Case 5: Hyperkalemia During Coronary Artery Bypass Graft

Abstract

A 76-year-old male (5 ft 8 in. and 82 kg) is scheduled for a three vessel CABG and Aortic valve replacement. His past history is significant for three vessel CAD (70% LAD, 70 Circ, and 70% RCA). The aortic stenostic valve area is 0.69 cm² and the gradient is 36 mmHg. The patient also has chronic renal insufficiency with a (Cr) of 1.4–1.9 in the past year. He also is a non-insulin diabetic and has obstructive sleep apnea. Surgery is now indicated because of increased shortness of breath on minimal exercise. His medication was gemfibrozil, amitriptyline, aspirin, HCTZ, and atenolol. On physical exam, you find a cardiac murmur at right upper sternal border radiating to the carotids. The lungs are clear and EKG shows NSR with no ischemic changes. The ECHO shows an ejection fraction of 55–60%. The laboratory values are within normal levels with a K of 4.4 mmol/L, but the Cr is 1.4.