We've all heard the horror stories about patients being sewn up after surgery with sponges, clamps, or scissors left inside of them and you don't have to be a doctor to know that this is definitely a bad thing. According to this article, about 4,000 cases of retained surgical items are reported in the US each year, with the vast majority being sponges. Sponges are easy to miss because so many are used in surgery to soak up blood and they wouldn't look as obviously wrong in the surgical cavity as something like scissors (hopefully) would.
According to the same article, currently, most hospitals rely on old-fashioned counting to keep track of sponges; a nurse is generally assigned to counting and recounting sponges to make sure they all end up outside the stitches. But given that nurses are only human, and I can't imagine a surgery room being the calmest place in the world, sometimes things are miscounted. In fact, this article estimates that all sponges were accounted for in 4 out of 5 times they were accidentally sewn up inside patients.
Enter electronic tracking tags. A few companies have developed ways to keep track of sponges at all times, either through a radiofrequency tag or a bar code associated with every sponge. In one study of 2,300 patients, an RF tag helped resolve about 35 sponge miscounts.
But like all things, these tags are associated with a cost that hospitals may not be willing to pay. With major markets such as the US, Europe, and Japan facing economic uncertainty and increasingly cost-constrained facilities, even convincing administrators to spend $10 extra on a procedure for this tracking system might be too much.
From a patient's perspective though, I'd sure want to know that the doctors and nurses had a thoroughly effective way of making sure there weren't any stray surgical instruments floating around inside of me when I woke up.