A case report on the role of plasma exchange in the management of a massive amlodipine besylate intoxication.

Therapeutic plasma exchange is a procedure used to remove pathologic substances from a patient's blood that has proven useful in some cases of drug overdose. Overdose by calcium channel blocker antihypertensive agents has been shown to be a cause of significant morbidity and can often times prove fatal. These agents cause systemic hypotension by inhibiting cell membrane calcium channels, which leads to a slowing of intracardiac electric conduction with consequent impairment of myocardial function and widespread vasodilation. Shock and metabolic acidosis result from the persistent hypotension. In high doses, calcium channel blocking agents cause insulin resistance. We describe the case of a previously healthy young woman who ingested a massive dose of amlodipine and was treated by therapeutic plasma exchange after non-responsiveness to conventional therapy. The case illustrates the need for utilization of therapeutic plasma exchange in the emergency management of certain cases of severe amlodipine overdose.

Mean arterial pressure and systolic blood pressure for detection of hypotension during hemapheresis: implications for patients with baseline hypertension.

Mean arterial pressure (MAP) has been characterized as a more sensitive and physiologically appropriate hemodynamic parameter in the detection of hemapheresis-related hypotension, resulting in a much closer correlation with the presence of symptomatic hypotension. Patients were enrolled over a 12-month period and data collected on any previous diagnosis of hypertension, antihypertensive therapy used, indication for apheresis, age decile, and gender. Baseline vital signs, any hypotensive signs or symptoms observed, and the patient's vital signs at the time of any hypotensive episode were recorded. Patients were assigned to a subgroup, sensitivity and specificity analysis performed, positive likelihood ratios calculated, receiver operating characteristic curves constructed, and ideal cutoff values identified. The incidence of hypotension among our study population was found to be 6.8%. Over all procedures, systolic blood pressure (SBP) was determined to be a "poor" test for detecting hypotension, while MAP demonstrated a "fair" capacity. A downward normalization was evident in the ideal cutoff value based upon a patient's hypertensive history. The currently accepted SBP less than 80 mmHg cutoff failed to detect hypotensive episodes among baseline hypertensive patients, raising questions about its sensitivity. Based upon physiologic principles and study findings, a MAP-based criterion is preferable in the diagnosis of hypotension during hemapheresis.

Febrile nonhemolytic transfusion reactions. Management by premedication and cost implications in adult patients.

CONTEXT: Febrile nonhemolytic transfusion reactions (FNHTRs) cause unwelcome interruptions during the course of blood product transfusions and necessitate measures to verify the nature of the reaction and to exclude certain dangerous reactions, such as hemolytic and septic phenomena. OBJECTIVE: To examine transfusion medicine data to determine the clinical implications of the routine administration of antipyretic medication to adult patients before transfusion for the prevention of FNHTRs. DESIGN: A retrospective review was conducted of FNHTR data during 5 years (1998-2002), and a determination was made of the cost of a transfusion complicated by an FNHTR. In addition, a comparative cost analysis was performed using our data and published data on the incidence of FNHTRs. The clinical implications of medication with respect to possible drug-induced adverse effects were assessed, as well as the potential interference with diagnosing other forms of transfusion reactions and the mitigation of the clinical effect of an FNHTR. RESULTS: For nearly 120,000 U of transfused blood components, approximately 80% of which were preceded by antipyretic medication during the study period, the overall incidence of FNHTR was found to be 0.09%. Furthermore, there was no evidence of antipyretic-associated complications, nor any evidence that antipyretics prevented the recognition of other more dangerous complications of transfusions. CONCLUSION: Our findings indicate that this practice provides significant advantages to the recipient of a transfusion, but does not appear to yield significant cost benefits for the health care provider.