[Artificial nutrition in patients with chronic respiratory insufficiency undergoing surgery].

Denutrition is a common finding in patients with chronic respiratory failure (CRF). Preoperative denutrition increases the risk of nosocomial pneumonia and difficulties in weaning from mechanical ventilation. A preoperative nutritional support may have beneficial effects on respiratory muscles performance. However, prospective studies need to be carried out in patients with CRF to substantiate this hypothesis. Postoperative nutritional support is indicated if weaning from the ventilator is expected to require more than several days, in order to preserve the diaphragmatic function. Lipid-enriched nutrition may have a beneficial effect, when energy supply is high, as the resulting decrease in CO2 production may facilitate the weaning from the ventilator. A beneficial effect of branched-chain amino acid-enriched solutions has not been demonstrated in patients with CRF.