When facing a surgery you have enough to worry about without fretting over whether or not the hospital staff will leave a foreign object inside you. The horror of an object left behind is referred to as "retained surgical instruments," and it happens frequently enough to be a real concern. An estimated 4,500 to 6,000 cases occur each year.
The most common items left behind are sponges and needles, but clamps and tools can be forgotten as well. Sponges and towels used to soak up blood are often overlooked because they blend in with organs. Due to their porous and absorbent nature, sponges and towels are actually the most dangerous retained foreign object. They soak up fluids and begin to deteriorate, which can cause painful infections and tissue damage.
Barcodes and radio frequency
To prevent human error, hospitals have barcoded tools and sponges. The items are scanned before the surgery and re-scanned afterwards so all items are accounted for. The items are visible in an x-ray and the patient is x-rayed in the operating room before the surgery is completed. This is of little comfort, however, because of how often those procedures break down.
Even with tracking systems in place, you're still at risk as a patient. If you were injured due to negligent care you may feel vulnerable and unsure of how to proceed, but you have right to hold the medical staff accountable for their mistakes.