Cyanide toxicity during cardiopulmonary bypass with small dose of nitroprusside: a case report / 대한마취과학회지

Sodium nitroprusside (SNP) is an anti-hypertensive drug, commonly used to decrease the systemic vascular resistance and lower the blood pressure. When the amount of cyanide generated by the SNP exceeds the metabolic capacity for detoxification, cyanide toxicity occurs. Under general anesthesia and cardiopulmonary bypass (CPB), it may be difficult to detect the development of cyanide toxicity. In cardiac surgical patients, hemolysis, hypothermia and decreased organ perfusion, which emphasize the risk of cyanide toxicity, may develop as a consequence of CPB. In particular, hemolysis during CPB may cause an unexpected overproduction of cyanide due to free hemoglobin release. We experienced a patient who demonstrated SNP tachyphylaxis and cyanide toxicity during CPB, even though the total amount of SNP administered was much lower than the recommended dose. We therefore report this case with a review of the relevant literature.

Intraoperative paravalvular leakage after sutureless aortic valve replacement corrected with secondary balloon dilatation: A case report

Sutureless aortic valve replacement was performed in a 72-year-old female patient with severe aortic stenosis who had undergone coronary revascularization and pacemaker implantation. After valve excision, decalcification was deliberately incompletely performed at the commissure of the left- and non-coronary cusp to obtain a regular and circular annular margin. After implantation of the stented valve, no paravalvular leakage was noted on water irrigation testing. Upon weaning from cardiopulmonary bypass, a moderate degree of paravalvular leakage was observed by transesophageal echocardiography at the junction of the left- and non-coronary cusp. Instead of removing the valve and performing more complete decalcification to implant a larger valve, secondary balloon dilatation and warm sterile water irrigation were performed to allow further expansion and fixing of the metal alloy stent around the aortic wall to minimize the duration of aortic cross-clamp. No paravalvular leakage was observed thereafter and the patient was discharged without any complications.