Retained surgical instruments

In any given typical surgery, an estimated 250–300 surgical tools are used.[5] The number significantly increases to 600 when a larger surgery is performed, thus increasing the chance of the surgeon losing an instrument.[5]

Types of forgotten instruments

SmartSponge system, an RFID system to aid doctors in tracking sponges and other surgical items during surgery

There are many different types of tools that have been left behind during a surgery. Common instruments are needles, knife blades, safety pins, scalpels, clamps, scissors, sponges, towels, and electrosurgical adapters. Also retained are tweezers, forceps, suction tips and tubes, scopes, ultrasound tissue disruptors, asepto bulbs,[6] cryotomes and cutting laser guides, and measuring devices. The single most common left behind object is a sponge.[7]

Many studies have taken place to pinpoint the causes of tools being forgotten in hopes that they may be avoided in the future. It has been thought that the amount of blood lost in a surgery or the changing of nurses during the surgery would influence the risk of losing something, but studies do not support this. Human factors such as exhaustion, lack of tools necessary to aid in producing an accurate count, and a chaotic environment all have been seen to increase the risk of forgetting a tool.[13] These factors cannot be controlled and surgeons must learn to mitigate them.

Inaccurate counts are a main reason why tools can be left behind. Many cases of a retained instrument originally reported a correct sponge count when the patient was released.[1] An inaccurate count can occur when nurses are deprived of sleep, when the operation is particularly difficult, long, and mentally draining, when the operation is an emergency, or when there are unforeseen changes in the procedure.

An increased amount of chaos and distractions lead to a higher risk of a surgeon forgetting a tool. Mark Hulse from North Shore Medical Center said the following about surgery; “It’s a process that’s definitely subject to interruption and can be prone to errors. You’re doing a hundred other things at the same time, and as much as you try to keep your attention on it [sponge counts] if the surgeon needs something, it’s easy to get distracted.”[8] Some aspects of surgery that can add to chaos are performing unforeseen changes in the procedure and undergoing emergency surgery.[14] Consequently, the emergency room is the place most likely to make mistakes.[15]

Studies have shown having a high body mass index increases risk. Boston researchers found that a one-point increase in BMI related to a higher risk by 10%. The researchers suggest that “they [surgeons] chalk it up to more room in a patient in which to lose things.”[16]

In 2008, the US Food and Drug Administration (FDA) published a Public Health Notification advising on serious adverse events arising from fragments of medical devices left behind after surgical procedures, known as unretrieved device fragments (UDFs). The FDA's Centre for Devices and Radiological Health receives around 1000 adverse event reports each year relating to UDFs.[17][18] One major source of UDFs is from the failure of surgical instruments.[19]

There are many risks from UDFs. The FDA states: "The adverse events reported include local tissue reaction, infection, perforation and obstruction of blood vessels, and death. Contributing factors may include biocompatibility of the device materials, location of the fragment, potential migration of the fragment, and patient anatomy. During MRI procedures, magnetic fields may cause metallic fragments to migrate, and radiofrequency fields may cause them to heat, causing internal tissue damage and/or burns"[19]

Improvement in lowering the number of mistakes likely depends upon improving the surgical system, and not in individual scapegoating.[5] According to the Institute of Medicine, “the problem is not bad people; the problem is that the system needs to be made safer.”[20]

In order to improve the system and reduce the number of accidents, some hospitals require four counts of sponges and instruments.[21] The first count happens when the instruments are being set up and the sponges unwrapped.[21] The next count is required right before surgery begins, another count as closure begins, and finally a count during skin closure.[21] This is a general guideline and there are different count methods according to different hospitals.[1]

While careful counting could prevent some mistakes, counting carries its own risks. Sometimes the patient must be worked on immediately, leaving no time to count the instruments to be used beforehand. Another risk of counting after is having to leave the patient under anesthesia longer.[22] In addition, counting may not be entirely beneficial as counting is prone to human error and the majority of the cases of gossypiboma and other retained tools happen under a reported correct count.[8] Dr. Atul A. Gawande, a surgeon, said in an article published in The New England Journal of Medicine that “even though you're following procedures, the priority is the patient, not the procedures.”[23]

A new technique that is developing is similar to the Bar Code Medication Administration. The University of California at San Francisco and North Shore Medical Center have installed a “bar coded sponge management system”,[8] reasoning that technological error is smaller than human error.[8] Each surgical instrument has a bar code placed on it and nurses pass the items through a hand scanner. The bar code allows each sponge to be identified, resulting in little to no room for error. UCSF reported in April 2008 to have not had "any unintended retained gauze or sponges” since the installation of the system in April 2007.[8]