Can entropy predict neurologic complications after cardiac surgery?
A 59-year-old, 74 kg, 165 cm, female was presented with a non-ST segment elevation myocardial infarction. Preoperative echocardiography findings included an ejection fraction (EF) of 50%, tight aortic valve stenosis, peak systolic gradient across the aortic valve of 45 mm Hg, trivial aortic regurgitation, no detected wall motions abnormalities, and normal right ventricular (RV) diameters. Cardiac catheterization showed two-vessel disease and fair left ventricular (LV) function. She was treated with clopidogrel, aspirin, captopril, bisoprolol, and intravenous infusions of heparin and nitroglycerin. She underwent an urgent bypass grafting for the left-anterior descending (LAD), diagonal and right coronary arteries (RCA), and prosthetic replacement of the aortic valve under the standardized target-controlled (TCI) propofol-sufentanil anesthesia and cisatracurium infusion.[] After heparinization, aortic cannulation was performed. It resulted in an abrupt decreases of RE and SE values from 49 and 46, respectively, to isoelectric silence. Transoesophageal echocardiogram (TOE) failed to detect aortic intraluminal thrombi and plaques. Target effect site concentrations (Ce) of propofol and sufentanil were lowered to 1 and 0.1 μg/mL, respectively, and continued till the end of surgery. Mild hypothermic cardiopulmonary bypass (CPB) was used. The cross-clamp time was 148 min and the CPB time was 289 min.\nIsoelectric silence persisted till the end of reperfusion time. Then, gradual increases in RE and SE toward the low 30 s levels were noted and they persisted till the transfer of the patient to the intensive care unit (ICU).\nThe patient was subsequently successfully separated from CPB with intravenous epinephrine (7 μg/min). The cisatracurium, sufentanil, and propofol infusions were discontinued after surgical homeostasis, sternal closure, and skin closure, respectively.[]\nMean arterial and central venous blood pressures (MAP and CVP, respectively), arterial oxygen saturation (SaO2), normocapnia, and euglycemia were well maintained throughout the perioperative period. Rectal temperature >36°C was maintained before and after the CPB.\nPostoperative ventilation was performed with synchronized intermittent mandatory (SIMV). Mediastinal bleeding of 750 mL during the first three postoperative hours was treated with transfusion of two U-packed red blood cells, five U platelets, and three U fresh frozen plasma. Unfortunately, the lady did not wake up even 8 h after the discontinuation of anesthetics. After that, she showed agitation and left-sided paresis. Brain CT showed a nonhemorrhagic right tempro-parietal infarction. Dexmedetomidine infusion was used to alleviate her agitation. Her consciousness was recovered and her trachea was extubated on the second postoperative day.