Nurses' workload and its relation with physiological stress reactions1

OBJECTIVE: to analyze the relation between the workload and the physiological stress reactions among nurses working at a hospital service. METHODS: cross-sectional, correlational, quantitative study, involving 95 nurses, in 2011 and 2012. Spearman's bivariate Correlation Test was used. RESULTS: most subjects are female, between 23 and 61 years old and working between 21 and 78 hours per week. The most frequent physiological reactions were back pain, fatigue/exhaustion, stiff neck and stomach acidity, with 46.3% of the subjects presenting low and 42.1% moderate physiological stress responses. No correlation was found between the workload and the physiological stress responses. CONCLUSION: although most of the nurses work more than 36 hours/week, physiologically, they do not present high reaction levels in response to stress. These workers deal with conflicts in the vertical and horizontal relations between professionals, family members and patients. In that sense, taking care of professionals who offer health services can be a fundamental strategy, as good user care mainly depends on healthy teams.


Introduction
The current labor conditions involve production and service models with accelerated and intensified work characteristics. The models determine increased productivity, through the combination of the work rhythm, responsibility burden and reduction of rest intervals in the work journey. These facts can lead to a progressive occupational risk trend, which can give rise to chronic effects in the workers' health.
In that sense, the work journey represents an important dimension of the job quality, affecting the occupational safety and health, in the personal and family aspects as well as in the work organization inside the institution (1) .
The work journey can turn into an element that causes exhaustion and suffering for the workers; when the organizational context triggers suffering, individuals aim to develop defense mechanisms to try and reduce it. In case of increased conflicts and deadlocks between the workers and the organization, however, when they are no longer able to give an outlet to their desires and creative/inventive processes, they end up getting ill (2) and the organizational environments can become stressful for the workers. On the other hand, work is a form of being for humans and they can get remuneration and satisfaction through their work, avoiding or mitigating stress situations (3) . Stress can be acute or chronic, and the consequences of high chronic stress levels are perceived through absenteeism, productivity drop, demotivation, interpersonal difficulties, different physical illnesses, depression, anxiety and unhappiness in the personal sphere. In the work sphere, the consequences of stress can also include low spirits, lack of involvement with work and the organization, frequent absences and delays, excessive visits to the medical clinic and medication dependence (4) .
In nursing work, the concern with these professionals' suffering and pleasures emerges, arousing questions about how they are able to bear exhausting situations, mainly due to the constant contact with suffering, pain, death and so many other feelings and reactions the disease process triggers. Nursing has worked to attend to human beings and, therefore, gain knowledge and scientific principles that support their practice. Nevertheless, the nurses' work conditions lead to physical and emotional exhaustion (5)(6) .
In parallel, it was observed that the stress experience is multifaceted, with a reasonable range of dimensions that can contribute to the nurses' work problems. This experience indicates the need for intervention problems that aim to "combat" the different work problems and include various strategies, as it is totally different to outline an intervention aimed at improving the relation with the patients and another that helps the workers to better manage the stress associated with the "fear of committing errors" (7) .
Stressed nurses are more susceptible to the occurrence of work-related accidents and diseases and can also develop their activities inefficiently, certainly resulting in negative consequences for the attended individuals and/or population (8) . In addition to this problem, there is the large hour load the health workers, including the nursing professionals, tend to accomplish, making them work excessively.
The work overload seems to favor mental and/or physical illnesses in health workers, besides facilitating the occurrence of absenteeism, occupational accidents, medication errors, exhaustion, work overload and absence of leisure (9) . To overcome the adversities of their work, the nurses seek motivation, such as money and knowledge, to keep up a double work journey, challenging the extrinsic and intrinsic factors that constantly emerge (5) .
Although the literature indicates the presence of stress and exhaustion among nurses due to different reasons, including overtime and involving physical and/ or mental symptoms due to the work they perform (6) , with work overload and lack of time even to rest (5) , no studies have been identified that address the physiological reactions caused by stress, specifically

Method
Cross-sectional, quantitative correlation study.
Undertaken at a public hospital located in Ribeirão Preto, São Paulo, Brazil between the second semester of 2011 and the first semester of 2012.
The study population consisted of 131 nurses, working in all sectors and work shifts. Due to the population size, the decision was made to work with the complete universe of workers, without any sample size calculation.
The following selection criteria were established: being available on the dates set for the data collection. The nurses could be hired by the hospital's Support Foundation or by the State, underlining that these contracts are independent. In the first situation, the nurses were not admitted through a public exam and, in the second, they did take part in this exam. After the application of the selection criteria, the population consisted of 95 subjects, that is, 72.5% of the total population.
The data collection instrument for the personal and professional characteristics consisted of 12 questions, focused on the variables that were aimed at identifying the workers and their professional activity. The diagnosis of the physiological stress response reactions was assessed using the Inventory of Physiological Responses to Stress, previously validated for Brazil (10) , which consists of 39 stress-related symptoms, to be scored on a Likert scale [never (1), rarely (2), sometimes (3), frequently (4) and constantly (5) At the workplace, the primary author provided the nurses with orientations on the proposed study objective and the data collection procedures, in compliance with the guidelines of Resolution 196/96-CNS (11) , in force at the time of the approval and data collection. The study received approval from the Scientific Council of the For this model, the significance level was set at α= 0.05.

Discussion
Most of the subjects are female (89.4%), which shows that nursing remains an essentially female profession, as shown in the course of history (12) .
As regards the number of employment bonds, week (1) .
The nurses' professional stress reveals its importance, increasingly leading to exhaustion in the profession. One of the most frequent problems in a literature review about health changes due to excess work among health workers was occupational stress (9) .
The present study data, however, show that most of the nurses work their normal work hours and overtime at the same institution, which can favor a better adaptation to that sector, avoiding the stress that often results from a change of workplace during the daily work hours. When they remain at the same place, the nurses know the reality of the shift they assume, that is, they know the nursing technicians and auxiliary nurses subordinated to them, the medical team and other professionals on duty, the number and conditions of the patients under their responsibility, the availability of material and equipment, among others.
Results different from the above were presented in a research undertaken with nurses working at army hospitals in Taiwan, which detected an excessive workload as the main source of stress among them (14) .
Each person has a particular form of reacting to the stimuli of life and, therefore, also has different exhaustion thresholds due to stress. According to each person's viewpoint on reality, valuation of the past or future perspectives, the stress responses can vary (15) , a highly relevant factor in the emergence of diseases or not.
Nursing workers present an experience marked by occupational accidents, diseases, disability, absenteeism and abandonment of the profession (16) , factors that produce stress, but the subjects do not always know what to use as defense mechanisms.
Among the responses reported in this study, back pain was the most mentioned. This result coincides with the literature review involving nursing workers, which demonstrated that the prevailing diseases in these professionals were musculoskeletal (17) . Another study of nursing professionals working at the surgery center found musculoskeletal symptoms in the lumbar region (20.4%) in these workers (18) .
Also regarding the reactions, a study of Iranian nurses showed that they are exposed to high stress levels and the prevalence of musculoskeletal injuries was high, i.e. 89.9% of them presented some type of these injuries in the last 12 months before the research; lumbar complaints were the most commonly mentioned problems (6.8%) (19) .
Inappropriate environments, badly organized activities, little valuation of workers, unsatisfactory participation in decisions, excessive demand, low salaries and repetitive work, which favors incorrect postures in undesirable work situations, are elements that can favor illness among health professionals (9) . A study of nurses found that the stressors and measures to cope with these situations need to be investigated in their work environment, promoting benefits not only for the workers, but for all the individuals they attend to (20) .
The individuals try to find motives for satisfaction and accomplishment in their work. In the performance of their functions, but mainly when confronted with adverse situations, the organism tries to maintain its balance, using forms of adaptation.
In the health area, dealing directly with human lives, the professionals' performance comes with expectations of high competency and accountability levels in their work. Thus, studies and actions to improve the professionals' work conditions and quality of life are increasingly frequent (21) .
A study to investigate nursing workers' level of resilience, aiming to discover these professionals' strengths and weaknesses in view of the adversities they are submitted to, showed their excessive control of impulses and difficulties in the regulation of emotions, demanding great energy, as they do not externalize their emotions, especially in the work environment, justifying the high stress level found among the subjects (22) .
In that sense, taking care of professionals who offer health services can be a fundamental strategy, as good user care mainly depends on healthy work teams.

Conclusion
As verified, most of the nurses studied work more than 36 hours/week but, physiologically, did not present high stress responses. Therefore, no statistical evidence was found that proves the existence of correlations between the weekly workload and the physiological stress responses among these subjects.