Stress-related changes of saliva cortisol in VDU operators

Randomized controlled trial of multidisciplinary team stress and performance in immersive simulation for management of infant in shock: study protocol

BACKGROUND

Human error and system failures continue to play a substantial role in adverse outcomes in healthcare. Simulation improves management of patients in critical condition, especially if it is undertaken by a multidisciplinary team. It covers technical skills (technical and therapeutic procedures) and non-technical skills, known as Crisis Resource Management. The relationship between stress and performance is theoretically described by the Yerkes-Dodson law as an inverted U-shaped curve. Performance is very low for a low level of stress and increases with an increased level of stress, up to a point, after which performance decreases and becomes severely impaired. The objectives of this randomized trial are to study the effect of stress on performance and the effect of repeated simulation sessions on performance and stress.

METHODS

This study is a single-center, investigator-initiated randomized controlled trial including 48 participants distributed in 12 multidisciplinary teams. Each team is made up of 4 persons: an emergency physician, a resident, a nurse, and an ambulance driver who usually constitute a French Emergency Medical Service team. Six multidisciplinary teams are planning to undergo 9 simulation sessions over 1 year (experimental group), and 6 multidisciplinary teams are planning to undergo 3 simulation sessions over 1 year (control group). Evidence of the existence of stress will be assessed according to 3 criteria: biological, electrophysiological, and psychological stress. The impact of stress on overall team performance, technical procedure and teamwork will be evaluated. Participant self-assessment of the perceived impact of simulations on clinical practice will be collected. Detection of post-traumatic stress disorder will be performed by self-assessment questionnaire on the 7(th) day and after 1 month.

DISCUSSION

We will concomitantly evaluate technical and non-technical performance, and the impact of stress on both. This is the first randomized trial studying repetition of simulation sessions and its impact on both clinical performance and stress, which is explored by objective and subjective assessments. We expect that stress decreases team performance and that repeated simulation will increase it. We expect no variation of stress parameters regardless of the level of performance.

TRIAL REGISTRATION

ClinicalTrials.gov registration number NCT02424890.

Les effets du bruit sur la santé mentale : recension des écrits

La présente étude est une revue critique de la documentation scientifique sur les effets du bruit sur la santé mentale. Cette étude a été réalisée sur la base de la recherche de mots-clés, de l’impact factor des revues, du nombre de fois que l’article a été cité. Hinari a servi de base des données. L’analyse et la sélection des articles scientifiques nous ont permis de les regrouper en trois catégories d’études. Les études fondamentales ont dosé les taux des hormones de stress dans le plasma, les urines et la salive. Les études expérimentales ont exposé les sujets humains à la pollution sonore pour évaluer les déficits de leurs mémoire, attention et performance. Les études épidémiologiques ont évalué les déficits cognitifs chez les élèves étudiant dans des milieux bruyants et l’état de santé mentale des individus habitant aux alentours des aéroports, voies ferrées et des autoroutes. Les études fondamentales et expérimentales ont abouti à un consensus scientifique sur les effets négatifs du bruit tandis que les résultats des études épidémiologiques ne permettent pas de tirer des conclusions solides, des études ultérieures s’avèrent donc nécessaires.

Lifestyle, stress and cortisol response: Review I : Mental stress

The incidences of diseases related to mental stress are increasing in Japan. Mental stress, unacknowledged for long periods, has been shown to lead to the development of a number of diseases. Thus, an index for mental stress is important to induce awareness of its presence. We focused on the relationship between cortisol and mental stress in this review. We will discuss both the usefulness and problems of cortisol as a mental stress index by summarizing the relationship between cortisol and mental stress. The present findings suggested that cortisol appears to be an adequate index for mental stress. However, there are several problems; the present group clarifies these problems and builds the comprehensive mental stress assessment systems by using saliva samples.

Impact of stressors in a natural context on release of cortisol in healthy adult humans: a meta-analysis

Increased hypothalamic-pituitary-adrenal (HPA) activation, culminating in elevated circulating cortisol levels is a fundamental response to stressors. In animals, this neuroendocrine change is highly reliable and marked (approximately 5-10-fold elevations), whereas in humans, the increase of cortisol release is less pronounced, and even some potent life-threatening events (anticipation of surgery) only elicit modest cortisol increases. Meta-analysis of factors that influenced the increase of cortisol release in a laboratory context pointed to the importance of social evaluative threats and stressor controllability in accounting for the cortisol rise. The present meta-analysis, covering the period from 1978 through March 2007, was undertaken to identify the factors most closely aligned with cortisol increases in natural settings. It appeared that stressor chronicity was fundamental in predicting cortisol changes; however, this variable is often confounded by the stressor type, the stressor's controllability, as well as contextual factors, making it difficult to disentangle their relative contributions to the cortisol response. Moreover, several experiential factors (e.g. previous stressor experiences) may influence the cortisol response to ongoing stressors, but these are not readily deduced through a meta-analysis. Nevertheless, there are ample data suggesting that stressful events, through their actions on cortisol levels and reactivity, may influence psychological and physical pathology.

Diurnal cycles of salivary cortisol in older adults

Cortisol has a well-documented circadian pattern. However, recent studies have demonstrated that individual variation in diurnal cortisol patterns occurs in young adult populations. Since older adults experience altered sleep-wake cycles and changes in circadian rhythmicity, we may see even greater variations in diurnal cortisol patterns in older adults. This study examined salivary cortisol patterns in 48 community dwelling older adults. Participants (mean age 76+/-6) collected saliva every 2 h over a three-day period. Cortisol was assayed by using RIA. Cortisol cycles were defined as inconsistent, typical or flat based on the slopes of two sequential daily cortisol patterns. Demographic, physical, psychological and behavioral measures were tested for group differences using t-tests and chi-square analyses. Forty-eight percent of the sample had inconsistent cycles, 50% had typical cycles and 2% had flat cycles. This sample had a higher percentage of inconsistent cycles and fewer flat cycles than reported for young adults (p=0.008) (Psychoneuroendocrinology 22 (1997) 89). Those with inconsistent cycles were younger and reported higher caffeine and food intake than those with typical cycles. This study demonstrates that normal diurnal rhythms of cortisol can be maintained in older adults, while day-to-day variation may increase.

Reactivity and recovery from different types of work measured by catecholamines and cortisol: a systematic literature overview

OBJECTIVES

To review occupational health, laboratory, and sports literature on neuroendocrine reactivity and recovery from mental, combined mental and physical, or physical tasks.

METHODS

A systematic literature search was performed in eight databases. Studies with catecholamines or cortisol as effect variables measured in blood, urine, or saliva were included.

RESULTS

After application of inclusion and exclusion criteria, 77 studies from the initial 559 identified were taken into account. In occupational settings it was found that relatively few studies were conclusive about recovery, which formed a contrast with sports research. For reactivity and recovery up to 1 hour after performing the task, half of the studies considered physical tasks and more than two thirds showed incomplete recovery compared with baseline excretion of catecholamines and cortisol. Recovery extending to 3 days after the task was performed was often incomplete for cortisol after combined mentally and physically demanding tasks, and less often after solely mental or physical tasks. This type of recovery was more often incomplete for adrenaline (epinephrine) than for noradrenaline (norepinephrine), which was the case after mental as well as combined mental and physical tasks.

CONCLUSIONS

The results from laboratory and sports research may be transferable to some occupations, but more research is needed on the course of recovery relative to health effects in occupational settings.

Working with new technologies: hormone excretion as an indicator for sustained arousal. A pilot study

Effects of working with new technologies (visual display units) on hormone levels were investigated in a pilot study. The relationship between subjective strain and hormone levels was also assessed. Twenty subjects participated in the study reported here, which is a part of a comprehensive longitudinal study, in which 279 employees participated. Measurements were taken two months before the new technology was installed (baseline: work with conventional technology), during the implementation phase of the new technology, and at a 12-month interval. Fourteen complete data sets were analysed. The introduction of new technologies was accompanied by enhanced levels of catecholamines (epinephrine and norepinephrine). Levels also remained high one year after the implementation. Similar values were found on work days and rest days. Cortisol changes were less evident; excretion tended to increase after the implementation had been completed. The relationship was weak between hormone levels and subjective strain measurements. The results indicate that working with new technologies was accompanied by enhanced physiological arousal of the employee. Reactivity was related more to a particular occupational setting than to scales of subjective assessment.

Salivary cortisol in psychoneuroendocrine research: recent developments and applications

The assessment of cortisol in saliva has proven a valid and reliable reflection of the respective unbound hormone in blood. To date, assessment of cortisol in saliva is a widely accepted and frequently employed method in psychoneuroendocrinology. Due to several advantages over blood cortisol analyses (e.g., stress-free sampling, laboratory independence, lower costs) saliva cortisol assessment can be the method of choice in basic research and clinical environments. The determination of cortisol in saliva can facilitate stress studies including newborns and infants and replace blood sampling for diagnostic endocrine tests like the dexamethasone suppression test. The present paper provides an up-to-date overview of recent methodological developments, novel applications as well as a discussion of possible future applications of salivary cortisol determination.

Comparison of cortisol concentrations in saliva and plasma of dogs

It is increasingly important to have simple, non-invasive indicators of stress in animals. Studies in various species have shown that concentrations of cortisol in saliva relate closely to plasma levels of the free hormone; the aim of the present procedure was to show a similar correlation in the dog. Baseline blood and saliva samples were collected concurrently from six male beagles. Synthetic adrenocorticotrophic hormone was given and further samples were collected at 0.25, 0.5, one, two and 2.5 hours later. The results indicated a statistically significant correlation between the levels of cortisol in blood and saliva. Concentrations in saliva were between 5 and 10 per cent of those in plasma at each collection time. To demonstrate a response to a more natural stimulus, saliva samples were taken from a dog during exposure to a known stressor for that individual. The results showed a marked, delayed increase from baseline which was maintained for at least 0.5 hours after stressing.