Nutritional Management of Extreme Anorexia Nervosa in the Intensive Care Unit: A Case Report

Abstract

Background: Severe anorexia nervosa (AN) is a life-threatening condition characterized by extreme malnutrition and multisystem complications that may require intensive care management. Nutritional support in these patients is particularly challenging because of the high risk of metabolic instability and refeeding syndrome, especially in individuals with extremely low body mass index (BMI).

Case presentation: We report the case of a 22-year-old woman with severe AN (BMI 9.9 kg/m²) who was admitted to the emergency department with hypoglycemia, dehydration, electrolyte imbalance, and altered consciousness. Imaging revealed pneumomediastinum, pneumothorax, and pneumoperitoneum associated with suspected aspiration pneumonia. Due to clinical deterioration with hypotension and septic shock, the patient was transferred to the intensive care unit (ICU), where she experienced cardiac arrest requiring cardiopulmonary resuscitation, endotracheal intubation, and mechanical ventilation. An exploratory laparotomy was performed because of suspected abdominal perforation, which was not confirmed. Nutritional support was initiated with low-dose parenteral nutrition due to dysphagia and aspiration risk, with proactive supplementation of electrolytes and thiamine to prevent refeeding syndrome. Indirect calorimetry was used to estimate resting energy expenditure and guide the adjustment of caloric and protein intake. Enteral nutrition was progressively introduced via nasogastric tube during the ICU stay.

Discussion: This case illustrates the complexity of managing extreme AN in a critical care setting, where nutritional therapy must balance the risk of refeeding syndrome with the need to prevent underfeeding. The use of indirect calorimetry supported individualized nutritional management in a patient with severe metabolic instability.

Conclusions: Although conclusions from a single case are limited, this report highlights the potential role of individualized nutritional assessment, cautious progression of refeeding, and multidisciplinary collaboration in supporting the stabilization of patients with extreme AN requiring intensive care.