Stephanie Guerlain

A systems approach to surgical safety.

ConclusionThe documented and “accepted” incident rates in surgery are unacceptably high. Incident rates of 1–5% are generally accepted as a normal part of practice. Current morbidity and mortality reporting, while important, does not sufficiently examine or expose the active and latent errors that lead to adverse outcomes. Further. there is no process in place for systematically learning from surgical incident data so that appropriate changes can be incorporated in practice. Other high-risk industries have shown that process improvements, as well as the promotion of a culture of safety, can have a significant impact on an industry’s safety record. The establishment of surgical protocols and checklists has the potential to improve the standards of training and practice, as well as enhancing operating room communications. Data collection and analysis can identify latent errors that could be addressed through better training, device design, or surgical methods. Computerbased training could be instituted to allow surgeons to practice the perceptual, decision-making, and problemsolving skills that are a major part of surgery. These kinds of activities have been incorporated successfully into other industries and should also be applied to the practice of surgery.

Human factors approach for evaluation and redesign of human–system interfaces of a nuclear power plant simulator

Abstract Nuclear power production is a safety-critical process where ultimate execution of process change decisions lie with the operators. Thus it is important to provide the best possible decision support through effective supervisory control operator interfaces. This requires a human factors/ergonomics approach in the modernization of analog instrumentation and control systems of the existing nuclear power plants. In this article, we describe how this approach is being used for modernization of the ANGRA I power plant. Using a cognitive task analysis (CTA) approach, we observed operators working on an advanced control room of a nuclear power plant digital simulator and noted several opportunities for improvement in the human/system interfaces related to the graphics design, alarm systems and procedure integration. A redesigned prototype was constructed as an alternative to the current simulator and hardcopy procedure manuals. The design improves upon the graphical layout of system information and provides better integration of procedures, automation and alarm systems. The design was validated by expert opinion and a scenario-based comparison. Relevance to industry Human factors/ergonomics are not playing the role they deserve in the design of process control systems making them less controllable than they could be if human factors were adequately incorporated. The use of human factors approach in the design of process control systems throughout the industry presents many opportunities for improvements with regard to system effectiveness, efficiency, reliability and safety.

DiAs User Interface: A Patient-Centric Interface for Mobile Artificial Pancreas Systems

Background: Recent in-hospital studies of artificial pancreas (AP) systems have shown promising results in improving glycemic control in patients with type 1 diabetes mellitus. The next logical step in AP development is to conduct transitional outpatient clinical trials with a mobile system that is controlled by the patient. In this article, we present the user interface (UI) of the Diabetes Assistant (DiAs), an experimental smartphone-based mobile AP system, and describe the reactions of a round of focus groups to the UI. This work is an initial inquiry involving a relatively small number of potential users, many of whom had never seen an AP system before, and the results should be understood in that light. Methods: We began by considering how the UI of an AP system could be designed to make use of the familiar touch-based graphical UI of a consumer smartphone. After developing a working prototype UI, we enlisted a human factors specialist to perform a heuristic expert analysis. Next we conducted a formative evaluation of the UI through a series of three focus groups with N = 13 potential end users as participants. The UI was modified based upon the results of these studies, and the resulting DiAs system was used in transitional outpatient AP studies of adults in the United States and Europe. Results: The DiAs UI was modified based on focus group feedback from potential users. The DiAs was subsequently used in JDRF- and AP@Home-sponsored transitional outpatient AP studies in the United States and Europe by 40 subjects for 2400 h with no adverse events. Conclusions: Adult patients with type 1 diabetes mellitus are able to control an AP system successfully using a patient-centric UI on a commercial smartphone in a transitional outpatient environment.

A comparison of 4 epinephrine autoinjector delivery systems: usability and patient preference.

BACKGROUND Prefilled epinephrine autoinjectors are sometimes improperly used by patients, caregivers, and physicians. A user-centered design process led to the development of 2 prototype epinephrine autoinjectors (INT01 and INT02) that have a unidirectional perceived injection end, a self-retracting needle, and, with INT02, voice instructions to assist in guiding users through administration. OBJECTIVE To compare the usability and patient preference among 4 epinephrine autoinjectors: EpiPen, TwinJect, INT01, and INT02. METHODS A total of 48 participants were divided equally among 3 age groups: 7 to 10, 11 to 15, and 16 to 55 years. In each group, half had prior TwinJect or EpiPen training. In 1-hour sessions, without training, participants performed simulated-use testing under observation for all 4 epinephrine delivery systems. Usability (i.e., the ability to perform the manufacturers labeled instructions), task completion time, and preferences were assessed and analyzed based on device, age, previous experience, sex, device malfunction, and testing order. RESULTS More participants correctly followed all device instructions with INT02 (22 [46%]) than with INT01 (13 [27%]), EpiPen (6 [12%]), or TwinJect (0 [0%]). The difference among devices was significant (P < .01) after adjusting for device malfunctions and age group (the youngest age group [those aged 7-10 years] performed significantly worse than the other 2 groups). Prior experience, sex, and testing order did not significantly affect this measure. The first choice of overall preference was greater (P < .001) for INT02 (35 participants [73%]) vs. INT01 (7 participants [15%]), EpiPen (5 participants [10%]), and TwinJect (1 participant [2%]). CONCLUSION The user-centered device design may have a significant impact on correct epinephrine autoinjector use and patient preference.

The MPC elucidator: a case study in the design for human-automation interaction

In this paper, we describe the design of a decision support system for operators of model-based predictive controllers (MPC). MPC is a form of advanced automatic control that is increasingly common in process operations due to its ability to control and optimize large sections of a process. A cognitive task analysis revealed that current operating displays, which rely on displaying tables of numeric information across several display pages, do not effectively support human operator monitoring, diagnosis, and control of MPC. This case study shows how we applied representation aiding and workspace management design principles to better support the human-automation interaction requirements of monitoring, understanding, and adjusting these complex, semi-autonomous; process controllers. We show how effective user interface design can significantly reduce the complexity of operating with advanced automation, and can lead to improved understanding of how the automation works.

Thirty-day postoperative death rate at an academic medical center.

ObjectiveTo improve understanding of perioperative deaths at an academic medical center. Summary Background DataBecause published data have typically focused on specific patient populations, diagnoses, or procedures, there are few data regarding surgical deaths and complications in institutional or regional studies. Specifically, surgical adverse events and errors are generally not studied comprehensively. This limits the overall understanding of complications and deaths. MethodsData from all operations performed in the main operating suite of the University of Virginia Health Sciences Center from January 1 to June 30, 1999, were compared with state death records to gain a dataset of patients dying within 30 days of surgery. All clinical records from patients who died were screened for adverse events and subsequently reviewed by three surgeons who identified adverse events and errors and performed comparisons with survivors. ResultsOne hundred nineteen deaths followed 7,379 operations performed on 6,296 patients, yielding a patient death rate of 1.9%. Patients dying within 30 days of surgery were older and had higher American Society of Anesthesiologists scores. Of 119 deaths, 86 (72.3%) were attributable to the patient’s primary disease. Twenty-three patient deaths (19.3% of all deaths, 0.37% of all patients) could not be attributed to the patient’s primary disease and thus were suspicious for an adverse event (AE) as the cause of the death. Of the 23 deaths suspicious for AE, 15 (12.6% of all deaths, and 65.2% of AE deaths) followed an error in care and thus were classified as potentially preventable, affecting 0.24% of the study population. ConclusionsOverall, the 30-day postoperative death rate was low in the total surgical population at an academic medical center. Errors and AEs were associated with 12.6% and 19.3% of deaths, respectively. Retrospective review inadequately characterized the nature of AEs and failed to determine causality. Prospective audits of outcomes will enhance our understanding of surgical AEs.

Improving surgical pattern recognition through repetitive viewing of video clips

Previous field studies show that surgery residents and medical students have difficulty recognizing appropriate anatomic cues during laparoscopic surgery, causing delays in procedures and errors. Such observations led to the development of an anatomy recognition training intervention, specifically the use of an ordered set of video clips that show the main steps of a laparoscopic procedure. Each procedural step is shown several times in succession, with each repetition coming from a different surgery, thus exposing the learner to varied anatomy and crucial maneuvers. A factorial experiment with 30 medical students showed that the group using these ordered, perceptual learning modules had a significant increase in scores on questions assessing perceptual knowledge and procedural knowledge, with no corresponding increase for the control group who watched the videos from the same cases but in an unstructured format for the same amount of time (p< 0.05). Neither group showed improvement on strategic or declarative knowledge tests. The study suggests that ordered perceptual learning modules are a potential means for training perceptual and procedural knowledge in an effective, safe, and efficient manner, serving as a complement to other types of training methods that teach physical dexterity, strategic and declarative knowledge.

Morbidity, Mortality, Cost, and Survival Estimates of Gastrointestinal Anastomotic Leaks

BACKGROUND Anastomotic leak, a potentially deadly postoperative occurrence, particularly interests surgeons performing gastrointestinal procedures. We investigated incidence, cost, and impact on survival of anastomotic leak in gastrointestinal surgical procedures at an academic center. STUDY DESIGN We conducted a chart review of American College of Surgeons NSQIP operative procedures with gastrointestinal anastomosis from January 1, 2003 through April 30, 2006. Each case with an American College of Surgeons NSQIP 30-day postoperative complication was systematically reviewed for evidence of anastomotic leak for 12 months after the operative date. We tracked patients for up to 10 years to determine survival. Morbidity, mortality, and cost for patients with gastrointestinal anastomotic leaks were compared with patients with anastomoses that remained intact. RESULTS Unadjusted analyses revealed significant differences between patients who had anastomotic leaks develop and those who did not: morbidity (98.0% vs. 28.4%; p < 0.0001), length of stay (13 vs. 5 days; p ≤ 0.0001), 30-day mortality (8.4% vs. 2.5%; p < 0.0001), long-term mortality (36.4% vs. 20.0%; p ≤ 0.0001), and hospital costs (chi-square [2] = 359.8; p < 0.0001). Multivariable regression demonstrated that anastomotic leak was associated with congestive heart failure (odds ratio [OR] = 31.5; 95% CI, 2.6-381.4; p = 0.007), peripheral vascular disease (OR = 4.6; 95% CI, 1.0-20.5; p = 0.048), alcohol abuse (OR = 3.7; 95% CI, 1.6-8.3; p = 0.002), steroid use (OR = 2.3; 95% CI: 1.1-5.0; p = 0.027), abnormal sodium (OR = 0.4; 95% CI, 0.2-0.7; p = 0.002), weight loss (OR = 0.2; 95% CI, 0.06-0.7; p = 0.011), and location of anastomosis: rectum (OR = 14.0; 95% CI, 2.6-75.5; p = 0.002), esophagus (OR = 13.0; 95% CI, 3.6-46.2; p < 0.0001), pancreas (OR = 12.4; 95% CI, 3.3-46.2; p < 0.0001), small intestine (OR = 6.9; 95% CI, 1.8-26.4; p = 0.005), and colon (OR = 5.2; 95% CI, 1.5-17.7; p = 0.009). CONCLUSIONS Significant morbidity, mortality, and cost accompany gastrointestinal anastomotic leaks. Patients who experience an anastomotic leak have lower rates of survival at 30 days and long term.

Intelligent decision support systems

We examine characteristics common to successful intelligent decision support systems. In doing this, we attempt to bridge the gap between disparate communities engaged in building various parts of these systems. Three systems were examined in detail from widely different applications and more than 20 additional systems were considered at a lower level of detail. By examining deployed decision support systems within the context of a broad framework we hope to capture the characteristics that can guide future development efforts. We see this as a first step in developing an in-depth compendium that will help bridge the gap between important yet typically isolated fields.

Using video data for the analysis and training of medical personnel

This paper describes a set of studies that use audio–visual recording in an actual environment (surgery) to study the effectiveness of various patient safety interventions. Video is used in several different ways: as the intervention in one of the studies, and as a means to capture team behavior during surgeries for the other two studies. This paper summarises the logistical, legal, regulatory, technical, financial, social and methodological factors that must be considered and discusses solutions to many of these potential barriers. Although audio–visual recording has a long history in human factors research, only now are the technical, financial and logistic barriers less of a concern, as all data can now be stored and analysed electronically, making many previously cumbersome factors less so through the use of technology. Perhaps the most challenging areas that require more research are the methodological difficulties encountered when observing teams in an uncontrolled environment.