Severe acute malnutrition (SAM) is the most critical and life-threatening form of undernutrition. It develops rapidly due to recent, severe food shortages or illness and is a major public health concern, particularly in low- and middle-income countries. Recognizing and managing SAM effectively can save countless lives and prevent long-term health complications.
What is Severe Acute Malnutrition (SAM)?
SAM is defined by the World Health Organization (WHO) using specific criteria for infants and children. These include:
- Extremely low weight-for-height/length (Wasting): A weight-for-height/length z-score below -3 standard deviations (SD) of the median WHO growth standards.
- Very low Mid-Upper Arm Circumference (MUAC): A MUAC measurement less than 115 mm in children aged 6 to 59 months.
- Bilateral Pitting Edema: The presence of swelling in both feet, caused by fluid retention due to a combination of factors including hypoalbuminemia. Edematous malnutrition was historically known as kwashiorkor.
Historically, SAM was divided into two clinical syndromes, marasmus and kwashiorkor. While the WHO now uses the single term SAM, the distinct clinical presentations still guide treatment strategies.
Causes of Severe Acute Malnutrition
The development of SAM is a complex interplay of immediate and underlying factors. A child's nutritional status is influenced by a range of determinants.
Immediate causes:
- Inadequate Dietary Intake: Insufficient quantity or quality of food, lacking essential energy, protein, vitamins, and minerals.
- Infectious Diseases: Conditions like diarrhea, pneumonia, and measles can deplete the body of nutrients and increase metabolic demands, exacerbating malnutrition. This creates a vicious cycle of malnutrition and infection.
Underlying causes:
- Food Insecurity: Limited access to sufficient, safe, and nutritious food due to poverty, war, natural disasters, or economic instability.
- Poor Sanitation and Hygiene: Unsafe drinking water and poor hygiene practices increase exposure to waterborne pathogens, leading to frequent infections and diarrhea.
- Poor Maternal Health and Education: A mother's own health and educational status can directly impact her child's nutritional outcomes.
- Suboptimal Infant and Young Child Feeding: Lack of exclusive breastfeeding for the first six months, or inappropriate complementary feeding practices after that, can predispose infants to SAM.
Recognizing the Signs and Symptoms of SAM
Recognizing the symptoms of SAM early is critical for effective intervention. The signs can vary depending on the clinical type.
Clinical Presentation of Marasmus vs. Kwashiorkor
| Feature | Marasmus | Kwashiorkor |
|---|---|---|
| Appearance | Emaciated, skeletal, 'old man' face from loss of buccal fat. | Swollen appearance due to edema, particularly in legs, face, and abdomen. |
| Body Composition | Severe muscle wasting and loss of subcutaneous fat. | Muscle wasting may be masked by swelling. |
| Skin & Hair | Dry, thin, and inelastic skin. | Skin changes, including peeling, hyperpigmentation, and sores. Hair can be thin and discolored. |
| Appetite | Often has a normal or increased appetite. | Poor or absent appetite, often irritable and apathetic. |
| Key Danger Signs | Hypothermia, hypoglycemia, shock. | Bilateral pitting edema, apathy, poor appetite. |
Diagnosing and Measuring SAM
Accurate diagnosis relies on a combination of clinical signs and standard anthropometric measurements. Health workers use the following methods:
- Mid-Upper Arm Circumference (MUAC) Tape: A simple colored tape is used to measure the circumference of the upper arm. A reading of less than 115 mm in children 6-59 months indicates SAM.
- Weight-for-Height Z-score: The child's weight is compared to their height and a standardized reference population. A z-score of less than -3 is a key diagnostic criterion.
- Bilateral Pitting Edema: A health worker applies gentle pressure to both feet for a few seconds. If a dent or 'pit' remains, it indicates the presence of edema.
The Management of Severe Acute Malnutrition
The WHO protocol for managing SAM involves two phases: initial stabilization and rehabilitation. Treatment is tailored depending on whether the case is uncomplicated or has medical complications.
1. Stabilization Phase (First 1-2 days):
- Correcting complications such as hypoglycemia, hypothermia, and dehydration.
- Starting broad-spectrum antibiotics to treat infection, as signs of infection may be absent.
- Correcting electrolyte imbalances and providing initial micronutrient supplementation (excluding iron).
- Beginning gradual re-feeding using low-protein, low-lactose therapeutic milks like F-75, given in small, frequent feeds.
2. Rehabilitation Phase (Weeks 2-6):
- Promoting rapid catch-up growth by increasing the amount and density of therapeutic feeds.
- Transitioning from F-75 to higher-energy feeds like F-100 and Ready-to-Use Therapeutic Food (RUTF), such as peanut-based pastes.
- Adding iron supplementation once the child begins to gain weight.
- Providing sensory stimulation and emotional support.
- Community-based management (CMAM) allows for outpatient treatment of uncomplicated cases with RUTF, while complicated cases require inpatient care.
Preventing Severe Acute Malnutrition
Prevention is the most effective long-term strategy against SAM. It requires addressing both immediate and underlying causes.
- Optimal Infant and Young Child Feeding: Exclusive breastfeeding for the first six months, followed by safe and nutritious complementary foods.
- Immunization and Disease Prevention: Providing vaccines, particularly for measles, helps prevent illness that can trigger malnutrition.
- Micronutrient Supplementation: Providing vital vitamins and minerals, especially vitamin A, to at-risk populations.
- Improved Water, Sanitation, and Hygiene (WASH): Access to clean water and sanitary facilities reduces the risk of infectious diseases.
- Poverty Reduction and Food Security Programs: Livelihood support, social protection schemes, and efforts to improve access to diverse foods are essential for addressing the root causes.
Conclusion
What is SAM in nutrition? It is a medical emergency that demands prompt and comprehensive care to prevent death and long-term health consequences. Affecting millions of children globally, it is characterized by severe wasting, edema, and a compromised immune system. The WHO's phased treatment protocol, including the use of therapeutic foods and antibiotics, has proven effective in improving recovery rates. However, lasting success relies on robust prevention strategies that address the systemic issues of poverty, food insecurity, and inadequate sanitation. For more information on the management of severe acute malnutrition, refer to the WHO guidelines on the management of severe acute malnutrition in infants and children.
