Intravenous Lidocaine and Cerebral Blood Flow: Impaired Microvascular Reactivity in Diabetic Patients

Abstract

Lidocaine infusions are used for treatment of ventricular arrhythmias and painful diabetic neuropathy. In animals high doses of lidocaine reduces cerebral blood flow (CBF). The effect of lidocaine on CBF in humans is unknown. Cerebrovascular reactivity may be impaired in long-term diabetic patients. The effect of intravenous lidocaine (5 mg/kg body weight) on CBF was investigated in eight healthy subjects and eight long-term diabetic patients with painful neuropathy. Cerebral blood flow was measured with the intravenous 133-Xenon method immediately before and after lidocaine infusion and 60 minutes later. In healthy subjects, CBF decreased 12% (P less than .02) during lidocaine infusion and normalized within 60 minutes. Diabetic patients had identical CBF level before and after lidocaine suggesting decreased cerebrovascular reactivity.