OBJECTIVES:To determine the difference in aspiration rates between gastrically and transpylorically fed patients in the intensive care unit. DESIGN:A prospective controlled study of critically ill patients randomized to receive either a gastrically placed feeding tube or a transpylorically placed feeding tube. SETTING:University teaching hospital's medical intensive care unit. The study was conducted over 14 months. PATIENTS:Fifty-four critically ill subjects (with an overall 40% mortality) with similar baseline age, severity of illness, and nutritional needs requiring enteral nutrition, with 51 completing the study. INTERVENTIONS:All feeds were tagged with technetium-99m radiolabeled sulfur colloid, and the pulmonary secretions or lungs of each patient were scanned on a daily basis to determine whether aspiration had occurred. Patients were fed according to their assigned tube placement which was verified daily by continuous electromyography. MEASUREMENTS AND RESULTS:Of 27 gastrically fed patients 2 (7%) had evidence of scanned feed in pulmonary secretions or the lung, compared to 3 of 24 (13%) transpylorically fed patients (n.s.). Clinical suspicion of aspiration was insensitive and detected only 60% of isotopically documented aspirations with a positive predictive value of 27%. CONCLUSION:There was no difference in aspiration rates between gastrically and transpylorically fed critically ill patients.