The concentration of calcium in neonatal cardioplegia

• Published in: The Annals of thoracic surgery Vol. 50; no. 2; pp. 262 - 267
• Main Authors: Zweng, Thomas N., Iannettoni, Mark D., Bove, Edward L., Pridjian, Ara K., Fox, Mark H., Bolling, Steven F., Gallagher, Kim P.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-08-1990; Elsevier Science
• Subjects: Anesthesia; Anesthesia depending on type of surgery; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animals; Animals, Newborn; Bicarbonates - analysis; Biological and medical sciences; Calcium - administration & dosage; Calcium - pharmacology; Calcium Chloride - analysis; Cardioplegic Solutions - analysis; Heart Arrest, Induced; Magnesium - analysis; Medical sciences; Myocardial Reperfusion Injury - prevention & control; Potassium Chloride - analysis; Rabbits; Sodium Chloride - analysis; Thoracic and cardiovascular surgery. Cardiopulmonary bypass; Cardioplegic solution; Animal model; Cardiac performance; Biochemical analysis; Calcium; Rabbit; Cardiovascular disease; Exploration; Concentration; Lagomorpha; Inorganic element; Blood flow; Isolated organ; Vertebrata; Mammalia; Ischemia; Newborn animal; Animal; Surgery; Myocardium; Anesthesia; Aorta; Cations; Hemodynamics
• ISSN: 0003-4975; 1552-6259
• DOI: 10.1016/0003-4975(90)90746-S

The optimal calcium concentration in cardioplegia for the newborn has not been determined. Therefore, the effect of 0, 0.6, 1.2, 1.8, and 2.4 mmol/L calcium in modified St. Thomas cardioplegia was evaluated in isolated working hearts of 7- to 10-day-old rabbits. Functional recovery was determined by comparing aortic flow, developed pressure, and first derivative of left ventricular pressure (
dP
/
dt
) before and after 1 hour of normothermic (37 °C) ischemia. As percentages of baseline values, recovery of developed pressure and
dP
/
dt
averaged 10% ± 1% (mean ± standard error of the mean) and 10% ± 1% with 0 mmol/L, 46% ± 7% and 44% ± 8% with 0.6 mmol/L, 79% ± 2% and 76% ± 2% with 1.2 mmol/L, 67% ± 2% and 61% ± 5% with 1.8 mmol/L, and 65% ± 5% and 65% ± 7% with 2.4 mmol/L calcium, respectively. Significant improvement in recovery of developed pressure and
dP
/
dt
was detected when the calcium concentration was increased from 0 to 0.6 mmol/ L and from 0.6 to 1.2 mmol/L, but the groups with 1.2, 1.8, and 2.4 mmol/L did not differ from one another significantly in terms of developed pressure and
dP
/
dt
recovery. There was no recovery of aortic flow when 0 mmol/L calcium was used; at calcium concentrations of 0.6, 1.2, 1.8, and 2.4 mmol/L, recovery of aortic flow averaged 16% ± 7%, 63% ± 10%, 23% ± 10%, and 36% ± 11% of baseline values, respectively. Recovery of aortic flow with 1.2 mmol/L calcium was significantly higher than at concentrations of 0.6 and 1.8 mmol/L. In the rabbit exposed to normothermic ischemia, we conclude that neonatal cardioplegia requires calcium to be effective and that 1.2 mmol/L represents the optimal calcium concentration for the best combination of recovery in aortic flow and developed pressure.