Hospital surgery environments are dynamic and high risk. They require coordination across multiple groups whose incentives, cultures, and routines can conflict. In this paper, we describe a field study of multi-group coordination in the operating room (OR) environment. We studied work trajectories from the perspective of each group involved. Coordination breakdowns at group boundaries involving patients, doctors, nurses, and other staff led to local problem solving, but also to delays and interpersonal tension and conflict across groups. We conclude with design recommendations for multiple group coordination support that would promote trajectory awareness and learning at the organizational level