A system and method determine when fluid is not flowing properly from a secondary infusion source during a secondary infusion. The system includes an upstream pressure sensor and a processor programmed to receive signals from the sensor and analyze the signals to determine if secondary fluid flow is proper. The processor samples the output signals from the upstream pressure sensor and analyzes the sampled signals to determine if a pressure rise in the infusion line has occurred when the secondary infusion is initiated. If a pressure rise, indicating that fluid from the secondary container has begun flowing into the infusion line, has not been detected, the processor is programmed to provide a signal indicating that attention should be given to the infusion set up.
