Specialized Enteral Formulas in Acute and Chronic Pulmonary Disease

Nutritional State and COPD: Effects on Dyspnoea and Exercise Tolerance

Chronic Obstructive Pulmonary Disease (COPD) is a disease that is spreading worldwide and is responsible for a huge number of deaths annually. It is characterized by progressive and often irreversible airflow obstruction, with a heterogeneous clinical manifestation based on disease severity. Along with pulmonary impairment, COPD patients display different grades of malnutrition that can be linked to a worsening of respiratory function and to a negative prognosis. Nutritional impairment seems to be related to a reduced exercise tolerance and to dyspnoea becoming a major determinant in patient-perceived quality of life. Many strategies have been proposed to limit the effects of malnutrition on disease progression, but there are still limited data available to determine which of them is the best option to manage COPD patients. The purpose of this review is to highlight the main aspects of COPD-related malnutrition and to underline the importance of poor nutritional state on muscle energetics, exercise tolerance and dyspnoea.

Nutritional supplementation in patients with chronic obstructive pulmonary disease

Malnutrition in patients with chronic obstructive pulmonary disease (COPD) is associated with cachexia, sarcopenia, and weight loss, and may result in poorer pulmonary function, decreased exercise capacity, and increased risk of exacerbations. Providing nutritional supplementation is an important therapeutic intervention, particularly for severely ill COPD patients with malnutrition. Higher calorie intake through nutritional supplementation significantly increases body weight and muscle strength, and improves quality of life in malnourished COPD patients. Difficulties may be experienced by these COPD patients, who are struggling to breathe and eliminate CO2 from the lungs, resulting in dyspnea, hypercapnia, hypoxia, and respiratory acidosis, which exacerbates muscle loss through oxidative stress and inflammatory responses. To overcome these problems, nutritional supplements should aim to reduce metabolic CO2 production, lower respiratory quotient, and improve lung function. Several studies have shown that high-fat supplements produce less CO2 and have lower respiratory quotient value than high-carbohydrate supplements. In addition, high-fat supplements may be the most efficient means of providing a low-volume, calorie-dense supplement to COPD patients, and may be most beneficial to patients with prolonged mechanical ventilation where hypercapnia and malnutrition are most pronounced. Further studies are required to investigate the optimal nutritional supplements for COPD patients according to their disease severity.

Nutrition management for the patient requiring prolonged mechanical ventilation

Patients requiring prolonged mechanical ventilation are often medically complex and present with a wide range of pulmonary conditions, including neuromuscular diseases, chronic pulmonary diseases, and chronic critical illness. These patients present the nutrition support professional with many challenges. However, accurate nutrition assessment, timely and effective nutrition interventions, and careful monitoring will help patients meet their medical and nutrition goals.