[Effects of the nutritional status on the respiratory system]

Mechanically ventilated patients are at high risk for malnutrition, and it is now accepted that nutrition can influence the respiratory function. In particular, malnutrition can adversely affect lung function and the adverse effects of such malnutrition include: decreased ventilatory drive, decreased respiratory muscle function, alterations of lung parenchyma and depressed lung defense mechanisms. Therefore, nutrition support should be considered if a patients has a severe chronic pulmonary disease or an acute respiratory disease. Recent studies showed that malnourished patients have a reduced respiratory muscle strength and that nutritional intervention can return muscle ventilatory function to normal levels. Furthermore, it seems very likely that the ventilatory drive can be influenced by dietary intake of amino acids and glucose. The structure of the pulmonary parenchyma can be affected by starvation and the pulmonary defense mechanisms are depressed in malnourished patients. The incidence of post-operative pneumonia or atelectasis is higher in protein-depleted patients. in comparison with well-nourished patients. In conclusion, the importance of nutrition support in the management of patients with respiratory failure, particularly those mechanically ventilated, is stressed in the paper.