Cardioplegic Solution

Solution:

• Calcium chloride: 17.6mg/100mL
• Magnesium chloride: 325.3mg/100mL
• Potassium chloride: 119.3mg/100mL
• Sodium chloride: 643mg/100mL

• It must be diluted before use.
• 10mL (840 mg) of 8.4% Sodium Bicarbonate Injection is added be added aseptically and thoroughly mixed with each 1L of cardioplegic solution to achieve the approximate pH of 7.8 when measured at room temperature
• Due to its inherent instability with other components, sodium bicarbonate must be added just prior to administration.
• The solution is cooled to 2-8°C prior to use and the solution is administered by rapid instillation into the aortic root, after institution of cardiopulmonary bypass and cross clamping of the ascending aorta, at the rate of 300ml/m² body surface area/min., for 3 times, initially.
• External cardiac cooling helps to ensure maintenance of a continuously cold heart.
• Warmed instillate can be removed by cold solu
• Extemporaneous alternative buffering to the described formulation of this solution is not recommended.

Cardioplegic Solution with added sodium bicarbonate when cooled and instilled into the coronary artery vasculature, causes prompt arrest of cardiac electromechanical activity, combats intracellular ion losses and buffers ischemic acidosis. When used with hypothermia and ischemia, the action may be characterized as cold ischemic potassium-induced cardioplegia.

This is conducive to providing the surgeon with a quiet, relaxed heart and bloodless field of operation.

• Calcium (Ca++) ion in low concentration is included in the solution to maintain integrity of cell membrane to ensure that there is no likelihood of calcium paradox during reperfusion.

• Magnesium (Mg++) ion may help stabilize the myocardial membrane by inhibiting a myosin phosphorylase, which protects adenosine triphosphate (ATP) reserves for postischemic activity. The protective effects of magnesium and potassium have been shown to be additive.

• Potassium (K+) ion concentration is responsible for prompt cessation of mechanical myocardial contractile activity. The immediacy of the arrest thus preserves energy supplies for postischemic contractile activity in diastole.

• The chloride (Cl-) and sodium (Na+) ions have no specific role in the production of cardiac arrest. Sodium is essential to maintain ionic integrity of myocardial tissue. The chloride ions are present to maintain the electroneutrality of the solution.

• Added bicarbonate (HCO3-) anion is included as a buffer to render the solution slightly alkaline and compensate for the metabolic acidosis that accompanies ischemia.

• Myocardial infarction
• Electrocardiographic abnormalities
• Arrhythmias

• Intravenous use

• Additives may be incompatible