Fluid balance abnormality was observed during plasmapheresis performed using a blood purification device (ACH-Σ; Asahi Kasei Medical Co. Ltd., Tokyo, Japan). Based on this case finding, it was thought that some problems may have occurred in the fluid control system. We verified the operation of the fluid system with obstruction in its circuit. When the circuit for fluid replacement was obstructed, an alarm indicated “abnormalities in filling of fluid replacement”. The alarm could not be reset unless the cause was removed. When the filtration circuit directly behind the plasma separator was obstructed, an alarm indicated “blood leak detection 1”. When the circuit directly before the filter pump was obstructed, an alarm indicated “abnormalities in plasma balance”. For the first and second alerts, it was possible to reset the alarm even if the cause of the alarm was not removed. For the third alert, however, the alarm could not be reset unless the cause of the alarm was removed. When the filtration circuit directly behind the filter pump was obstructed, the status of fluid replacement alone was observed. Thus, excessive body fluid due to excessive fluid replacement may trigger side effects (e.g., elevated blood pressure, cardiac failure, cyanosis, dyspnea, and pulmonary edema).
