Fewer Wrong-Site Peripheral Nerve Blocks Following Updates to Anesthesia Time-Out Policy

Abstract

Background: Peripheral nerve block (PNB) has been shown to be safe and effective, and its use has continued to increase, but it is not without risks. One potentially preventable risk is wrong-site blocks (WSBs). Our institution mandated a time-out process before PNB in 2003, and then in 2007 made two more changes to our policy to mitigate risk: (1) the circulating/block nurse was the only person permitted to access the block needles; after a time-out period was complete, the nurse gave the needles to the anesthesiologist; and (2) the nurse remained at the patient’s bedside until the PNB was initiated. Purpose: We sought to compare the incidence of WSBs before and after this time-out process was implemented in 2003 and the enhanced form of it was implemented in 2007. We hypothesized that the enhanced process would decrease the incidence of WSBs. Methods: We retrospectively analyzed data, from January 2003 to December 2016, taken from the quality assurance and performance improvement (QA/PI) division of the anesthesiology department at our institution, which maintained daily statistics on anesthetic types using quality audits from paper or electronic anesthesia records. All WSBs from this period were reported to the QA/PI division and root cause analyses performed. The incidence of WSB was compared pre- and post-implementation of the enhanced time-out policy for upper extremity, lower extremity, and all blocks by calculating relative risks with 95% score confidence intervals and performing Fisher’s exact tests. Results: The incidence of WSBs decreased from 1.10/10,000 before changes to the policy were initiated to 0.24/10,000 afterward. Conclusion: We observed an association between the implementation of a dynamic, team-focused time-out process and a reduction in the incidence of WSBs at our institution. A causal effect of the enhanced time-out cannot be determined given the risk of bias associated with before-after study designs and our lack of adjustment for potential confounders. Further research is therefore warranted.

Introduction

The use of the peripheral nerve block (PNB) as an important component of anesthetic and analgesic pathways continues to increase. Its role in limiting opioid use, as well as the advent of ultrasound guidance improving success rates, may explain this increase. While relatively safe, PNBs are not without complications. Wrong-site peripheral nerve block (WSB) is one troubling, yet avoidable, complication. Similar to wrong-sided surgery, this complication (deemed a “never-event” by various regulatory agencies [1]) continues to occur with alarming frequency [3]. As determined by 3 registries, the incidence of WSBs in worldwide [17], national [13] and multihospital health care system [9] cohorts were 3.63/10,000, 1.6/10,000, and 1.28/10,000, respectively. It is unclear whether a formal pre-anesthetic time-out process was in effect in any of these reports.

WSBs continue to occur at an unacceptable frequency [3,9,13,17,18]. Although they are a significant complication, for many years they have been overlooked. In one study surveying academic regional anesthesiologists, WSBs were not considered a complication of PNBs [4]. Over the past decade, however, multiple reports of WSBs [3,6,9,13,17,19] and a focus on patient safety initiatives [16] have brought this issue into the spotlight.

Not only do WSBs result in patient dissatisfaction, but they also carry the same risks of intended PNBs, including infection, persistent pain and paresthesia, and local anesthetic systemic toxicity. WSBs may be preventable; the success of a formal time-out process has been well-documented in reducing the risk of wrong-site surgeries [7,11,14,15]. The Joint Commission mandated formal time-out procedures in 2004 [2].

In 2003, following several WSBs at our hospital, we instituted a formal pre-anesthetic time-out process that takes place before all PNBs [6]. While we were hopeful that this would eliminate all future WSBs, we were wrong—they continued to occur [19]. In response, we performed root cause analyses, as required by New York State. Two issues were identified that may have contributed to the complications. First, we found that the time-out was not being performed in all cases, so the policy was ineffective. Second, significant delays between time-out and procedure were resulting in WSBs. As a result of these findings, in 2007 we added two additional steps to our time-out procedure [19]. As a reminder to perform the time-out before every PNB placement, the circulating or block nurse sequestered all PNB needles and gave them to the anesthesiologist after the time-out. To reduce the time between the time-out and the block, the nurse was required to remain at the patient’s bedside until the PNB was initiated. These two modifications addressed the issues identified in the root cause analysis.

The purpose of this study was to compare the incidence of WSBs before and after the institution of this enhanced time-out process (i.e., 2003–2006 vs 2007–2016). We hypothesized that the revised process would decrease the incidence of WSBs.

Methods

After obtaining institutional review board approval, we collected and evaluated data from January 2003 to December 2016. During this time, the quality assessment/performance improvement (QA/PI) division of the anesthesiology department maintained daily statistics on all anesthetic procedures, by manually tallying data from paper anesthesia records. Beginning in February 2016, the anesthetic procedures were collected from reports generated by our electronic medical record system. We excluded neuraxial blocks as they are not associated with laterality. All WSBs from January 2003 to December 2016 have been reported to the QA/PI division and had root cause analyses performed. Furthermore, all WSBs have been reported to the New York Patient Occurrence Reporting and Tracking System, the mandatory state occurrence reporting system. We, therefore, believe we have captured every incidence of WSB during this time period. PNB types are separated into upper extremity PNBs and lower extremity PNBs. Upper extremity PNBs included axillary, infraclavicular, interscalene, and supraclavicular. Lower extremity PNBs included adductor canal, ankle, fascia iliaca, femoral, popliteal, psoas compartment, and sciatic.

After the initial implementation of a time-out procedure in 2003, the policy was amended and enhanced in 2007 to include the two additional elements (sequestration of the needles and continuous presence of the nurse) as noted above. After 2007, several minor modifications were made to the time-out process, including pointing to the surgeon’s initials on the surgical site and reading the surgical consent out loud during the time-out.

The incidence of WSBs from 2003 to 2016 is presented as a point estimate (count per 10,000 blocks) with a 95% Wilson [20] score confidence interval (CI). The incidence of WSBs after versus before institution of the enhanced time-out process (i.e., 2007–2016 vs 2003–2006, respectively) was compared, stratified by extremity (upper or lower) and overall, by calculating relative risks (i.e., ratio of incidences) with 95% score CIs [10] and performing Fisher’s exact tests. The Breslow-Day test was used to assess whether the association between the enhanced time-out process and odds of WSBs varied by extremity. All statistical hypothesis tests were two-sided, with no correction for multiple testing. Statistical analyses were performed, and bar charts produced, using SAS software version 9.4 (SAS Institute, Cary, NC, USA). The forest plot was produced using R software version 3.5.1 (R Foundation for Statistical Computing, Vienna, Austria).

Results

The data for this study included 160,857 PNBs performed over a period of 13 years. Between 2003 and 2006, 14,674 upper extremity PNBs and 20,179 lower extremity PNBs were performed. Between 2007 and 2016, 51,326 upper extremity PNBs and 74,678 lower extremity PNBs were performed (Figs. 1 and 2).

Fig. 1.

Upper extremity peripheral nerve blocks performed annually.

Fig. 2.

Lower extremity peripheral nerve blocks performed annually.

The incidence (count per 10,000 blocks) of WSBs for all PNB types (upper and lower extremity) from 2003 to 2016 was 0.50 (95% CI: 0.25, 0.98).

The incidence of WSBs decreased for all PNB types from 1.10 to 0.24 pre- (2003–2006) to post- (2007–2016) policy change, respectively (relative risk [95% CI]: 0.17 [0.04, 0.63]; P = .015) (Fig. 3). While the decrease in incidence appeared to be more pronounced for lower extremity blocks (relative risk [95% CI]: 0.14 [0.03, 0.63]; P = .021) than upper extremity blocks (0.29 [0.03. 2.74]; P = .395), we did not detect an interaction between time period and extremity via the Breslow-Day test (P = .648) (Fig. 3).

Fig. 3.

Risk of wrong-site block pre- versus post-time-out enhancements. WSPNB wrong-sit peripheral nerve block, CI confidence interval.

Discussion

As clinicians at an institution that uses a preponderance of regional anesthetics, we sought to investigate the incidence of WSBs before and after the implementation of the time-out process described above. As we hypothesized we would, we found a decrease in the incidence of WSBs after the implementation of the time-out process. We believe it served to engage team members and provide moments to stop and verify the correct site.

Our study was limited to one institution for block performance and data collection. This eased data collection and the adoption of process modifications by both nursing and anesthesia staff, adding to the strength of this study, but this is also a limitation, since our policy may not be readily adaptable by other institutions. For example, our lack of a separate service placing blocks ahead of time in a “block room” is not a universal characteristic of all institutions. The specific practice pattern may have contributed to our results. Also, a causal effect of the enhanced time-out cannot be determined given the risk of bias associated with before-after study designs and our lack of adjustment for potential confounders. After the initial enhancements were made to the time-out (2007–2016), several other minor adjustments were made as well. These included viewing and pointing to the surgeon’s initials as well as reading the surgical consent aloud during the anesthesia time-out. We therefore cannot exclude these elements as playing a role in the reduction of WSBs.

We compared the incidence of WSBs before and after enhancements were instituted to the anesthesia time-out. The enhancements included removing the anesthesiologist’s ability to perform the PNB without involving the circulating/block nurse by removing all PNB needles from the possession of the anesthesiologist. The needles were given to the anesthesiologist by the circulating/block nurse immediately after the time-out confirming site and laterality. This ensured that the time-out process would take place before PNB placement. It also encouraged anesthesiologists’ engagement, focusing their attention on completing this procedure to obtain a block needle. In fact, the entire team was involved, adding “sets of eyes” at this critical time. Second, the circulating/block nurse also remained at the bedside until initiation of the PNB. This ensured that minimal time passes between performance of the time-out and initiation of PNB. The concept of a delay contributing to the incidence of WSBs is highlighted in a survey of New Zealand anesthetists [8]. The results of our study confirmed an association between the enhancement in our time-out process and a significant reduction in the incidence of WSBs, from 1.10/10,000 to 0.24/10,000 PNB.

In addition, we gained insight and understanding of operating room dynamics, the time-out process, and interventions helpful in optimizing interdisciplinary team interactions for the goal of increased patient safety. Literature supports that time-out processes are most successful when there is a strong team dynamic, the time between the time-out and the actual procedure is minimal, and everyone is engaged [6,19,21]. As such, these were the aims of the changes we implemented to the process. Clark et al [5] addressed the challenges team members face in carrying out patient safety checks including feelings of haste, intimidation by senior team members, or even—in familiar teams—a sense of trust leading to complacency. In our analysis, we focused only on the change made to the policy in 2007 and understand that many other factors contribute to the success or failure of any time-out process. Furthermore, we conduct regular live audits of time-out procedures to ensure continued compliance and to serve as real-time education when any failure to adhere to the policy is observed. Policies and systems are intended to prevent human error, but our institution recognizes that they must also be dynamic. Institutional culture, staff, procedures, regulations, and operating room environments are ever-changing. For policies to remain effective, they must continue to be evaluated and evolve, when necessary.

Suggested risk factors for WSBs include performance pressure in the operating room, positioning of the patients prior to the block, or patient sedation rendering them unable to participate in site confirmation [12]. Our policy intended to address some of these issues by engaging all team members and minimizing any delays (such as patient positioning) between time-out and block placement.

Before we revised our time-out policy, our incidence of WSB (1.10/10,000) was consistent with several other studies in the literature. Sites et al [17] used a prospective multicenter registry to report on complications of various regional anesthetic techniques. Their study period was June 2001 to May 2014. Member institutions, located primarily in Australia and New Zealand, reported all complications associated with regional anesthetics, one of which was WSB. They noted 7 WSBs in a cohort of 19,268 anesthetics for an incidence of 3.63/10,000 PNB. No other information on time-out processes or details of the blocks were provided.

Pandit et al [13] reported data from various British audits conducted between 2007 and 2015 throughout the National Health Service. They estimated the incidence of WSBs to be approximately 1.6/10,000 PNB. Again, no other information on time-out processes or details of the blocks were provided.

Finally, Hudson et al [9] retrospectively evaluated the incidence of WSB over a 10 year (July 2002–June 2012) period in a large multihospital health care system. They studied unilateral blocks performed by an interventional pain service or those performed by an anesthesia team in a total of 13 hospitals. All blocks were performed outside of the operating room in block room areas. An overall incidence of WSBs of 1.28/10,000, or 9 WSBs per 70,441 unilateral blocks, was reported. Before instituting a time-out policy, there was a WSB rate of 1.39/10,000. Following initiation of a time-out policy, a rate of 0.70/10,000 was observed. The interventional pain service WSB rate was 0.84/10,000 compared with anesthetic team rate of 1.51/10,000. They noted that the highest incidence of WSBs occurred with femoral nerve block placement.

Similarly, the data we collected before revising our time-out policy also suggested that lower extremity PNBs may be at a greater risk of being performed on the wrong side (1.82/10,000) compared with upper extremity PNBs (0.44/10,000). We can speculate on several reasons why this may be so. Positioning issues, especially for sciatic blocks placed in the prone position, may contribute to right/left confusion. Alternatively, visual cues present for upper extremity blocks such as intravenous site, placement of electrocardiography leads, and a noninvasive blood pressure cuff may help prevent right/left confusion when performing upper extremity PNBs.

We recognize that many challenges still exist, despite our best efforts to improve the time-out process. After examining the 3 WSBs that occurred after we initiated the enhancements, we noted that two occurred because the policy was not followed. During the first of these, the time-out was completed as the patient was being prepped, while the circulating nurse was across the room—not, as the policy describes, immediately before placing the block with the nurse in attendance. Another occurred when a time-out was not conducted, as the anesthesiologist retrieved the needle himself. The third WSB occurred on a patient who was scheduled to have a left knee injection and a right knee replacement. Therefore, the surgeon signed both knees. The surgical consent also had both sites indicated; a left femoral nerve block was placed inadvertently.

In conclusion, our findings suggest that adherence to a time-out procedure and minimal time lapses between the time-out and the PNB were associated with a reduction in the incidence of WSBs. We acknowledge that institutions can be creative in ensuring how these elements occur. The key is a team approach. Furthermore, it is essential to provide continual education and to regularly assess compliance through live auditing and evaluation. Through our successes and failures, we have learned that the process must be dynamic and adaptable as teams, procedures, and engagement levels are ever-changing. The overarching process of evaluating and subsequently adjusting policies and procedures is essential to optimizing risk-reduction strategies.