Low Incidence of Aspiration and Subsequent Pneumonia Associated with Emesis and/or Endotracheal Suction of Enteral Formula During Intragastric Feeding and Mechanical Ventilation.

Abstract

Enteral feeding is historically identified as a risk factor for pulmonary aspiration leading to pneumonia and death. Efforts are made to detect aspiration early to help prevent subsequent morbidity and mortality. However, lack of a clear definition of clinically significant aspiration makes it difficult to interpret reported aspiration events. A prospective pilot study was conducted in a medical intensive care unit to determine the incidence of emesis and/or suctioned enteral formula with added blue dye from endotracheal tubes (ETT) and subsequent pneumonia during intragastric feeding and mechanical ventilation. Concurrently, a case series study was performed to determine the adequacy of nutritional intake in this group of patients. Pneumonia was confirmed when at least 3 of the following 5 criteria were met; new infiltrate by chest x-ray within 24 to 48 hours, increased white cell count, change in temperature >2 degrees, increased purulent sputum from ETT, or newly prescribed antibiotic. Energy requirements were calculated from Harris Benedict equations and adequate intake was defined as ≥90% calculated goals. Thirty patients were selected which included 250 tube-feeding days (mean=8±6, range 4–38). Adequate intake was achieved in 72% of patients by day four and maintained in 90 of 138 days (65%) beyond day four (n=24). Incidence rates were determined to be 2% for emesis events and 0.8% for blue dye suctioned from ETT for the 250 tube-feeding days. Criteria for pneumonia was met in only 1 patient, an incidence of 0.4% in 250 days or 3% of patients studied. The low incidence of aspiration and subsequent pneumonia in this group of patients has led us to reevaluate routine recommendations for post-pyloric delivery of enteral formula during mechanical ventilation.