Neha Malhotra

Development and validation of a surgical workload measure: the surgery task load index (SURG-TLX).

BackgroundThe purpose of the present study was to develop and validate a multidimensional, surgery-specific workload measure (the SURG-TLX), and to determine its utility in providing diagnostic information about the impact of various sources of stress on the perceived demands of trained surgical operators. As a wide range of stressors have been identified for surgeons in the operating room, the current approach of considering stress as a unidimensional construct may not only limit the degree to which underlying mechanisms may be understood but also the degree to which training interventions may be successfully matched to particular sources of stress.MethodsThe dimensions of the SURG-TLX were based on two current multidimensional workload measures and developed via focus group discussion. The six dimensions were defined as mental demands, physical demands, temporal demands, task complexity, situational stress, and distractions. Thirty novices were trained on the Fundamentals of Laparoscopic Surgery (FLS) peg transfer task and then completed the task under various conditions designed to manipulate the degree and source of stress experienced: task novelty, physical fatigue, time pressure, evaluation apprehension, multitasking, and distraction.ResultsThe results were supportive of the discriminant sensitivity of the SURG-TLX to different sources of stress. The sub-factors loaded on the relevant stressors as hypothesized, although the evaluation pressure manipulation was not strong enough to cause a significant rise in situational stress.ConclusionsThe present study provides support for the validity of the SURG-TLX instrument and also highlights the importance of considering how different stressors may load surgeons. Implications for categorizing the difficulty of certain procedures, the implementation of new technology in the operating room (man–machine interface issues), and the targeting of stress training strategies to the sources of demand are discussed. Modifications to the scale to enhance clinical utility are also suggested.

Conscious monitoring and control (reinvestment) in surgical performance under pressure

BackgroundResearch on intraoperative stressors has focused on external factors without considering individual differences in the ability to cope with stress. One individual difference that is implicated in adverse effects of stress on performance is “reinvestment,” the propensity for conscious monitoring and control of movements. The aim of this study was to examine the impact of reinvestment on laparoscopic performance under time pressure.MethodsThirty-one medical students (surgery rotation) were divided into high- and low-reinvestment groups. Participants were first trained to proficiency on a peg transfer task and then tested on the same task in a control and time pressure condition. Outcome measures included generic performance and process measures. Stress levels were assessed using heart rate and the State Trait Anxiety Inventory (STAI).ResultsHigh and low reinvestors demonstrated increased anxiety levels from control to time pressure conditions as indicated by their STAI scores, although no differences in heart rate were found. Low reinvestors performed significantly faster when under time pressure, whereas high reinvestors showed no change in performance times. Low reinvestors tended to display greater performance efficiency (shorter path lengths, fewer hand movements) than high reinvestors.ConclusionTrained medical students with a high individual propensity to consciously monitor and control their movements (high reinvestors) displayed less capability (than low reinvestors) to meet the demands imposed by time pressure during a laparoscopic task. The finding implies that the propensity for reinvestment may have a moderating effect on laparoscopic performance under time pressure.

A comparison of evaluation, time pressure, and multitasking as stressors of psychomotor operative performance

BACKGROUND There is gathering interest in determining the typical sources of stress for an operating surgeon and the effect that stressors might have on operative performance. Much of the research in this field, however, has failed to measure stress levels and performance concurrently or has not acknowledged the differential impact of potential stressors. Our aim was to examine empirically the influence of different sources of stress on trained laparoscopic performance. METHODS A total of 30 medical students were trained to proficiency on the validated Fundamentals of Laparoscopic Surgery peg transfer task, and then were tested under 4 counterbalanced test conditions: control, evaluation threat, multitasking, and time pressure. Performance was assessed via completion time and a process measure reflecting the efficiency of movement (ie, path length). Stress levels in each test condition were measured using a multidimensional approach that included the State-Trait Anxiety Inventory (STAI) and the subjects heart rate while performing a task. RESULTS The time pressure condition caused the only significant increase in stress levels but did not influence completion time or the path length of movement. Only the multitasking condition significantly increased completion time and path length, despite there being no significant increase in stress levels. Overall, the STAI and heart rate measures were not correlated strongly. CONCLUSION Recommended measures of stress levels do not necessarily reflect the demands of an operative task, highlighting the need to understand better the mechanisms that influence performance in surgery. This understanding will help inform the development of training programs that encourage the complete transfer of skills from simulators to the operating room.

Exploring Personality Dimensions That Influence Practice and Performance of a Simulated Laparoscopic Task in the Objective Structured Clinical Examination

BACKGROUND Surgical educators have encouraged the investigation of individual differences in aptitude and personality in surgical performance. An individual personality difference that has been shown to influence laparoscopic performance under time pressure is movement specific reinvestment. Movement specific reinvestment has 2 dimensions, movement self-consciousness (MS-C) (i.e., the propensity to consciously monitor movements) and conscious motor processing (CMP) (i.e., the propensity to consciously control movements), which have been shown to differentially influence laparoscopic performance in practice but have yet to be investigated in the context of psychological stress (e.g., the objective structured clinical examination [OSCE]). OBJECTIVE This study investigated the role of individual differences in propensity for MS-C and CMP in practice of a fundamental laparoscopic skill and in laparoscopic performance during the OSCE. Furthermore, this study examined whether individual differences during practice of a fundamental laparoscopic skill were predictive of laparoscopic performance during the OSCE. METHODS Overall, 77 final-year undergraduate medical students completed the movement specific reinvestment scale, an assessment tool that quantifies the propensity for MS-C and CMP. Participants were trained to proficiency on a fundamental laparoscopic skill. The number of trials to reach proficiency was measured, and completion times were recorded during early practice, later practice, and the OSCE. RESULTS There was a trend for CMP to be negatively associated with the number of trials to reach proficiency (p = 0.064). A higher propensity for CMP was associated with fewer trials to reach proficiency (β = -0.70, p = 0.023). CMP and MS-C did not significantly predict completion times in the OSCE (p > 0.05). Completion times in early practice (β = 0.05, p = 0.016) and later practice (β = 0.47, p < 0.001) and number of trials to reach proficiency (β = 0.23, p = 0.003) significantly predicted completion times in the OSCE. CONCLUSION It appears that a higher propensity for CMP predicts faster rates of learning of a fundamental laparoscopic skill. Furthermore, laparoscopic performance during practice is indicative of laparoscopic performance in the challenging conditions of the OSCE. The lack of association between the 2 dimensions of movement specific reinvestment and performance during the OSCE is explained using the theory of reinvestment as a framework. Overall, consideration of personality differences and individual differences in ability during practice could help inform the development of individualized surgical training programs.

Clarifying Assumptions about Intraoperative Stress during Surgical Performance: More Than a Stab in the Dark: Reply

We thank Dr. Ali for his concise annotation of our efforts to validate a tool that evaluates mental workload in surgery [1, 2]. Unlike other safety critical domains, the field of surgery has been slow to acknowledge the impact of intraoperative stress on surgical performance, but recently a sea change has been triggered by authorities in the field of surgical education [3]. We agree with Ali that stress is not by default detrimental to performance. Our aim was to develop a diagnostic tool that identifies the factors that contribute to disrupted performance, should it occur. Indeed, studies of the effects of acute stress on operating performance have shown considerable variability, ranging from no effect to either facilitative or debilitative effects [3–5]. The Yerkes-Dodson law emerged from the earliest attempts to explain the relationship between physiological arousal and performance, but it has been criticized for treating stress as a unitary construct, influenced solely by physiological factors [6]. More recently, Catastrophe Theory has been invoked to model the relationship, using both physiological and psychological (cognitive anxiety) components of stress [7]. The model proposes that physiological arousal displays a mild inverted-U relationship with performance when cognitive anxiety is low, but that catastrophic declines in performance can occur if both physiological arousal and cognitive anxiety are high. Recent surgical literature has elucidated the complexity of stress as a construct and signaled the need for a multidimensional approach to the examination of stress in surgery [3]. The importance of investigating both subjective evaluations of stress and objective measures of performance under intraoperative conditions is evident when the workload measures from our study [2] are compared with the performance and stress measures that we used in a previous study [5]. In the previous study, we investigated laparoscopic peg transfer performance under time pressure, multitasking, and evaluation apprehension conditions using a multidimensional approach. That is, we included objective measures of motor performance (Imperial College Surgical Assessment Device; ICSAD) and both subjective (state anxiety) and objective (heart rate) measures of stress. Time pressure was perceived as most stressful, yet performance was maintained at baseline levels. In contrast, multitasking was not perceived as stressful, yet performance was disrupted [5]. Mental workload is an extremely useful construct when the intention is to examine the mechanisms underpinning such effects, as performance is governed by interacting demands of the task, circumstances in which the task is completed, and the skills, propensities, and perceptions of the individual performing that task [2]. Consequently, while multitasking was not perceived as stressful in our earlier study, it was rated subjectively as causing the highest task complexity, mental demands, and distraction on our SURG-TLX measure [2]. Based on these findings, it is not enough simply to reveal that a particular intraoperative condition caused a surgeon objectively to perform worse (as suggested by Ali); without clues to why performance was affected, prevention of potential catastrophes in the future is a “stab in the dark.” Ali makes a valid point that individuals react differently to stress. For example, a surgeon who feels that he or she has sufficient resources to meet the demands of a situation may view stress in a positive, “challenge” state, but a surgeon who feels dispossessed of the resources required to meet the demands of the situation may view stress in a negative, “threat” state [8]. We have previously shown that individual differences in trait anxiety [9] or the propensity for reinvestment [10, 11] have a significant influence on how efficiently an individual performs a motor task when under evaluative pressure, and recently we have begun to examine these questions in the surgical performance context.

Propensity for movement specific reinvestment by physiotherapists: Implications for education

ABSTRACT Previous studies have shown that the propensity for conscious monitoring and control of movement (i.e. movement specific reinvestment) influences the acquisition of movement skills. Physiotherapists, whose primary function is to promote effective human movement, also develop specialized movement skills that are necessary to perform diagnostic and therapeutic procedures. To explore the implications for promoting expertise, this current study examined physiotherapists’ propensity for movement-specific reinvestment. Practitioners and students in physiotherapy, and other rehabilitation, and non-health professionals, completed the Movement Specific Reinvestment Scale, which measures two dimensions of reinvestment: 1) conscious motor processing (CMP); and 2) movement self-consciousness (MS-C). Physiotherapists scored significantly higher than other professionals on both CMP and MS-C. Specifically among physiotherapists, those with relatively fewer years of practice tended to have higher MS-C scores. Movement-specific reinvestment appears to be a characteristic of physiotherapists that could be relevant for understanding the ways in which novices think and act as they progress to expertise. Further research is recommended to examine the role of reinvestment in performance of different tasks of varying complexity by novice physiotherapists.

Cutting errors in surgery: experience limits underestimation bias in a simulated surgical environment.

OBJECTIVE Error management is crucial in surgery and needs to be developed through appropriate training and education. Research suggests that perceptual errors may be more likely in laparoscopic environments. The objective of this work is to investigate error management by novices compared with experienced surgeons when performing a simple simulated incision in a visually challenging environment. METHODS Novices (n = 20) and experienced surgeons (n = 11) viewed pairs of horizontal lines on a laparoscopic monitor. Participants were asked to replicate the line lengths by making simulated incisions. The task was completed with or without online visual feedback of the incising hand. In a second phase of the study, the task was complicated by embedding the lines within a perceptual illusion (i.e., Ponzo illusion). RESULTS Incision lengths generally were shorter than the actual lengths of the viewed lines for all participants. For the novices, however, this underestimation bias was exacerbated when visual feedback of the incising hand was unavailable (p < 0.001), whereas the surgeons were not affected by loss of vision of the incising hand (p = 0.864). Furthermore, novices were influenced by the perceptual illusion designed to alter perceptions of line length (p = 0.021), whereas the surgeons did not appear to be influenced by the illusion (p = 0.945). CONCLUSIONS A perceptual bias towards incision length underestimation may be present when surgery involves a laparoscopic monitor; however, surgical experience may protect against accentuation of the underestimation bias when the task becomes more visually challenging. The bias is discussed using the framework of error management theory.