RALEIGH - Over two months last year, 3,800 patients at two hospitals run by Duke University Health System were exposed to surgery with instruments that were washed in hydraulic fluid instead of detergent, hospital regulators say. Duke Health Raleigh (formerly Raleigh Community) and Durham Regional hospitals put patients in "immediate jeopardy" in November and December by not detecting the problem, despite complaints from medical staff about slick tools, the regulators said. The hospitals did not fix the problem for weeks, said the report from the Centers for Medicare & Medicaid Services, which The News & Observer of Raleigh reported Sunday....