Cardiac performance during unilateral lumbar spinal block after crystalloid preload

Area of Science:

• Anesthesiology
• Cardiovascular Physiology
• Surgical Procedures

Background:

• Unilateral spinal anesthesia is often used for leg surgery.
• Hemodynamic stability is crucial during anesthesia.
• The role of fluid preloading in low-dose spinal anesthesia requires investigation.

Purpose of the Study:

• To evaluate the hemodynamic effects of crystalloid preload in patients undergoing unilateral spinal anesthesia.
• To compare cardiovascular function between patients receiving crystalloid preload and those who did not.
• To assess the impact of preload on spinal block characteristics.

Main Methods:

• A randomized blind study involving 20 patients (ASA I-II, 50-80 years old).
• Patients received either 10 ml/kg Ringer's Lactate (preload group) or no fluid (no-preload group).
• Hemodynamic variables (blood pressure, heart rate, stroke volume, cardiac index) were measured using non-invasive methods and transthoracic electrical bioimpedance.

Main Results:

• No significant differences in sensory or motor block levels were observed between groups.
• The no-preload group experienced a significant decrease in diastolic blood pressure.
• Stroke volume and cardiac index decreased significantly in the no-preload group compared to the preload group and baseline.

Conclusions:

• Crystalloid preload positively influences cardiovascular function during unilateral spinal block.
• Fluid preloading may be a beneficial strategy when using low doses of bupivacaine with lateral decubitus positioning for unilateral spinal anesthesia.
• This approach can help maintain hemodynamic stability in specific surgical contexts.