PA PSRS Patient Saf Advis 2007 Dec;4(4):109,112-23.
Insight into Preventing Wrong-Site Surgery
Anesthesiology; Nursing; Surgery
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Wrong-site surgery can be national news, as it was in November 2007 when Rhode Island Hospital was fined $50,000 for doing their third wrong-side craniotomy of the year.1 Although the frequency of wrong-site surgery has decreased in Pennsylvania, PA-PSRS continues to receive reports, despite disseminating information from our retrospective analysis of wrong-site events and near misses (see Figure 1).2,3 To gain further insight into the elusive and apparently intractable causes of wrong-site surgery, we have undertaken a number of initiatives. We have done site visits at volunteer facilities. We have begun collecting specific detailed information about wrong-site surgery near misses and actual events. We will be setting up a Web resource that will provide the latest information for facilities interested in decreasing their risks for experiencing wrong-site surgery.

Figure 1. The Cumulative Number of Reports of Wrong-Site Surgery Events to PA-PSRS, July 2004 through December 2007

Figure 1. The Cumulative Number of Reports of Wrong-Site Surgery Events to PA-PSRS, July 2004 through December 2007 Here, we will summarize our insights and conclusions from our site visits and give some preliminary findings from our in-depth queries of wrong-site surgery events and near misses. We intend to contribute a detailed analysis of our observations in the future. These insights and conclusions form the basis of a self-assessment checklist that facilities can use to evaluate and monitor their programs for preventing wrong-site surgery (this checklist is available online; for information, see Preventing Wrong-Site Surgery).

A Synopsis of Observations of Site Verification Processes at Six Pennsylvania Facilities

We wanted to understand the variations in how the Joint Commission Universal Protocol for Preventing Wrong Site, Wrong Procedure, Wrong Person Surgery™4 was interpreted and implemented and particularly how those variations might be related to the risk of wrong-site surgery. We selected hospitals from a list of hospitals licensed for more than 350 beds to avoid variations due to small numbers.

We identified hospitals that averaged more than one report of a wrong-site surgery event per year and those that had no reports of a wrong-site surgery event during the two-and-a-half-year reporting period. We adjusted for the difference in hospital sizes by calculating the number of reports of wrong-site surgery events per 100 beds.

Nine of the hospitals on our list had more than one report of a wrong-site surgery event/400 beds/year. We approached four of those hospitals that we knew were committed to patient safety despite their experiences with wrong-site surgery. They all agreed to site visits, with the requirement of confidentiality stipulated by Act 13.5

Two of the hospitals on the list had no reports of wrong-site surgery during the reporting period, even though they averaged more than three reports per week for other problems in their operating rooms (ORs). These hospitals also agreed to site visits, with the requirement of confidentiality stipulated by Act 13.5

Our PA-PSRS team, consisting of the clinical director and two nurse analysts, spent a day at each of the six hospitals. Our team also visited an ambulatory surgical facility (ASF) attached to one of the hospitals reporting multiple wrong-site surgery events. We observed one or more steps for each of 48 procedures. We were pleased with the openness and candor of everyone we spoke to during these visits. We felt that we obtained an honest picture of the activities at every facility. We are very grateful that they were willing to let us observe their practices so that everyone in the state might benefit from the observations.

In general, we noted considerable variation in how the Universal Protocol4 was implemented—how perioperative information was verified, how operative sites were marked, and how time outs were done—and all the other steps of taking a patient through the OR.

We describe our observations at the six hospitals in the Appendix. We not only noted considerable variation in how the Universal Protocol4 was implemented but also in how compliant hospitals were with their own policies. While reading the observations, consider attempting to predict which hospitals have had multiple wrong-site surgery events and which hospitals have had none. The answers are provided at the end of the article.

A Synthesis of Our Observations and Our Previous Retrospective Analysis

Wrong-site errors usually result from one of two problems: misinformation or misperception. In both our retrospective analysis3 and our observations, we noted that wrong-site surgery errors were associated with the failure to identify incorrect information in the documents related to surgery, such as the schedule,

consent, and surgeon’s history and physical examination (H&P), before the operation. Misperception can result from right/left confusion and from confirmation bias, the tendency to confirm a mental impression despite the physical facts.6 After reviewing the 155 actual wrong-site procedures in our retrospective analysis, we concluded that 25 resulted strictly from misinformation and 45 resulted strictly from misperception, a ratio of 1:2. The rest were mixed or ambiguous. We note that misinformation is the main source of errors that get started before the patient reaches the OR, and misperceptions typically initiate errors that start in the OR after the initial verification by the circulating nurse (see Figures 2 and 3).

Figure 2. The Flow of Information from before the Operation Until the Site Marking

Figure 2. The Flow of Information from before the Operation Until the Site Marking Note: The dashed lines indicate either option is possible.


Figure 3. The Awareness of Information in the Operating Room

Figure 3. The Awareness of Information in the Operating Room

Note: The dashed lines indicate either option is possible. The dotted lines indicate a path that is only taken if indicated.

The failure to identify incorrect information in documents prior to surgery can be illustrated by an edited version of a recent report to PA-PSRS:

Procedure scheduled as a right inguinal hernia repair. . . . Patient indicated his right side was the surgical side, right side was marked, and consent form was signed for the right side. The time out for a right inguinal hernia was done prior to beginning the procedure and acknowledged by everyone in the room. After opening the right side, hernia could not be located. H&P reviewed. Surgery resumed on the left side.

In our retrospective analysis, incorrect information was frequently conveyed when scheduling a procedure, sometimes included on the consent, and occasionally present in the H&P.3 Going back over the data in our retrospective analysis, we discovered a statistically significant correlation (p<0.01) between the number of reports from a facility of OR cases scheduled incorrectly and their number of actual wrong-site surgical events.  The number of reports of procedures scheduled incorrectly accounted for 5% of the prediction of the number of actual wrong-site surgical events (R2=0.05). On average, an increase in 10 reports of procedures scheduled incorrectly with the OR was associated with an increase in one wrong-site surgical event. When incorrect information was included on the consent, we got the impression it came from someone using secondhand information, such as the OR schedule, rather than from right/left confusion by the surgeon and patient. In our retrospective analysis, we noted two reports in which two conflicting consents were obtained:

OR list stated right breast mass excision. Patient stated left. There were two consents. One stated right and one stated left. . . .

Two conflicting, signed and dated permits in patient chart.  One stated R total hip revision; other stated L total hip revision. . . .

Both reports came from one hospital that had multiple reports of wrong-site surgery events and had no checks for inconsistencies prior to the day of surgery.

We have noted a correlation between the diligence in checking for inconsistencies in the documents and catching wrong-site errors before they occur. Hospitals that check for errors at every opportunity have more success in preventing misinformation from reaching the OR. The more independent checks, the better.

On the day of surgery, the patient frequently provides a further check to the accuracy of the documents.3 Verification of the patient’s information should be done with questions that require an active expression of information, not a passive acknowledgement. As an illustration of the latter, we observed the following question: “Before I put you to sleep, we’re doing your left ear, right?” When inconstancies are noted, the surgeon must resolve them, as the patient is not correct 100% of the time.3

We noted that one facility took a proactive position by educating patients to understand that the repetitive questions about their names, procedures, and sides was done to double check against errors.

In one of the reports in our retrospective analysis,3 the patient was awake in the OR and provided useful information:

While the nurse was prepping the left leg, the patient asked if both legs would be shaved. Nurse stopped shaving and reviewed the consent and saw the right leg was the correct side.

Our observations led us to appreciate that the mark on the operative site represents the patient’s voice after he or she is sedated or anesthetized. As such, consider the following:

  • The mark should be made with the involvement of the patient or surrogate. It should be made before the patient is sedated.
  • The mark should be made accurately and in a way that is consistent with the facility’s convention. It should be consistent with all the perioperative documents and they should all be checked prior to the marking. It should be made by someone knowledgeable about the procedure and the convention. It should not be ambiguous, such as an “X” that could mean “here” or “not here.”
  • The mark should be made before any interventions are done, including anesthetic blocks.
  • The mark should be visible from the time the patient is sedated until the final time out is done with the patient prepped and draped.

During our site visits, we heard arguments both ways about who should mark the site. Some argued that only the surgeon could mark the site accurately. Others argued that the preoperative nurses were more attentive to the process and therefore more accurate. We noted marks placed by nurses that were covered by drapes during the time outs, and we noted surgeons who neither checked the documents nor talked to the patient when marking the site. Both problems have led to wrong-site surgery.3 We believe that the question as to which person should mark the site is an open scientific question. If the preoperative nurse marks the site, the marking should be confirmed by the surgeon.

The complaint that delays occur because a surgeon must mark the site or at least visit the patient in the preoperative holding area between operations was belied by the experience in many of the hospitals we visited. The most common solution was for the surgeon to visit the first two patients before doing the first operation, then visit the third patient after the first operation, and so forth. The concern that the patient would have to be brought to the holding area earlier was not supported by perioperative staff members. They noted that rapid turnover between cases for efficiency was only useful for short procedures, so the time a patient waited for an additional case was of short duration. For longer cases with longer delays, rapid turnover was not done because it did not impact efficiency.

Problems with right/left confusion and confirmation bias in the OR can be illustrated by this edited report to PA-PSRS:

[Patient] admitted . . . for left knee [surgery]. Patient properly identified, site properly marked and brought to OR. Physician elevated right leg for procedure. Nurse prepped and draped patient. During time out, no one recognized that wrong leg had been prepared. Procedure was performed on incorrect leg.

Turning the patient prone seems to increase the chances of right/left confusion, as illustrated by this edited report to PA-PSRS:

The patient was scheduled for a left popliteal endarterectomy. The time out was done identifying the correct side. Following the procedure, it was realized that the right side was done instead of the left. The patient was placed in a prone position for the procedure.

In our retrospective analysis, we identified wrong-site regional blocks occurring because anesthesiologists did their procedures before the time outs.3 We observed that the anesthesiologists are now aware of that risk and follow policies to do a time out after the patient is marked, before starting a regional block. However, our observations at one hospital were that the time outs were not done with the formality of the time outs in the OR before starting the operation. Interestingly, this hospital had reported a wrong-site anesthesia block.

In our retrospective analysis, we noted that the most common factor associated with wrong-site surgery was the action of the surgeon in the operating room.3 In our observations, we noted a lack of engagement by some surgeons, anesthesia providers, and scrub technicians. Only nurses seemed consistently engaged in the steps of the Universal Protocol,4 as evidenced in the following observations:

The surgeon approached the patient’s bed. There was no conversation. The surgeon used his pen to put a small “X” on the right side of the patient’s neck. There was no review of the medical record.

After the nurse completed the time out, no one acknowledged it. Between 30 and 60 seconds later, the attending surgeon asked, “Are we going to do a time out?” The nurse said, “We did the time out. We already did it.” The surgeon then started the operation.

The circulating nurse started the time out, saying “Time out.” The surgeon turned to scrub tech and said, “I need a 10 [scalpel with a no. 10 blade].” The circulating nurse said, “We are doing [the name of the procedure] on [the patient’s name].” The surgeon was already making the skin incision.

In June 2005, we reported that a hospital in Pennsylvania responded to a similar situation that resulted in wrong-site surgery by establishing a policy that blades will not be available to the surgeon until after the time out is satisfactorily completed.7

 The surgeons seemed more engaged when they led the time outs, although the circulating nurse, not being scrubbed, has the advantage of being able to verify the information in the medical record. We note an inconsistency between how patients are queried during the verification step and how surgeons are queried during the time out step of the Universal Protocol.4 The patient is asked to give information (i.e., an active response). The surgeon is asked to agree with information that has been given (i.e., a passive response). Even this passive level of response was uncommon.

For a time out to be effective, the OR team members must not only be engaged, they must be prepared to speak up.  During our visits, we were told of instances in which nurses spoke up, preventing wrong-site surgery, and instances when they did not speak up, even when they thought there was the possibility of wrong-site surgery occurring.

For a time out to be effective, the surgeon must also be prepared to acknowledge the concerns of OR team members. We observed a nurse object to a surgeon doing a second procedure on a patient that was not on the consent. The surgeon did not stop what he was doing to address that concern.

Anatomic confirmation of spinal levels occurs after the Universal Protocol time out. The North American Spine Society adds elements to their protocol, asking surgeons to consider an intraoperative image to verify the vertebral level and consider verification by a radiologist.8 We observed that surgeons operating on the spine verified the vertebral level with an image, but did not get verification from a radiologist. Surgeons have occasionally misinterpreted the images.3

In our retrospective analysis, we noted errors involving specimens.3 These errors have the potential to set patients up for wrong-site surgery in the future. Some of these errors were right/left confusions resulting from poor communication. Others were misidentification of the patient resulting from the use of labels leftover from earlier procedures in the OR. During our visits, OR nurses at several hospitals expressed concern that leftover labels were a potential source of error.

In all the hospitals we visited, we observed surgeons who were perceived by us and identified by staff as safe surgeons, unlikely to experience wrong-site surgery. In general, these surgeons reviewed all the relevant information available, including imaging studies, and shared the information with other OR team members. They were engaged in the verification, site marking, and time out processes, sometimes referring to documents during the time out. In contrast, we know from our reports that disruptive behavior by surgeons has been associated with both wrong-site events and near misses.

Preliminary Findings from Pennsylvania

The PA-PSRS analytical team began contemporary in-depth queries of wrong-site surgery reports in August 2007. Facilities have been cooperative in providing this extra information to help us all understand the problem better. Even our preliminary data has produced useful information about the differences between near-miss events and actual wrong-site surgery events in ORs and ASFs. As of December 16, 2007, we have received the results of 16 completed in-depth queries about near-miss events and 6 about actual wrong-site surgery events from cooperating facilities. The compliance rate with our request for detailed information within 30 days of the event has been 56%.

Two-thirds of the near-miss events (8 of 12) had errors in the information communicated to the OR from the surgeon’s office staff when scheduling the case. One of the six actual wrong-site surgery events had scheduling errors, a significant difference. This observation is consistent with the previous observations on our retrospective review that most scheduling errors are detected and corrected during the preoperative verification and reconciliation process.3

All of the near-miss reports indicated the use of a checklist to document the verification and reconciliation process. A checklist was used in only four of the six wrong-site surgery events, again a statistically significant difference by chi-square test. This observation suggests that the checklist may be valuable in detecting inconsistencies in the documents before they lead to wrong-site surgery.

The surgeon responded to a specific concern that a member of the OR team voiced about possible wrong-site surgery in all 11 replies about near-miss events, but only in 1 of 4 replies about wrong-site surgery events. This statistically significant difference suggests that reluctance to either express or acknowledge concerns may contribute to a situation becoming a wrong-site surgery rather than a near miss. The following report provides an example:

Patient for left inguinal hernia repair via laparoscopy. The documentation and marked site was on the left. Procedure requires opposite of side of repair to be prepped, and the surgeon directed the nurse to [prep the left]. The surgeon was questioned about the site and [said] to proceed with that side. The surgeon completed the procedure and when completed went to document on the chart and recognized the right side had been done, not the left. The patient was immediately prepped for the left inguinal hernia repair.

We are optimistic that the ongoing cooperation of facilities in providing in-depth information about wrong-site surgery events and near misses will reveal more clues about processes that are successful in preventing wrong-site surgery.


Based on our retrospective analyses, observations, and preliminary, contemporary comparisons, we believe that the opportunities for wrong-site surgery are minimized when all salient information is in agreement. For elective surgery, reconciliation of all the important information, such as the OR schedule, the consent, the H&P, and definitive diagnostic studies, can occur before the day of surgery. We also believe that confusion is minimized when all members of the OR team assume a personal responsibility to have firsthand knowledge that the correct patient is getting the correct procedure at the correct location. The mark on the operative site is the patient’s voice, continuing to speak after sedation or induction of anesthesia. We have concluded that the time out is commonly perceived as the opportunity to make sure that the correct procedure was being done on the correct patient. It is not; it is the final opportunity of many that began when the patient was scheduled for surgery. Many steps of preparing the patient for an operation and performing an operation can lead down the path of wrong-site surgery. Preventing wrong-site surgery may require attention at every step of the process, not just the three advocated by the Universal Protocol.

We will continue to analyze the wrong-site surgery events and near misses. In the meantime, we encourage hospitals and ASFs—that wish to have the success of the Hospitals C and E described in the Appendix—to assess their program for preventing wrong-site surgery using the aforementioned self-assessment checklist. We encourage you to share your assessments and the success or failure of your efforts to improve your wrong-site surgery programs with us. We welcome interest from facilities outside Pennsylvania as well as in Pennsylvania.


  1. Childs D. Medical error, past and present. 2007 Nov 27 [cited 2007 Nov 28]. Available from Internet:
  2. Pennsylvania Patient Safety Reporting System. Doing the “right” things to correct wrong-site surgery. PA PSRS Patient Saf Advis [online] 2007 Jun [cited 2007 Nov 29]. Available at:
  3. Clarke JR, Johnston J, Finley ED. Getting surgery right. Ann Surg 2007 Sep; 246(3):395-405.
  4. Joint Commission. Universal protocol for preventing wrong site, wrong procedure, wrong person surgery [online]. 2003 [cited 2007 Oct 31]. Available from Internet:
  5. Medical Care Availability and Reduction of Error (Mcare) Act. 40 P.S. § 1303.311 (2002).
  6. Reason J. Safety in the operating theatre—part 2: human error and organisational failure. Qual Saf Health Care 2005 Feb;14(1):56-60.
  7. Pennsylvania Patient Safety Reporting System. Tips from PA facilities: enforcing the time out and preventing retained foreign bodies. PA PSRS Patient Saf Advis [online] 2005 June [cited 2007 Nov 29]. Available from Internet:
  8. North American Spine Society. Sign, mark & x-ray (SMaX):  a checklist for safety [online]. 2001 [cited 2007 Dec 21]. Available from Internet:

Supplemental Material

Self-Assessment Questions

The following questions about this article may be useful for internal education and assessment. You may use the following examples or come up with your own.

  1. Actions associated with wrong-site surgery in Pennsylvania include all EXCEPT which one of the following?
    1. Scheduling the operation incorrectly
    2. Having the surgeon refer to office records to verify the site
    3. Having the patient mark the site
    4. Having the surgeon mark the site
    5. Having the surgeon indicate agreement with the information the nurse provides during the time out
  2. The accuracy of which of the following document(s) should be checked and should agree prior to doing a time out?
    1. The consent
    2. The consent and the schedule
    3. The consent, the schedule, and the history & physical examination
  3. Actions associated with preventing wrong-site surgery in Pennsylvania include all EXCEPT which one of the following?
    1. Using a checklist for verification of the documents
    2. Doing a time out before administering a regional anesthetic
    3. Marking the correct extremity anteriorly for surgery in the prone position so that it can be seen best before anesthesia is induced
    4. Allowing staff to interrupt the time out with the surgeon to voice their own concerns
    5. Having the correct spinal level confirmed by a radiologist



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