Understanding the Two Phases of Malnutrition Treatment
Severe acute malnutrition (SAM) treatment is a carefully managed, two-phase process guided by international health organizations like the World Health Organization (WHO). The initial phase is called the stabilization phase, where the primary focus is on correcting metabolic disturbances and treating life-threatening complications. This phase uses a specific therapeutic milk, F-75. The second phase is the rehabilitation or catch-up phase, which promotes rapid weight gain using a higher-energy formula, F-100, or a ready-to-use therapeutic food (RUTF). The transition between these two phases is a critical clinical decision based on specific signs of patient improvement.
The Stabilisation Phase with F-75
F-75 is a specialized therapeutic milk formulated for the initial, medically fragile stage of SAM. Its lower protein, fat, and sodium content and specific mineral balance are designed to prevent refeeding syndrome, a dangerous metabolic shift that can occur when severely malnourished individuals are fed too aggressively. During this phase, medical staff focuses on:
- Managing dehydration and electrolyte imbalances.
- Treating underlying infections.
- Correcting hypothermia and hypoglycemia.
- Restoring normal metabolism gradually.
The duration of the stabilization phase can vary but typically lasts 2–7 days, depending on the patient's clinical progress. The primary goal is not weight gain but to stabilize the child to a point where their body can tolerate higher levels of nutrients.
Key Clinical Markers for Transitioning
The decision of when to switch from F-75 to F-100 is based on the patient achieving specific clinical milestones that indicate metabolic stability. Health professionals must carefully monitor several key markers:
- Return of appetite: The child should show a clear return of appetite and be able to consistently consume the prescribed amount of F-75 without difficulty. This is a crucial indicator that their gastrointestinal system is recovering.
- Resolution of oedema: If the child has oedematous malnutrition (kwashiorkor), the bilateral pitting oedema should be resolving or be minimal before transitioning. Significant oedema is a sign of metabolic instability.
- Resolution of medical complications: Any life-threatening infections, dehydration, or metabolic issues must be resolved before proceeding to the rehabilitation phase.
- Weight gain (for some protocols): Some protocols, particularly those in research settings, track a specific rate of weight gain on F-75 (e.g., 0.5g per kg/day for three consecutive days) before transitioning to F-100. However, this is not a universal requirement, with clinical signs often taking precedence.
The Transition and Rehabilitation Phase with F-100
Once the clinical markers are met, a gradual transition to F-100 begins. The purpose of this transition is to allow the child's digestive system to adapt to the higher caloric and protein load of the F-100 formula. The WHO recommends a gradual switch over two to three days.
During this transition period, a mix of F-75 and F-100 can be used, with the proportion of F-100 gradually increasing. The overall energy intake is carefully managed to avoid refeeding complications. For example, some protocols start with half the energy from F-100 and the other half from F-75, gradually increasing the F-100 component until it is the sole source.
After a successful transition, the patient moves into the full rehabilitation phase using F-100. This higher-energy formula, with 100 kcal and 2.9 g protein per 100 mL, supports rapid catch-up growth. The feeding volume and frequency are increased, and iron supplementation is initiated once the child starts gaining weight. An alternative to F-100 for the rehabilitation phase is RUTF, which is often used in community-based treatment for its practical benefits.
Comparison of F-75 and F-100
| Feature | F-75 Therapeutic Milk | F-100 Therapeutic Milk |
|---|---|---|
| Phase of Treatment | Initial Stabilisation Phase | Rehabilitation Phase |
| Energy Content | 75 kcal per 100 mL | 100 kcal per 100 mL |
| Protein Content | Lower (approx. 0.9 g per 100 mL) | Higher (approx. 2.9 g per 100 mL) |
| Key Minerals | Lower sodium, balanced electrolytes | Higher sodium, designed for catch-up |
| Purpose | Correct metabolic imbalances, treat complications | Promote rapid weight gain and catch-up growth |
| Duration of Use | Typically 2–7 days | Weeks, until target weight is reached |
| Risk of Refeeding | Minimized due to controlled nutrient load | Higher if introduced prematurely |
Monitoring During Transition
Monitoring is crucial during the transition to F-100. The clinical team must watch for signs of intolerance or complications, which would necessitate reverting to F-75. Key indicators to monitor include:
- Tolerance of feeds: Is the child accepting the new formula without vomiting or excessive diarrhoea?
- Diarrhoea: Excessive watery stools could indicate carbohydrate malabsorption or lactose intolerance, and the child may need to be returned to F-75 or a specialized formula.
- Oedema: Re-accumulation of oedema is a serious sign of metabolic instability.
- Respiratory and pulse rates: Increases in these vital signs can be signs of overhydration or emerging heart failure.
Conclusion
The transition from F-75 to F-100 in malnutrition is not based on a fixed timeline but on a patient's clinical readiness. Key markers include the return of appetite, the resolution of oedema, and the treatment of all acute medical complications. Health professionals must exercise careful judgement and monitor the patient closely during the two-to-three-day transition period to prevent refeeding complications. Successfully navigating this transition is a vital step towards the child's full recovery and catch-up growth. For comprehensive guidelines on the management of severe acute malnutrition, consult resources from the World Health Organization.
