Understanding the Purpose of F-75
F-75 therapeutic milk is a low-protein, low-sodium formula designed specifically for the initial, or stabilization, phase of treating severe acute malnutrition (SAM). Its purpose is not to promote rapid weight gain but to safely restore the patient's metabolic function and correct severe electrolyte imbalances. In severely malnourished children, starting immediately with a high-calorie, high-protein diet (like F-100) can overwhelm the body and lead to refeeding syndrome, a potentially fatal metabolic complication. The World Health Organization (WHO) outlines a phased treatment protocol for SAM, with F-75 being the cornerstone of the first, most delicate phase.
Core Principles of F-75 Calculation
Calculating F-75 involves a two-step process: determining the patient’s overall daily requirement and then accurately preparing the feed from ingredients. The standard daily requirement for F-75 is approximately 130 ml of reconstituted formula per kilogram of body weight per day. For children with severe oedema, this volume is reduced to 100 ml/kg/day to prevent fluid overload.
To calculate the total daily volume of F-75 needed, use this formula:
- Total Daily F-75 (ml) = Patient's Weight (kg) × 130 ml/kg (or 100 ml/kg for oedema)
This total volume is then divided into small, frequent feeds, typically every 2 to 3 hours, especially during the first few days of treatment.
Example Calculation
For a child weighing 8 kg with no oedema:
- Daily F-75 need = 8 kg × 130 ml/kg = 1040 ml per day.
- If fed every 3 hours (8 feeds per day), each feed would be 1040 ml / 8 feeds = 130 ml per feed.
Preparing F-75 from Ingredients
While commercial, pre-packed F-75 powder is available, improvised recipes based on WHO specifications can be prepared in clinical settings with local ingredients. Accurate measuring is critical. The following are standard WHO-approved recipes for producing 1000 ml of F-75.
Recipe Using Dried Skimmed Milk (Powdered)
This recipe does not require cooking, making it suitable for environments without cooking facilities, though the higher osmolarity may affect some children with diarrhoea.
- Ingredients for 1000 ml:
- Dried skimmed milk: 25 g
- Sugar (sucrose): 100 g
- Vegetable oil: 30 g
- Mineral mix (CMV): 20 ml
- Water: Add water to make up a final volume of 1000 ml.
Recipe Using Dried Whole Milk (Powdered)
This recipe also requires no cooking.
- Ingredients for 1000 ml:
- Dried whole milk: 35 g
- Sugar (sucrose): 100 g
- Vegetable oil: 20 g
- Mineral mix (CMV): 20 ml
- Water: Add water to make up a final volume of 1000 ml.
Recipe Using Fresh Cow's Milk (Full-Cream)
This recipe requires cooking due to the addition of cereal flour, which also helps to lower its osmolarity.
- Ingredients for 1000 ml:
- Fresh cow's milk: 300 ml
- Cream (whole) long-life milk: 300 ml
- Sugar (sucrose): 70 g
- Cereal flour (e.g., rice, maize): 35 g
- Vegetable oil: 20 g
- Mineral mix (CMV): 20 ml
- Water: Add water to make up a final volume of 1000 ml.
Comparison of F-75 and F-100
The transition from F-75 to F-100 is a critical step in a patient's recovery from SAM. Understanding the differences between these two therapeutic foods is essential for healthcare providers.
| Feature | F-75 | F-100 |
|---|---|---|
| Energy (kcal/100ml) | 75 | 100 |
| Protein (g/100ml) | 0.9 | 2.9 |
| Primary Goal | Stabilization of metabolic functions, correction of electrolytes | Catch-up growth and weight gain |
| Treatment Phase | Initial/stabilization phase (typically 2-7 days) | Rehabilitation phase |
| Protein Content | Low (5% of total energy) | High (12% of total energy) |
| Sodium Content | Low (0.6 mmol/100ml) | High (1.9 mmol/100ml) |
| Carbohydrate Content | High (64% of total energy) | Modest (35% of total energy in pre-mixed formulas) |
Preparation Guidelines
Accurate and hygienic preparation is paramount to avoid feeding complications. Here are the key steps for preparing F-75 from raw ingredients:
- Boil Water: Use previously boiled water, and allow it to cool to no less than 70°C before adding ingredients. This helps kill bacteria but prevents clumping of the powder.
- Measure Accurately: Use a reliable scale and a 1-litre measuring jug. Measure all powdered and liquid ingredients precisely. For water, add the other ingredients first and then top up the water to the 1000 ml mark to account for volume displacement.
- Mix Thoroughly: Add the oil last and mix it vigorously using a whisk or blender. Ensure the oil is completely emulsified and doesn't separate, which could lead to inconsistent nutrient distribution.
- Cook if Necessary: If using a cereal-based recipe, cook gently for about 4 minutes while stirring continuously. Replace any evaporated water after cooking to ensure the final volume is 1000 ml.
- Cool and Store: Cool the prepared formula to feeding temperature. Reconstituted formula should be used within 2 hours at room temperature or 24 hours if refrigerated.
Important Considerations
Calculating and preparing F-75 must be done under strict medical supervision. The fragile metabolic state of a severely malnourished patient means any error in preparation could be dangerous. The formula is not a substitute for breast milk in infants and should never be given to well-nourished children. Additionally, patients must be closely monitored for signs of refeeding syndrome and overhydration during this initial phase.
Conclusion
Understanding how to calculate F-75 is a fundamental skill for healthcare professionals managing severe acute malnutrition. It requires a precise approach to dosage calculation based on patient weight and careful preparation of the therapeutic formula according to WHO protocols. By prioritizing stabilization with F-75, medical teams can safely navigate the initial phase of treatment, correct underlying metabolic disturbances, and pave the way for successful rehabilitation using higher-energy diets like F-100. This deliberate and cautious nutritional strategy is instrumental in reducing mortality rates among the most vulnerable patients.
For more in-depth information and up-to-date guidelines on the management of severe malnutrition, refer to the World Health Organization's official manuals on the topic.
