Abstract
The accidental disconnection of venous circulation during CBP (Continuous blood purification therapy) is a life-threatening medical condition. Therefore, I investigated the implementation of an appropriate venous pressure lower limit alarm to detect the accidental disconnection of blood circulation. The experiment used a bypass model that simulated venous pressure during CBP and a model that simulated a deviation in the normal blood circuit (i.e., venous pressure decrease). I manipulated the conditions of blood flow quantity and Hct levels, as well as the stabilization of the blood circuit. I examined a venous pressure lower limit warning derived from the venous pressure differential between the bypass and the circuit solution models. The venous pressure changed relative to blood flow quantity and Hct levels, as did the circuit stabilization in each model, The change in blood flow quantity most greatly influenced venous pressure, and changes in the differential pressure increased in conjunction with blood flow quantity. Therefore, I determined a minimum for the differential pressure identified as the experiment’s lower limit alarm level. It became clear that the lower limit alarm level was higher than the venous pressure when blood circulation decreased under all conditions. It was determined that a machine’s sensitivity to a drop in venous pressure of less than 37mmHg was most appropriate for the purpose of the alarm.
