A spoonful of sugar--improving the sensitivity of the glucose oxidase test strip method for detecting subclinical pulmonary aspiration of enteral feed.

A 74-year-old woman was admitted to the intensive care unit (ICU) with respiratory failure. Following intubation and mechanical ventilation, nasogastric enteral feeding was begun. The sensitivity of the glucose oxidase strip method for detecting aspiration of enteral feed has been questioned because the glucose levels in commonly used feeds are similar to those of normal tracheal aspirates. In order to increase the glucose concentration of the feed, 10 g of glucose was added to each 500 ml feed carton. Testing oral and tracheal secretions with standard glucose oxidase strips allowed the accurate detection of both pharyngeal regurgitation and tracheal aspiration. An episode of subclinical aspiration was detected and this was associated with a fall in the PaO2/FiO2 ratio. There were no further episodes of aspiration following the introduction of a gastric motility agent, maintaining the patient in the semi-recumbent position and an increase in the positive end expiratory pressure (PEEP).