Ionized calcium concentration and cardiovascular function after cardiopulmonary bypass

Area of Science:

• Cardiovascular Surgery
• Anesthesiology
• Critical Care Medicine

Background:

• Cardiopulmonary bypass surgery frequently leads to hypocalcemia.
• The impact of hypocalcemia on cardiac function post-surgery requires clarification.

Purpose of the Study:

• To determine the incidence of postoperative hypocalcemia.
• To evaluate the effects of intravenous calcium chloride on ionized calcium levels and cardiac function.

Main Methods:

• Studied patients undergoing cardiopulmonary bypass.
• Administered intravenous calcium chloride (bolus or infusion) to correct low ionized calcium (Ca++) levels (<1.8 mEq/L).
• Monitored hemodynamic profiles, including cardiac index, stroke index, and vascular resistance, for two postoperative hours.

Main Results:

• Postoperative hypocalcemia was frequently observed.
• No significant differences in cardiac indices, stroke indices, or vascular resistances were found across groups, regardless of calcium therapy.
• Intravenous calcium chloride effectively corrected ionized calcium (Ca++) concentrations.

Conclusions:

• Postoperative hypocalcemia after cardiopulmonary bypass is common but typically not severe enough to cause significant cardiovascular depression.
• Intravenous calcium chloride is an effective treatment for correcting hypocalcemia in this patient population.
• Myocardial depression observed in patients likely stemmed from causes other than hypocalcemia.