THE EFFECTS OF NUTRITIONAL SUPPORT OF CRITICALLY ILL PATIENTS REQUIRING MECHANICAL VENTILATION AS ASSESSED BY V/Q RATIO

This study is looking at how tube feeding affects the lungs of critically ill patients on breathing machines (mechanical ventilators) in intensive care. Specifically, researchers are measuring the ratio of air to blood flow in the lungs (V/Q ratio) to see whether the type or amount of tube feeding affects how well the lungs work. This could help improve nutritional care for ICU patients. You may be eligible if: - You are 18 years or older - You have been admitted to ICU with acute respiratory failure and need a breathing machine for more than 48 hours - You are receiving or about to start tube feeding through the stomach or small bowel - You or your next-of-kin have given consent to participate You may NOT be eligible if: - You have diabetes, kidney failure, or liver failure - You are receiving nutrition through a vein (total parenteral nutrition) - You are not expected to survive more than 24 hours, or are not receiving active medical treatment - You are under 18 years old - You have a condition that prevents tube feeding - You are already enrolled in another study that might affect the results Talk to your doctor about whether this trial might be right for you.