[Incidence of pulmonary aspiration with different kinds of artificial airways]

A patient with an artificial airway in place, pulmonary aspiration is a serious complication. A prospective study was conducted to investigate the incidence of pulmonary aspiration in patients with all kinds of modern artificial airways with high-volume low-pressure cuffs. In ICU and NSCU (neurosurgery care unit), 40 patients with a tracheostomy or endotracheal tube were included. Before study, cuff pressure was checked and remained at 25 cmH2 O if possible. Then, 0.2 ml of 1% methylene blue was applied on the tongue of each patient every 4 hours. Routine tube care was performed including frequent suction at least once an hour. Any evidence of the blue dye-marker obtained on suctioning was considered positive. The duration of study was 24 hours. Among these 40 patients, the procedure was performed in 50 episodes because some of the patients were evaluated with different kinds of artificial airways. Thirty episodes were evaluated with endotracheal tube, including 7 oral and 23 nasotracheal tubes. No episode of aspiration could be found (0/30). With tracheostomy tubes, 5 of 20 episodes showed positive result (5/20). The difference of incidence between these 2 groups was statistically significant (p less than 0.01). Some possible contributing factors were evaluated between positive and negative episodes, including age, sex, respiration rate, different brands of tracheostomy tubes, modes of ventilation, PEEP level, cuff pressure, nasogastric tubes, coma scale, posture, and ratio of tube and tracheal diameters in tracheostomy group.(ABSTRACT TRUNCATED AT 250 WORDS)