Nutritional management of chronic disease — structured clinical encounter

Task

You have twelve minutes to read this case and prepare, then a structured discussion with the examiner covering the recognition, the assessment, the management, the feeding route and the rationale for treating nutrition as an outcome. [9]

Domain 1 — Recognition and mechanism

The examiner asks you to summarise the key findings and name the dominant mechanism of his malnutrition. [9]

A strong answer names the large ventricular septal defect with pulmonary hypertension as the driver and ties the failure to thrive to increased metabolic demand from the over-circulated heart, compounded by decreased intake as the tachypnoeic, tiring infant cannot take enough volume. The sweating with feeds and the rapid tiring are the bedside markers, and the weight that has fallen across centile lines while the length has held shows an acute energy deficit driven by demand rather than a chronic stunting process. [9]

Domain 2 — Anthropometric assessment

The examiner asks how you formally assess and grade his malnutrition. [1]

The assessment plots the weight, length and body mass index on the appropriate chart and converts them to z-scores, and measures the mid-upper arm circumference as a muscle and fat marker less confounded by any fluid overload than the weight. The Academy of Nutrition and Dietetics and ASPEN consensus diagnoses malnutrition when two or more of six indicators are abnormal, each graded mild, moderate or severe, namely the weight-for-length z-score, the body mass index for age z-score, the length for age z-score, the mid-upper arm circumference z-score, the rate of weight gain and the rate of length gain. His falling weight-for-length and arm circumference, with a normal length, would grade him as acute moderate or severe malnutrition. [1]

Domain 3 — Nutrition management

The examiner asks for the energy target and the feed strategy, and why you would not simply increase the volume. [9]

The energy target is around one hundred and thirty to one hundred and fifty kilocalories per kilogram per day, achieved by fortifying the formula to a higher calorie density with added carbohydrate and fat modules in the same or a smaller volume rather than by increasing the volume, because volume loading worsens the tachypnoea, the sweating and the heart failure, and the tiring infant cannot take the larger volume anyway. Smaller, more frequent fortified feeds that he can manage are the strategy, and the diuretics and the cardiac medication are reviewed for their effect on electrolytes and appetite. [9]

Domain 4 — Feeding route and escalation

The examiner asks when you would use a feeding tube and why you would act early. [10]

A nasogastric tube is used early for bolus or continuous feeds when the oral intake cannot meet the energy target, because the infant who reaches surgical repair well grown has the better perioperative course and the better developmental outcome. Waiting for spontaneous catch-up while the heart works harder and the centiles fall is the wrong strategy, and a gastrostomy is considered for the longer-term cardiac child who cannot sustain oral feeding. The feeding plan is written, calculated against the target, and reviewed at set intervals with a dietitian. [10]

Domain 5 — Nutrition as an outcome

The examiner closes by asking why nutrition is treated as an outcome of congenital heart disease care rather than an afterthought. [9]

Untreated malnutrition in the cardiac infant raises the perioperative risk at surgical repair, impairs wound healing and immune defence, and slows the recovery after intervention, while the well-grown infant has the better operative and developmental course. The faltering centile is therefore a signal to act, not to wait, and the nutrition plan is integrated with the surgical and cardiology pathway so that growth is protected as an outcome equal to the repair itself. [9]