Decreased platelet aggregation of platelet concentrate during storage recovers in the body after transfusion.

BACKGROUND: Previous reports have shown that storage decrease the ability of PLTs to aggregate in the form of PLT concentrate (PC). Nevertheless, there are few reports that have studied the PLT function in blood samples obtained from recipients after PLT transfusion. In this study, this issue was addressed by examining the ability of PLTs to aggregate after being transfused into the blood stream. STUDY DESIGN AND METHODS: PC was transfused to the patients with extremely low PLT counts resulting from chemotherapy. The maximum extent of PLT aggregation and size of the aggregates were compared between PLT in stored PC before transfusion with the PLT-rich plasma (PRP) from the recipients after transfusion and with PRP from patients with moderate decrease in PLT counts after chemotherapy. RESULTS: The maximum extent of PLT aggregation was significantly higher in PRP collected from the patients after transfusion compared to the extent obtained before transfusion. There were no significant differences in the maximum extents of PLT aggregation between the PRP collected from the recipients after PC transfusion and, in the same patients, when PLT counts were moderately low. CONCLUSION: These results suggest that the observed decreased in PLT aggregation after storage can improve in the body after transfusion, and transfused PLTs have similar aggregation ability compared to the PLTs derived from the patient.

Profound ionized hypomagnesemia induced by therapeutic plasma exchange in liver failure patients.

BACKGROUND: Various adverse effects, including cardiac arrest, have been induced by plasma exchange (PE). Electrolyte derangement is frequently observed. The purpose of this study was to assess the effect of PE on the serum ionized magnesium (Mg2+) concentration in acute liver failure patients. STUDY DESIGN AND METHODS: Seven liver failure patients requiring PE were enrolled in this study. PE was performed 21 times in total. Blood samples were drawn before PE and serially after the start of the PE. Serum Mg2+ was measured by the ion- selective electrode method. RESULTS: After PE was started, Mg2+ concentrations began to fall significantly. The low Mg2+ blood concentration continued during PE. After PE, the Mg2+ level recovered to about 80 percent of the control value within 2 hours in six patients. However, in one patient, the Mg2+ concentration was still low even at 2 hours after PE. This patient complained of chest discomfort during PE and ECG analysis showed sporadic supraventricular premature contractions. CONCLUSION: Profound ionized hypomagnesemia was induced by PE in liver failure patients.