Study identifies risk factors for retained objects after surgery

Research shows errors occur more often in emergency surgeries, and in operations involving obese patients

Wednesday, January 15, 2003

After analyzing medical malpractice insurance claims that involved 22 hospitals, researchers at Brigham and Women's Hospital (BWH) have identified risk factors underlying medical errors that involve leaving surgical sponges or instruments inside patients after an operation, a rare but serious complication. Their findings appear in the January 16 edition of the New England Journal of Medicine.

The study found that in the instances when these types of errors do occur, they happen during emergency procedures, or in operations where there is a sudden change in plan. Additionally the research revealed that the higher a patient's weight the more statistically likely it is that an object will be inadvertently left behind.

"Often when you hear about these kinds of cases, people assume it is due to negligence," said Atul Gawande, MD, MPH, of BWH. "But we found that these errors usually occur despite teams following proper procedures. These errors tend to occur in unpredictable situations, such as emergency operations, that challenge standard protocols."

Gawande and his colleagues analyzed malpractice claims filed with one particular insurance company between 1985 and 2001. In all, 54 cases were confirmed to involve retained objects. Sixty-nine percent of the cases involved sponges, and 31 percent involved instruments. These cases were then compared to data from patients undergoing the same operations who did not have this complication.

In emergency operations, retained object errors are nine times more likely to happen, the study showed. It was also determined that these errors were four times as likely to happen when the operation involved a change in procedure.

All hospitals follow procedures that mandate an inventory of all tools and sponges be taken before and after a procedure. But Gawande's research concluded that, while the careful counting of instruments is a valuable safety precaution, in over two-thirds of the cases objects were retained despite proper procedures being followed.

After statistical analysis of the records, Gawande estimated that at least 1500 errors of this type occur each year in the United States. However, given that over 28.4 million inpatient operations were performed in 1999 alone, such errors happen rarely, the study found. In fact, the current research showed that these type of errors occur in approximately 1 in every 9,000 to 19,000 surgeries that involve an open cavity.

When it does happen, however, retained objects can bring on serious medical problems, including perforation of the bowel, sepsis, and even death. Only one case studied resulted in a death, however, and the study found that 69% of the examined cases resulted in successful reoperations.

"Again, it's important to note that the urgency inherent to emergency situations may impact the effectiveness of an otherwise well-intentioned inventorying of instruments," said Gawande. "The way to further reduce these errors from happening is to step-up the use of x-rays, CT scans, and other radiographic technologies to ensure that surgical objects are not left behind."

BWH is a 716-bed nonprofit teaching affiliate of Harvard Medical School and a founding member of Partners HealthCare System, an integrated health care delivery network. Internationally recognized as a leading academic health care institution, BWH is committed to excellence in patient care, medical research, and the training and education of health care professionals. The hospital’s preeminence in all aspects of clinical care is coupled with its strength in medical research. A leading recipient of research grants from the National Institutes of Health, BWH conducts internationally acclaimed clinical, basic and epidemiological studies.

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