In nursing, highly complex tasks must be performed and decisions are taken in situations that are often difficult and stressful. Moreover, appropriate attention must be provided not only to patients but also to visiting family members. The working environment can include long days, rotating shifts, a severe emotional burden, and sometimes aggression expressed by patients, their families, or even colleagues (1). If this circumstance persists for an extended period of time, it can provoke fatigue, anxiety, distress, and discomfort, any or all of which may reduce the quality of care provided and heighten the probability of error. In such a case, there may be an evident imbalance between the human resources available and the demands placed on them (2).

The tasks performed by nurses are determined, on the one hand, by the day-to-day healthcare demands encountered, and on the other hand, by the resources available—personal, situational, and organizational. This balance is reflected in the job demands–resources model (JD-R) (3). Occupational demands may be physiological and/or psychological, and each type imposes a cost on the individual. In many situations, workers are subjected to stress and heavy workloads, although these may be counteracted by the application of situational resources (4), such as companionship, autonomy, opportunities to learn, institutional recognition, and the possibility of promotion, as well as personal resources such as resilience, self-efficacy, and optimism (5). Both types of resources help the professional adapt to the work environment, fostering the ability to cope (6), generating motivation and work engagement (WE), and thus reducing the probability of burnout (7, 8).

Burnout is a consequence of long-term harmful stress in the workplace. If the individual lacks resources to deal with this situation, the response made may be maladaptive and prolonged (9). Maslach and Leiter defined three domains of burnout syndrome: emotional exhaustion, depersonalization, and low personal accomplishment (10). It may be counteracted, however, by high levels of WE, that is, a state of satisfaction, commitment, and motivation. This, too, consists of three domains: vigor (effort, self-generated energy, and resolve), dedication (exaltation, empowerment, and active assistance), and absorption (immersion and high levels of concentration in the activity being performed) (11).

Traditionally, the concepts of burnout and WE have been considered opposing and independent. Paradoxically, however, some studies have observed the simultaneous presence of burnout (12) and WE (13–15), which suggests that these concepts, while independent, have a certain negative correlation (3, 16). Nevertheless, demanding occupational conditions are associated with burnout, while the availability of appropriate resources contributes to WE (16), although the beneficial impact of these resources varies according to the population considered and the environment in question.

As members of the multidisciplinary team in critical and emergency care services, nurses play a vital role in improving the quality of care and in reducing morbidity, mortality, and their associated health costs (17). Moreover, incorporating nurses into the multidisciplinary oncology team benefits the team's overall performance and can shorten the duration of treatment (18). Therefore, a good understanding of the working conditions experienced by nurses and other health workers will facilitate an organizational approach to help prevent burnout and foster WE, thus enhancing the care provided (19).

In summary, the aim of this study is to identify and analyse the factors that affect WE and burnout in nurses and then to determine the relationship between these reactions to the occupational environment.

The literature search obtained 404 articles. After excluding duplicates and applying the inclusion and exclusion criteria, 65 remained for full-text reading. This led to a further 58 being excluded, leaving seven for the final analysis review. In addition, a reverse search performed on these articles led to another two being included. Thus, nine studies were finally reviewed (Figure 1).

This study aims to enhance our understanding of how personal characteristics and workplace-related factors may influence WE and trigger the presence of burnout among nurses. Given this information, appropriate measures can be adopted to reduce the risk of burnout and to foster greater participation and commitment by these workers.

Our analysis shows that nurses' WE is favored by environments in which they have autonomy of decision-making, where they are given sufficient resources to carry out their work, and where there is greater altruism among workers (33). In other words, WE benefits from a strengthening of the nursing identity, which generates pride in job performance and enhances the working experience (34). In turn, higher levels of support among nurses will decrease the burnout experienced (33, 35). The hospital area in which a nurse work is also relevant to WE and job satisfaction, which are both affected by the emotional impact or workload experienced in different areas of health care (36). According to previous research, when WE is high, nurses are less likely to request a transfer to a different work unit or service. Moreover, favorable occupational health conditions are expected to improve relationships and collaboration among workers, which enhances the care provided, and thus generates a positive gains spiral (24).

Among the factors found to increase the risk of burnout is the hospital area in which the nurses work. Those employed in an Accident and Emergency (A&E) department are more likely to generate a psychologically distant relationship with patients, as a consequence of the high level of burnout experienced (16). This, in turn, can cause patients to have negative perceptions of the quality, effectiveness, and efficiency of the healthcare received (37, 38). Another relevant factor is the type of work shift performed; thus, nurses who work night shifts have been shown to present higher levels of burnout. In short, professionals who undergo high levels of stress and fatigue are more liable to present detachment and dysfunctional attitudes (39). Burnout can also be caused by lengthy employment in the same medical unit/service. In response, and seeking to alleviate this condition, long-standing workers might request to be transferred elsewhere (40). In addition to the above, many other elements can influence the appearance of burnout syndrome among nurses, such as the female stereotype of the profession, the lack of recognition of the ‘invisible' tasks performed, and an excessive level of bureaucracy, as pointed out by Manzano Garcia et al. in their qualitative e-Delphi study (41). These questions have received little previous research attention.

Finally, consideration should be given to the COVID-19 pandemic, which has had a negative impact on the mental health of critical care nurses and their families, as public safety considerations have been prioritized over those of patient care. This situation has generated great unhappiness among the nurses affected, despite the support received from friends and colleagues (42, 43).

After considering the factors relevant to burnout and WE, we then determined the relationship between them, taking into account the three dimensions of each. Our analysis confirms previous findings that there is indeed a close relationship between the two concepts, and specifically that greater WE (as concerns each of its constituent elements) reduces the risk of burnout (40, 44).

A lack of vigor is associated with higher levels of emotional exhaustion. This is in line with the Utrecht Work Engagement Scale, according to which there is a strong interaction between these two dimensions (45). Therefore, the goal of recognizing WE among nurses and establishing strategies to promote it may be limited by the presence of emotional exhaustion (46). Conversely, dedication is inversely related to the presence and impact of burnout. Some of the studies in our analysis concluded that professionals who were unable to perform the work expected of them, or who were unable to meet the needs raised, whether by the patient or by the organization, due to decreased levels of dedication and perceptions of insufficiency, were at a high risk of developing burnout (47). In this respect, too, some authors indicate that a feeling of low personal fulfillment may arise from the view that the tasks performed are not considered important or productive. This impression would tend to reduce dedication and hence WE (48). Finally, high levels of absorption might provoke burnout, if this absorption prevents the worker from achieving an objective emotional balance (37, 40).

Our study is subject to certain limitations, which should be acknowledged. First, by restricting the articles considered to those published in English or Spanish, we may have omitted potentially significant research findings from studies published in other languages which otherwise met the inclusion requirements. Furthermore, the studies included did not all use the same measurement instruments, so the results presented may not be homogeneous. Finally, the relationship between burnout and WE has only recently been the object of academic study, and so relatively few articles are available for consideration.

The correlation between low WE and burnout in nurses not only impacts these professionals but also has damaging consequences for patients and the health system in general.

The studies considered in our review describe varying degrees of burnout and WE. The relevant factors identified include employment conditions (such as work overload and type of shift or service area), personal characteristics (such as perceived support and the individual's own values), and organizational resources. All of these factors influence WE and hence the possibility of burnout.

The results obtained from our analysis highlight the need to design and implement effective interventions in the workplace in order to address the problematic areas identified and thus reduce the risk or degree of burnout among nursing personnel. This, in turn, would enhance levels of WE. Failure to do so might be damaging not just for the workers concerned but also for the quality and safety of public healthcare.

As a final observation, further studies in this area are needed in order to better understand the phenomenon of burnout among nursing staff.

The original contributions presented in the study are included in the article/Supplementary material, further inquiries can be directed to the corresponding author.

MAV-B, FJI-E, and GAC-F: conceptualization. FJI-E, AV-S, and LA-G: data curation. NC-M, JLG-U, and AV-S: formal analysis. MAV-B, JLG-U, and AV-S: investigation. AV-S, JLG-U, and GAC-F: methodology. MAV-B and AV-S: resources. JLG-U: software. LA-G and GAC-F: supervision. JLG-U, NC-M, and GAC-F: visualization and validation. MAV-B, NC-M, and FJI-E: writing—original draft, review, and editing. GAC-F: funding acquisition and project administration. All authors contributed to the article and approved the submitted version.