What is Severe Acute Malnutrition (SAM)?
Severe acute malnutrition (SAM) is the most extreme and visible form of undernutrition. It is characterized by severe wasting—a low weight-for-height ratio—or by the presence of bilateral pitting edema, which is swelling caused by fluid retention. SAM primarily affects young children under five and is a major cause of child mortality globally. The condition arises from a sudden, significant deficit in nutrient and energy intake, often combined with repeated infections.
How is Severe Acute Malnutrition Diagnosed?
The World Health Organization (WHO) outlines clear diagnostic criteria for identifying SAM, which are based on anthropometric measurements and clinical signs. These methods allow for timely detection and intervention, even in community-based settings where specialized medical equipment is not readily available.
Diagnostic Criteria
- Weight-for-Height/Length (WHZ): A weight-for-height or weight-for-length z-score of less than -3 standard deviations (SD) below the median of the WHO growth standards is a key indicator. This measure, also known as severe wasting, signifies a child is dangerously thin for their height due to recent, rapid weight loss.
- Mid-Upper Arm Circumference (MUAC): For children aged 6 to 59 months, a MUAC measurement of less than 115 mm is a reliable and independent indicator of SAM. This simple, non-invasive test can be performed by community health workers to screen and identify cases in remote areas.
- Bilateral Pitting Edema: The presence of bilateral pitting edema, or swelling that leaves a pit when pressed, is a definitive clinical sign of SAM. Edema is associated with Kwashiorkor and can be life-threatening, even without severe wasting.
The Two Faces of SAM: Marasmus vs. Kwashiorkor
Historically, SAM was categorized into marasmus, kwashiorkor, and marasmic-kwashiorkor. While modern treatment protocols have merged management approaches, understanding the traditional classifications based on clinical presentation remains relevant.
| Feature | Marasmus | Kwashiorkor |
|---|---|---|
| Primary Cause | Severe overall energy and protein deficiency. | Severe protein deficiency, potentially with adequate caloric intake. |
| Physical Appearance | Extremely thin, skeletal-like body due to severe muscle and fat wasting. | Generalized swelling (bilateral pitting edema), often masking underlying wasting. |
| Edema | Absent. | Present (bilateral pitting edema), starting in the feet and sometimes spreading to the legs, hands, and face. |
| Hair and Skin Changes | Minimal skin and hair changes. Skin is dry and loose. | Dermatosis (skin lesions), hair discoloration, and easy pluckability are common. |
| Behavior | May be irritable but often has a normal appetite. | Listless, apathetic, and poor appetite are frequent signs. |
Causes and Risk Factors
SAM results from a complex interplay of factors, often linked to poverty and food insecurity. Key drivers include:
- Inadequate Dietary Intake: Insufficient access to nutritious foods due to poverty, food shortages, or inappropriate feeding practices is a primary cause.
- Infections: Frequent and recurrent infections, such as diarrhea, pneumonia, or measles, deplete the body's nutrient stores and suppress appetite, creating a vicious cycle of malnutrition and infection.
- Underlying Health Conditions: Chronic diseases like HIV/AIDS or other conditions that impair nutrient absorption and increase metabolic needs contribute to SAM.
- Poor Sanitation and Hygiene: Unsanitary living conditions and a lack of access to clean water increase the risk of infectious diseases that trigger or worsen malnutrition.
The Urgent Need for Treatment
SAM requires immediate and specialized medical care to prevent life-threatening complications like hypoglycemia (low blood sugar), hypothermia (low body temperature), and severe infection. Treatment follows a phased approach, with the initial focus on stabilization and addressing medical emergencies.
The 10-Step Treatment Protocol
The WHO outlines a 10-step protocol for inpatient management of complicated SAM, covering both the initial stabilization phase and the longer-term rehabilitation phase.
- Treat Hypoglycemia: Administer glucose orally or intravenously to correct low blood sugar.
- Treat Hypothermia: Keep the child warm and treat for coexisting infections and hypoglycemia.
- Manage Dehydration: Carefully rehydrate with a low-sodium solution, such as ReSoMal, to avoid fluid overload, especially in cases with edema.
- Correct Electrolyte Imbalance: Supplement potassium and magnesium, which are often deficient, without adding extra salt to food.
- Treat Infections: Give broad-spectrum antibiotics, as malnourished children may not show typical signs of infection.
- Correct Micronutrient Deficiencies: Administer necessary vitamins and minerals, except for iron, which is delayed until the child is recovering.
- Initiate Feeding: Begin with small, frequent feeds of low-lactose, low-osmolality formula (F-75) during stabilization.
- Achieve Catch-Up Growth: Gradually increase feeding with a higher-energy formula (F-100) to promote rapid weight gain during the rehabilitation phase.
- Provide Sensory Stimulation: Engage the child with sensory stimulation and emotional support throughout treatment to aid development.
- Prepare for Follow-up: Prepare caregivers for ongoing follow-up care and continued nutritional support.
Community-Based Management
For children with uncomplicated SAM and a good appetite, community-based management with Ready-to-Use Therapeutic Foods (RUTFs) is highly effective. RUTFs are energy-dense, vitamin-rich pastes that can be safely administered at home without refrigeration. This decentralized approach significantly increases access to treatment and improves recovery rates by preventing complications.
The Long-Term Impact and Prevention
The consequences of SAM extend beyond immediate survival. It can cause irreversible physical and cognitive damage, affecting a child's learning capacity and future productivity. Prevention is crucial and involves improving food security, promoting exclusive breastfeeding for the first six months, ensuring safe water and sanitation, and expanding access to healthcare and immunizations. Addressing the root causes requires multi-sectoral efforts involving economic development, social protection, and health education.
Conclusion
Severe acute malnutrition is a severe form of undernutrition with devastating consequences, particularly for children. Defined by extreme wasting or edema, it demands urgent, multi-faceted treatment that addresses both the immediate medical complications and the underlying nutritional deficiencies. While inpatient care is essential for complex cases, community-based programs using RUTFs have revolutionized treatment accessibility for many. Efforts to combat SAM must focus not only on effective treatment but also on comprehensive prevention strategies that tackle the interconnected issues of poverty, infection, and food insecurity to secure a healthier future for all children.
