Defining Severe Acute Malnutrition (SAM)
In nutritional and medical contexts, SAM is the acronym for Severe Acute Malnutrition. The World Health Organization (WHO) provides clear, standardized diagnostic criteria for identifying SAM, primarily in children aged 6 to 59 months. The diagnosis of SAM is typically confirmed by one or more of the following indicators:
- Low weight-for-height/length: This is measured as a z-score of less than -3 standard deviations (SD) below the median of the WHO Child Growth Standards. This indicates severe wasting.
- Low mid-upper arm circumference (MUAC): A MUAC measurement of less than 115 mm in children aged 6–59 months is a key indicator. The MUAC measurement is especially useful for community-level screening, as it requires only a simple tape measure.
- Bilateral pitting oedema: This is defined as the presence of swelling in both feet. If pressure is applied for a few seconds, a pit remains after the finger is removed. The presence of nutritional oedema is considered a definitive sign of SAM, regardless of anthropometric measurements like weight-for-height.
SAM is distinct from Moderate Acute Malnutrition (MAM) and Chronic Malnutrition (stunting), although they can and often do coexist. It is considered the most severe form of undernutrition and represents a major global public health crisis.
The different types of SAM
SAM presents in several forms, each with characteristic clinical features. The three main types are Marasmus, Kwashiorkor, and Marasmic Kwashiorkor.
Marasmus
This form of SAM results from a severe deficiency in overall energy intake, including calories, protein, and other nutrients. The body's response is to break down its own tissues for energy, leading to a profound loss of muscle mass and subcutaneous fat. Key features of marasmus include:
- Severe wasting: An emaciated, skeletal appearance, often described as an "old man" or "wizened" look due to the loss of facial fat.
- No oedema: There is no fluid retention or swelling.
- Irritability and anxiety: Children are often fretful and appear very unhappy.
- Visible bones: Ribs, chest bones, and other skeletal structures are clearly visible beneath thin, dry skin.
Kwashiorkor
Kwashiorkor was historically attributed to a primary protein deficiency but is now understood to involve a combination of factors, including inadequate protein and micronutrients, oxidative stress, and altered gut microbiota. The hallmark sign is oedema. Kwashiorkor is characterized by:
- Bilateral pitting oedema: Fluid retention causes swelling, which can mask severe wasting and lead to a rounded, plump appearance in some body parts.
- Hair and skin changes: The hair may become thin, brittle, and discolored, often with hyperpigmentation or scaly patches on the skin.
- Enlarged liver: This is often a sign of hepatic steatosis (fatty liver).
- Apathy and fatigue: Children with kwashiorkor are typically lethargic and apathetic, with a poor appetite.
Marasmic Kwashiorkor
This is the most severe form of SAM, where the child presents with clinical features of both marasmus and kwashiorkor. The child has severe wasting but also exhibits bilateral pitting oedema. This combined manifestation indicates a very high risk of complications and mortality.
Causes and risk factors of SAM
SAM is a complex health issue with interconnected causes, as outlined in the UNICEF conceptual framework. The factors are broadly categorized into immediate, underlying, and basic causes:
- Immediate Causes:
- Inadequate dietary intake: Insufficient quantity or quality of food, particularly lacking energy, protein, and micronutrients.
- Infections: Diarrhea, pneumonia, measles, HIV, and intestinal parasites can lead to malnutrition by decreasing appetite, hindering nutrient absorption, and increasing metabolic needs.
- Underlying Causes:
- Household food insecurity: Inadequate access to sufficient, safe, and nutritious food.
- Poor maternal education: A lack of knowledge about optimal infant feeding, sanitation, and hygiene practices can increase a child's risk of malnutrition and infection.
- Lack of clean water and sanitation: Poor hygiene and unsafe drinking water increase the risk of infectious diseases like diarrhea, which exacerbates malnutrition.
- Basic Causes:
- Poverty: The fundamental root cause, limiting access to food, healthcare, and education.
- Social instability: War, civil unrest, and natural disasters can disrupt food systems and displace families, leading to extreme food insecurity.
Diagnosis and treatment of SAM
Diagnostic protocols
The diagnosis of SAM is based on a combination of anthropometric measurements and clinical assessment, as per WHO guidelines. A thorough clinical examination is performed to identify any general danger signs or medical complications. A key part of the assessment is the appetite test, where the child is offered a Ready-to-Use Therapeutic Food (RUTF) to see if they can eat. Children with a good appetite and no complications can be treated as outpatients, while those with a poor appetite or medical issues require inpatient care.
Treatment protocol: The 10-step plan
For inpatient care, the WHO recommends a two-phase, 10-step approach:
Stabilization Phase (First 1-2 days)
- Treat hypoglycemia: Feed the child with glucose or sucrose solution.
- Treat hypothermia: Keep the child warm, especially at night.
- Treat dehydration: Use a special rehydration solution for malnourished children (ReSoMal) and avoid standard IV rehydration unless in shock.
- Correct electrolyte imbalance: Supplement with potassium and magnesium.
- Treat infection: Administer broad-spectrum antibiotics, as infections are often present but masked by malnutrition.
- Correct micronutrient deficiencies: Provide a mix of vitamins and minerals, withholding iron initially due to infection risks.
- Start cautious feeding: Offer small, frequent feeds of low-lactose, high-energy formula (F-75).
Rehabilitation Phase (Days 3-7 to 6 weeks)
- Achieve catch-up growth: Gradually increase feeds using a higher-energy formula (F-100) or RUTF to promote rapid weight gain.
- Provide sensory stimulation and emotional support: This is crucial for overall development.
- Prepare for follow-up: Plan for discharge and continued management.
Community-based management (CMAM)
In the Community-based Management of Acute Malnutrition (CMAM) approach, children with uncomplicated SAM (good appetite, no medical complications) can be treated at home with Ready-to-Use Therapeutic Food (RUTF). RUTF is a nutrient-dense, shelf-stable paste that is safe for consumption without water, reducing infection risk. This approach increases treatment coverage and is highly effective.
Comparison of Kwashiorkor and Marasmus
| Feature | Marasmus | Kwashiorkor |
|---|---|---|
| Primary Deficiency | All macronutrients (calories and protein) | Primarily protein (often with sufficient calories) |
| Appearance | Wasted, emaciated, skeletal, loss of subcutaneous fat | Swollen due to oedema, can appear 'plump' |
| Oedema | Absent | Present (bilateral pitting) |
| Fat and Muscle Loss | Severe loss of both fat and muscle mass | Muscle atrophy, but fat is often preserved due to oedema |
| Mental State | Irritable, alert but anxious | Apathetic, withdrawn, lethargic |
| Appetite | Often a ravenous, hungry appearance | Poor or absent |
| Hair/Skin Changes | Thin, dry skin with sparse hair | Discolored, brittle, or sparse hair; flaky, peeling skin |
| Infections | High susceptibility | High susceptibility, exacerbated by metabolic dysfunction |
Prevention strategies for SAM
Prevention is critical to combating malnutrition. Key strategies include:
- Promoting exclusive breastfeeding for the first six months of life, followed by age-appropriate complementary feeding.
- Improving food security and access to nutritious foods at the household level.
- Improving water, sanitation, and hygiene (WASH) infrastructure and practices to reduce infections.
- Providing micronutrient supplementation for at-risk groups.
- Improving access to healthcare for early disease prevention and treatment.
- Addressing underlying social and economic inequalities, such as poverty and maternal education levels.
- Implementing seasonal blanket feeding programs in chronically food-insecure regions to prevent seasonal spikes in malnutrition.
Conclusion
Severe Acute Malnutrition (SAM) represents the most severe form of undernutrition, posing a significant threat to global child survival and development. By understanding what is SAM in full nutrition, including its distinct forms like marasmus and kwashiorkor, clinicians and public health workers can implement effective diagnosis and treatment strategies. The development of Community-based Management of Acute Malnutrition (CMAM) and Ready-to-Use Therapeutic Foods (RUTF) has revolutionized treatment, making it accessible to many children previously out of reach. Beyond treatment, however, a multi-faceted approach focusing on prevention through improved nutrition, sanitation, and addressing socio-economic disparities is essential to tackle this ongoing public health crisis. For more on global nutritional standards, consult authoritative sources like the World Health Organization (WHO).
