Some perianesthesia areas may require more than one charge nurse per day. The preoperative and postoperative areas may each need charge nurses, and if there are separate units for different patient populations, charge nurses may be necessary for each unit to ensure safe patient care and coordination of resources. If the unit has a variety of shifts or is open all night, there may be more than one charge nurse per day in any given area for different shift coverage. In bigger and busier perianesthesia areas with larger caseloads, having charge nurses that overlap on staggered shifts may be helpful for break relief, assisting staff with difficult patient assignments, and in maintaining unit flow.