RESUMO
Aim: To evaluate the knowledge of nursing professionals in the Intensive Care Unit (ICU) about endotracheal aspiration (ETA) for open system. Method: This an exploratory descriptive study in which a quantitative approach was used, performed in July 2011 in two ICUs of a large university hospital in Mato Grosso do Sul, Brazil. Data were collected through the means of a questionnaire. The sample consisted of 27 professionals of whom 51.9% were male. Results: Globally, the knowledge of professionals was qualified as fair (73.2% correct), but worryingly, it was considered poor in five areas with differing results among the professional categories. Discussion: Taking into account that incorrect knowledge generates inappropriate behavior, it is inferred that the practice of these subjects may compromise patient safety. Conclusion: The studied individuals showed knowledge deficits in some aspects of ETA, a fact that deserves investment regarding teaching and nursing.