**2. Background**

The term burnout was first used in the clinical setting in 1974 by the psychologist Herbert Freudenberger, who carried out a study on the change of attitude of health personnel relating burnout with states of anxiety and depression, considering it "a set of non-specific medical-biological and psychosocial symptoms that develop in work activity as a result of an excessive demand for energy" [36]. From this point, the research stage in Burnout begins [37], characterized by the first clinical analyses of the syndrome and the ratification of its regularity. Later on, Cristina Maslach elaborates a representation of the responses of the workers related to the care environment, when they feel vulnerable due to emotional stress [38]. In 1981, the social psychologist Christina Maslach defined it as "a three-dimensional syndrome characterized by emotional exhaustion, depersonalization and low personal realization that can occur among individuals who work in direct contact with clients and/or patients" [39]. Together with Dr. Jackson, they created one of the most widely used instruments to measure burnout: the Maslach burnout inventory (MBI) by evaluating the three dimensions mentioned.

The most vulnerable professionals to suffer from burnout are those who develop their work in relation to other people such as health and teaching professionals [27,40,41].

Studies on burnout in health professionals have been conducted on numerous occasions relating symptoms of mood disorders, anxiety, and depression as this syndrome consequences [42–44]. Its effects are usually evident within a depressive symptomatology which scope transcends the merely occupational scenario and involves the personal, family, and social sphere [45,46].

Under normal circumstances, the health profession generates work-related stress or burnout for a variety of reasons, including continuous contact with pain and suffering [47,48], as well as monotonous tasks, heavy or excessive workloads, the frequency and amount of time spent with patients, and even work development and management styles [49,50]. On the other hand, there are more personal factors such as one's ability to cope with death and suffering and poor or bad interpersonal relationships, which can also be a cause of stress and psychological distress.

In this sense, and taking into account the clinical point of view, it is considered that work stress, characterized by workload, time pressure, demands, resources or management control, among others, can trigger burnout syndrome (as a state). However, the psychosocial approach considers that it is the work and personal environment that can trigger the appearance of this syndrome (as a process) [51], i.e., it arises as a response to labor stress [52] without there being an exact cause that precipitates it, but the realization of which is not capable of minimizing the dissatisfaction or lack of motivation that is present.

Maslach defined burnout as "a chronic stress produced by contact with clients that leads to emotional exhaustion and alienation from clients in their work" [53]. This definition was widespread

during the decades of the late twentieth century [54,55]. Today, however, burnout is defined as a "prolonged response to chronic personal and relational stressors at work, determined from dimensions known as burnout, depersonalization, and professional cynicism and inefficiency" [45].

In the face of a threat such as that posed by COVID-19 disease, as well as other special emergency situations, where rapid action is required and the workload is high, it often happens that the primary reaction is to act, without thinking about the individual's emotional needs. In contrast, we can find protective factors that improve professional practice. In this respect, a recent study by Kisely et al. showed that "clear communication, access to adequate personal protection, adequate rest and both practical and psychological support were associated with a reduction in morbidity" [56].

At the first stage of exposure to the virus, health professionals had to make a great effort, which usually leads to anxiety and consequently the possible intake of anxiolytics, to maintain a constant capacity for work, which could lead to depression on an ongoing basis and after a few months of maintaining this habit, a post-traumatic stress disorder as occurred in other epidemics such as SARS, MERS, influenza A/H1N1 or Ebola [57,58].

At a physical level, burnout syndrome is associated with the appearance of certain disorders that often force the affected person to request sick leave from work [59,60], such as high muscle tension and generalized musculoskeletal pain (fibromyalgia), headaches or backaches, central nervous system dysfunctions, sexual dysfunctions or various cardiovascular and gastrointestinal problems [61].

All these elements guide the need to study the effects that the current pandemic may be having on health professionals from the different subscales of burnout, and thus enable a learning process to prevent possible future situations similar to the COVID-19 pandemic or new waves of this same virus. The World Health Organization [62,63] and many researchers notice the importance of initial and continuing training for health professionals [64–68], especially in the context of emergency situations [69–72].

In this context, training for mental health professionals in these extreme scenarios, which have a huge psychological impact, is essential [73–75]. Most studies focusing on this problem highlight that training and prevention processes can reduce the incidence of burnout syndrome in health professionals [76–84]. It is even argued that a combination of actions (including organizational, support and changes in the work environment) can have an even greater effect [85,86].

However, most of these contributions have focused on the prevention of burnout syndrome in everyday work situations. Although there are studies on professionals working in emergency services [87–92], which would offer similar results, we lack more knowledge when it comes to borderline situations in disasters and catastrophes contexts. These include a global pandemic, a global health emergency that has been unknown for almost a century, when the terrible Spanish flu of 1918–1919 occurred [93]. It is, therefore, necessary, prior to develop programs designed for this purpose, to know the impact on health workers, of a situation of such stress and tension, caused by the COVID-19 epidemic in its most extreme phases.

In this sense, different studies have found that along with service sector workers and teachers, physicians and nurses had high burnout rates [27,94], related to job dissatisfaction, little control over work, lack of recognition, low pay and caring for people in a terminal situation [62,95]. It is, therefore, necessary to establish a description of the state of health professionals, in relation to this important issue, at the most critical moments of the first wave of the pandemic. We are at a critical moment and this data can be very valuable, especially when thinking about the future of health professionals and comparative studies can determine an evolution in this area.

## **3. Materials and Methods**

#### *3.1. Objectives*

In the health emergency caused by COVID-19 disease, the occupational stressors and anxiety of health professionals could have been aggravated by the virulence of the pandemic and the shortage of PPE. In this context, the aim of this research is to find out how the current health crisis has affected health professionals, considering the Maslach and Jackson burnout subscales of the Maslach burnout inventory [55], adapted by Seisdedos [96] and validated by García, Herrero y León [97], during the most critical weeks of the spread of the virus. We decided, therefore, to undertake a study that would describe the situation at that specific moment, in the absence of research at the time, although after this research was carried out, works with similar objectives have been published [98,99] which reinforce the need for knowledge of this problem. In this way, the object of study was centered on the appearance of burnout in health centers in situations of need for an immediate and effective approach, as is the case of the COVID-19 pandemic, where the lives of many patients were in serious danger. This information would be very valuable for the construction of future prevention protocols and training of healthcare personnel in the face of pandemics of these characteristics or borderline scenarios.
