Teacher: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.
Teacher: Now, understand the problem? Solve this instance: Context: The purpose of this investigation was to determine the influence of cardiopulmonary bypass (CPB) on the minimum alveolar concentration (MAC) of isoflurane in a rat model of CPB.', 'Prospective.', 'University research laboratory.', 'Sprague-Dawley rats.', 'Using tail-clamp methodology, the pre- and post-CPB MAC for isoflurane was studied.', 'Rats were anesthetized with isoflurane, intubated, ventilated, and surgically prepared for CPB, after which they were randomized to either Sham-operated or CPB groups. The CPB group (n = 10) underwent 90 minutes of normothermic nonpulsatile CPB. The Sham group (n = 13) were cannulated but did not undergo CPB. Pre- and post-CPB MAC determinations were compared within groups using a paired Student t test. The CPB group had a pre-CPB baseline isoflurane MAC of 1.09% +/- 0.11% versus 1.09% +/- 0.08% in the Sham group (p = 0.90). Twenty minutes after CPB, the CPB group exhibited a decrease in MAC to 0.98% +/- 0.14% (p = 0.0026, compared with baseline). The MAC in the Sham group was unchanged (p = 0.5852, compared with baseline). Two hours after CPB, the MAC in the CPB group remained lower compared with baseline at 0.99% +/- 0.14% (p = 0.0032).
Answer: CPB resulted in a small (10%) but significant reduction in the MAC for isoflurane. The mechanism behind this reduction in MAC is not clear but may be related to CPB-induced cerebral injury.
Student:
Does cardiopulmonary bypass reduce the minimum alveolar concentration for isoflurane?