Catatonic stupor after off-pump coronary artery bypass grafting

A 75‐year‐old male, with no history of any medical or neuropsychiatric disease, was admitted with acute coronary syndrome. He was investigated and found to have non-ST-elevation myocardial infarction, with normal left ventricular ejection fraction of 60% and mild mitral regurgitation. The patient was stabilized with antianginal medications. Elective coronary angiogram revealed 60% left main coronary artery stenosis with significant triple vessels disease. Off-pump coronary artery bypass grafting was performed with anastomosis of the left internal mammary artery to left anterior descending artery, saphenous vein grafts to posterior descending artery, obtuse marginal and diagonal artery. The surgery was uneventful, and the patient was transferred to the Intensive Care Unit (ICU) in stable condition with minimal dose of inotropic supports. The patient was shifted to the ICU late in the evening; hence, after overnight ventilation, the patient was extubated in the morning. On the second postoperative day (POD), the patient was found to be drowsy and gradually became stuporous. The patient was hemodynamically stable with no signs of low cardiac output or infection. Blood gases, serum electrolytes, blood sugar, liver function tests, and transthoracic echocardiography were within normal limits. Neurological examination revealed the muscular rigidity of both upper and lower limbs. On passive Letters to Editor