Background: During coronary artery bypass grafting (CABG), the myocardium is subjected to endure periods of ischemia and reperfusion, which may result in post-ischemic contractile dysfunction. That is a major contributor to early and late morbidity and mortality and increased requirement of pharmacologic and mechanical circulatory support. Glucose insulin potassium (GIK) infusion was thought to provide a cardioprotective effect. Objective: To investigate whether the use of GIK solution in patients undergoing on-pump CABG affects requirements of inotropes. Patients and Method: In this prospective, randomized placebo-controlled trial, 64 patients were assigned into two groups: the GIK group in which glucose-insulin and potassium infusion was given during CABG surgery, and the non-GIK group in which only saline infusion was given during the procedure. Results: In the GIK group, all patient needed not more than two inotropes with mean of 1.28 ± 0.46, while in the non-GIK group there were patients who need up to three inotropes with mean of 1.56 ± 0.56 (P. value of 0.032). Conclusion: GIK infusion during on-pump CABG reduces perioperative inotropic requirements.

Introduction: Our clinical experience in cardiac surgery teaches us that a subset of patients show signs of unexplained end-organ hypoperfusion after an otherwise unremarkable procedure. The objective of this study is to comprehensively examine cardiopulmonary bypass (CPB) management parameters and end-organ perfusion. Hypothesis: Despite advancements in CPB management, CPB does not provide adequate end-organ perfusion. Methods: Retrospective analysis was performed using data from 1462 cardiac operations performed from 2/2019 to 4/2020, excluding circulatory arrest and non-CPB cases. CPB management parameters included cardiac index (CI), mean arterial pressure (MAP), vasopressor-phenylephrine use, lines and bladder temperatures, hemoglobin (Hgb), indexed oxygen delivery (iDO 2 ), and intravenous fluid infusion. End-organ perfusion markers included lactate levels, mixed venous oxygen saturation (SvO 2 ), oxygen consumption (VO 2 ), and arterial pH. Results were expressed as means with first standard deviation. Results: During CPB, CI, MAP, iDO 2 and Hgb were 2.2 ± 0.4 l/min/m 2 , 67 ± 16 mmHg, 270 ± 71 ml/min/m 2 , and 9.3 ± 1.6 g/dl respectively (Figure 1). Phenylephrine cumulative dose increased with CPB duration, 11 ± 9 mg at 1h and 20 ± 15 mg at 2h. Fluid administration showed similar trend. Core mean temperature was maintained with nadir being 33.5 ± 3.4°C. SvO 2 rapidly increased with institution of CPB, peaking at 85%, and then slowly declined. Inversely, VO 2 dropped and then slowly increased. Lactate continuously increased with duration of CPB. Conclusions: Our findings suggest that despite hemodynamic values being maintained at goal by continuously high vasopressor use and fluid administration during CPB, tissue perfusion was inadequate.Our study suggests that, using data-driven approaches, it may be time to revisit the assumptions regarding all aspects of managing CPB.

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