidism, Vitamin A deficiency, Zinc deficiency
• Transferrin
  
  • Normal values: 200-400 mg/dl
  • Half-life: 1 week
  • Increased: Iron deficiency, Estrogens/oral contraceptives, Acute hepatitis, Pregnancy
  • Decreased: Malnutrition, Inflammatory response, Nephrotic syndrome, Marked liver disease

Question 12

Laboratory data

• Serum Albumin:
  
  • Normal levels
  • synthesized by
  • Half-life
  • Negative acute phase reactant
• Prealbumin (transthyretin):
  
  • Normal levels
  • Synthesized in
  • Half-life
  • Negative acute-phase reactant
  • Useful in monitoring
• Other indirect measures of nutritional status:
  
  • BUN
    
    • Normal
    • Reflects
    • Can be elevated in
    • Can be decreased in
  • Creatinine
    
    • Normal
    • In a steady state (euvolemia) and with normal renal function
  • Hemoglobin / Hematocrit:

Answer 12

• Serum Albumin:
  
  • Normal levels 3.5 – 5.2 g/dl
  • synthesized by the liver, and is the most abundant plasma protein, providing 80% of the oncotic pressure
  • Half-life 21 days; therefore albumin is a lagging indicator of poor nutritional status
  • Negative acute phase reactant (decreases rapidly with inflammation)
• Prealbumin (transthyretin):
  
  • Normal levels 19-43 mg/dl
  • Synthesized in the liver
  • Half-life: 2 days; therefore it is generally a good indicator of recent changes in nutritional status (typically measured weekly)
  • Negative acute-phase reactant
  • Useful in monitoring improvements in protein-energy status especially when a baseline value is obtained; increasing values correlate with improved nutritional status
• Other indirect measures of nutritional status:
  
  • BUN:
    
    • Normal 7 – 20 mg/dl
    • Reflects protein breakdown
    • Can be elevated in catabolic state or with high protein intake
    • Can be decreased in low metabolic states or with very low protein intake
  • Creatinine:
    
    • Normal 0.5 – 1.1 mg/dl
    • In a steady state (euvolemia) and with normal renal function, creatinine levels reflect lean muscle mass (higher creatinine with greater lean body mass; creatinine can be nearly undetectable in those with severe cachexia).
  • Hemoglobin / Hematocrit:
    
    • Anemia and mean corpuscular volume (MCV) can be indicative of iron (low MCV), or B12 / folate deficiencies (high MCV)

Question 13

Pathophysiology of Malnutrition / Undernutrition (p.17)

• People lose weight when:
• Body Composition
  
  • The human body stores
  • The remaining fat-free mass (FFM)
  • In addition to body fat, energy reserves are provided by
  • The BCM

Answer 13

• People lose weight when:
  
  • the intake or gastrointestinal assimilation of dietary calories is insufficient to meet normal energy expenditure
  • the expenditure of body energy stores is greater than the energy normally consumed or assimilated
  • the metabolism of energy, protein, and other nutrients is impaired by a disease process
• Body Composition
  
  • The human body stores between 15 and 25% of its energy as fat (generally greater in women than men), which becomes available for metabolism of endogenous fatty acids (FAs) during starvation.
  • The remaining fat-free mass (FFM) is composed of extracellular and intracellular water, the bony skeleton, glycogen and cellular visceral proteins.
  • In addition to body fat, energy reserves are provided by intracellular glycogen and protein, which together with intracellular water constitute the body cell mass (BCM).
  • The BCM, particularly from muscle stores, provides reserve protein for energy production via gluconeogenesis during metabolic stress.

Question 14

Metabolic Responses to Starvation and Stress

• The rate of changes in various fluid compartments and body stores of energy
• unstressed starvation
• stressed starvation

Answer 14

• The rate of changes in various fluid compartments and body stores of energy (fat, glycogen, protein) differs during unstressed starvation and stressed starvation.
• General unstressed starvation slowly decreases the size of all body compartments,
• stressed starvation more specifically reduces BCM (mostly via rapid muscle protein catabolism), increases extracellular water, and has variable effects on body fat.

Question 15

Unstressed Starvation:
Metabolic adaptations to unstressed starvation

• Early starvation (<24 hours):
• Medium-term starvation (days to less than 3 weeks):
• Late starvation (> 3 weeks):

Answer 15

• Early starvation (<24 hours):
  
  • Glycogen stores are used to provide circulating glucose;
  • insulin concentrations decrease as glycogen is depleted;
  • glucagon concentrations increase;
  • amino acids (AAs) are released from muscle for gluconeogenesis;
  • fatty acids (FAs) are released from adipose tissue for additional energy.
• Medium-term starvation (days to less than 3 weeks):
  
  • Glycogen is depleted,
  • glucose is derived solely from gluconeogenesis.
  • Protein breakdown occurs at a high rate to provide substrate for gluconeogenesis.
  • Lipolysis provides the primary energy source (via ketone bodies from FA metabolism).
  • After about one week, the brain can adapt to use both glucose and ketones for energy.
• Late starvation (> 3 weeks):
  
  • Ketone body production (from lipid metabolism) accelerates
  • blood levels of ketone bodies rise, facilitating transfer into brain (which has adapted to use ketones for energy).
  • less need for gluconeogenesis,
  • reduction in the rate of protein breakdown.
  • Hormonal adaptations include: increased levels of growth hormone, TSH, free cortisol, renin, aldosterone, and ADH; decreased levels of glucagon, insulin, LH, FSH, T4, T3, prolactin, IGF-1 (somatomedin C).

Question 16

Unstressed Starvation:
Organ function adaptations to prolonged starvation

• Metabolic/behavioral changes
• Temperature
• Cardiovascular changes
• Renal function changes
• Respiratory function changes
• Gastrointestinal function changes
• Immune system changes
• Changes in body composition

Answer 16

• Metabolic/behavioral changes: decrease in resting energy expenditure (REE) including decreased physical activity
• Hypothermia
• Cardiovascular changes: decreased cardiac output, blood pressure and heart rate
• Renal function changes: decreases in urine output and glomerular filtration rate (GFR)
• Respiratory function changes: decreased ventilation leading to increased risk of infections (pneumonia, bronchitis)
• Gastrointestinal function changes: decreases in enterocyte villus height and brush border enzyme levels (e.g. lactase)
• Immune system changes: decreased delayed cutaneous hypersensitivity (DCH), generalized impaired immune function (increased predisposition to infections)
• Changes in body composition:
  
  • Increased water and sodium (Na+) retention
  • Increased extracellular and decreased intracellular water
  • Decreased total body potassium (K+) and magnesium (Mg++)
  • Decreased total body fat and increased fatty liver (due to increased circulating fatty acids)

Question 17

Stressed Starvation

• Starvation with significant metabolic stress (sepsis, trauma, surgery, burns) results in:
• When untreated, body protein catabolism/

Answer 17

• Starvation with significant metabolic stress (sepsis, trauma, surgery, burns) results in:
  
  • Hypermetabolism – increased basal metabolic rate (BMR)
  • Increased rates of skeletal and visceral proteolysis to provide amino acid substrates for gluconeogenesis, and tissue/wound repair
  • High levels of circulating catecholamines, glucagon, cortisol and cytokines including tumor necrosis factor (TNF) alpha and interleukins 1 and 6
  • Insulin resistance and hyperglycemia
  • Increases in total body extracellular water (edema)
• When untreated, body protein catabolism of up to 240 g/d during an acute illness can deplete 50% of a typical body’s protein stores within 2-3 weeks.

Question 18

Consequences of Malnutrition

Answer 18

• Growth retardation / Delayed puberty
• Amenorrhea
• Reduced IQ
• Decreased physical activity / Reduced work capacity
• Increased risk of infection
• Increased risk of anemia
• Increased operative risk
• Increased length of hospital stay
• Decubitus ulcers / wound dehiscence
• Death / mortality
  
  • Immediate causes are usually infections (pneumonia, local and systemic infections due to gut/skin breakdown), and diarrhea with dehydration or worsening of secondary diseases.
  • Contributing factors are starvation-induced immune deficiency, hypothermia, anemia and other micronutrient deficiencies.
  • Cardiac arrhythmias may result in death.

Question 19

Treatment

• In principle, to treat malnutrition, one must /
  
  • Primary malnutrition
  • When nutrition is provided to previously starved patients
  • refeeding syndrome.
• small amounts of energy (glucose, fat, protein) should be given to undernourished patients for the first few days, accompanied by/
  
  • Water
  • Some malabsorption of enteral nutrients

Answer 19

• In principle, to treat malnutrition, one must provide enough nutrition to replace losses and to initiate and maintain growth and health.
  
  • Primary malnutrition develops slowly and severely malnourished patients are fragile, as their metabolic and hormonal milieu has adapted in order to minimize energy and nutrient losses.
    
    • these patients in particular cannot tolerate a large load of nutrients delivered immediately.
  • When nutrition is provided to previously starved patients, anabolism is quickly induced and a rapid shift of minerals (from extracellular to intracellular compartments) occurs.
    
    • Hypokalemia, hypomagnesemia and hypophosphatemia frequently ensue.
    • The need for vitamins increases and subclinical vitamin deficiencies become apparent (particularly thiamine).
    • Such abnormalities may result in organ failure (heart, lung, cardiac arrhythmias) and/or death if not anticipated and managed carefully.
  • Collectively, this dramatic response to the reintroduction of nutrition after periods of prolonged starvation is known as the refeeding syndrome.
• small amounts of energy (glucose, fat, protein) should be given to undernourished patients for the first few days, accompanied by abundant amounts of potassium (K+), magnesium (Mg2+), phosphate (PO42-), vitamins and trace elements.
  
  • Water is needed to correct dehydration, but excessive amounts of sodium and water should be avoided to decrease the risk of developing congestive heart failure.
  • Some malabsorption of enteral nutrients is anticipated early in refeeding syndrome due to chronic blunting of mucosal villi and decreased expression of enteral digestive enzymes; this typically recovers in several days.

Question 20

Choosing a Mode of Feeding

• preferred route
• trophic effect (i.e. “gut stimulation” effect)
• There are some situations where using the gut is not feasible.

Answer 20

• The oral or enteral route is always the preferred route for nutrition repletion.
• There is inherently a trophic effect (i.e. “gut stimulation” effect) in the gut mucosa when it is exposed to nutrients.
  
  • Thus enteral feeding in of itself is protective and maintains a tight barrier.
  • Gut breakdown during malnutrition leads to bacterial translocation and typically sepsis.
• There are some situations where using the gut is not feasible.
  
  • in intestinal obstruction, gut ischemia, profound ileus (i.e. absence of motility), or gut loss (trauma, multiple bowel resections or gut necrosis) the gut may need to be bypassed.
  • In these cases, nutrition can be given via IV, ultimately as total parenteral nutrition (requires central venous access).

Question 21

Enteral Nutrition (p.40-41)

• If possible
• If oral intake is not feasible
• If oral intake is restricted on a longer term (i.e. 6+ weeks) and more durable enteral access is needed
• Enteral
• Enteral tube feeds
• Comparatively

Answer 21

• If possible, oral intake is best
• If oral intake is not feasible (sedated patient; dysphagia and aspiration risk), then direct infusion of nutrient liquids into the gut can be accomplished via a feeding tube.
  
  • Typical routes include a nasogastric or nasojejunal feeding tube
• If oral intake is restricted on a longer term (i.e. 6+ weeks) and more durable enteral access is needed, typically a gastrostomy tube (PEG – endoscopically placed; or a directly placed, surgically- or interventional radiologically-placed G-tube)
• Enteral is always the preferred route for nutritional delivery (trophic effect of enteral nutrition maintains gut barrier integrity, with benefits in preventing gut bacterial translocation / sepsis)
• Enteral tube feeds are started a slow rates and steadily increased to a goal rate
• Comparatively inexpensive

Question 22

Peripheral / Total Parenteral Nutrition (TPN) (p.43-44)

• Peripheral parenteral nutrition
• Total parenteral nutrition
• Both PPN and TPN
• Multiple chronic complications

Answer 22

• Peripheral parenteral nutrition – a lower osmotic solution (900 Osm or less) with mix of amino acids, dextrose, and lipids + vitamins and mineral salts (can be given via peripheral IV)
• Total parenteral nutrition – a high osmotic solution (>900 Osm) with mix of amino acids, dextrose, and lipid emulsion + vitamins and mineral salts (can ONLY be given via central venous access)
• Both PPN and TPN requires daily monitoring of lab values during initiation
  
  • Very costly
• Multiple chronic complications: central line infections, hepatic steatosis, cholestasis, and bone metabolic complications

Question 23

Calculating Fluid and Caloric Requirements

• In research settings, highly accurate estimates of nutrient requirements can be made using/
• in clinical settings, a few simple empiric formulas are commonly used and this approach comes fairly close to estimating/
• Daily fluid requirements
• Daily total calorie requirements
• Daily total protein requirements
• An additional consideration is given to clinical state – in systemic inflammatory illnesses/

Answer 23

• In research settings, highly accurate estimates of nutrient requirements can be made using complex predictive equation (i.e. Harris-Benedict equation) and/or the use of direct and indirect calorimetry.
• in clinical settings, a few simple empiric formulas are commonly used and this approach comes fairly close to estimating a patient’s true fluid and nutrient needs, both in health and disease.
• Daily fluid requirements – Based on age and IBW
  
  • 16-30 yrs: 40 ml/kg IBW
  • 30-55 yrs: 35 ml/kg IBW
  • 55-75 yrs: 30 ml/kg IBW
  • >75 yrs: 25 ml/kg IBW
• Daily total calorie requirements – Based on BMI category and IBW
  
  • BMI < 25 (normal or underweight) – 25-35 kcal / kg IBW
  • BMI 25-29.9 (overweight) – 20-25 kcal/kg IBW
  • BMI 30-34.9 (obese) – 15-20 kcal / kg IBW
  • BMI 35+ (morbidly obese) – ~15 kcal / kg IBW
• Daily total protein requirements – 1.2–1.5 g/kg IBW
• An additional consideration is given to clinical state – in systemic inflammatory illnesses, the estimated daily protein requirements increase with severity of illness.
  
  • Acute infection (pneumonia, etc.) / Surgery – 1.6-1.8 g/kg IBW
  • Severe trauma / burns – 1.9-2.5 g/kg IBW