Nutritional Disorders

Summary

Nutritional disorders encompass a spectrum of clinical syndromes caused by inadequate, excessive, or imbalanced nutrient intake. In pediatric practice, anthropometric indicators — weight-for-age, height-for-age, and weight-for-height — are the cornerstone of nutritional assessment, each pointing toward acute versus chronic malnutrition.

Key clinical complications of severe malnutrition — including hypoglycemia, hypothermia, electrolyte derangements, infections, and micronutrient deficiencies — are reviewed alongside a structured diagnostic approach. The management section outlines the WHO 10-step protocol for inpatient care, emphasizing gradual caloric restoration to prevent the potentially fatal Refeeding Syndrome (characterized by hypophosphatemia, hypokalemia, and hypomagnesemia upon rapid nutritional replenishment).

Introduction

• Nutritional Disorders are a group of disorders that refer to clinical syndromes resulting from abnormal nutrition.
• There are several indicators used to assess the nutritional status, including; weight-for-age, height-for-age, weight for height.
• Weight for age is the most commonly used parameter for nutritional status

Weight for Age Classification

• There are several classification systems that use weight for age parameter for the classification of protein deficiency.
• These classification; include: Gomez, Jelliffe, IAP, and wellcome-trust classification systems.
• The most commonly used is; Wellcome-Trust/International Classification.

Weight for Height, and Height for Age Classification

Acute Malnutrition Disorders

• Malnutrition definition: acute deficiency of one or more nutritional elements regardless of the total caloric intake, for example: protein deficiency, vitamin deficiency.
• The WHO, and UNICEF define severe acute malnutrition for children between the ages of 6 months to 60 months, as the following;
  
  1. Weight for height is below 3 standard deviation score of the median WHO growth standards.
  2. Visible severe wasting, Bipedal edema, and Mid upper arm circumference below 115mm.
• There are two main categories for malnutrition disorders:
  1. Kwashiorkor
  2. Marasmus

↳ Kwashiorkor (KWO)

• Definition
  • A malnutrition disorder characterized by acute protein energy deficiency with normal or high caloric intake.
• Etiology
  • Primary Kwashiorkor
    • Inadequate diet that does not cover the protein energy requirements of an otherwise healthy patient
    • It’s the most common etiology worldwide
  • Secondary Kwashiorkor
    • Occurs in the settings of a pathology or disease that causes decreased protein intake, decreased absorption or utilization, increased nutritional losses, or increased energy expenditure.
• Pathophysiology
  • Acute protein deficiency leads to a series of reductive adaptation processes in the several body systems.
  • These changes are less prominent in marasmus compared to kwashiorkor
  • These mechanisms include the following:

    • Pathophysiology
      Cardiovascular System	Degenerative changes in cardiac muscle
      Musculoskeletal System	Degenerative changes in muscle proteins to compensate for the drop in plasma proteins Reduction in bone mass and delayed growth
      Gastrointestinal System	Atrophy of the intestinal villi, with decreased level of enzymes responsible for digestion and absorption
      Hepatobiliary System	Fatty infiltration(steatosis) Atrophy of the pancreatic acini causing steatorrhea
      Central Nervous System	Slow brain tissue atrophy, and decreased cognitive function

• Clinical Features

  • Feature	Etiology	Signs and Symptoms
    Edema/Swelling	Decreased plasma proteins →hypoalbuminemia →decreased oncotic pressure →fluid shift from IVC to EVC Increased ADH →water retention Decreased inactivation of Aldosterone →salt and water retention	Progressive bilateral, pitting edema Starts in the dorsal aspect of both arms and feet, the progress gradually to involve the face (prominent cheeks, moon face)
    Growth Faltering/Retardation	Decreased protein intake cause weight loss masked by edema Length/Height is less likely to be affected	Preserved Subcutaneous fat
    Muscle Wasting	Degenerative changes of the muscle protein to compensate for the low plasma proteins	Decreased mid arm and chest circumference
    Hair changes	Hair changes are due to amino acid tyrosine deficiency and Copper deficiency necessary for melanin synthesis	Dry,brittle, easily epilated hair with progressive lightening of color
    Skin Changes	Vitamins, Fatty acid, and zinc deficiency	Dry scaling skin with hyperpigmentation and desquamations Skin infection
    Gastrointestinal Changes	High carbohydrate diet cause the accumulation of glycogen in the liver Fatty infiltration of the liver due to increased fatty acid synthesis Infectious and non infectious diarrhea Malabsorption	Hepatomegaly with no cirrhosis Abdominal distension Diarrhea
    Hematological Changes	Iron,protein , folic acid, B12 deficiency Prothrombin deficiency	Anemia ranging from microcytic to macrocytic Bleeding tendency
    Vitamin Deficiencies	A,B complex, D, and K	Features discussed in details in Vitamin Deficiencies Lectures
    Behavioral Changes	Decreased production of serotonin, nicotinic acid, and adrenergic neurotransmitters	Apathetic, anorexic, depression, anhedonia

     

    

Marasmus (non edematous Protein Calorie Malnutrition)

• Definition
  • Severe wasting due to nutritional deficiency of both protein, and total caloric intake.
• Etiology

  • Type	Age	Cause
    Primary	6m-24m	Decreased amount/frequency of feeds Prolonged exclusive breast feedings
    Secondary	>24m	Inability to feed due to illness Recurrent gastroenteritis, chronic diarrhea Malabsorption syndromes Chronic infections Prematurity Twins Congenital anomalies Metabolic disorders Child abuse Edncorinopathies Malignancies

• Clinical Features
  • Muscle wasting
    • Degenerative changes of the muscle protein to compensate for the low plasma proteins.
  • Loss of subcutaneous fat
    • Prominent costochondral junctions (false rosaries).
    • Hypothermia <35.5C
  • Scaphoid, distended Abdomen
    • Absence of edema
  • Zinc Deficiency
    • acrodermatitis enteropathica: rash, alopecia, diarrhea, recurrent infections

Complications of Malnutrition Disorders

1. Dehydration
2. Electrolyte Disturbances
3. Recurrent Infections and Septic Shock
4. Hypothermia
5. Heart Failure
6. Failure to Thrive
7. Death

Diagnosis of Malnutrition Disorders

• Rule out primary causes of marasmus.
• If a secondary cause is suspected, laboratory tests and radiological imaging are used to identify the cause.

Management of Acute Severe Malnutrition Disorders

• Treatment generally progresses through three phases: Stabilization phase, Rehabilitation preparation, and Rehabilitation phase.
• The duration of management varies according to severity, and continues until the child’s weight is back to normal levels (6-8 weeks).

Refeeding Syndrome after Acute Malnutrition Treatment

• Definition
  • A life-threatening condition that occurs during the reintroduction of nutrition to individuals after prolonged starvation or severe malnutrition.
  • It is a state of metabolic and electrolyte disturbances, particularly involving shifts in phosphorus, potassium, magnesium, glucose, and fluids.
• Pathophysiology:
  • During the starvation or severe malnutrition Phase
    • The body consumes its own stores of minerals, and nutrients, with decreased insulin secretion.
    • Intracellular minerals (phosphate, potassium, and magnesium) stores are depleted but remain normal in the serum due to the lack of insulin-driven intracellular shift.
  • During the refeeding Phase
    • The rapid, and sudden intake of carbohydrates cause an insulin surge to facilitate glucose metabolism.
    • Insulin release leads to the rapid uptake of glucose, potassium, magnesium, and phosphate into the cells, which lowers their serum levels.
    • These sudden intracellular shifts cause fluid retention, electrolyte imbalances, and an overall systematic dysfunction.
• Clinical Picture
  • The clinical signs and symptoms of refeeding syndrome are variable, but typical begin within 3-5 days of initiating refeeding.
    

    Clinical Features
    Electrolyte Disturbances	Hypophosphatemia: muscle weakness and pain, rhabdomyolysis, respiratory failure. Hypokalemia: Cardiac arrhythmias, muscle weakness and cramps. Hypomagnesemia: tetany, arrhythmias, seizures.
    Cardiovascular manifestations	Arrhythmias (low potassium and magnesium). Congestive heart failure (fluid overload, peripheral edema).
    Respiratory manifestations	Respiratory failure (low phosphate levels can weaken the diaphragm and respiratory muscles).
    Gastrointestinal manifestations	Nausea, vomiting, diarrhea, and abdominal pain.
    Hematological manifestations	Hemolytic anemia ( low phosphate level).
    Neurological manifestations	Confusion, irritability, seizures (low magnesium and phosphate).
• Treatment
  • Correction of Electrolytes with continuous monitoring of levels
  • Fluid and Glucose Management
  • Vitamin Supplementation