Summary of Chapter 16 – Nutrition in Metabolic and Respiratory Stress
The stress response and inflammatory response are nonspecific responses to stressors that cause infection and injury. The stress response is mediated by the catecholamine hormones, cortisol, and glucagon, which together raise nutrient levels in blood, stimulate heart rate, and constrict blood vessels. Aldosterone and antidiuretic hormone help to maintain adequate blood volume. The inflammatory process can also cause systemic effects that alter metabolism, heart rate, blood pressure, body temperature, and immune cell functions.
Severe metabolic stress causes hypermetabolism and negative nitrogen balance and may result in wasting. The nutrition objectives during stress are to provide a diet that can preserve muscle tissue, maintain immune defenses, and promote healing. Energy intake should sustain nitrogen balance but should not result in overfeeding. Protein recommendations are increased to help prevent tissue losses and allow healing of damaged tissue. Enteral and parenteral feedings are sometimes needed to meet the high nutrient requirements of acutely stressed patients.
Chronic obstructive pulmonary disease (COPD) is a debilitating, progressive illness that can lead to malnutrition, muscle wasting, and activity intolerance. Depending on individual needs, the goals of nutrition therapy are to improve food intake, maintain proper weight, preserve muscle mass, and improve exercise endurance. Acute respiratory failure can develop from COPD or arise in persons with no history of lung disease. It often follows acute lung injury due to infection, trauma, or inhalation of toxic substances. Medical nutrition therapy may include nutrition support and fluid restrictions.