A prospective study of heart rate variability in endocrine surgery: surgical training increases consultant's mental strain

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.

Unpacking the Broad Landscape of Intraoperative Stressors for Clinical Personnel: A Mixed-Methods Systematic Review

Purpose

The main goals of this mixed-methods systematic review are to identify what types of intraoperative stressors for operating room personnel have been reported in collected studies and examine the characteristics of each intraoperative stressor.

Methods

With a systematic literature search, we retrieved empirical studies examining intraoperative stress published between 2010 and 2020. To synthesize findings, we applied two approaches. First, a textual narrative synthesis was employed to summarize key study information of the selected studies by focusing on surgical platforms and study participants. Second, a thematic synthesis was employed to identify and characterize intraoperative stressors and their subtypes.

Results

Ninety-four studies were included in the review. Regarding the surgical platforms, the selected studies mainly focused on minimally invasive surgery and few studies examined issues around robotic surgery. Most studies examined intra-operative stress from surgeons' perspectives but rarely considered other clinical personnel such as nurses and anesthetists. Among seven identified stressors, technical factors were the most frequently examined followed by individual, operating room environmental, interpersonal, temporal, patient, and organizational factors.

Conclusion

By presenting stressors as multifaceted elements affecting collaboration and interaction between multidisciplinary team members in the operating room, we discuss the potential interactions between stressors which should be further investigated to build a safe and efficient environment for operating room personnel.

[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.

Stress in surgical educational environments: a systematic review

BACKGROUND

The effects of stress on surgical residents and how stress management training can prepare residents to effectively manage stressful situations is a relevant topic. This systematic review aimed to analyze the literature regarding (1) the current stress monitoring tools and their use in surgical environments, (2) the current methods in surgical stress management training, and (3) how stress affects surgical performance.

METHODS

A search strategy was implemented to retrieve relevant articles from Web of Science, Scopus, and PubMed. The 787 initially retrieved articles were reviewed for further evaluation according to the inclusion/exclusion criteria (Prospero registration number CRD42021252682).

RESULTS

Sixty-one articles were included in the review. The stress monitoring methods found in the articles showed heart rate analysis as the most used monitoring tool for physiological parameters while the STAI-6 scale was preferred for psychological parameters. The stress management methods found in the articles were mental-, simulation- and feedback-based training, with the mental-based training showing clear positive effects on participants. The studies analyzing the effects of stress on surgical performance showed both negative and positive effects on technical and non-technical performance.

CONCLUSIONS

The impact of stress responses presents an important factor in surgical environments, affecting residents' training and performance. This study identified the main methods used for monitoring stress parameters in surgical educational environments. The applied surgical stress management training methods were diverse and demonstrated positive effects on surgeons' stress levels and performance. There were negative and positive effects of stress on surgical performance, although a collective pattern on their effects was not clear.

Methods and Measures for Mental Stress Assessment in Surgery: A Systematic Review of 20 Years of Literature

Real-time mental stress monitoring from surgeons and surgical staff in operating rooms may reduce surgical injuries, improve performance and quality of medical care, and accelerate implementation of stress-management strategies. Motivated by the increase in usage of objective and subjective metrics for cognitive monitoring and by the gap in reviews of experimental design setups and data analytics, a systematic review of 71 studies on mental stress and workload measurement in surgical settings, published in 2001-2020, is presented. Almost 61% of selected papers used both objective and subjective measures, followed by 25% that only administered subjective tools - mostly consisting of validated instruments and customized surveys. An overall increase in the total number of publications on intraoperative stress assessment was observed from mid-2010 s along with a momentum in the use of both subjective and real-time objective measures. Cardiac activity, including heart-rate variability metrics, stress hormones, and eye-tracking metrics were the most frequently and electroencephalography (EEG) was the least frequently used objective measures. Around 40% of selected papers collected at least two objective measures, 41% used wearable devices, 23% performed synchronization and annotation, and 76% conducted baseline or multi-point data acquisition. Furthermore, 93% used a variety of statistical techniques, 14% applied regression models, and only one study released a public, anonymized dataset. This review of data modalities, experimental setups, and analysis techniques for intraoperative stress monitoring highlights the initiatives of surgical data science and motivates research on computational techniques for mental and surgical skills assessment and cognition-guided surgery.

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.

Evaluation of Stress Levels of Trainee Cardiac Surgery Residents during Training Interventions Using Physiological Stress Parameters

Background: This study analysed the psychological and psycho-emotional stress in cardiac surgery. Using heart rate variability (HRV) analysis, it is possible to record intraoperative objective stress responses in surgeons. The aim of the study was to assess with the help of HRV parameters the postulated increased stress levels of cardiac surgeons in training compared to experienced senior cardiothoracic surgeons in exactly the same work situation in order to make qualification-differentiated statements about physiological stress during surgical interventions. Methods: During surgical teaching procedures, long-term ECG data (n = 15 each) for two operating residents and their assisting senior physicians were recorded. Time and frequency domain HRV parameters were analysed. Results: The time-related parasympathetic-dominated HRV parameters RMSSD (19.5 ms vs. 28.1 ms), NN50 (297.67 vs. 693.40), and cardiac interval mean RR (692.8 ms vs. 737.3 ms) indicate a higher stress level in the operating residents compared to the experienced surgeons. The higher stress index (11.61 vs. 8.86) confirms this. Conclusion: Compared to experienced surgeons, operating residents showed lower parasympathetic activity and higher stress levels during cardiac surgery training procedures.

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.

Measuring Mental Stress During Otologic Surgery Using Heart Rate Variability Analysis

OBJECTIVES

Healthy individuals have significant beat-to-beat variability in heart rate, and this variability decreases with mental stress. We aim to use heart rate variability (HRV) to objectively compare mental stress levels in otologic surgeons at rest and during key portions of procedures.

DESIGN

Pilot study.

SETTING

Operating room and laboratory.

PARTICIPANTS

Two neurotology fellows performed six mastoidectomy and facial nerve (FN) dissections in the operating room and six in a cadaver lab while continuous electrocardiograms were measured wirelessly. Five-minute samples were recorded during resting, preoperative, mastoidectomy, and FN dissection. Beat-to-beat time intervals were analyzed in time and frequency domains. The standard deviation of normal beat-to-beat intervals (SDNN) and the ratio of low frequency to high frequency power (LF/HF, measure of sympathetic tone) were calculated. Decreases in SDNN and increases in LF/HF indicate elevated mental stress.

RESULTS

Mean resting SDNN was 43.9 ± 9.2 ms, not statistically different from preoperative SDNN (34.1 ± 8.2 ms, p = 0.13). SDNN decreased during mastoidectomy (29.4 ± 11.7 ms) and FN dissection (22.8 ± 3.1 ms), which was significant compared to preoperative values (p = 0.03). Intraoperative LF/HF increased for FN dissection (6.8 ± 2.6) compared to resting (2.2 ± 0.7, p = 0.004), indicating increased sympathetic tone. Mastoid and FN cadaveric procedures resulted in SDNN of 33.6 ± 3.8 and 32.9 ± 4.7 ms, respectively, not statistically different from preoperative values (p = 0.82 and p = 0.94, respectively). Cadaveric FN dissection did not result in increased LF/HF (2.4 ± 0.9) compared to resting (p = 0.94).

CONCLUSIONS

Decreased HRV and increased sympathetic tone were observed intraoperatively, indicating high levels of mental stress, particularly with FN dissection. Similar changes were not found during cadaveric dissections.

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.

Electronic supplementary material

The online version of this article (10.1007/s00420-020-01525-6) contains supplementary material, which is available to authorized users.

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.

Systematic review of measurement tools to assess surgeons' intraoperative cognitive workload

BACKGROUND

Surgeons in the operating theatre deal constantly with high-demand tasks that require simultaneous processing of a large amount of information. In certain situations, high cognitive load occurs, which may impact negatively on a surgeon's performance. This systematic review aims to provide a comprehensive understanding of the different methods used to assess surgeons' cognitive load, and a critique of the reliability and validity of current assessment metrics.

METHODS

A search strategy encompassing MEDLINE, Embase, Web of Science, PsycINFO, ACM Digital Library, IEEE Xplore, PROSPERO and the Cochrane database was developed to identify peer-reviewed articles published from inception to November 2016. Quality was assessed by using the Medical Education Research Study Quality Instrument (MERSQI). A summary table was created to describe study design, setting, specialty, participants, cognitive load measures and MERSQI score.

RESULTS

Of 391 articles retrieved, 84 met the inclusion criteria, totalling 2053 unique participants. Most studies were carried out in a simulated setting (59 studies, 70 per cent). Sixty studies (71 per cent) used self-reporting methods, of which the NASA Task Load Index (NASA-TLX) was the most commonly applied tool (44 studies, 52 per cent). Heart rate variability analysis was the most used real-time method (11 studies, 13 per cent).

CONCLUSION

Self-report instruments are valuable when the aim is to assess the overall cognitive load in different surgical procedures and assess learning curves within competence-based surgical education. When the aim is to assess cognitive load related to specific operative stages, real-time tools should be used, as they allow capture of cognitive load fluctuation. A combination of both subjective and objective methods might provide optimal measurement of surgeons' cognition.

Surgeons' and surgical trainees' acute stress in real operations or simulation: A systematic review

BACKGROUND AND PURPOSE

Acute stress in surgery is ubiquitous and has an immediate impact on surgical performance and patient safety. Surgeons react with several coping strategies; however, they recognise the necessity of formal stress management training. Thus, stress assessment is a direct need. Surgical simulation is a validated standardised training milieu designed to replicate real-life situations. It replicates stress, prevents biases, and provides objective metrics. The complexity of stress mechanisms makes stress measurement difficult to quantify and interpret. This systematic review aims to identify studies that have used acute stress estimation measurements in surgeons or surgical trainees during real operations or surgical simulation, and to collectively present the rationale of these tools, with special emphasis in salivary markers.

METHODS

A search strategy was implemented to retrieve relevant articles from MEDLINE and SCOPUS databases. The 738 articles retrieved were reviewed for further evaluation according to the predetermined inclusion/exclusion criteria.

RESULTS

Thirty-three studies were included in this systematic review. The methods for acute stress assessment varied greatly among studies with the non-invasive techniques being the most commonly used. Subjective and objective tests for surgeons' acute stress assessment are being presented.

CONCLUSION

There is a broad spectrum of acute mental stress assessment tools in the surgical field and simulation and salivary biomarkers have recently gained popularity. There is a need to maintain a consistent methodology in future research, towards a deeper understanding of acute stress in the surgical field.

Increase in Operator's Sympathetic Nerve Activity during Complicated Hepatobiliary Surgery: Evidence for Surgeons' Mental Stress

Surgeons often experience stress during operations. The heart rate variability (HRV) is the variability in the beat-to-beat interval, which has been used as parameters of stress. The purpose of this study was to evaluate mental stress of surgeons before, during and after operations, especially during pancreaticoduodenectomy (PD) and living donor liver transplantation (LDLT). Additionally, the parameters were compared in various procedures during the operations. By frequency domain method using electrocardiograph, we measured the high frequency (HF) component, representing the parasympathetic activity, and the low frequency (LF)/HF ratio, representing the sympathetic activity. In all 5 cases of PD, the surgeon showed significantly lower HF component and higher LF/HF during operation, indicating predominance of sympathetic nervous system and increased stress, than those before the operation (p < 0.01) and these did not return to the baseline level one hour after the operation. Out of the 4 LDLT cases, the value of HF was decreased in two and the LF/HF increased in three cases (p < 0.01) during the operation compared to those before the operation. In all cases, the value of HF was decreased and/or the LF/HF increased significantly during the reconstruction of the vessels or bile ducts than during the removal of the liver. Thus, sympathetic nerve activity increased during hepatobiliary surgery compared with the level before the operation, and various procedures during the operations induced diverse changes in the autonomic nervous activities. The HRV analysis could assess the chronological changes of mental stress by measuring the autonomic nervous balances.

Assessing surgeon stress when operating using heart rate variability and the State Trait Anxiety Inventory: will surgery be the death of us?

AIM

Performance in the operating room is affected by a combination of individual, patient and environmental factors amongst others. Stress has a potential negative impact on performance with the quality of surgical practice and patient safety being affected as a result. In order to appreciate the level of stress encountered during surgical procedures both objective and subjective methods can be used. This study reports the use of a combined objective (physiological) and subjective (psychological) method for evaluating stress experienced by the operating surgeon.

METHOD

Six consultant colorectal surgeons were evaluated performing eighteen anterior resections. Heart rate was recorded using a wireless chest strap at eight pre-determined operative steps. Heart Rate Variability indices were calculated offline using computerized software. Surgeon reported stress was collected using the State Trait Anxiety Inventory, a validated clinical stress scale.

RESULTS

A significant increase in stress was demonstrated in all surgeons whilst operating as indicated by sympathetic tone (control: 4.02 ± 2.28 vs operative: 11.42 ± 4.63; P < 0.0001). Peaks in stress according to operative step were comparable across procedures and surgeons. There was a significant positive correlation with subjective reporting of stress across procedures (r = 0.766; P = 0.0005).

CONCLUSION

This study demonstrates a significant increase in sympathetic tone in consultant surgeons measured using heart rate variability during elective colorectal resections. A significant correlation can be demonstrated between HRV measurements and perceived stress using the State Trait Anxiety Inventory. A combined approach to assessing operative stress is required to evaluate any effect on performance and outcomes.