Heart rate and heart rate variability as indirect markers of surgeons’ intraoperative stress

Applying augmented reality in teaching of surgical residents-telementoring, a "stress-free" way to surgical autonomy?

BACKGROUND

Achieving surgical autonomy can be considered the ultimate goal of surgical training. Innovative head-mounted augmented reality (AR) devices enable visualization of the operating field and teaching from remote. Therefore, utilization of AR glasses may be a novel approach to achieve autonomy. The aim of this pilot study is to analyze the feasibility of AR application in surgical training and to assess its impact on intraoperative stress.

METHODS

A head-mounted RealWear Navigator® 500 glasses and the TeamViewer software were used. Initial "dry lab" testing of AR glasses was performed in combination with the Symbionix LAP Mentor™. Subsequently, residents performed various stage-adapted surgical procedures semi-autonomously (SA) (on-demand consultation of senior surgeon, who is in theatre but not scrubbed) versus permanent remote supervision (senior surgeon not present) via augmented reality (AR) glasses, worn by the resident in theatre. Stress was measured by intraoperative heart rate (Polar® pulse belt) and State-Trait Anxiety Inventory (STAI) questionnaire.

RESULTS

After "dry lab" testing, N = 5 senior residents performed equally N = 25 procedures SA and with AR glasses. For both, open and laparoscopic procedure AR remote assistance showed satisfactory applicability. Utilization of AR significantly reduced intraoperative peak pulse rate from 131 to 119 bpm (p = 0.004), as compared with the semi-autonomous group. Likewise, subjectively perceived stress according to STAI was significantly lower in the AR group (p = 0.011).

CONCLUSION

AR can be applied in surgical training and may help to reduce stress in theatre. In the future, AR has a huge potential to become a stepping stone to surgical autonomy.

Cognitive ergonomics and robotic surgery

Cognitive ergonomics refer to mental resources and is associated with memory, sensory motor response, and perception. Cognitive workload (CWL) involves use of working memory (mental strain and effort) to complete a task. The three types of cognitive loads have been divided into intrinsic (dependent on complexity and expertise), extraneous (the presentation of tasks) and germane (the learning process) components. The effect of robotic surgery on CWL is complex because the postural, visualisation, and manipulation ergonomic benefits for the surgeon may be offset by the disadvantages associated with team separation and reduced situation awareness. Physical fatigue and workflow disruptions have a negative impact on CWL. Intraoperative CWL can be measured subjectively post hoc with the use of self-reported instruments or objectively with real-time physiological response metrics. Cognitive training can play a crucial role in the process of skill acquisition during the three stages of motor learning: from cognitive to integrative and then to autonomous. Mentorship, technical practice and watching videos are the most common traditional cognitive training methods in surgery. Cognitive training can also occur with computer-based cognitive simulation, mental rehearsal, and cognitive task analysis. Assessment of cognitive skills may offer a more effective way to differentiate robotic expertise level than automated performance (tool-based) metrics.

The effect of music on the operating surgeon: a pilot randomized crossover trial (the MOSART study)

OBJECTIVE

The experience of stress is common among surgeons while working in the operating theatre (OT). Understanding and finding ways to mitigate this stress is important for optimizing surgical quality and maintaining clinician wellbeing. In this pilot study, we tested the feasibility and reported the outcomes of measuring the effect of background music on intra-operative surgeon stress in the clinical environment.

METHODS

The effect of Music on the Operating Surgeon: A pilot Randomized crossover Trial (the MOSART study) was conducted over a 9-month period in a single-centre. Vascular and general surgeons acting as primary operators (POs) performing elective, general anaesthetic operations were included. The intervention was surgeon-selected music, and the control was the absence of music. Outcome measures were feasibility (recruitment rate, practicability, and completeness of data), heart rate variability (HRV) indices, the Six-Item State-Trait Anxiety Inventory (STAI-6), and the Surgical Task-load Index (SURG-TLX).

RESULTS

Five POs performed 74 eligible randomized cases. The protocol was well tolerated, and no cases were abandoned. Data was incomplete in 8% of cases. The overall mean (SD) operative SURG-TLX score was 48 (±22). Mean HR increased and RMSSD decreased significantly from baseline, suggesting reduced parasympathetic activity while operating. The presence of intra-operative music was not found to affect the psychological or physiological outcomes.

CONCLUSIONS

A music interventional study of this nature is feasible in the operating theatre environment, though no difference was found between in the music and non-music conditions. Follow-up research in a simulated environment with intensive physiological monitoring could be considered.

Energy Consumption and Substrate Utilization During Spinal Surgery

INTRODUCTION

This study aims to measure surgeon physiologic stress and energy expenditure during adult spine surgery. Energy expenditures were assessed based on patient BMI, lead use, instrumentation/intraoperative navigation, primary/revision surgeries, tranexamic acid (TXA) use, and anatomic region involved.

METHODS

The senior author wore a heart rate (HR) monitor and triaxial accelerometer during spinal surgeries, providing assessments of mean HR, maximum HR, calories consumed/minute, and calories as measured by a Polar device (P calories) and Fitbit device (F calories).

RESULTS

One hundred sixty-two surgeries were included. Median patient age was 62 years. Median BMI was 29.02. Significant differences existed for BMI and estimated blood loss (P < 0.05). TXA use had a significant effect on case time, estimated blood loss, P calories, F calories, and Kcal/min (P < 0.05). Instrumentation use was significant for all variables (P < 0.05), except for mean HR and Kcal/min (P > 0.05). Lead use did not have a significant effect on max HR, P calories, F calories, and Kcal/min (P > 0.05). Navigation use was associated with significant differences for every variable tested (P ≤ 0.05). Differences were observed between primary and revision surgeries for case time, estimated blood loss, and F calories (P < 0.05).

CONCLUSIONS

In spinal surgery, the use of navigation, instrumentation use, TXA use, and performing revision surgeries were associated with increased energy expenditure and can potentially increase surgeon fatigue.

A Framework for the Evaluation of Human Machine Interfaces of Robot-Assisted Colonoscopy

The Human Machine Interface (HMI) of intraluminal robots has a crucial impact on the clinician's performance. It increases or decreases the difficulty of the tasks, and is connected to the users' physical and mental stress.

OBJECTIVE

This article presents a framework to compare and evaluate different HMIs for robotic colonoscopy, with the objective of identifying the optimal HMI that minimises the clinician's effort and maximises the clinical outcomes.

METHODS

The framework comprises a 1) a virtual simulator (clinically validated), 2) wearable sensors measuring the cognitive load, 3) a data collection unit of metrics correlated to the clinical performance, and 4) questionnaires exploring the users' impressions and perceived stress. The framework was tested with 42 clinicians investigating the optimal device for tele-operated control of robotic colonoscopes. Two control devices were selected and compared: a haptic serial-kinematic device and a standard videogame joypad.

RESULTS

The haptic device was preferred by the endoscopists, but the joypad enabled better clinical performance and reduced cognitive and physical load.

CONCLUSION

The framework can be used to evaluate different aspects of a HMI, both hardware and software, and determine the optimal HMI that can reduce the burden on clinicians while improving the clinical outcome.

SIGNIFICANCE

The findings of this study, and of future studies performed with this framework, can inform the design and development of HMIs for intraluminal robots, leading to improved clinical performance, reduced physical and mental stress for clinicians, and ultimately better patient outcomes.

Examining workload variations among different surgical team roles, specialties, and techniques: a multicenter cross-sectional descriptive study

BACKGROUND

A high workload may negatively impact the surgical team's performance and jeopardize patient safety. The aim of this study was to measure the workload of the surgical team across different surgical roles, specialties, and techniques in several hospitals.

METHODS

This cross-sectional multicenter study was performed in the operating rooms of eight teaching hospitals affiliated with Isfahan University of Medical Sciences, Iran. At the conclusion of each surgical procedure, all members of the surgical team completed the Surgery Task Load Index (SURG-TLX) questionnaire to assess workload levels. Descriptive statistics, analysis of variance (ANOVA), and Pearson correlations, were performed to compare surgical roles, specialties, techniques, and surgical time on workload overall and by subscale.

RESULTS

A total of 409 workload questionnaires were obtained from 76 surgical teams or cases, involving 346 surgical team members. The total workload among all participants was 32.41 ± 17.21. Surgical complexity, physical demands, and mental demands were the highest workload subscales and distraction was the lowest workload subscale. Cardiovascular specialty had a higher workload compared to other specialties. Open techniques resulted in a higher workload compared to minimally invasive techniques. Surgical technologists who act in both the role of circulating and scrub nurse (C&Ss) experienced the highest workload, followed by surgical residents and surgeons.

CONCLUSIONS

The results of the study showed that the workload for some members of the surgical team is disproportionately high and is influenced by factors such as specialty, technique, role, and surgical duration. By knowing the distribution of workload among the members of the surgical team, efforts can be made to optimize the team members' workload.

Wearable Systems for Unveiling Collective Intelligence in Clinical Settings

Nowadays, there is an ever-growing interest in assessing the collective intelligence (CI) of a team in a wide range of scenarios, thanks to its potential in enhancing teamwork and group performance. Recently, special attention has been devoted on the clinical setting, where breakdowns in teamwork, leadership, and communication can lead to adverse events, compromising patient safety. So far, researchers have mostly relied on surveys to study human behavior and group dynamics; however, this method is ineffective. In contrast, a promising solution to monitor behavioral and individual features that are reflective of CI is represented by wearable technologies. To date, the field of CI assessment still appears unstructured; therefore, the aim of this narrative review is to provide a detailed overview of the main group and individual parameters that can be monitored to evaluate CI in clinical settings, together with the wearables either already used to assess them or that have the potential to be applied in this scenario. The working principles, advantages, and disadvantages of each device are introduced in order to try to bring order in this field and provide a guide for future CI investigations in medical contexts.

Relationship Between Residents' Physiological Stress and Faculty Leadership Skills in a Department of Surgery

BACKGROUND

Leadership skills of team leaders can impact the functioning of their teams. It is unknown whether attending surgeons' leadership skills impact residents' physiological stress. This study sought to (1) assess the relationship between attending surgeons' leadership skills and residents' physiological stress and (2) to characterize lifestyle behaviors associated with resident physiological stress. We hypothesized that strong attending leadership skills would be associated with low resident physiological stress.

STUDY DESIGN

This prospective observational cohort study was conducted at a single urban, academic medical center in the US, over 12 months. Residents were enrolled during their rotation of 1 to 2 months on the Trauma and ICU services. The primary predictor was the attending surgeons' leadership skills that were measured using a weekly survey filled out by residents, using the Surgeons' Leadership Inventory (SLI). The SLI uses a 4-point Likert scale to measure surgeons' leadership skills across eight domains. The primary outcome was residents' physiological stress, which was measured by their Heart Rate Variability (HRV). We recorded the residents' HRV with a WHOOP strap that was continuously worn on the wrist or the bicep. We used multivariate repeated measures gamma regression to assess the relationship between attending leadership skills and residents' physiological stress, adjusting for hours of sleep, age, and service.

RESULTS

Sixteen residents were enrolled over 12 months. The median attending surgeons' leadership score was 3.8 (IQR: 3.2-4.0). The median residents' percent of maximal HRV was 70.8% (IQR: 56.7-83.7). Repeated measure gamma regression model demonstrated a minimal nonsignificant increase of 1.6 % (95% CI: -5.6, 8.9; p-value = 0.65) in the percent of maximal HRV (less resident physiological stress) for every unit increase in leadership score. There was an increase of 2.9% (95% CI= 1.6, 4.2; p-value < 0.001) in the percent of maximal HRV per hour increase in sleep and a significant decrease of 10.9% (95% CI= -16.8, -5.2; < 0.001) in the percent of HRV when working in the ICU compared to the Trauma service.

CONCLUSION

This study revealed that more residents' sleep was associated with lower physiological stress. Attending surgeons' leadership skills were not associated with residents' physiological stress.

Group Changes in Cortisol and Heart Rate Variability of Children with Down Syndrome and Children with Autism Spectrum Disorder during Dog-Assisted Therapy

Dog-assisted therapy is hypothesized to lower stress in children with autism spectrum disorder (ASD) and children with Down syndrome (DS), which may be visible on a physiological level. In this study, we measured heart rate variability (HRV) and salivary cortisol of 20 children with DS or ASD at the beginning and end of six weekly sessions of dog-assisted therapy. We found a decrease of cortisol levels during single sessions, but no overall effect after six sessions (six weeks). The effect of dog-assisted therapy on the increase of HRV could not be confirmed. This study is one of the first to use physiological measurements to test the effects of DAT.

Using Digital Biomarkers for Objective Assessment of Perfusionists' Workload and Acute Stress During Cardiac Surgery

The cardiac operating room (OR) is a high-risk, high-stakes environment inserted into a complex socio-technical healthcare system. During cardiopulmonary bypass (CPB), the most critical phase of cardiac surgery, the perfusionist has a crucial role within the interprofessional OR team, being responsible for optimizing patient perfusion while coordinating other tasks with the surgeon, anesthesiologist, and nurses. The aim of this study was to investigate objective digital biomarkers of perfusionists' workload and stress derived from heart rate variability (HRV) metrics captured via a wearable physiological sensor in a real cardiac OR. We explored the relationships between several HRV parameters and validated self-report measures of surgical task workload (SURG-TLX) and acute stress (STAI-SF), as well as surgical processes and outcome measures. We found that the frequency-domain HRV parameter HF relative power - FFT (%) presented the strongest association with task workload (correlation coefficient: -0.491, p-value: 0.003). We also found that the time-domain HRV parameter RMSSD (ms) presented the strongest correlation with perfusionists' acute stress (correlation coefficient: -0.489, p-value: 0.005). A few workload and stress biomarkers were also associated with bypass time and patient length of stay in the hospital. The findings from this study will inform future research regarding which HRV-based biomarkers are best suited for the development of cognitive support systems capable of monitoring surgical workload and stress in real time.

[Assessment method of cognitive load and stress inducer factors of surgeons and anesthetists in the operating room]

INTRODUCTION

For many years, surgeons and anesthetists have recognized that stress can be present in their daily professional practice. The goal of this study was to identify tools for assessing stress and cognitive load in the operating room.

MATERIAL AND METHODS

We conducted a literature review in the PubMed database of scientific articles published on the subject without date limit using the keywords anesthesia, surgery, surgeon, cognitive workload, definition, pathophysiology, physiological measurement, objective, subjective, stress.

RESULTS

Nineteen articles were selected, focusing on cardiac surgery, gastrointestinal surgery, vascular surgery and urology. No publications concerning ophthalmology were found through the literature search. The means of measurement found were either subjective, such as questionnaires, or objective, such as the study of heart rate variability (HRV), reaction time, eye movements, electrical conductivity of the skin, biological markers and electroencephalogram. Of all these measurement tools, the NASA-TLX questionnaire, used in four articles, and the HRV study, used in eight articles, appear to be the most widely used and are strongly correlated with stress.

CONCLUSION

The articles reviewed use only some of the available tools for assessment of stress and cognitive load. The main objective is to improve the quality of care and the quality of life of caregivers. It would be interesting to develop other methods to identify and better characterize the risk factors that increase stress and cognitive load.

Heart rate and heart rate variability during diagnostic and interventional neuroendovascular procedures

INTRODUCTION

Heart rate variability (HRV) reflects the activity of the autonomic nervous system (ANS) and can be used as a potential predictor of stress-related cardiovascular diseases. This study aimed to assess whether physical and mental strain during the performance of cerebral endovascular procedure influence time-domain HRV parameters in operating surgeon.

MATERIALS AND METHODS

Heart rate (HR) and HRV metrics were measured using a HR sensor chest strap before, during, and after neuroendovascular interventions performed by a single neurosurgeon. Three consecutive data series were reported by recording time domain: before procedure, during and after performing endovascular procedures. HR and HRV parameters were recorded during diagnostic and interventional neuroendovascular procedures. HR and HRV measures were analyzed by procedure type and recording time domain.

RESULTS

HRV measures of a single endovascular neurosurgeon were recorded during 50 procedures. The median intraprocedural HRV score was the lowest and the median HR was the highest (HRV: 52, HR: 89 bpm) compared to preprocedural (HRV: 59, HR: 70 bpm) and postprocedural cardiovascular measures (HRV: 53, HR: 79, bpm, p < 0.001). On univariate linear regression, a negative association of interventional procedures with lower intraprocedural (β = -0.905, p = 0.001) and postprocedural (β = -1.12, p < 0.001) HRV scores compared to the diagnostic procedures was noted.

CONCLUSIONS

HRV is a reliable tool to measure cardiovascular and mental stress. Interventional neuro-endovascular procedures seem to negatively impact the cardiovascular measures of neurointerventionalists. Further longitudinal studies utilizing HRV are warranted to address their long-term effects on the mental health of physicians.

The physiology of intraoperative error: using electrokardiograms to understand operator performance during robot-assisted surgery simulations

BACKGROUND

No platform for objective, synchronous and on-line evaluation of both intraoperative error and surgeon physiology yet exists. Electrokardiogram (EKG) metrics have been associated with cognitive and affective features that are known to impact surgical performance but have not yet been analyzed in conjunction with real-time error signals using objective, real-time methods.

METHODS

EKGs and operating console point-of-views (POVs) for fifteen general surgery residents and five non-medically trained participants were captured during three simulated robotic-assisted surgery (RAS) procedures. Time and frequency-domain EKG statistics were extracted from recorded EKGs. Intraoperative errors were detected from operating console POV videos. EKG statistics were synchronized with intraoperative error signals.

RESULTS

Relative to personalized baselines, IBI, SDNN and RMSSD decreased 0.15% (S.E. 3.603e-04; P = 3.25e-05), 3.08% (S.E. 1.603e-03; P < 2e-16) and 1.19% (S.E. 2.631e-03; P = 5.66e-06), respectively, during error. Relative LF RMS power decreased 1.44% (S.E. 2.337e-03; P = 8.38e-10), and relative HF RMS power increased 5.51% (S.E. 1.945e-03; P < 2e-16).

CONCLUSIONS

Use of a novel, on-line biometric and operating room data capture and analysis platform enabled detection of distinct operator physiological changes during intraoperative errors. Monitoring operator EKG metrics during surgery may help improve patient outcomes through real-time assessments of intraoperative surgical proficiency and perceived difficulty as well as inform personalized surgical skills development.

Cardiac autonomic and cortisol stress responses to real operations in surgeons: relationship with individual psychobiological characteristics and experience

BACKGROUND

Surgeons are exposed to high levels of intraoperative stress, which could compromise their psychological well-being in the long term. This study aimed at exploring the effects of real operations on the activity of stress response systems (i.e., cardiac autonomic function and hypothalamic-pituitary-adrenal axis) during and in the aftermath of surgery, and the moderating role of individual psychobiological characteristics and different levels of experience (senior vs expert surgeons).

METHODS

Heart rate, heart rate variability, and salivary cortisol measures (as indexes of cardiac autonomic and hypothalamic-pituitary-adrenal axis activity, respectively) were assessed during real operations and in the perioperative period in a sample of surgeons (n = 16). Surgeons' psychometric characteristics were collected using questionnaires.

RESULTS

Real operations triggered both cardiac autonomic and cortisol stress responses which were independent from surgeons' level of experience. Intraoperative stress responses did not affect cardiac autonomic activity during the following night but were associated with a blunted cortisol awakening response. Moreover, senior surgeons reported higher levels of negative affectivity and depressive symptoms than expert surgeons prior to the surgery. Lastly, the magnitude of heart rate responses to surgery positively correlated with scores on negative affectivity, depression, perceived stress, and trait anxiety scales.

CONCLUSION

This exploratory study allows to put forward the hypotheses that in surgeons cardiac autonomic and cortisol stress responses to real operations (i) may be associated with specific individual psychological characteristics regardless of the level of experience, (ii) and may have a longer lasting impact on hypothalamic-pituitary-adrenal axis function with potential implications for surgeons' physical and psychological well-being.

Physiological Responses and Training Satisfaction During National Rollout of a Neurosurgical Intraoperative Catastrophe Simulator for Resident Training

BACKGROUND

Systematic use of neurosurgical training simulators across institutions is significantly hindered by logistical and financial constraints.

OBJECTIVE

To evaluate feasibility of large-scale implementation of an intraoperative catastrophe simulation, we introduced a highly portable and low-cost immersive neurosurgical simulator into a nationwide curriculum for neurosurgery residents, during years 2016 to 2019.

METHODS

The simulator was deployed at 9 Society of Neurological Surgeons junior resident courses and a Congress of Neurological Surgeons education course for a cohort of 526 residents. Heart rate was tracked to monitor physiological responses to simulated stress. Experiential survey data were collected to evaluate simulator fidelity and resident attitudes toward simulation.

RESULTS

Residents rated the simulator positively with a statistically significant increase in satisfaction over time accompanying refinements in the simulator model and clinical scenario. The simulated complications induced stress-related tachycardia in most participants (n = 249); however, a cohort of participants was identified that experienced significant bradycardia (n = 24) in response to simulated stress.

CONCLUSION

Incorporation of immersive neurosurgical simulation into the US national curriculum is logistically feasible and cost-effective for neurosurgical learners. Participant surveys and physiological data suggest that the simulation model recreates the situational physiological stress experienced during practice in the live clinical environment. Simulation may provide an opportunity to identify trainees with maladaptive responses to operative stress who could benefit from additional simulated exposure to mitigate stress impacts on performance.

A Systematic Review of Heart Rate Variability as a Measure of Stress in Medical Professionals

Understanding the physiological effects of responding to crises is a critical component in understanding how to manage and prepare medical professionals to be crisis responders. Heart rate variability (HRV) is the variation in rate between a succession of R-R intervals. This variation is not only affected by physiological processes such as respiration or metabolic rate but is also directly controlled by the autonomic nervous system. As such, heart rate variability has been proposed as a noninvasive tool to measure the physiological stress response. The aim of this systematic review is to consolidate heart rate variability literature in the context of medical emergencies to determine if heart rate variability changes predictably from baseline when responding to medical crises. This may demonstrate utility as an objective, noninvasive measure of stress response. A systematic literature review of six databases yielded 413 articles, 17 of which met our inclusion criteria of being written in English, measuring HRV in healthcare providers, and measuring HRV in real or simulated medical resuscitations or procedures. Articles were then analyzed using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) scoring system. Out of the 17 articles reviewed, 11 demonstrated statistically significant results showing heart rate variability responding in a predictable manner to stress. Three articles utilized a medical simulation as the stressor, six used medical procedures, and eight used medical emergencies encountered during clinical work. Overall, a predictable trend in heart rate variability metrics of standard deviation from the mean value of normal-to-normal (N-N) intervals (SDNN), root mean square of the successive differences (RMSSD), mean number of times per time interval in which the change in successive normal sinus (N-N) intervals exceeds 50 ms (PNN50), low frequency % (LF%), and low-frequency-to-high-frequency ratio (LF/HF) was observed when responding to stress. This systematic literature review showed that heart rate variability among healthcare providers responding to stressful scenarios follows a predictable pattern of change and expands our understanding of the physiology of stress in healthcare providers. This review supports the use of HRV to monitor stress during high-fidelity simulation to ensure that appropriate physiological arousal is achieved during the training of medical personnel.

Determination of Waste Management Workers' Physical and Psychological Load: A Cross-Sectional Study Using Biometric Data

Waste management workers experience high stress and physical strain in their work environment, but very little empirical evidence supports effective health management practices for waste management workers. Hence, this study investigated the effects of worker characteristics and biometric indices on workers' physical and psychological loads during waste-handling operations. A biometric measurement system was installed in an industrial waste management facility in Japan to understand the actual working conditions of 29 workers in the facility. It comprised sensing wear for data collection and biometric sensors to measure heart rate (HR) and physical activity (PA) based on electrocardiogram signals. Multiple regression analysis was performed to evaluate significant relationships between the parameters. Although stress level is indicated by the ratio of low frequency (LF) to high frequency (HF) or high LF power in HR, the results showed that compared with workers who did not handle waste, those who did had lower PA and body surface temperature, higher stress, and lower HR variability parameters associated with higher psychological load. There were no significant differences in HR, heart rate interval (RRI), and workload. The psychological load of workers dealing directly with waste was high, regardless of their PA, whereas others had a low psychological load even with high PA. These findings suggest the need to promote sustainable work relationships and a quantitative understanding of harsh working conditions to improve work quality and reduce health hazards.

A Pilot Study of Heart Rate Variability Synchrony as a Marker of Intraoperative Surgical Teamwork and Its Correlation to the Length of Procedure

Objective: Quality of intraoperative teamwork may have a direct impact on patient outcomes. Heart rate variability (HRV) synchrony may be useful for objective assessment of team cohesion and good teamwork. The primary aim of this study was to investigate the feasibility of using HRV synchrony in surgical teams. Secondary aims were to investigate the association of HRV synchrony with length of procedure (LOP), complications, number of intraoperative glitches and length of stay (LOS). We also investigated the correlation between HRV synchrony and team familiarity, pre- and intraoperative stress levels (STAI questionnaire), NOTECHS score and experience of team members. Methods: Ear, nose and throat (ENT) and vascular surgeons (consultant and registrar team members) were recruited into the study. Baseline demographics including level of team members’ experience were gathered before each procedure. For each procedure, continuous electrocardiogram (ECG) recording was performed and questionnaires regarding pre- and intraoperative stress levels and non-technical skills (NOTECHS) scores were collected for each team member. An independent observer documented the time of each intraoperative glitch. Statistical analysis was conducted using stepwise multiple linear regression. Results: Four HRV synchrony metrics which may be markers of efficient surgical collaboration were identified from the data: 1. number of HRV synchronies per hour of procedure, 2. number of HRV synchrony trends per hour of procedure, 3. length of HRV synchrony trends per hour of procedure, 4. area under the HRV synchrony trend curve per hour of procedure. LOP was inversely correlated with number of HRV synchrony trends per hour of procedure (p < 0.0001), area under HRV synchrony trend curve per hour of procedure (p = 0.001), length of HRV synchrony trends per hour of procedure (p = 0.002) and number of HRV synchronies per hour of procedure (p < 0.0001). LOP was positively correlated with: FS (p = 0.043; R = 0.358) and intraoperative STAI score of the whole team (p = 0.007; R = 0.493). Conclusions: HRV synchrony metrics within operating teams may be used as an objective marker to quantify surgical teamwork. We have shown that LOP is shorter when the intraoperative surgical teams’ HRV is more synchronised.

Alignment Between Heart Rate Variability From Fitness Trackers and Perceived Stress: Perspectives From a Large-Scale In Situ Longitudinal Study of Information Workers

BACKGROUND

Stress can have adverse effects on health and well-being. Informed by laboratory findings that heart rate variability (HRV) decreases in response to an induced stress response, recent efforts to monitor perceived stress in the wild have focused on HRV measured using wearable devices. However, it is not clear that the well-established association between perceived stress and HRV replicates in naturalistic settings without explicit stress inductions and research-grade sensors.

OBJECTIVE

This study aims to quantify the strength of the associations between HRV and perceived daily stress using wearable devices in real-world settings.

METHODS

In the main study, 657 participants wore a fitness tracker and completed 14,695 ecological momentary assessments (EMAs) assessing perceived stress, anxiety, positive affect, and negative affect across 8 weeks. In the follow-up study, approximately a year later, 49.8% (327/657) of the same participants wore the same fitness tracker and completed 1373 EMAs assessing perceived stress at the most stressful time of the day over a 1-week period. We used mixed-effects generalized linear models to predict EMA responses from HRV features calculated over varying time windows from 5 minutes to 24 hours.

RESULTS

Across all time windows, the models explained an average of 1% (SD 0.5%; marginal R2) of the variance. Models using HRV features computed from an 8 AM to 6 PM time window (namely work hours) outperformed other time windows using HRV features calculated closer to the survey response time but still explained a small amount (2.2%) of the variance. HRV features that were associated with perceived stress were the low frequency to high frequency ratio, very low frequency power, triangular index, and SD of the averages of normal-to-normal intervals. In addition, we found that although HRV was also predictive of other related measures, namely, anxiety, negative affect, and positive affect, it was a significant predictor of stress after controlling for these other constructs. In the follow-up study, calculating HRV when participants reported their most stressful time of the day was less predictive and provided a worse fit (R2=0.022) than the work hours time window (R2=0.032).

CONCLUSIONS

A significant but small relationship between perceived stress and HRV was found. Thus, although HRV is associated with perceived stress in laboratory settings, the strength of that association diminishes in real-life settings. HRV might be more reflective of perceived stress in the presence of specific and isolated stressors and research-grade sensing. Relying on wearable-derived HRV alone might not be sufficient to detect stress in naturalistic settings and should not be considered a proxy for perceived stress but rather a component of a complex phenomenon.

Stress Management in Pre- and Postoperative Care Amongst Practitioners and Patients in Cardiac Catheterization Laboratory: A Study Protocol

Background

As the number of cardiac diseases continuously increases within the last years in modern society, so does cardiac treatment, especially cardiac catheterization. The procedure of a cardiac catheterization is challenging for both patients and practitioners. Several potential stressors of psychological or physical nature can occur during the procedure. The objective of the study is to develop and implement a stress management intervention for both practitioners and patients that aims to reduce the psychological and physical strain of a cardiac catheterization.

Methods

The clinical study (DRKS00026624) includes two randomized controlled intervention trials with parallel groups, for patients with elective cardiac catheterization and practitioners at the catheterization lab, in two clinic sites of the Ernst-von-Bergmann clinic network in Brandenburg, Germany. Both groups received different interventions for stress management. The intervention for patients comprises a psychoeducational video with different stress management technics and additional a standardized medical information about the cardiac catheterization examination. The control condition includes the in hospitals practiced medical patient education before the examination (usual care). Primary and secondary outcomes are measured by physiological parameters and validated questionnaires, the day before (M1) and after (M2) the cardiac catheterization and at a postal follow-up 6 months later (M3). It is expected that people with standardized information and psychoeducation show reduced complications during cardiac catheterization procedures, better pre- and post-operative wellbeing, regeneration, mood and lower stress levels over time. The intervention for practitioners includes a Mindfulness-based stress reduction program (MBSR) over 8 weeks supervised by an experienced MBSR practitioner directly at the clinic site and an operative guideline. It is expected that practitioners with intervention show improved perceived and chronic stress, occupational health, physical and mental function, higher effort-reward balance, regeneration and quality of life. Primary and secondary outcomes are measured by physiological parameters (heart rate variability, saliva cortisol) and validated questionnaires and will be assessed before (M1) and after (M2) the MBSR intervention and at a postal follow-up 6 months later (M3). Physiological biomarkers in practitioners will be assessed before (M1) and after intervention (M2) on two work days and a two days off. Intervention effects in both groups (practitioners and patients) will be evaluated separately using multivariate variance analysis.

Discussion

This study evaluates the effectiveness of two stress management intervention programs for patients and practitioners within cardiac catheter laboratory. Study will disclose strains during a cardiac catheterization affecting both patients and practitioners. For practitioners it may contribute to improved working conditions and occupational safety, preservation of earning capacity, avoidance of participation restrictions and loss of performance. In both groups less anxiety, stress and complications before and during the procedures can be expected. The study may add knowledge how to eliminate stressful exposures and to contribute to more (psychological) security, less output losses and exhaustion during work. The evolved stress management guidelines, training manuals and the standardized patient education should be transferred into clinical routines.

Activation of the stress response among the cardiac surgical residents: comparison of teaching procedures and other (daily) medical activities

BACKGROUND

The aim of this Pilot study was to investigate the cardiac surgical residents' workload during different surgical teaching interventions and to compare their stress levels with other working time spent in the intensive care unit or normal ward.

METHODS

The objective stress was assessed using two cardiac surgical residents' heart rate variability (HRV) both during surgical activities (32 selected teaching operations (coronary artery bypass graft n = 26 and transcatheter aortic valve implantation n = 6), and during non-surgical periods. Heart rate, time and frequency domains as well as non-linear parameters were analyzed using the Wilcoxon test.

RESULTS

The parasympathetic activity was significantly reduced during the surgical phase, compared to the non-surgical phase: Mean RR (675.7 ms vs. 777.3 ms), RMSSD (23.1 ms vs. 34.0 ms) and pNN50 (4.7% vs. 10.6%). This indicates that the residents had a higher stress level during surgical activities in comparison to the non-surgical times. The evaluation of the Stress Index during the operations and outside the operating room (8.07 vs. 10.6) and the parasympathetic nervous system index (- 1.75 to - 0.91) as well as the sympathetic nervous system index (1.84 vs. 0.65) confirm the higher stress level during surgery. This can be seen too used the FFT Analysis with higher intraoperative LF/HF ratio (6.7 vs. 3.8).

CONCLUSION

HRV proved to be a good, objective method of identifying stress among physicians both in and outside the operating room. Our results show that residents are exposed to high psychological workloads during surgical activities, especially as the operating surgeon.

Objective Measures of Surgeon Non-Technical Skills in Surgery: A Scoping Review

OBJECTIVE

The purpose of this study was to identify, synthesize, and discuss objective behavioral or physiological metrics of surgeons' nontechnical skills (NTS) in the literature.

BACKGROUND

NTS, or interpersonal or cognitive skills, have been identified to contribute to safe and efficient surgical performance; however, current assessments are subjective, checklist-based tools. Intraoperative skill evaluation, such as technical skills, has been previously utilized as an objective measure to address such limitations.

METHODS

Five databases in engineering, behavioral science, and medicine were searched following PRISMA reporting guidelines. Eligibility criteria included studies with NTS objective measurements, surgeons, and took place within simulated or live operations.

RESULTS

Twenty-three articles were included in this review. Objective metrics included communication metrics and measures from physiological responses such as changes in brain activation and motion of the eye. Frequencies of content-coded communication in surgery were utilized in 16 studies and were associated with not only the communication construct but also cognitive constructs of situation awareness and decision making. This indicates the underlying importance of communication in evaluating the NTS constructs. To synthesize the scoped literature, a framework based on the one-way communication model was used to map the objective measures to NTS constructs.

CONCLUSION

Objective NTS measurement of surgeons is still preliminary, and future work on leveraging objective metrics in parallel with current assessment tools is needed.

APPLICATION

Findings from this work identify objective NTS metrics for measurement applications in a surgical environment.

Psychological Effects of Heart Rate and Physical Vibration on the Operation of Construction Machines: Experimental Study

BACKGROUND

A construction method has emerged in which a camera is installed around a construction machine, and the operator remotely controls the machine while synchronizing the vibration of the machine with the images seen from the operator's seat using virtual reality (VR) technology. Indices related to changes in heart rate (HR) and physical vibration, such as heart rate variability (HRV) and multiscale entropy (MSE), can then be measured among the operators. As these indices are quantitative measures of autonomic regulation in the cardiovascular system, they can provide a useful means of assessing operational stress.

OBJECTIVE

In this study, we aimed to evaluate changes in HR and body vibration of machine operators and investigate appropriate methods of machine operation while considering the psychological load.

METHODS

We enrolled 9 remote operators (18-50 years old) in the experiment, which involved 42 measurements. A construction machine was driven on a test course simulating a construction site, and three patterns of operation-riding operation, remote operation using monitor images, and VR operation combining monitor images and machine vibration-were compared. The heartbeat, body vibration, and driving time of the participants were measured using sensing wear made of a woven film-like conductive material and a three-axis acceleration measurement device (WHS-2). We used HRV analysis in the time and frequency domains, MSE analysis as a measure of the complexity of heart rate changes, and the ISO (International Standards Organization) 2631 vibration index. Multiple regression analysis was conducted to model the relationship among the low frequency (LF)/high frequency (HF) HRV, MSE, vibration index, and driving time of construction equipment. Efficiency in driving time was investigated with a focus on stress reduction.

RESULTS

Multiple comparisons conducted via the Bonferroni test and Kruskal-Wallis test showed statistically significant differences (P=.05) in HRV-LF/HF, the vibration index, weighted acceleration, motion sickness dose value (MSDVz), and the driving time among the three operation patterns. The riding operation was found to reduce the driving time of the machine, but the operation stress was the highest in this case; operation based on the monitor image was found to have the lowest operation stress but the longest operation time. Multiple regression analysis showed that the explanatory variables (LH/HF), RR interval, and vibration index (MSDVz by vertical oscillation at 0.5-5 Hz) had a negative effect on the driving time (adjusted coefficient of determination R2=0.449).

CONCLUSIONS

A new method was developed to calculate the appropriate operating time by considering operational stress and suppressing the physical vibration within an acceptable range. By focusing on the relationship between psychological load and physical vibration, which has not been explored in previous studies, the relationship of these variables with the driving time of construction machines was clarified.

The Impact of Thermal Stress on Cognition and the Use of Cooling Wear for Alleviation - an Explorative Study

Increased ambient temperatures during the care of severely burned patients are essential for mitigating hypothermia and minimizing the impact of the consecutive hypermetabolism. For involved medical staff, those conditions may lead to impaired concentration, possibly negatively affecting an optimal patient care. Yet, alleviation strategies are lacking. As a novel coping strategy, cooling wear may be an effective means. This explorative study aimed to investigate the effect of high ambient temperatures on the concentration capacity and cooling wear to alleviate thermal stress. The effects of high ambient temperatures and the additional use of cooling wear on the concentration capacity of medical staff were investigated in six subjects during two simulated burn surgeries. Each individual served as his/her own control undergoing one simulation with and one without cooling wear. Concentration capacity was measured before and after each simulation with a standardized test. The results suggested that high ambient temperatures, as used in burn medicine, negatively affect human concentration capacity. The initial assessment of concentration capacity yielded homogenous values. After heat exposure, subjects wearing cooling wear showed a higher concentration capacity and a lower error rate compared to subjects without cooling wear. Summing up, temperature-related decrements in vigilance and performance among medical personnel may impair the patients' outcome. As an opportunity to withstand thermal stress and improve medical care and safety, cooling wear showed promising results and may be used as heat alleviator. Burn medicine may particularly benefit from further development and rigorous investigation of cooling strategies.

[Subjective certainty to increase the acceptance of automated and connected driving]

An important factor for the acceptance and thus the spread of automated and connected driving (ACD) is the degree of subjective uncertainty that users experience when interacting with automated vehicles. Subjective uncertainties always occur when people are not able to predict the further course of a situation or future events due to lack of experience or information. If such uncertainties occur during the use of automated vehicles, the development of trust and thus acceptance of this technology is impaired by the negative emotions accompanying subjective uncertainties. Within the AutoAkzept project (which full title translates to: Automation without uncertainty to increase the acceptance of automated and connected driving), solutions for user-focused automation have been developed that put vehicle occupants at the center of system development. User-focused systems take into account two basic human needs in human-machine interaction, the need to understand and the need to be understood. For this purpose, user-focused systems use different sensors to detect subjective uncertainties and their influencing factors in real time, integrate this information with context data and make adjustments that reduce subjective uncertainties. The systemic adaptations of user-focused systems follow a holistic approach that includes the levels of vehicle guidance, interior adaptation and information presentation as well as target guidance are included. By reducing or avoiding subjective uncertainties, the project developments contribute to a positive, comfortable user experience and help to increase the acceptance of ACD. This paper presents research results of AutoAkzept on the topics of user state and activity modelling as well as needs-based adaptation strategies, which represent key components for the implementation of user-focused automation.

High density optical neuroimaging predicts surgeons's subjective experience and skill levels

Measuring cognitive load is important for surgical education and patient safety. Traditional approaches of measuring cognitive load of surgeons utilise behavioural metrics to measure performance and surveys and questionnaires to collect reports of subjective experience. These have disadvantages such as sporadic data, occasionally intrusive methodologies, subjective or misleading self-reporting. In addition, traditional approaches use subjective metrics that cannot distinguish between skill levels. Functional neuroimaging data was collected using a high density, wireless NIRS device from sixteen surgeons (11 attending surgeons and 5 surgery resident) and 17 students while they performed two laparoscopic tasks (Peg transfer and String pass). Participant’s subjective mental load was assessed using the NASA-TLX survey. Machine learning approaches were used for predicting the subjective experience and skill levels. The Prefrontal cortex (PFC) activations were greater in students who reported higher-than-median task load, as measured by the NASA-TLX survey. However in the case of attending surgeons the opposite tendency was observed, namely higher activations in the lower v higher task loaded subjects. We found that response was greater in the left PFC of students particularly near the dorso- and ventrolateral areas. We quantified the ability of PFC activation to predict the differences in skill and task load using machine learning while focussing on the effects of NIRS channel separation distance on the results. Our results showed that the classification of skill level and subjective task load could be predicted based on PFC activation with an accuracy of nearly 90%. Our finding shows that there is sufficient information available in the optical signals to make accurate predictions about the surgeons’ subjective experiences and skill levels. The high accuracy of results is encouraging and suggest the integration of the strategy developed in this study as a promising approach to design automated, more accurate and objective evaluation methods.

Wearable Devices Suitable for Monitoring Twenty Four Hour Heart Rate Variability in Military Populations

Heart rate variability (HRV) measurements provide information on the autonomic nervous system and the balance between parasympathetic and sympathetic activity. A high HRV can be advantageous, reflecting the ability of the autonomic nervous system to adapt, whereas a low HRV can be indicative of fatigue, overtraining or health issues. There has been a surge in wearable devices that claim to measure HRV. Some of these include spot measurements, whilst others only record during periods of rest and/or sleep. Few are capable of continuously measuring HRV (≥24 h). We undertook a narrative review of the literature with the aim to determine which currently available wearable devices are capable of measuring continuous, precise HRV measures. The review also aims to evaluate which devices would be suitable in a field setting specific to military populations. The Polar H10 appears to be the most accurate wearable device when compared to criterion measures and even appears to supersede traditional methods during exercise. However, currently, the H10 must be paired with a watch to enable the raw data to be extracted for HRV analysis if users need to avoid using an app (for security or data ownership reasons) which incurs additional cost.

General Anxiety in Dental Staff and Hemodynamic Changes over Endodontists' Workday during the Coronavirus Disease 2019 Pandemic: A Prospective Longitudinal Study

INTRODUCTION

The aim of this study was to assess general anxiety levels in endodontists and dental assistants related to different conditions during the pandemic and lockdown and to evaluate hemodynamic changes in endodontists' heart rate (HR), blood pressure, and blood oxygenation during their workday.

METHODS

Anxiety levels in endodontists and dental assistants were recorded weekly during the state of alarm declared because of the coronavirus disease 2019 pandemic. Hemodynamic parameters were monitored using a sphygmomanometer for HR and blood pressure and a pulse oximeter for oxygen saturation. Measurements were taken before and after each root canal treatment as well as on arrival at the clinic and at the end of the working day. Rest data, recorded every Saturday, served as a control. Data analysis was performed using chi-square, paired t, Mann-Whitney, and analysis of variance tests (P < .05).

RESULTS

General anxiety decreased over the weeks, with significant differences between weeks 1 and 4 (P < .05). Endodontists perceived higher anxiety levels of anxiety during anesthesia inoculation and dental assistants during the dental unit's disinfection and equipment material (P < .05). There was a significant increase in the cardiovascular response in all endodontists in the clinic registrations compared with rest data (P < .05). Values were higher in the strict confinement period and significant for HR when arriving at the clinic (P < .05).

CONCLUSIONS

Levels of general anxiety were higher during the first weeks. The chief perceived factors related to anxiety in endodontists and dental assistants were the risk of contagion and protection measures. Higher HR and blood pressure levels were registered during the workday, especially when arriving at the clinic.

Personal protective equipment in the COVID-19 pandemic and the use of cooling-wear as alleviator of thermal stress : A pilot study in plastic surgery staff members

Background

High temperatures at workplaces lead to health-related risks and premature exhaustion. The coronavirus disease 2019 (COVID-19) pandemic requires many health professionals to perform under unfavorable conditions. Personal protective equipment (PPE) causes thermal stress and negatively affects performance.

Patients, materials and methods

This pilot project investigated the effects of PPE and additional cooling wear on physiological parameters and concentration of six healthy staff members of the Plastic Surgery Department of the Medical University of Graz, Austria during simulated patient care. In this study two 1‑hour cycles with patient care-related tasks with PPE and PPE + cooling-wear, respectively, were conducted. A third cycle with scrubs exclusively served as baseline/negative control. The assessment occurred immediately pre-cycles and post-cycles.

Results

Pre-cycle assessments showed no significant differences between the cycles. After PPE cycle, increased physical stress levels and decrements in concentration capacity were observed. Physiological parameters were significantly less affected in the cooling cycle, while concentration capacity slightly increased.

Conclusion

COVID-19 PPE causes considerable thermal stress, ultimately affecting human performance. As opportunity to withstand thermal stress, and improve patients’ and professionals’ safety, cooling-wear can be considered relevant. Medical personnel performing in exceptional situations may particularly benefit from further development and investigation of cooling strategies.

Heart rate variability as a measure of mental stress in surgery: a systematic review

PURPOSE

There is increasing interest in the use of heart rate variability (HRV) as an objective measurement of mental stress in the surgical setting. To identify areas of improvement, the aim of our study was to review current use of HRV measurements in the surgical setting, evaluate the different methods used for the analysis of HRV, and to assess whether HRV is being measured correctly.

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). 17 studies regarding HRV as a measurement of mental stress in the surgical setting were included and analysed.

RESULTS

24% of the studies performed long-term measurements (24 h and longer) to assess the long-term effects of and recovery from mental stress. In 24% of the studies, artefact correction took place.

CONCLUSIONS

HRV showed to be a good objective assessment method of stress induced in the workplace environment: it was able to pinpoint stressors during operations, determine which operating techniques induced most stress for surgeons, and indicate differences in stress levels between performing and assisting surgery. For future research, this review recommends using singular guidelines to standardize research, and performing artefact correction. This will improve further evaluation of the long-term effects of mental stress and its recovery.

Biosensors, Biomarkers and Biometrics: a Bootcamp Perspective

Introduction

Competitive physical performance is routinely monitored by wearable technology (biosensors), yet professional healthcare is not, despite high prevalence of trainee stress and burnout, notwithstanding the corresponding risk to patient safety. This study aimed to document the physiological stress response of UK Core Surgical Trainees (CSTs) during simulation training.

Methods

CSTs (n=20, 10 male) were fitted with Vital Scout Wellness Monitors (VivaLNK, Campbell, California, USA) for an intensive 3-day training bootcamp. In addition to physiological parameters, CST demographics, event diaries and Maslach Burnout Inventory scores were recorded prospectively during exposure to three scenarios: interactive lectures, clinical skills simulation and non-technical (communication) training.

Results

Baseline heart rate (BHR, 60 bpm (range 39–81 bpm)) and baseline respiratory rate (14/min (11–18/min)) varied considerably and did not correlate (rho 0.076, p=0.772). BHR was associated with weekly exercise performed (66 bpm (<1 hour) vs 43 bpm (>5 hour), rho −0.663, p=0.004). Trainee response (standardised median heart rate vs BHR) revealed heart rate was related proportionately to lectures (71 bpm, p<0.001), non-technical skills training (79 bpm, p<0.001) and clinical skills simulation (88 bpm, p<0.001). Respiratory rate responded similarly (p<0.001 in each case). Heart rate during clinical skills simulation was associated with emotional exhaustion (rho 0.493, p=0.044), but maximum heart rate was unrelated to CSTs’ perceived peak stressors.

Discussion

Stress response, as derived from positive sympathetic heart rate drive varied over two-fold, with a direct implication on oxygen uptake and energy expenditure, and highlighting the daily physical demands placed upon clinicians.

Physiological correlates of cognitive load in laparoscopic surgery

Laparoscopic surgery can be exhausting and frustrating, and the cognitive load experienced by surgeons may have a major impact on patient safety as well as healthcare economics. As cognitive load decreases with increasing proficiency, its robust assessment through physiological data can help to develop more effective training and certification procedures in this area. We measured data from 31 novices during laparoscopic exercises to extract features based on cardiac and ocular variables. These were compared with traditional behavioural and subjective measures in a dual-task setting. We found significant correlations between the features and the traditional measures. The subjective task difficulty, reaction time, and completion time were well predicted by the physiology features. Reaction times to randomly timed auditory stimuli were correlated with the mean of the heart rate (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$r = - 0.29$$\end{document}r=-0.29) and heart rate variability (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$r = 0.4$$\end{document}r=0.4). Completion times were correlated with the physiologically predicted values with a correlation coefficient of 0.84. We found that the multi-modal set of physiology features was a better predictor than any individual feature and artificial neural networks performed better than linear regression. The physiological correlates studied in this paper, translated into technological products, could help develop standardised and more easily regulated frameworks for training and certification.

Multimodal Physiological Signals for Workload Prediction in Robot-assisted Surgery

Monitoring surgeon workload during robot-assisted surgery can guide allocation of task demands, adapt system interfaces, and assess the robotic system's usability. Current practices for measuring cognitive load primarily rely on questionnaires that are subjective and disrupt surgical workflow. To address this limitation, a computational framework is demonstrated to predict user workload during telerobotic surgery. This framework leverages wireless sensors to monitor surgeons’ cognitive load and predict their cognitive states. Continuous data across multiple physiological modalities (e.g., heart rate variability, electrodermal, and electroencephalogram activity) were simultaneously recorded for twelve surgeons performing surgical skills tasks on the validated da Vinci Skills Simulator. These surgical tasks varied in difficulty levels, e.g., requiring varying visual processing demand and degree of fine motor control. Collected multimodal physiological signals were fused using independent component analysis, and the predicted results were compared to the ground-truth workload level. Results compared performance of different classifiers, sensor fusion schemes, and physiological modality (i.e., prediction with single vs. multiple modalities). It was found that our multisensor approach outperformed individual signals and can correctly predict cognitive workload levels 83.2% of the time during basic and complex surgical skills tasks.

Patient, thyroid, and surgeon related factors that make thyroidectomy difficult-cohort study

INTRODUCTION

When thyroidectomy is performed under optimal conditions within a milieu of sound anatomical and physiological knowledge combined with meticulous surgical skills, complications are minimal. However, thyroidectomy can be difficult, and its complications can be life-threatening. The factors that predict difficult thyroidectomy can be patient-, thyroid-, or surgeon-related, and we aimed to study these three factors. .

MATERIALS AND METHODS

This prospective study was performed in a tertiary care center between September 2016 and March 2017. We developed and validated modified thyroidectomy difficulty scale (TDS), with 11 items. Preoperatively, height, weight, neck length, and other parameters were recorded. Postoperatively, the modified TDS form was filled out by the surgeon and assistant, blinded to each other's responses. The minimum score was 19 and maximum was 54. The surgeon's baseline pulse rate was monitored throughout the procedure using a pulse oximeter probe that was On-The-Go (OTG) compatible. The probe was placed over the ear lobule/pinna of the surgeon and connected to an Android phone that was comfortably placed in the surgeon's pocket inside the gown. An application USB SPO2, was used in recording the pulse rate.

RESULTS

A total of 52 patients undergoing hemi- or total thyroidectomy were included in this study. All had benign cytology on fine needle aspiration cytology (colloid, 71.42%). A total of 104 modified TDS questionnaires filled by the operating surgeon and assistant were analyzed. The pulse rate of the operating surgeon, as measured by the novel pulse oximeter, was recorded in 52 surgeries. The minimum score was 20, maximum score was 35.50, and mean score was 26.85 ± 2.80. There was an interobserver agreement in most domains of the modified TDS except mobility. The surgeon was found to have the maximum heart rate when performing recurrent laryngeal nerve (RLN) dissection in 38 patients (73.07%).

DISCUSSION

We found that majority of the trainees found thyroidectomy to be a vigorously intense activity. Thyroidectomy is a demanding surgery, which requires meticulous identification and dissection of the RLN and parathyroid glands for optimum outcome.

Multi-Sensor-Fusion Approach for a Data-Science-Oriented Preventive Health Management System: Concept and Development of a Decentralized Data Collection Approach for Heterogeneous Data Sources

Investigations in preventive and occupational medicine are often based on the acquisition of data in the customer's daily routine. This requires convenient measurement solutions including physiological, psychological, physical, and sometimes emotional parameters. In this paper, the introduction of a decentralized multi-sensor-fusion approach for a preventive health-management system is described. The aim is the provision of a flexible mobile data-collection platform, which can be used in many different health-care related applications. Different heterogeneous data sources can be integrated and measured data are prepared and transferred to a superordinated data-science-oriented cloud-solution. The presented novel approach focuses on the integration and fusion of different mobile data sources on a mobile data collection system (mDCS). This includes directly coupled wireless sensor devices, indirectly coupled devices offering the datasets via vendor-specific cloud solutions (as e.g., Fitbit, San Francisco, USA and Nokia, Espoo, Finland) and questionnaires to acquire subjective and objective parameters. The mDCS functions as a user-specific interface adapter and data concentrator decentralized from a data-science-oriented processing cloud. A low-level data fusion in the mDCS includes the synchronization of the data sources, the individual selection of required data sets and the execution of pre-processing procedures. Thus, the mDCS increases the availability of the processing cloud and in consequence also of the higher level data-fusion procedures. The developed system can be easily adapted to changing health-care applications by using different sensor combinations. The complex processing for data analysis can be supported and intervention measures can be provided.

Pulse Rate Variability in Emergency Physicians During Shifts: Pilot Cross-Sectional Study

Background

The high prevalence of physician burnout, particularly in emergency medicine, has garnered national attention in recent years. Objective means of measuring stress while at work can facilitate research into stress reduction interventions, and wearable photoplethysmography (PPG) technology has been proposed as a potential solution. However, the use of low-burden wearable biosensors to study training and clinical practice among emergency physicians (EP) remains untested.

Objective

This pilot study aimed to (1) determine the feasibility of recording on-shift photoplethysmographic data from EP, (2) assess the quality of these data, and (3) calculate standard pulse rate variability (PRV) metrics from the acquired dataset and examine patterns in these variables over the course of an academic year.

Methods

A total of 21 EP wore PPG biosensors on their wrists during clinical work in the emergency department during a 9-hour shift. Recordings were collected during the first quarter of the academic year, then again during the fourth quarter of the same year for comparison. The overall rate of usable data collection per time was computed. Standard pulse rate (PR) and PRV metrics from these two time points were calculated and entered into Student t tests.

Results

More than 400 hours of data were entered into these analyses. Interpretable data were captured during 8.54% of the total recording time overall. In the fourth quarter of the academic year compared with the first quarter, there was no significant difference in median PR (75.8 vs 76.8; P=.57), mean R-R interval (0.81 vs 0.80; P=.32), SD of R-R interval (0.11 vs 0.11; P=.93), root mean square of successive difference of R-R interval (0.81 vs 0.80; P=.96), low-frequency power (3.5×103 vs 3.4×103; P=.79), high-frequency power (8.5×103 vs 8.3×103; P=.91), or low-frequency to high-frequency ratio (0.42 vs 0.41; P=.43), respectively. Power estimates for each of these tests exceeded .90. A secondary analysis of the resident-only subgroup similarly showed no significant differences over time, despite power estimates greater than .80.

Conclusions

Although the use of PPG biosensors to record real-time physiological data from EP while providing clinical care seems operationally feasible, this study fails to support the notion that such an approach can efficiently provide reliable estimates of metrics of interest. No significant differences in PR or PRV metrics were found at the end of the year compared with the beginning. Although these methods may offer useful applications to other domains, it may currently have limited utility in the contexts of physician training and wellness.

Surgeon Energy Expenditure and Substrate Utilization During Simulated Spine Surgery

INTRODUCTION

Orthopaedic surgery can be a physically demanding occupation with high rates of fatigue and burnout. Fatigue has been shown to affect surgeon performance with higher rates of errors in fatigued surgeons. The metabolic cost of performing surgery has yet to be quantified. A better understanding of these costs may provide insights into surgeon fatigue and its effect on patient safety.

METHODS

Eight subjects performed a one-level lumbar laminectomy and fusion on cadavers. Oxygen consumption (VO2) was measured via indirect calorimetry and used to calculate energy expenditure (EE). Substrate utilization was estimated from measurements of inspired and expired gases (ie, O2 and CO2, respectively). EE was also measured with the use of triaxial accelerometers.

RESULTS

The peak VO2 was 11.3 ± 0.4 mL/kg/min. The EEtotal was 132 ± 6 kcal corresponding to the EEtotal/hr of 142 ± 7 kcal/hr. Upper arm accelerometers (154.8 ± 9.8 kcal; r = 0.54) accurately estimated total EE. Subjects used, on average, 53% ± 4% CHO versus 47% ± 7% fat, with peak utilization of 65% ± 5% CHO versus 35% ± 15% fat.

DISCUSSION

Simulated orthopaedic spine surgery elicited modest but significant increases in EE over resting. Surgeons used a higher percentage of carbohydrate than would be expected for the intensity of the activity.

Physiological synchronization and entropy as measures of team cognitive load

The operating room (OR) is a high-risk and complex environment, where multiple specialized professionals work as a team to effectively care for patients in need of surgical interventions. Surgical tasks impose high cognitive demands on OR staff and cognitive overload may have deleterious effects on team performance and patient safety. The aim of the present study was to investigate the feasibility and describe a novel methodological approach to characterize dynamic changes in team cognitive load by measuring synchronization and entropy of heart rate variability parameters during real-life cardiac surgery. Cognitive load was measured by capturing interbeat intervals (IBI) from three team members (surgeon, anesthesiologist and perfusionist) using an unobtrusive wearable heart rate sensor and transmitted in real-time to a smartphone application. Clinical data and operating room audio/video recordings were also collected to provide behavioral and contextual information. We developed symbolic representations of the transient cognitive state of individual team members (Individual Cognitive State - ICS), and overall team (Team Cognitive State - TCS) by comparing IBI data from each team member with themselves and with others. The distribution of TCS symbols during surgery enabled us to display and analyze temporal states and dynamic changes of team cognitive load. Shannon's entropy was calculated to estimate the changing levels of team organization and to detect fluctuations resulting from a variety of cognitive demands and/or specific situations (e.g. medical error, emergency, flow disruptions). An illustrative example from a real cardiac surgery team shows how cognitive load patterns shifted rapidly after an actual near-miss medication event, leading the team to a more organized and synchronized state. The methodological approach described in this study provides a measurement technique for the assessment of team physiological synchronization, which can be applied to many other team-based environments. Future research should gather additional validity evidence to support the proposed methods for team cognitive load measurement.

To Sleep, Perchance to Dream: Acute and Chronic Sleep Deprivation in Acute Care Surgeons

BACKGROUND

Acute and chronic sleep deprivation are significantly associated with depressive symptoms and are thought to be contributors to the development of burnout. In-house call inherently includes frequent periods of disrupted sleep and is common among acute care surgeons. The relationship between in-house call and sleep deprivation among acute care surgeons has not been previously studied. The goal of this study was to determine prevalence and patterns of sleep deprivation in acute care surgeons.

STUDY DESIGN

A prospective study of acute care surgeons with in-house call responsibilities from 2 level I trauma centers was performed. Participants wore a sleep-tracking device continuously over a 3-month period. Data collected included age, sex, schedule of in-house call, hours and pattern of each sleep stage (light, slow wave, and rapid eye movement [REM]), and total hours of sleep. Sleep patterns were analyzed for each night, excluding in-house call, and categorized as normal, acute sleep deprivation, or chronic sleep deprivation.

RESULTS

There were 1,421 nights recorded among 17 acute care surgeons (35.3% female; ages 37 to 65 years, mean 45.5 years). Excluding in-house call, the average amount of sleep was 6.54 hours, with 64.8% of sleep patterns categorized as acute sleep deprivation or chronic sleep deprivation. Average amount of sleep was significantly higher on post-call day 1 (6.96 hours, p = 0.0016), but decreased significantly on post-call day 2 (6.33 hours, p = 0.0006). Sleep patterns with acute and chronic sleep deprivation peaked on post-call day 2, and returned to baseline on post-call day 3 (p = 0.046).

CONCLUSIONS

Sleep patterns consistent with acute and chronic sleep deprivation are common among acute care surgeons and worsen on post-call day 2. Baseline sleep patterns were not recovered until post-call day 3. Future study is needed to identify factors that affect physiologic recovery after in-house call and further elucidate the relationship between sleep deprivation and burnout.

Measurement of physiological responses to acute stress in multiple occupations: A systematic review and implications for front line healthcare providers

Optimizing performance of individuals in acutely stressful work-related situations requires a deeper understanding of the interaction between the demands of the stimuli and an individual's associated physiological response. Identifying these responses is particularly germane for healthcare professionals, who experience episodes of acute stress on a regular basis. The purpose of this review was to examine and synthesize empirical literature to identify studies assessing physiological responses to acute stress, determine common methods for measuring acute stress in near real-time, and identify common research designs employed across industries. A modified PRISMA approach was followed. Systematic searches were conducted of four databases (PsycINFO, Medline, PubMed, and Turning Research into Practice [TRIP]) to access eligibility. Reference list searches and a hand search were also conducted to identify other articles suitable for inclusion. Studies selected examined an acute physiological response while participants were engaged in a stress-inducing task. Twenty-two articles were included. Fifteen (68.2%) were centered on the human service industry while only three (13.6%) focused on healthcare professionals. Half of the studies incorporated a simulation into the research design while only two (9.1%) articles looked at physiological responses in real-world settings. Heart rate and cortisol emerged as the most common physiological measures collected. This review demonstrates that acute stress is primarily assessed retrospectively, and that there is a pragmatic gap in methodological approach, with many data collection methods inappropriate for the healthcare environment. Future research should capitalize on advancements in sensor technology to passively examine acute stress in healthcare professionals.

Unpacking the Literature on Stress and Resiliency: A Narrative Review Focused on Learners in the Operating Room

PURPOSE

The operating room is a high pressure environment for surgical trainees as they attempt to reach a high level of performance in the midst of a multitude of stressors. The purpose of this work was to examine the relationships between stress, coping, and psychological resilience and their effects on performance and learning in surgical training.

METHODS

A narrative review was carried out of the existing literature on stress, coping, and resilience in surgeons and surgical trainees. Multiple fields of study were examined including medical education, surgery, surgical safety, anesthesia, workplace ergonomics, and psychology.

RESULTS

Sources of intraoperative stress include fatigue, disruptions, interpersonal conflicts, time pressure, a complex case or high risk patient, surgical errors, and surgeon temperament. These stressors can negatively impact the performance of surgeons and trainees and may inhibit learning. How a learner responds to stress in the operating room is highly variable and influenced by the context of the stress, the coping mechanisms available, and individual psychological resilience. Stress management techniques, such as mental rehearsal, are beneficial for reducing stress. Resilience is protective against stress and burnout, and resilience training is useful for reducing stress and improving mental health in physicians and medical students.

CONCLUSIONS

Surgical trainees experience significant stress in the operating room and their experience of stress is modulated by cognitive and behavioral factors. Further research is required on the development of effective interventions to help trainees manage intraoperative stress, with the potential to improve surgical performance, learning, and patient safety.

Evaluation of emotional excitation during standardized endotracheal intubation in simulated conditions

Objective

To assess how stressful conditions in endotracheal intubation could induct emotional excitation in a population of acute care physicians.

Materials and methods

Two situations were randomly tested: one in standard and easy intubation conditions the other under difficult conditions presumed to induce stress (monitoring alarms, manikin lying on the floor, difficult intubation). Emotional excitation was assessed using several physiological (cardiac patterns, electrodermal activity and eye-tracking) and psycho-cognitive patterns. Auto-evaluations of video recordings and mental workload were performed immediately after simulation.

Results

Significant physiological parameter modifications were observed under the stressful intubation conditions (SDNN 35 ± 15 vs. 42 ± 21; p = 0.035—AVNN 514 ± 94 vs. 548 ± 110; p < 0.0001). Emotional excitation was demonstrated to lead a higher mental workload (NASA-TLX = 39 ± 18 vs. 63 ± 15; p = 0.001), frustration and effort dimensions being its determinant components (p < 0.01). Video recording auto-evaluations depicted significant emotional excitation occurrence under the difficult conditions, with few differences according to the operator’s experience.

Conclusion

This study highlights the fact that a stress condition during ETI on a simulation model leads to an important emotional excitation as compared to the neutral condition.

Surgical teaching does not increase the risk of intraoperative adverse events

INTRODUCTION

Training and teaching are cornerstones in developing surgical skills. The present study aimed to compare intraoperative outcomes of colonic resections among fellows, consultants, and supervised trainees.

METHODS

Data of consecutive colonic resections including demographics, surgical details, and intraoperative outcomes were recorded in a prospectively maintained institutional database. All procedures were standardized and divided in three groups according to the main surgeons experience (fellow or consultant) and whether the procedure was taught. After weighting by inverse treatment probability, intraoperative adverse events including reactive conversion, blood loss, and operating time were compared between these three groups.

RESULTS

Six hundred sixty-four colectomies were analyzed between January 2014 and October 2017. Among them, 289 (43.5%) were taught. After weighted propensity score analysis, there was no difference between the three groups (fellow taken as reference), for intraoperative adverse event rate (odd ratio (OR) consultant 1.448 (IQR 0.728-2.878), p = 0.282; OR teaching 0.689 (IQR 0.295-1.609), p = 0.381), operating time (beta coefficient 0.76 (- 21.91-23.42), p = 0.947; beta coefficient - 10.79 (- 28.34-6.75), p = 0.919), conversion rates (OR 0.748 (0.329-1.515), p = 0.412; OR 1.025 (0.537-1.954), p = 0.940), pre-emptive conversion (OR 1.994 (0.198-20.032), p = 0.552; OR 0.659 (0.145-2.991), p = 0.583), intraoperative blood loss (beta coefficient 21.19 (- 25.87-68.25), p = 0.368; beta coefficient - 12.34 (- 56.13-31.44), p = 0.573), intraoperative transfusion (OR 1.962 (0.813-4.735), p = 0.127; OR 0.670 (0.260-1.727), p = 0.397), and rates of unusual bleeding (OR 1.273 (0.698-2.321), p = 0.422; OR 0.572 (0.290-1.126), p = 0.099). Time to preemptive conversion was shorter when procedures were performed by consultants (beta coefficient - 25.51 (- 47.71 to - 3.31), p = 0.025), while no difference was found for the teaching group (beta coefficient 4.48 (- 30.95-40.62), p = 0.788).

CONCLUSION

Within a standardized teaching environment, colonic resections were safely performed regardless of the surgical setting in the present cohort. Teaching does not increase intraoperative adverse events.

Heart rate variability and occupational stress-systematic review

The aim of this systematic review was to explore studies regarding association between occupational stress and heart rate variability (HRV) during work. We searched PubMed, Web of Science, Scopus, Cinahl and PsycINFO for peer-reviewed articles published in English between January 2005 and September 2017. A total of 10 articles met the inclusion criteria. The included articles were analyzed in terms of study design, study population, assessment of occupational stress and HRV, and the study limitations. Among the studies there were cross-sectional (n=9) studies and one longitudinal study design. Sample size varied from 19 to 653 participants and both females and males were included. The most common assessment methods of occupational stress were the Job Content Questionnaire (JCQ) and the Effort-Reward Imbalance (ERI) questionnaire. HRV was assessed using 24 h or longer Holter ECG or HR monitoring and analyzed mostly using standard time-domain and frequency-domain parameters. The main finding was that heightened occupational stress was found associated with lowered HRV, specifically with reduced parasympathetic activation. Reduced parasympathetic activation was seen as decreases in RMSSD and HF power, and increase in LF/HF ratio. The assessment and analysis methods of occupational stress and HRV were diverse.

Acute mental stress and surgical performance

Background

Stress has been shown to impact adversely on multiple facets critical to optimal performance. Advancements in wearable technology can reduce barriers to observing stress during surgery. This study aimed to investigate the association between acute intraoperative mental stress and technical surgical performance.

Methods

Continuous electrocardiogram data for a single attending surgeon were captured during surgical procedures to obtain heart rate variability (HRV) measures that were used as a proxy for acute mental stress. Two different measures were used: root mean square of successive differences (RMSSD) and standard deviation of RR intervals (SDNN). Technical surgical performance was assessed on the Operating Room Black Box® platform using the Generic Error Rating Tool (GERT). Both HRV recording and procedure video recording were time‐stamped. Surgical procedures were fragmented to non‐overlapping intervals of 1, 2 and 5 min, and subjected to data analysis. An event was defined as any deviation that caused injury to the patient or posed a risk of harm.

Results

Rates of events were significantly higher (47–66 per cent higher) in the higher stress quantiles than in the lower stress quantiles for all measured interval lengths using both proxy measures for acute mental stress. The strongest association was observed using 1‐min intervals with RMSSD as the HRV measure (P < 0·001).

Conclusion

There is an association between measures of acute mental stress and worse technical surgical performance. Further study will help delineate the interdependence of these variables and identify triggers for increased stress levels to improve surgical safety.