Abstract
During renal replacement therapy for clinical patients, we sometimes encounter problems such as bolus infusion of the anticoagulant with a syringe pump (hereinafter simply called “pump”), and regurgitation of blood into the syringe and delayed start of the infusion due to regurgitation. These problems are primarily related to the structural space remaining after installation of the syringe onto the pump attached to a renal replacement therapy machine. In addition, some other factors (compliance of the syringe and pump, and sudden change of pressure within the blood circuit) can also produce problems. The volume of regurgitation or bolus infusion is about 1 ml or less. However, if the frequency of poor blood removal becomes higher, the exact amount of the anticoagulant remaining in the system becomes unclear, making proper management of dosing difficult. Regarding delayed start of infusion, the delay has been reported to be about 40 minutes for both the maintenance hemodialysis devices and the slow continuous renal replacement therapy machines. Thus, when drugs with short half-live are used, delayed start of infusion can cause coagulation of blood within the circuit. The routine countermeasures advisable clinically to prevent these problems are: (1) avoidance of the formation of a structural space, (2) use of low-compliance and low-volume syringes, and (3) increasing the drug infusion rate per unit time. Henceforth, we shall take actions to promote standardization of this kind of pump by the manufacturing enterprises concerned.
