Relationship between serum lactate and ionized calcium in open-heart surgery

Area of Science:

• Cardiovascular Science
• Biochemistry
• Critical Care Medicine

Background:

• Open-heart surgery and cardiopulmonary bypass (heart-lung bypass) are complex procedures.
• Maintaining electrolyte balance, particularly ionized calcium, is crucial during such surgeries.
• Lactate levels are a known indicator of metabolic stress and tissue perfusion.

Purpose of the Study:

• To investigate the relationship between ionized calcium and lactate levels in patients undergoing open-heart surgery.
• To determine if this relationship persists after adjusting for confounding factors like pH and hemodilution.

Main Methods:

• Blood samples were collected from 16 patients at various stages of open-heart surgery.
• Measurements included ionized calcium, total calcium, lactate, blood gases, pH, and hematocrit.
• Statistical analysis, including correlation and linear regression, was performed.

Main Results:

• A statistically significant positive correlation (p < 0.05) was observed between ionized calcium and lactate levels.
• This correlation remained highly significant (p < 0.0001) after adjusting for patient variability, operative stages, pH, and hemodilution.
• The relationship was evident both before and after calcium administration.

Conclusions:

• A significant association exists between ionized calcium and lactate in patients undergoing open-heart surgery.
• This relationship is independent of several key physiological variables.
• Further research may explore the clinical implications of this calcium-lactate interaction in cardiac surgery patients.