Low‐frequency positive pressure ventilation with extracorporeal carbon dioxide removal, a new form of respiratory assist, has been applied to 12 patients with terminal respiratory failure, for a cumulative time of 1706 hours (range 27–309). Survival rate was 65% versus an expected 10%. During the procedure, the patients were kept under continuous anesthesia and muscle relaxation.Nutritional support was provided in all but one patient after an initial fasting lag of 13.4 ± 1.8 (SEM) hours, time devoted to bypass connection and subsequent hemodynamic and respiratory equilibration (9% of the total time on bypass).Three patients received only parenteral nutrition, two underwent, from the beginning, mixed, parenteral, and enteral nutrition, whereas the other six patients switched from parenteral to mixed treatment during the extracorporeal procedure.Under parenteral nutrition we were careful to refrain from excessive calorie administration and in water intake restriction.Enteral nutrition was administered for an overall time of 860 hours in eight patients, ie, for 62% of the bypass duration, and provided about two‐thirds of the energy and protein intake. It had to be interrupted in four cases for: intolerance to the diet, gastric hypotone due to polyradiculoneuritis, and two episodes of gastric bleeding in septic shock.In our opinion, effective nutritional support can be provided safely to patients acutely and severely ill, undergoing highly invasive and long‐term procedures such as extracorporeal respiratory assist. Moreover, enteral nutrition is generally possible, and well‐tolerated, even if the patients are kept continuously anesthetized and curarized.