Despite knowledge that most surgical adverse events occur in the operating room (OR), understanding of the intraoperative phase of care is incomplete; most studies measure surgical safety in terms of preoperative risk or postoperative morbidity and mortality. Because of the OR’s complexity, human factors engineering provides an ideal methodology for studies of intraoperative safety. This article reviews models of error and resilience as delineated by human factors experts, correlating them to OR performance. Existing methodologies for studying intraoperative safety are then outlined, focusing on video-based observational research. Finally, specific human and system factors examined in the OR are detailed.
- •
Human factors engineering is a methodology well suited for the study of complex intraoperative processes.
- •
Video provides a promising means of studying human factors in the OR.
- •
Providers are predisposed to committing active errors through latent conditions in the system.
- •
Adaptability is a positive aspect of human variability that constitutes the last line of defense against error.
Introduction
In 1999, the Institute of Medicine published “To Err is Human: Building a Safer Health Care System,” emphasizing the prevalence of preventable medical errors in American health care and the role of systems, processes, and conditions in ensuring (or undermining) safety. Because 50% to 65% of inpatient adverse events are experienced by surgical patients, and 75% of these occur intraoperatively, the operating room (OR) is a high-impact area for safety improvements.
Traditionally, surgical vulnerability has been measured in terms of preoperative risk (patient and procedural risk factors, surgeon volume, and institutional volume), whereas safety has been defined by the absence of postoperative morbidity or mortality. The intraoperative phase of care, despite its obvious relevance to the field of surgical safety and rich potential as a data source, has been largely neglected. Because it is understudied, many gaps exist in our knowledge of the intraoperative factors that contribute to or detract from patient safety. Therefore, few evidence-based guidelines or interventions exist to support hospitals or their providers in the OR.
Surgery is an inherently hazardous work domain requiring high reliability. Safe operations result from the successful coordination of individuals and teams of diverse training and experience levels, working within complex hospital systems, under constraints imposed by time, uncertainty, and health status. Human factors engineering, focusing on “the interaction among humans and other elements of a system…physical, cognitive, organizational, environmental, and other,” has been deployed and is responsible for safety and reliability advances in other, similarly high-risk industries, such as aeronautics or nuclear reactor control. Addressing the origins of error at all levels—individual, team, and system—human factors analysis is an ideal tool for the study of safety in the OR.
Theoretical models
Error
In his 1990 treatise, “Human Error,” Jim Reason describes his Swiss cheese model of error ( Fig. 1 ). In it, the system is represented by a stack of Swiss cheese slices, each analogous to a protective layer in the system, with holes symbolizing the potential for failure at each step in the process. Because the holes in Swiss cheese (the vulnerabilities of a system) are not continuous throughout a stack (the system), most problems are stopped at one layer or another, before they culminate in a larger, more consequential error. For a catastrophic failure to occur, the holes must be aligned at every level.
As per Reason, these holes may be of two types: active and latent. Active errors are those that are traditionally invoked during discussions about adverse events: readily apparent, they are committed by a human at “the sharp end,” or at the point of care. A retained foreign body, for example, represents an active error: the failure to remove an instrument at the end of an operation. However, humans do not make these errors in isolation; they are predisposed toward them by latent conditions at “the blunt end,” in the system. Leaving an instrument in a patient is not the act of an individual surgeon. Rather, it is one precipitated by existing flaws in the organizational design of the entire process: the cumbersome and error-prone nature of the counting protocol, for example.
Resilience
In recent years, human factors experts have begun to view the human as the hero rather than the source of error. In his follow-up book, “The Human Contribution,” Reason cautions against “an excessive reliance on system measures,” because it is individuals that constitute a system’s last line of defense against error. With the uniquely human ability to anticipate and adapt to changing circumstances, people are capable of recovering problems that have managed to propagate through even the most thoughtfully designed systems. This heroism, however, has its limits. Citing Carthey and colleagues’ observational study of arterial switch operations, in which an increased risk of death was demonstrated with higher numbers of minor events regardless of compensation, Reason proposes a knotted rubber band model of system resilience ( Fig. 2 ). In it, the system is analogous to a rubber band, with a knot in the middle to represent current operating conditions. To maintain safety, the knot must stay within a narrow operating zone; stretch applied in one direction by dangerous perturbations in the system must be counteracted by compensatory corrections in the opposite direction. With a rising number of perturbations and corrections, the system becomes distorted beyond its capacity to respond.
Theoretical models
Error
In his 1990 treatise, “Human Error,” Jim Reason describes his Swiss cheese model of error ( Fig. 1 ). In it, the system is represented by a stack of Swiss cheese slices, each analogous to a protective layer in the system, with holes symbolizing the potential for failure at each step in the process. Because the holes in Swiss cheese (the vulnerabilities of a system) are not continuous throughout a stack (the system), most problems are stopped at one layer or another, before they culminate in a larger, more consequential error. For a catastrophic failure to occur, the holes must be aligned at every level.
As per Reason, these holes may be of two types: active and latent. Active errors are those that are traditionally invoked during discussions about adverse events: readily apparent, they are committed by a human at “the sharp end,” or at the point of care. A retained foreign body, for example, represents an active error: the failure to remove an instrument at the end of an operation. However, humans do not make these errors in isolation; they are predisposed toward them by latent conditions at “the blunt end,” in the system. Leaving an instrument in a patient is not the act of an individual surgeon. Rather, it is one precipitated by existing flaws in the organizational design of the entire process: the cumbersome and error-prone nature of the counting protocol, for example.
Resilience
In recent years, human factors experts have begun to view the human as the hero rather than the source of error. In his follow-up book, “The Human Contribution,” Reason cautions against “an excessive reliance on system measures,” because it is individuals that constitute a system’s last line of defense against error. With the uniquely human ability to anticipate and adapt to changing circumstances, people are capable of recovering problems that have managed to propagate through even the most thoughtfully designed systems. This heroism, however, has its limits. Citing Carthey and colleagues’ observational study of arterial switch operations, in which an increased risk of death was demonstrated with higher numbers of minor events regardless of compensation, Reason proposes a knotted rubber band model of system resilience ( Fig. 2 ). In it, the system is analogous to a rubber band, with a knot in the middle to represent current operating conditions. To maintain safety, the knot must stay within a narrow operating zone; stretch applied in one direction by dangerous perturbations in the system must be counteracted by compensatory corrections in the opposite direction. With a rising number of perturbations and corrections, the system becomes distorted beyond its capacity to respond.
Methodologies
Retrospective Studies
The characterization of intraoperative human and system factors that impact safety has thus far been limited. Among available methodologies, the most widely used is the retrospective reconstruction of the intraoperative events: root or common cause analysis, for example, or the analysis of malpractice claims data. Although this research has been informative about the specific factors that may lead to adverse outcomes, it is susceptible to bias. These post hoc analyses suffer from inaccurate or incomplete recall; without a contemporaneous record, it is difficult to capture all of the mechanisms that have culminated in error. Furthermore, focusing research efforts on the negative effects of care selects for only part of all the available data; information regarding events that are averted or compensated, processes that would be highly instructive in understanding safety in the OR, is lost.
Field Observations
Prospective data collection in the OR, therefore, is needed to completely describe the intraoperative delivery of care. Field observations have been described by several groups but have yet to be broadly applied; most of these studies are restricted to small case series at single institutions, for several reasons. First, human factors engineering is a new field to medicine, and few people with experience in both disciplines (or multidisciplinary collaborations) exist. Access to the OR may be difficult to attain because of an underrecognition of intraoperative safety problems and cultural mores regarding provider privacy in the workplace. Those who are successful in gaining entry are likely to encounter additional cognitive barriers to the complete transcription of intraoperative events; it can be difficult to completely observe multiple simultaneous conversations or incidents, to link all downstream occurrences to all earlier preconditions, and to recall everything after the surgery has ended. Moreover, because only a few extra people may unobtrusively be present in any OR at one time, the comprehension of ongoing events may only be as complete as the knowledge base or memory of the observers; consultation with domain experts for clarification purposes may only be realized retrospectively. Nevertheless, most evidence about human factors in the OR has been generated using live field observations and will be reviewed.
Video-Based Observations
In circumventing many of the aforementioned methodological limitations, video-based analyses hold great potential for furthering the study of safety in the OR. Video may be recorded prospectively but reviewed retrospectively and repeatedly, until all events are fully understood and the connections between them are completely deciphered. Therefore, it eliminates many of the issues surrounding observer recall and subjectivity. Additionally, it may serve as an educational tool, a mechanism for providing targeted feedback to individuals, teams, and organizational leaders. However, video poses its own challenges. Although it is theoretically indiscriminate in its capture, it may still generate incomplete data, depending on the technologic capacity or functionality of the audiovisual equipment. Additionally, providers may be reluctant to be recorded because of fears that the recordings will be used during performance evaluations or in courts of law. These concerns may be addressed, at least partly, by carefully constructing research protocols with multiple layers of protection for study subjects, including restricted data access, scheduled data destruction, and acquisition of a Certificate of Confidentiality. This article reviews the evidence generated using video in the OR.
Human factors in the OR
For the purposes of this discussion, human factors are divided into those pertaining to humans and those corresponding to the system. Human attributes are relevant to performance both individually and within a team, and include qualities such as communication, coordination, cooperation, leadership, and vigilance. System features circumscribe the environment in which humans work, for example the equipment they use, the structure of the larger organization in which they work, or the policies that govern them. Several examples from the literature are detailed here. These examples are intended to be illustrative only; they are not exhaustive lists of human factors.
Humans
As active errors were originally conceived by Reason, human cognitive limitations were the most proximal causal factor. The imperfect behavior of individuals, it was thought, makes them prone to failures at all stages of performance: planning (mistakes, ie, flawed intentions), memory storage (lapses, ie, omissions), and task execution (slips, ie, failure to act as planned). Although humans are now viewed with increasing positivity, as agents of recovery, rather than sources of erraticism, their abilities are still subject to limitations. Although individuals are recognized for their ability to compensate, this capacity diminishes with progressive perturbations in the system. The most competent nurse can slip when counting, and is even more likely to do so if simultaneously juggling the surgeons’ requests for new instruments and the anesthesiologists’ need for blood products, coordinating with the preoperative and postoperative units, and answering the resident’s pager. In the past, human limitations have been countered with increased standardization, based upon the theory that these additional barriers to atypical behavior would protect against failure. Protocols requiring radiographs or automating the count procedure with bar-coding or radiofrequency identification technology decrease reliance on the error-prone manual count. However, recent human factors data indicate that flexibility is needed in the system to permit heroes to maneuver ; one must remain cognizant of the fact that even well-intended protocols (like the manual count) run the risk of inadvertently disabling providers. An appropriate balance between minimizing human slips, lapses, and mistakes and maximizing human heroic potential must be maintained.
Communication is one of the most studied and most critical human factors in medicine. Root cause analyses of sentinel events reported to the Joint Commission from 2004 through 2011 implicate faulty communication in 56% of operative or postoperative complications, 64% of retained foreign bodies, and 69% of wrong patient, wrong site, or wrong procedure cases. The importance of communication is further supported by reviews of surgical malpractice claims. Griffen and colleagues attribute 22% of complications to miscommunication, making it the most pervasive behavioral problem of all they investigated, whereas Greenberg and colleagues place 30% of all communication breakdowns in the OR. Lingard and colleagues estimate that 31% of all procedurally relevant communications in the OR fail; of these, 36% have tangible effects, such as inefficiency, delay, resource waste, or procedural error.
Miscommunication has multiple causes, and therefore is best addressed with a multipronged approach. Standardization may help in certain selected scenarios; protocols may serve as memory aids, for example, ensuring that all salient points are covered in a discussion. After standardized communication was integrated into handoffs at Northwestern University, surgical residents’ perceptions of accuracy, completeness, and clarity during the transfer of care improved significantly. After implementing the Situation, Background, Assessment, and Recommendation model of communication into their surgical curriculum, a decrease in order entry errors was seen at the Mount Sinai School of Medicine. The University of Washington’s computerized sign-out system allowed residents to spend more time with patients during prerounds and halved the number of patients missed on rounds, while improving resident ratings of continuity of care and workload.
Checklists work analogously in the OR, reminding providers to do the things that are relevant to almost every operation, but also have another important function. Unlike surgical inpatient teams, the OR team is multidisciplinary; the individuals that constitute it are more likely to differ in their understandings of the situation at hand. The checklist compels them to establish a shared mental model that enables each team member to better anticipate and plan his or her own role. Multinational studies have shown its impact on patient morbidity and mortality, as well as provider attitudes regarding safety.
However, standardized protocols cannot help with most communication in the OR, such as that which occurs spontaneously, in response to continuously evolving events. In these situations, communication is best accomplished ad hoc, with flexibility for individuals to speak up about arising threats to safety as they see fit. To achieve safety, a level of candidness, and hence a sense of team is needed. The OR must be an environment in which each team member recognizes and is comfortable in his or her role as an equal contributor; it is therefore a form of checks and balances for each individual and the system. The importance of OR teamwork to patient outcomes is well established. Across 44 Veterans Affairs Medical centers and eight academic hospitals, OR team members who reported higher levels of positive communication and collaboration with attending and resident physicians on the surgical service were found to have lower risk-adjusted morbidity rates. Mazzocco and colleagues showed an increased odds of complications or death when intraoperative information sharing, a communication behavior that they distinguish from briefing and that incorporates “mutual respect” and “appropriate[ness],” was observed to be low. In Catchpole and colleagues’ observational study of laparoscopic cholecystectomies and carotid endarterectomies, higher leadership and management skills scores for surgeons and nurses correlated with shorter operating times and lower rates of procedural problems and errors outside the operating field, respectively.
As these studies show, a high degree of variability surrounds teamwork in the OR. Even within a single OR team, the perception of it may differ, depending on the discipline of the reporting party. Compared with anesthesiologists and nurses, surgeons seem to overestimate the communication and teamwork in the room. These disparities may be the result of the traditional vertical hierarchy in surgery. Surgeons, at its top, are simply not the ones who feel constrained by it, and thus are less likely to recognize the value of a flattened one (ie, in the open communication or shared decision-making that it would promote). Likewise, although nurses, anesthesiologists, and surgeons are equally capable of recognizing tension in the OR, they disagree on the responsibility for creating and resolving it.
Although certainly more amorphous a target than a successful handoff or briefing, teamwork is amenable to intervention. After introducing a team training curriculum, Northwestern University reduced their observable intraoperative communication failure rate from 0.7 per hour to 0.3 per hour. At the University of Oxford, a nontechnical skills course decreased operative technical errors and nonoperative procedural errors during laparoscopic cholecystectomies. The Veterans Health Administration, having implemented a medical team training program for OR personnel in its facilities on a rolling basis, documented a decline in risk-adjusted surgical mortality rate that was 50% greater in the trained hospitals than in the untrained ones. These interventions represent adaptations of Crew Resource Management (CRM), a training module developed in aviation to educate cockpit crews about communication (eg, assertiveness, briefing/debriefing), error management (eg, the recognition of “red flag” situations), and teamwork (eg, cross-checking, interpersonal skills, shared mental models, conflict resolution, and flat hierarchies), and thus far have been conducted in a one-time fashion. Despite their apparent success, the investigators of these studies note the limitations of a single intervention; because the adoption of CRM techniques represents a significant cultural and professional shift in medicine, continuous training and feedback are needed.
Several instruments have been developed for measuring teamwork in the OR, and may be considered for assessments of baseline needs, and measurements of postintervention change and sustainability over time. The Observational Teamwork Assessment for Surgery (OTAS) consists of a teamwork-related task checklist (patient tasks, equipment/provisions tasks, and communication tasks) and a global rating scale for teamwork-related behaviors (communication, coordination, leadership, monitoring, and cooperation). Although its developers report good interobserver reliability and content validity, they have also described a learning curve for using it, which may limit its reproducibility by other groups. The Oxford Non-Technical Skills System (NOTECHS) rates each OR subteam (anesthesiology, nursing, surgery) on four dimensions: leadership and management; teamwork and cooperation; problem-solving and decision-making; and situation awareness. Its developers also have shown reliability and validity, and have correlated it with OTAS, but it also has not found widespread use outside of its home institution.
The System
In an operation, the system may refer to the physical environment of that particular OR or the policies, practices, and organizational structure of the department or hospital. It may also implicate the professional culture or values of an institution as a whole, or that of the discipline of surgery.
As a human factor that describes the system, equipment has face validity for most surgeons; it is easy to appreciate the value in having functional, well-designed equipment available at the appropriate times. Healey and colleagues documented 64 instances of unavailable or nonfunctional equipment in 35 of 50 observed general surgical procedures, and of all of the intraoperative distractions or interruption noted, these contributed the most to interference with the case. In 31 cardiac operations, Wiegmann and colleagues mapped 11% of surgical flow disruptions (“deviations from the natural process of an operation”) to difficulties with equipment or technology.
Perhaps less readily understood, but no less critical, are the organization processes of the OR. For example, in a traditional OR system, surgeons provides their own estimated case durations, a practice that introduces a great deal of subjectivity and variability, hindering attempts to match OR capacity to use. Without accurate approximations of case length, the appropriate allocation of human and equipment resources is difficult. The authors’ own study observed an instance in which more oncology cases were simultaneously booked than the number of oncology kits available; the team expended extra time and effort to obtain the necessary instruments in a piecemeal fashion, and the case was delayed. At the Mayo Clinic, the development of a surgeon-specific procedural database to provide estimates for case duration based on historical and prospective moving averages was among several initiatives that led to increased OR efficiency and financial performance.
Similarly, in a traditional OR system, surgeons specify the contents of their own instrument kits. With this practice, thousands of case-cards or pick-tickets may result, consuming a significant amount of nursing and central processing time and effort. After nursing leadership and surgical faculty collaborated to consolidate and streamline the instrument trays at the University of Alabama, tray and case cart errors decreased. Because circulators spent less time making phone calls to central sterile and flash-sterilizing instruments, their ability to attend to the case increased.
To the authors’ knowledge, no instruments are available to assess the system in isolation. The Safety Attitudes Questionnaire and the OR Management Attitudes Questionnaire ask respondents to rate teamwork and describe the organizational climate toward safety. Wiegmann and colleagues’ system includes a teamwork category, and Healey and colleagues’ contains several measures of communication and “procedural” interference, as well as the environment. The Disruptions in Surgery Index also incorporates individual and team factors in its list of potential disruptions, and is essentially a survey, rather than an observational tool, querying respondents about the perceived impact on themselves and their team members.
Related posts:
Variation in Mortality After High-Risk Cancer Surgery
Unexpected Readmissions After Major Cancer Surgery
Importance of and Adherence to Lymph Node Staging Standards in Gastrointestinal Cancer
Appropriate Use of Surgical Procedures for Patients with Cancer
Collaboration with the Community Cancer Center
Value-Based Health Care
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
