NUTRITIONAL ISSUES IN PULMONARY REHABILITATION

Since patients with COPD are at risk for weight loss, assessment of nutritional status is an important feature of a comprehensive management program. Weight gain in malnourished patients improves respiratory muscle performance and functional ability. Further studies are needed to determine whether nutritional intervention can lower the increased mortality and morbidity associated with weight loss. If nutritional supplementation is prescribed for malnourished patients with chronic lung disease (<90% IBW), it is necessary to satisfy energy and nitrogen requirements. Since patients with COPD have increased energy requirements, it is essential to provide sufficient caloric intake. To avoid excess calories with its associated increased carbon dioxide production and increased ventilatory demand, determination of REE by expired gas analysis may be necessary. Data that support the use of diets with altered fat to carbohydrate ratios is not conclusive, and high fat diets may cause loose stools and bloating. Therefore administration of diets with about 50% carbohydrate can be recommended and are well tolerated by patients with COPD and severe airflow limitation. To restore body mass in depleted patients, 200 to 450 mg of nitrogen/kg body weight is appropriate. Since most patients with COPD have normal gastrointestinal function, the composition of the diet can be altered, provided there is adequate protein as a source of nitrogen, fat and carbohydrates as the energy sources, and sufficient electrolytes, trace elements, and vitamins.