instruction:
Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
question:
Context: The aim of this study was to investigate the relationship between intraoperative vasopressin infusion and postoperative cardiac enzymes.', 'A prospective, double-blind, randomized, controlled study.', 'A single tertiary cardiac center.', 'One hundred consecutive patients undergoing cardiac surgery with or without cardiopulmonary bypass.', 'The study was approved by the Institutional Review Board, and patients provided informed consent to participate. Patients were randomized by computer into 2 equal groups: Vasopressin or control. The blinded study included vasopressin administered at a dose of 1.8 U/h or 1.8 mL/h of normal saline, along with catecholamines. The drug was administered continually during surgery while patients needed catecholamines. The intervention was discontinued upon admission to the intensive care unit when information regarding the true character of the drug was reported to the doctor in charge of patients in the intensive care unit by one of the investigators. Primary outcomes were CK-MB and troponin T levels measured at 0, 6, and 12 hours postoperatively.', 'Of the 100 patients, 8 were excluded; the remaining 92 were randomized to either the vasopressin (n = 47) or control (n = 45) group. There were no significant differences in demographic data between the groups. Postoperatively at 0, 6, and 12 hours, there were no differences in CK-MB (U/l) (37.5 ± 57.9 v 32.0 ± 21.5, 29.4 ± 41.1 v 24.4 ± 23.1, and 21.4 ± 21.3 v. 21.8 ± 32.4, respectively) and troponin T (752.4 ± 638.2 v 762.7 ± 557.1, 753.8 ± 507.3 v 777.6 ± 515.0, and 774.6 ± 572.6 v 698.7 ± 540.2, respectively) values.
Answer: Vasopressin infusion has been used to treat catecholamine-unresponsive shock. In this study, intraoperative vasopressin was used safely as a possible first-line drug for treating hypotension; however, it did not increase the levels of cardiac enzymes after cardiac surgery.
answer:
Does vasopressin raise cardiac enzymes following cardiac surgery : a randomized double-blind clinical trial?


question:
Context: Postoperative neurologic deficits after thoracic aortic reconstruction vary widely. Our previous study showed that delayed ischemic preconditioning could prevent spinal cord injury caused by occlusion of the descending thoracic aorta in pigs. We investigated early ischemic preconditioning in the same model.', 'Twenty-eight pigs were divided into 4 groups: group 1 (n = 6) underwent a sham operation, group 2 (n = 6) underwent aortic occlusion for 20 minutes, group 3 (n = 8) underwent aortic occlusion for 35 minutes, and group 4 (n = 8) underwent aortic occlusion for 20 minutes and underwent aortic occlusion 80 minutes later without hypotension for 35 minutes. Aortic occlusion was accomplished by using 2 balloon occlusion catheters placed fluoroscopically at T6 to T8 above the diaphragm and at the aortic bifurcation. Neurologic evaluation was performed by an independent observer according to the Tarlov scale (0-4). The lower thoracic and lumbar spinal cords were harvested at 120 hours and examined histologically with hematoxylin-and-eosin stain. Histologic results (number of neurons and grade of inflammation) were scored (0-4) and were similarly analyzed. Statistical analysis was by means of the Kruskal-Wallis test.', 'Group 4 had a better neurologic outcome at 24, 48, and 120 hours in comparison with group 3 (P <.001). The histologic changes were proportional to the neurologic test scores, with the more severe and extensive gray matter damage in animals of group 3 (number of neurons, P <.001; grade of inflammation, P <.001).
Answer: Early ischemic preconditioning without hypotension protects against spinal cord injury after aortic occlusion, as confirmed by using the Tarlov score and histopathology.
answer:
Does early ischemic preconditioning without hypotension prevent spinal cord injury caused by descending thoracic aortic occlusion?


question:
Context: Arginine vasopressin is a vasoactive drug commonly used in distributive shock states including mixed shock with a cardiac component. However, the direct effect of arginine vasopressin on the function of the ischemia/reperfusion injured heart has not been clearly elucidated.', 'We measured left ventricular ejection fraction using trans-thoracic echocardiography in C57B6 mice, both in normal controls and following ischemia/reperfusion injury induced by a one hour ligation of the left anterior descending coronary artery. Mice were treated with one of normal saline, dobutamine (8.33 microg/kg/min), or arginine vasopressin (0.00057 Units/kg/min, equivalent to 0.04 Units/min in a 70 kg human) delivered by an intraperitoneal micro-osmotic pump. Arterial blood pressure was measured using a micromanometer catheter. In addition, mortality was recorded and cardiac tissues processed for RNA and protein.', 'Baseline left ventricular ejection fraction was 65.6% (60 to 72). In normal control mice, there was no difference in left ventricular ejection fraction according to infusion group. Following ischemia/reperfusion injury, AVP treatment significantly reduced day 1 left ventricular ejection fraction 46.2% (34.4 to 52.0), both in comparison with baseline and day 1 saline treated controls 56.9% (42.4 to 60.2). There were no significant differences in preload (left ventricular end diastolic volume), afterload (blood pressure) or heart rate to account for the effect of AVP on left ventricular ejection fraction. The seven-day mortality rate was highest in the arginine vasopressin group. Following ischemia/reperfusion injury, we found no change in cardiac V1 Receptor expression but a 40% decrease in Oxytocin Receptor expression.
Answer: Arginine vasopressin infusion significantly depressed the myocardial function in an ischemia/reperfusion model and increased mortality in comparison with both saline and dobutamine treated animals. The use of vasopressin may be contraindicated in non-vasodilatory shock states associated with significant cardiac injury.
answer:

Does low-dose vasopressin infusion result in increased mortality and cardiac dysfunction following ischemia-reperfusion injury in mice?