Blood flow in the upper limb during brachial plexus anaesthesia

Area of Science:

• Anesthesiology
• Cardiovascular Physiology

Background:

• Brachial plexus anesthesia is a common regional anesthetic technique.
• The physiological effects of local anesthetics with epinephrine on cardiovascular parameters require further elucidation.

Purpose of the Study:

• To investigate the impact of brachial plexus anesthesia using lignocaine with adrenaline on cardiac output and peripheral blood flow.
• To assess changes in finger and arm blood flow following the administration of local anesthetic.

Main Methods:

• Utilized electrical impedance plethysmography to measure changes in finger blood flow, arm blood flow, and cardiac output.
• Studied 20 patients undergoing brachial plexus anesthesia with 1% lignocaine and 1:200,000 adrenaline.

Main Results:

• Observed significant increases in cardiac output immediately after effective anesthesia.
• Noted a significant increase in blood flow to the unanesthetized arm.
• Documented a highly significant increase in finger blood flow in the anesthetized hand throughout the procedure.
• Found no overall increase in blood flow to the anesthetized arm.

Conclusions:

• Adrenaline in the local anesthetic solution may increase cardiac output.
• The observed vasoconstriction at the injection site is likely due to adrenaline.
• Peripheral blood flow distribution is altered by brachial plexus anesthesia with adrenaline.