The structure of ICUs varies depending upon the type of unit (e.g., mixed medical/surgical, general surgical, or subspe­cialty surgical) and local culture and politics. ICUs typically function as open or closed, depending upon which physi­cians are able to admit and discharge patients, as well as write orders. In a purely open model, any physician has the authority to admit and manage patients. In this model, there tend to be multiple consultants, each managing a single organ system. In contrast, in closed units, the intensivist team completely manages the patients, streamlining care and allowing for a more holistic approach to the patient. In semi­open units, the surgical team and the critical care team comanage the patient, each having the authority to write orders. The hospital may require intensivist consultation for each patient admitted to this type of ICU. Surgical ICUs tend to have a more open or semi-open structure, allowing the surgical team to maintain signifi cant control of their patients’ care. Both closed and semi-open models are referred to as “high-intensity” staffi ng. This model of care delivery is asso­ciated with improved mortality compared to a “low- intensity” staffi ng model [ critical for the surgical team to remain closely involved in the patient’s care. The surgeon best knows the details of the operative intervention and the potential complications.