Minnesota's total number of reported adverse events rose slightly in 2011, up 3.6% to 316 from 305 in 2010, according to a report from the state's health department (PDF). All Minnesota hospitals and ambulatory surgery centers are required by law to report on 28 different types of events.

Two categories of adverse events—pressure ulcers and wrong procedures—were responsible for most of the increase, the department said in a news release. The number of reported pressure ulcers jumped nearly 20%, from 118 in 2010 to 141 in 2011.

The number of wrong procedures performed on patients increased considerably during the same period, from 16 to 26, or 63%.

“Ten of these events were related to incorrect implants being placed: five during cataract surgeries in which the wrong power lens was placed, two during breast implants in which the wrong type of implants were placed, two during knee replacement surgeries, and one during an ankle surgery,” according to the report. “Nearly all of the wrong procedure events took place in the OR; relatively few happened in interventional radiology or other procedural areas.”

Although the overall number of events increased, the state did see a nearly 17% drop in the number of events resulting in serious injury or death, the report said. Specifically, improvements were seen in the number of falls, wrong-site surgeries and retained foreign objects.