What is the best course of treatment for a 98-year-old patient with severe protein-calorie malnutrition, failure to thrive, and euthyroid sick syndrome, presenting with stable but significantly low weight, and abnormal thyroid function tests?

Management of Severe Protein-Calorie Malnutrition with Euthyroid Sick Syndrome in a 98-Year-Old Long-Term Care Patient

Continue the current supportive nutritional approach with oral supplements, mirtazapine, and comfort-focused care; do not treat the thyroid abnormalities as they represent adaptive euthyroid sick syndrome secondary to severe malnutrition, not primary thyroid disease requiring intervention. 1, 2

Thyroid Management Decision

No thyroid-directed treatment is indicated. The suppressed TSH (0.13 uIU/mL) with normal Free T4 (1.38 ng/dL) and low-normal Free T3 (2.4 pg/mL) represents euthyroid sick syndrome (non-thyroidal illness), which is an adaptive response to severe malnutrition rather than primary hyperthyroidism 3, 4. This pattern is characteristic of protein-calorie malnutrition where defective thyroid iodine concentration occurs but adequate hormone secretion is maintained 5. Thyroid hormone supplementation has never been shown to provide value in euthyroid patients with abnormal thyroid function tests and may indeed be harmful 3.

• The absence of hyperthyroid symptoms (no heat intolerance, tremor, palpitations, or diarrhea) confirms this is not primary thyroid disease 1
• Severe malnutrition itself causes impaired T4 production and thyroid iodine depletion, which can reverse with nutritional repletion 5, 6
• Reassess thyroid function only if hyperthyroid symptoms emerge or if nutritional status substantially improves 1

Primary Nutritional Management Strategy

Target 30 kcal/kg body weight per day with protein intake of 1.2-1.5 g/kg body weight per day. 2 Given the patient's severely low prealbumin (7-8 mg/dL) and chronic weight loss, aggressive nutritional support remains the cornerstone of therapy.

Current Interventions to Continue:

• Oral nutritional supplements (Ensure, Pro-Stat) providing at least 400 kcal/day with 30g or more protein/day 1, 2
• Mirtazapine (current dose) as the first-line pharmacological appetite stimulant for elderly patients with severe protein-calorie malnutrition 1
• Weekly weight monitoring and intake assessment to track response 1
• Texture-modified, enriched foods to facilitate intake given advanced age and cognitive impairment 2

Optimization Strategies:

• Offer small, frequent meals and additional snacks between main meals to increase total daily intake without overwhelming the patient 2
• Create pleasant meal ambience with social interaction during feeding times to stimulate appetite 1, 2
• Provide mealtime assistance given cognitive impairment and variable appetite 2
• Continue structured routine and redirection for behavioral management 1

Critical Monitoring Considerations

Monitor for refeeding syndrome risk, though less likely given gradual nutritional approach already in place. In severely malnourished individuals, monitor phosphate, magnesium, potassium, and thiamine during any intensification of nutritional therapy 2. The patient's stable weight over the past week suggests current intake is preventing further decline but not achieving repletion.

Weekly Assessment Parameters:

• Weight trends (currently stable but significantly below baseline) 1
• Oral intake percentage (currently inconsistent but supplements reliably accepted) 1
• Functional status and quality of life indicators 1
• Electrolyte panels if nutritional support is intensified 2

Addressing Contributing Factors

Optimize management of nutrition-impact symptoms:

• Continue bowel regimen for constipation, as stool burden suppresses appetite 1
• Maintain oxygen therapy for stable hypoxemia to reduce metabolic stress 1
• Continue behavioral strategies for anxiety, which increases metabolic demand 1
• Ensure adequate hydration to support bowel function and overall metabolism 1

Goals of Care Alignment

At 98 years with severe malnutrition, failure to thrive, and family preference against aggressive intervention, focus on comfort-oriented nutrition strategies. 1 The current approach appropriately balances:

• Supportive nutritional interventions without invasive measures (no feeding tube consideration given age, prognosis, and family wishes) 1
• Quality of life prioritization over aggressive nutritional goals 1
• Continued monitoring to prevent acute deterioration while respecting overall trajectory 1

Common Pitfalls to Avoid

Do not initiate thyroid hormone therapy based solely on the low TSH, as this represents adaptive euthyroid sick syndrome that will not respond to treatment and may cause harm 3, 4. Do not use hypoalbuminemia or prealbumin as the sole marker for treatment decisions, as these are affected by inflammation and metabolic stress beyond pure nutritional status 2. Do not implement restrictive diets (low-sodium, diabetic restrictions) that could further limit intake in this severely malnourished patient 2. Do not delay or discontinue current nutritional interventions expecting thyroid treatment to resolve the weight loss 1, 5.

Expected Clinical Course

With continued nutritional support, thyroid function abnormalities may partially improve if nutritional repletion occurs, though complete normalization is unlikely given the patient's age and severity of malnutrition 5, 6. The primary determinant of outcome is nutritional status and intake adequacy, not thyroid function 1. Protein-calorie malnutrition in this context typically shows gradual improvement over months with consistent support, or progressive decline if intake remains inadequate despite interventions 5.