Overuse of antibiotics is a critical problem in intensive care today. The situation is further complicated by the extremely data-intensive environment with clinical data presented in distributed, often stand-alone information systems. To access and interpret all data is a complex and time-consuming technical and cognitive challenge. We propose a holistic integrated visualization in the form of a patient overview to support physicians in decision making for use of antibiotics at intensive care units. Special emphasis is put on analysis of work processes to identify information needs, the development of a visualization tool based on an integrated data model, and usability testing of the tool in combination with an eye-tracking technology. The visualization tool was highly rated in terms of user performance and preferences, and the analysis of users' visual patterns showed that different types of data visualization may benefit specialist and resident intensive care physicians depending on the task to be performed. A highly interactive tool for integrated information visualization could potentially increase the understanding of a patient's infection status and ultimately enhance decision making for the use of antibiotics.