Malnutrition

Question 1

PEM definition

Answer 1

• Protein energy malnutrition:
  
  • Multi-nutritional deficiency complex in which deficiency of energy is most commonly the outstanding deficit –> if negative energy balance, obligatory negative N balance

Question 2

Causes of malnutrition (environmental and biological)

Answer 2

• Environmental: overcrowded or unsanitary living conditions, agricultural patterns, droughts, floods, wars
• Biological: maternal malnutrition (low birthweight infants), infectious diseases

Question 3

Clinical consequences of malnutrition

Answer 3

• Impaired immune and GI function
• Leads to vicious circles of malnutrition, infection, and diarrhea

Question 4

Energy/substrate metabolism in short term vs. long term starvation

Answer 4

• Short term: gluconeogenesis
• Long term: fatty acid oxidation –> production of ketone bodies

Question 5

Marasmus: definition

Answer 5

• Severe wasting of fat and muscle mass, due primarily to energy deficiency
• Most equivalent to “simple” starvation

Question 6

Marasmus: pathophysiology

Answer 6

• Reduction in energy expenditure –> decreased physical activity, bradycardia, hypothermia
• Decreased activity of sodium pump
• Shift in fuel utilization to mobilization of body fat –> increased ketones, decreased gluconeogenesis
• Muscle protein catabolism - but with increased overall protein turnover
• Decreased inflammatory response and impaired immune function
• Impaired function of GI tract (dysmotility, malabsorption)
• Result: loss of functional reserve, loss of physiological responsiveness to stress

Question 7

Kwashiorkor: definition

Answer 7

• Edematous protein energy malnutrition
• Without wasting
• Due predominantly to protein deficiency and metabolic stress
• Higher mortality than marasmus

Question 8

Kwashiorkor: pathophysiology

Answer 8

• Unknown, but thought to be failure of normal adaptive response of protein sparing usually seen in fasting state
• Contributing factors: infectious stress, cytokine release, relative micronutrient deficiencies, possibly free radical exposure and oxidative damage
• Fat reserves and muscle mass tend to be unaltered

Question 9

Kwashiorkor: signs/symptoms

Answer 9

• Skin lesions (“flaky paint”)
• Hair texture and pigmentation changes (“flag sign”)
• Hypoalbuminemia and enlarged fatty liver –> edema (“moon facies”)
• Increased insulin, decreased lipolysis
• Increased hepatic fatty acid synthesis
• Increased permeability of biological cell membranes –> edema
• Impaired sodium/potassium homeostasis (increased Na+, decreased K+)
• Hypotransferrinemia (anemia)
• Impairment of immune system (increased infection)
• Protein deficiency (especially on a multiple choice test)

Question 10

Marasmic kwashiorkor

Answer 10

• Combination of chronic energy deficiency and chronic or acute protein deficit
• Clinical evidence of both wasting and edema

Question 11

Relationship between age and marasmus/kwashiorkor

Answer 11

• 0-12 mo: marasmus/severe wasting most common form of PEM
  
  • Stunting common < 1 y/o
• 12-24 mo: kwashiorkor/edematous PEM more common
• Older children: stunting common; milder degree of wasting
• Pregnant/lactating women: with PEM, effects are primarily on fetus, neonates, and infants
• Elderly tend to suffer from PEM

Question 12

Physical exam findings associated with marasmus

Answer 12

• Weight loss ++++
• Loss of muscle ++++
• Loss of fat ++++
• Psych impairment ++
• Anorexia +/-
• Associated infections ++
• Diarrhea +++
• Hair changes +/-

NO edema, hepatomegaly, or skin lesions

Question 13

Physical exam findings associated with kwashiorkor

Answer 13

• Weight loss ++
• Loss of muscle +
• Loss of fat +
• Edema ++++
• Psych impairment ++++
• Anorexia ++++
• Hepatomegaly ++
• Associated infections ++++
• Diarrhea ++
• Skin lesions ++
• Hair changes ++

Question 14

General appropriate treatment approaches to PEM

Answer 14

• Go slow
• Resolving life-threatening conditions
• Restoring nutritional status without abruptly disrupting homeostasis
• Ensuring nutritional rehabilitation

Question 15

Resolving life-threatening conditions in PEM

Answer 15

• Enteral feeding preferred
• Avoid overhydration
• K+ and Mg++
• Avoid excessive Na+
• Treatment of infections
  
  • Signs/symptoms may be mild/absent
• Avoid hypoglycemia
  
  • Preferably by small, frequent oral feeds

Question 16

Restoring nutritional status in PEM (without disrupting homeostasis)

Answer 16

• Slow
• Small, frequent (q 4hr) feeds - liquid oral or nasogastric tube
• Initial goal = maintenance protein and energy requirements
  
  • NOT catch-up amounts
• Diet should be high protein, high fat
• Fix micronutrient deficiencies
  
  • K, Mg, P, Zn, Vit A

Question 17

Ensuring nutritional rehabilitation in PEM

Answer 17

• Gradually advance energy intakes to 1.5x normal and 3-4x protein needs
• Usually begins 1-2 weeks after initial stabilization - after resolution of edema
• Restoring appetite may take awhile
  
  • Especially in kwashiorkor
• Familiar foods
• Emotional and physical stimulation/exercise –> cardiorespiratory and skeletal function

Question 18

Metabolic derangements in refeeding syndrome

Answer 18

• Acute shifts form extracellular to intracellular spcaes
• Most common and potentially dangerous: K+, P, Mg++
  
  • Potassium: increased insulin secretion –> intracellular glucose and K+ –> decreased serum K+ –> altered nerve/muscle function
  • Phosphorus: increased insulin secretion –> intracellular P –> intracellular phosphorylated intermediates –> P trapped in intracellular space
  • Magnesium: increased requirements with increased metabolic rate –> co-factor for ATPase
• Any one of these derangements, if severe, can cause sudden death