Robert W. Albert

Development and Evaluation of a Graphical Anesthesia Drug Display

Background Usable real-time displays of intravenous anesthetic concentrations and effects could significantly enhance intraoperative clinical decision-making. Pharmacokinetic models are available to estimate past, present, and future drug effect-site concentrations, and pharmacodynamic models are available to predict the drugs associated physiologic effects. Methods An interdisciplinary research team (bioengineering, architecture, anesthesiology, computer engineering, and cognitive psychology) developed a graphic display that presents the real-time effect-site concentrations, normalized to the drugs’ EC95, of intravenous drugs. Graphical metaphors were created to show the drugs’ pharmacodynamics. To evaluate the effect of the display on the management of total intravenous anesthesia, 15 anesthesiologists participated in a computer-based simulation study. The participants cared for patients during two experimental conditions: with and without the drug display. Results With the drug display, clinicians administered more bolus doses of remifentanil during anesthesia maintenance. There was a significantly lower variation in the predicted effect-site concentrations for remifentanil and propofol, and effect-site concentrations were maintained closer to the drugs’ EC95. There was no significant difference in the simulated patient heart rate and blood pressure with respect to experimental condition. The perceived performance for the participants was increased with the drug display, whereas mental demand, effort, and frustration level were reduced. In a postsimulation questionnaire, participants rated the display to be a useful addition to anesthesia monitoring. Conclusions The drug display altered simulated clinical practice. These results, which will inform the next iteration of designs and evaluations, suggest promise for this approach to drug data visualization.

The Evaluation of a Pulmonary Display to Detect Adverse Respiratory Events Using High Resolution Human Simulator

OBJECTIVE Authors developed a picture-graphics display for pulmonary function to present typical respiratory data used in perioperative and intensive care environments. The display utilizes color, shape and emergent alerting to highlight abnormal pulmonary physiology. The display serves as an adjunct to traditional operating room displays and monitors. DESIGN To evaluate the prototype, nineteen clinician volunteers each managed four adverse respiratory events and one normal event using a high-resolution patient simulator which included the new displays (intervention subjects) and traditional displays (control subjects). Between-group comparisons included (i) time to diagnosis and treatment for each adverse respiratory event; (ii) the number of unnecessary treatments during the normal scenario; and (iii) self-reported workload estimates while managing study events. MEASUREMENTS Two expert anesthesiologists reviewed video-taped transcriptions of the volunteers to determine time to treat and time to diagnosis. Time values were then compared between groups using a Mann-Whitney-U Test. Estimated workload for both groups was assessed using the NASA-TLX and compared between groups using an ANOVA. P-values < 0.05 were considered significant. RESULTS Clinician volunteers detected and treated obstructed endotracheal tubes and intrinsic PEEP problems faster with graphical rather than conventional displays (p < 0.05). During the normal scenario simulation, 3 clinicians using the graphical display, and 5 clinicians using the conventional display gave unnecessary treatments. Clinician-volunteers reported significantly lower subjective workloads using the graphical display for the obstructed endotracheal tube scenario (p < 0.001) and the intrinsic PEEP scenario (p < 0.03). CONCLUSION Authors conclude that the graphical pulmonary display may serve as a useful adjunct to traditional displays in identifying adverse respiratory events.

A simulation-based evaluation of a graphic cardiovascular display.

INTRODUCTION:A graphic presentation of complex information can facilitate early detection and management of adverse events. Prior work found that graphical presentation of selected cardiovascular variables led to earlier detection of a simulated ischemic event. Based on these findings, a second evaluation explored the utility of a graphical cardiovascular display (GCD) in a variety of simulated adverse cardiopulmonary events for two different display configurations. In this evaluation, we revised the GCD to present hemodynamic variables with or without a pulmonary artery catheter. Our hypotheses were that the revised GCD would improve detection of adverse cardiopulmonary events and add no additional perceived workload. METHODS:Sixteen anesthesiologists and anesthesia residents were enrolled in a simulation-based evaluation of the GCD. Participants were randomly split into two groups balanced for expertise and asked to manage six simulated adverse cardiopulmonary events. The GCD was present in half of the simulations, balanced across scenarios and groups. Participants’ verbalizations and actions during each scenario were recorded and transcribed. Transcripts of treatment interventions were subsequently rated by two blinded expert anesthesiologists. Perceived workload, time to detection, and proper treatment of the adverse event were compared between groups. RESULTS:Experts ranked anesthesiologists using the GCD as being more effective overall and individually in three of six scenarios. Use of the GCD was demonstrated to influence the time to detection and the time to treatment of some critical events. There were no workload differences between display groups. DISCUSSION:Treatment intervention by participants using the GCD was rated superior by two blinded experts. The presence of the GCD resulted in a modest improvement in the time to detect myocardial ischemia and increased pulmonary capillary wedge pressure. The GCD may be a useful adjunct to monitor patients during adverse cardiopulmonary events.

Graphical user interface simplifies infusion pump programming and enhances the ability to detect pump-related faults

BACKGROUND:Drug administration errors are frequent and are often associated with the misuse of IV infusion pumps. One source of these errors may be the infusion pump’s user interface. METHODS:We used failure modes-and-effects analyses to identify programming errors and to guide the design of a new syringe pump user interface. We designed the new user interface to clearly show the pump’s operating state simultaneously in more than 1 monitoring location. We evaluated anesthesia residents in laboratory and simulated environments on programming accuracy and error detection between the new user interface and the user interface of a commercially available infusion pump. RESULTS:With the new user interface, we observed the number of programming errors reduced by 81%, the number of keystrokes per task reduced from 9.2 ± 5.0 to 7.5 ± 5.5 (mean ± SD), the time required per task reduced from 18.1 ± 14.1 seconds to 10.9 ± 9.5 seconds and significantly less perceived workload. Residents detected 38 of 70 (54%) of the events with the new user interface and 37 of 70 (53%) with the existing user interface, despite no experience with the new user interface and extensive experience with the existing interface. CONCLUSIONS:The number of programming errors and workload were reduced partly because it took less time and fewer keystrokes to program the pump when using the new user interface. Despite minimal training, residents quickly identified preexisting infusion pump problems with the new user interface. Intuitive and easy-to-program infusion pump interfaces may reduce drug administration errors and infusion pump-related adverse events.

Psychophysical scaling of a cardiovascular information display

A new method was developed to increase the saliency of changing variables in a cardiovascular visualization for use by anesthesiologists in the operating room (OR). Clinically meaningful changes in patient physiology were identified and then mapped to the inherent psychophysical properties of the visualization. A long history of psychophysical research has provided an understanding of the parameters within which the human information processing system is able to detect changes in the size, shape and color of visual objects (Gescheider, 1976, Spence, 1990, and Baird, 1970). These detection thresholds are known as just noticeable differences (JNDs) which characterize the amount of change in an objects attribute that is recognizable 50% of the time. A prototype version of the display has been demonstrated to facilitate anesthesiologists performance while reducing cognitive workload during simulated cardiac events (Agutter et al., 2002). In order to further improve the utility of the new cardiovascular visualization, the clinically relevant changes in cardiovascular variables are mapped to noticeable perceptual changes in the representational elements of the display. The results of the method described in this paper are used to merge information from the psychophysical properties of the cardiovascular visualization, with clinically relevant changes in the patients cardiovascular physiology as measured by the clinical meaningfulness questionnaire. The result of this combination will create a visualization that is sensitive to changes in the cardiovascular health of the patient and communicates this information to the user in a meaningful, salient and intuitive manner.

Negative priming and stimulus repetition: A reply to Neill and Joordens (2002)

Negative priming is reliably obtained with repeated items, but not with novel items. Here, we review why these stimulus repetition effects raise problems for memorybased theories of negative priming. Furthermore, we provide empirical evidence casting doubt on Neill and Joordens’s (2002) claim that perceptual facilitation masks the effects of episodic retrieval with novel items. Finally, we discuss several theoretical and methodological issues raised in the reply by Neill and Joordens. We conclude that a more straightforward interpretation of these stimulus repetition effects is one based on activation-sensitive inhibition.

Evaluating a Graphical Cardiovascular Display for Anesthesia

A multi-disciplinary team developed a graphical/object-based cardiovascular display to support anesthesiologists decision-making in the operating room. The process of designing the display incorporated central findings from the areas of naturalistic decision-making and medical cognition and used rapid iterative prototyping. To evaluate their performance when using the cardiovascular display, 20 anesthesiologists participated in a study in a high fidelity simulator (METI). Half the subjects used the cardiovascular display, the other half received the same information presented in a numeric format. The anesthesiologists treated two critical events in two simulated patients. In one case the patient suffered from anaphylactic shock, in the other case, severe blood loss and myocardial infarction occurred. Measurements were taken for detection, diagnosis, and treatment time. The cardiovascular display improved performance across these different indicators when anesthesiologists were dealing with a cardiovascular event.

Facilitation of Anesthetic Administration during Simulated Surgeries with a Drug Display

Monitors that show intravenous (IV) drug concentrations currently do not exist. However, using real-time displays of intravenous anesthetic concentrations and effects could significantly enhance intraoperative clinical decision-making. Pharmacokinetic models are available to estimate past, present and future drug concentrations in the brain, and pharmacodynamic models are available to predict the drugs associated physiological effects. An interdisciplinary research team developed a new graphic display incorporating these models to show the predicted concentrations and effects of anesthetic drugs in real-time. To evaluate the effectiveness of the display on the management of anesthesia, 15 anesthesiologists participated in a computer-based simulation study. Anesthesiologists maintained drug concentrations closer to an optimal target level when they used the prototype anesthesia drug display. Participants also reported lower levels of workload with the display and rated the display as a useful addition to anesthesia monitoring.