Pressure gradient and blood flow in human arm veins. -A proposed explanation of the pumping mechanism-.

Venous Response After Lidocaine Administration in Arm Veins

“…The decrease in Pv pulsations after lidocaine administrations lead us to infer that this could be caused by the spasmolytic effect of lidocaine on venous tone. Furthermore, the increase in Pv after drug administration could be explained as the result of blood stagnation in local veins caused by the depression of the venomuscular pump 5,6 due to the spasmolytic effect of lidocaine on the basal tone of VSM and this seemed to support our hypothesis. ∆Pv, however, tended to show initial increase followed by a drop in a dose-dependent response after various doses of lidocaine administrations in subjects with various diseases including valvular disease and systemic hypertension.…”

“…2 Regarding lidocaine administration, no significant change was observed in cardiac output and right atrial pressure after infusion of a rather small dose of the drug in a study on cardiac arrhythmias. 12 In our previous study, no changes were observed in Pcv after administration of from 1 to 26 mg of lidocaine in subjects with various diseases 5 and in group 1a. Consequently, we believe that it is reasonable to examine the effects of drug administration on peripheral venous circulation without measuring central venous pressure in groups 1b and 2.…”

“…14,15 Moreover, the cinephlebograms demonstrated slightly cylindrical dilation of the venous segments along with an increased X-ray attenuation rate, which may have been caused by increased contrast medium. Consequently, with regard to the cause of Pv rising in these subjects, we can deny venoconstriction as the cause, and instead suggest blood stagnation in the drug injected and proximal venous segments, this being caused by depression of the venomuscular pump, 5,6 itself caused by the spasmolytic effect of lidocaine on the local VSM tone. Although the number of cinephlebographic tests was limited, it can be presumed that the same would hold true in the subjects of group 1a and in patients with positive ∆Pv in group 2 because of the fact that Pv gradually rose after the end of drug injection in all subjects.…”

“…In group 1a, the tip of the latter was checked radiologically and the tip of the former was placed at the same hydrostatic level, and Pv or Pcv was recorded alternately using a 3-way stopcock as in our previous study. 5 That level was usually a few cm higher than midchest. In group 1b and group 2, the tip of the Pv measuring tube was placed at midchest level.…”

“…2,3 We previously reported on the change of venous pressure (Pv) after small-dose intravenous lidocaine administration in subjects with various diseases. 5 In that study, we observed that Pv pulsations subsided but concurrently Pv gradually increased after small doses of lidocaine administered to subjects with gastrointestinal or genitourinary disease, with no significant change in Pv (∆Pv) after saline administration. The decrease in Pv pulsations after lidocaine administrations lead us to infer that this could be caused by the spasmolytic effect of lidocaine on venous tone.…”