To the Editor:
An important study by Savilampi et al.1 demonstrating the rate of pulmonary aspiration in adults undergoing monitored anesthesia care with remifentanil was recently published in Anesthesiology. There is an important limitation of the study worth considering when interpreting the study results. The method of aspiration detection does not differentiate between pharyngeal-to-pulmonary aspiration (either oropharyngeal or nasopharyngeal) and gastric-to-pulmonary aspiration. A radionuclide-labeled solution was introduced into the nasopharynx during the study period; therefore, it is not clear whether its detection in the thorax represents aspiration of nasopharyngeal/oropharyngeal secretions, gastric contents, or both. The importance of this point is that gastric-to-pulmonary aspiration (via macroaspiration or gastroesophageal reflux disease) has been implicated in the development of aspiration pneumonitis, pneumonia, and acute respiratory distress syndrome,2–5 whereas aspiration of oropharyngeal secretions may contribute to the development of pneumonia but not necessarily pneumonitis or acute respiratory distress syndrome (other than acute respiratory distress syndrome secondary to pneumonia).6
The author declares no competing interests.