A new approach to defining and diagnosing malnutrition in adult critical illness

This review will highlight a new approach to defining malnutrition syndromes for critically ill adults that incorporates a modern understanding of the contributions of inflammatory response. A systematic approach to nutrition assessment is described to help support diagnosis.

Recent findings suggest that varying degrees of acute or chronic inflammation are key contributing factors in the pathogenesis of malnutrition in the setting of disease or injury. Newly proposed malnutrition syndromes include: 'starvation-associated malnutrition', when there is chronic starvation without inflammation; 'chronic disease-associated malnutrition', when inflammation is chronic and of mild to moderate degree; and 'acute disease or injury-associated malnutrition', when inflammation is acute and of severe degree.

Inflammation and malnutrition have an intimate interplay; the presence of inflammation contributes to the development of malnutrition and often limits the effectiveness of nutritional interventions. In turn, the associated malnutrition may blunt the effectiveness of medical therapies. A new approach to defining and diagnosing malnutrition syndromes can help to guide intervention and expected outcomes.