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: To maximize the benefit of carotid endarterectomy (CEA) in stroke prevention its complication rate must be minimized. The purpose of this study was to report the outcomes of a large series of CEA carried out under regional anaesthesia with selective shunting, with particular emphasis on identifying predictors for perioperative stroke and mortality.', 'Between 1987 and 2003 the data for 1665 consecutive regional anaesthetic CEA carried out in 1495 patients were collected prospectively; awake neurological testing facilitated selective shunting. Preoperative data, intraoperative events and postoperative in-hospital complications were recorded and analysed.', 'There were 38 non-fatal strokes (2.3%) and 10 deaths (0.6%), giving a combined stroke and mortality rate of 2.9%. Only patients who needed shunting were found to have significantly higher rate of postoperative stroke and mortality (7.0 vs 1.9%, P < 0.001). Patient characteristics, comorbidities, indication for operation (P = 0.34) and the degree of stenosis of the contralateral carotid artery (P = 0.65) were not found to be predictive of perioperative stroke or mortality, although the latter two were found to be predictive of the need for shunting (P < 0.001 and P = 0.002).
Answer: Regional anaesthetic CEA is a safe and effective technique with excellent morbidity and mortality rates. The technique can be undertaken safely regardless of the indication for endarterectomy or the status of the contralateral carotid artery. Patients who developed intraoperative neurological changes requiring shunting are identified as high risk for perioperative stroke or mortality and should therefore be carefully monitored postoperatively.
Student:
Does intraoperative neurological changes in 1665 regional anaesthetic carotid endarterectomies predict postoperative stroke?