Malnutrition: nutritional rehabilitation and monitoring — branching viva

Opening — recognising and grading the malnutrition

The examiner begins: a 16-month-old has lost weight over six weeks, his weight-for-height z-score is minus 3.4 and his MUAC is 108 mm, with no oedema. He is lethargic and refuses food. Talk me through your assessment. [1]

I would recognise this as severe acute malnutrition, because his z-score is below minus three and his MUAC is below 115 mm, either of which defines SAM. The decisive finding is that he refuses food, which means he has lost his appetite and therefore has complicated SAM, so he needs inpatient stabilisation rather than outpatient ready-to-use therapeutic food. I would check a bedside glucose, look for hypothermia and infection, and begin the WHO stabilisation pathway. [1] [3]

Branch A — the feeding phases

How would you feed him, and what is the aim of the first phase? [1]

I would start F-75, the stabilisation formula, which supplies about 75 kcal per 100 mL and is given as small frequent feeds at roughly 100 kcal per kg per day. The deliberate aim of stabilisation is to keep the child safe and correct the acute threats, not to produce weight gain, because the metabolism cannot yet handle catch-up. Once he is stable, hungry and free of complications, I would transition cautiously over a few days and then move to F-100 or ready-to-use therapeutic food at 100 to 200 kcal per kg per day to drive catch-up growth. [1] [8]

Branch B — refeeding syndrome

What is the danger of starting feeds, and how do you prevent it? [4]

The danger is refeeding syndrome. Starvation depletes the intracellular stores of phosphate, potassium and magnesium while the serum levels look normal, and the insulin surge of refeeding pulls those electrolytes back into the cells faster than intake can replace them, so the serum levels fall and can cause arrhythmia and heart failure. I would prevent it by giving thiamine before feeding, starting cautiously, correcting potassium and magnesium, and monitoring phosphate, potassium and magnesium at baseline and at least every twelve hours in the first days. A normal admission phosphate does not make him safe, because the fall happens only after feeding begins. [4] [6]

Branch C — the dehydrated malnourished child

If this child were dehydrated rather than refusing food, how would your fluid choice differ from a normal child? [1]

I would use ReSoMal, the reduced-sodium rehydration solution for malnutrition, rather than standard oral rehydration solution, because the wasted malnourished heart tolerates sodium and fluid poorly and standard solution or a rapid intravenous bolus can precipitate heart failure. I would give about 5 mL per kg every half hour for the first two hours, then continue more slowly and reassess, reserving cautious intravenous fluids for shock. The principle is gentle, low-sodium rehydration under close observation. [1]

Branch D — the pivot to anorexia nervosa

Now a 15-year-old with anorexia nervosa and rapid weight loss is admitted for refeeding. Does the same danger apply, and how does the high-resource approach differ? [5]

The same biology applies, because refeeding syndrome is driven by starvation and the insulin surge regardless of the setting. The difference is in the starting energy: high-resource guidance such as the ASPEN consensus starts at reduced energy for at-risk patients and advances only as phosphate and potassium remain stable, with thiamine given beforehand, whereas the WHO SAM pathway uses cautious F-75 with electrolyte monitoring. Either way the rule is the same: start low, go slow, and watch the electrolytes. [5] [4]

Closing — the safety point

Give me the single monitoring point you would emphasise on the ward round. [3]

I would check the phosphate, potassium and magnesium on admission and again within the first day of feeding, because refeeding syndrome develops silently and a falling phosphate is the earliest biochemical signal. I would give thiamine before the first feed, withhold iron during stabilisation, and watch for fluid overload and heart failure as the feeds become energy-dense. [3] [6]