Ascorbic acid and microcirculation in cardiothoracic surgery: a pilot feasibility trial and matched cohort study

Area of Science:

• Cardiothoracic Surgery
• Vascular Physiology
• Nutritional Biochemistry

Background:

• Ascorbic acid is vital for catecholamine synthesis and microcirculation.
• Early administration in cardiothoracic surgery may preserve microcirculatory integrity.
• Hypothesized to minimize postoperative vasoplegia.

Purpose of the Study:

• To assess the feasibility of early ascorbic acid administration in cardiothoracic surgery.
• To evaluate the impact of ascorbic acid on microcirculatory integrity and vasoplegia.
• To compare clinical outcomes against historical controls.

Main Methods:

• Pilot feasibility study with 15 adult patients undergoing septal myectomy.
• Intravenous ascorbic acid (1,500 mg) administered perioperatively.
• Compared against 45 matched historical controls.

Main Results:

• Feasibility endpoint not met due to challenges in microcirculation measurement (75% of participants).
• Similar incidence of vasoplegia, acute kidney injury, and length of stay compared to controls.
• No significant differences in vasopressor duration or clinical outcomes observed.

Conclusions:

• Microcirculation measurements are difficult in complex cardiothoracic surgery.
• Ascorbic acid showed no meaningful clinical benefit compared to historical controls.
• The role of ascorbic acid in preventing post-cardiopulmonary bypass vasoplegia requires further investigation.