Wrong-site nerve blocks: 10 yr experience in a large multihospital health-care system

Although wrong-site surgery has garnered extensive scrutiny, the incidence of wrong-site blocks remains unknown. Our study thus sought to quantify the incidence of wrong-site blocks and examine some of their associated risk factors in our multihospital health-care system.

Using quality-improvement and billing data, we quantified the total number of blocks and wrong-site blocks occurring between July 1, 2002 and June 30, 2012 within the University of Pittsburgh Medical Center Health System. The incidence of wrong-site block was determined by block type, hospital, and type of service involved in performing the block. The incidence of wrong-site block was compared with that of wrong-site surgery. Fisher's exact tests were performed to determine associations between the incidence of wrong-site block and any of the aforementioned variables. A root-cause analysis was performed to determine the source of wrong-site blocks after the implementation of a timeout policy.

Of the 85 915 patients receiving blocks, 70 441 received only unilateral blocks, yielding an overall incidence of wrong-site block of 1.28 (95% confidence interval 0.43-2.13) per 10 000 patients receiving unilateral blocks. The incidence of wrong-site block was highest with femoral blocks, and differed from the incidence of wrong-site surgery. All occurrences of wrong-site block after the implementation of the timeout policy involved policy violations.

Our study provides the first incidence data on wrong-site block in a large patient population and can help hospitals to develop policies based on these data. It is yet to be determined whether active intervention can eliminate this adverse event.