Factors Influencing Occupational Stress Perceived by Emergency Nurses During Prehospital Care: A Systematic Review

Introduction

The term stress, developed by Hans Selye in 1936 and which gave rise to the general adaptation syndrome, has acquired an increasingly important role in the work environment and in the health of workers.^1,2 It occurs as a harmful physical and emotional response when job requirements are not consistent with the competences and needs of the employees,^3–6 and is now considered to be a major cause of the increasing incidence of infectious and cardiovascular diseases, as well as increased mental and physical disorders.^2–6 Lazarus and Folkman, in 1986,⁷ went a step further and mentioned that stress refers to an existing relationship between the person and their environment, whose turning point is the personal evaluation of each situation. In this respect, these authors introduced two concepts, cognitive assessment and coping strategies. Coping was defined as the ability to make cognitive and behavioural efforts to respond to those external and/or internal demands that exceed the resources a person has. On the ability to make a personal cognitive assessment, Lazarus and Launier⁸ reasoned that an event can be analysed as loss (or damage), threat, or challenge, and it is the individual evaluation of the event what stimulates a particular set of coping reactions.^7–9

Stress has been identified as one of the main reasons for turnover in the nursing field, also playing a very notable role in 50% of sick leaves as well as causing reduced performance, absenteeism, greater situations of violence in the work environment, and increased turnover among different professionals.^4,6,10,11 Indeed, some work-related characteristics play a decisive role in the return-to-work process after a mental health sick leave. Aspects such as high job demands, low job control, limited opportunities for job promotion, and high job strain adversely affect return to work.^11–13 In this sense, the Community Programme for Employment and Social Solidarity, PROGRESS (2007–2013), has financed studies and publications of documents in this regard to overcome the barriers that may be encountered by the worker who returns after a leave due to mental health problems.¹⁴

Currently, health workers suffering from stress exceed 28%, which causes an approximate health expenditure of between 150 and 372 million euros per year due to its consequences on health.¹⁰ In the particular case of nurses who work as ambulance staff for the prehospital emergency system, the special characteristics of the service facilitate the presence of a large number of potential stressors that increase the predisposition to suffer a high rate of work-related stress.^3,4,10 Moreover, this problem could be aggravated when facing certain extraordinary situations such as, for example, terrorist attacks or health crises such as the COVID-19 pandemic.^15,16

The main axiom of the prehospital emergency service is to be a rapid resource with a high degree of effectiveness, requiring coordinated interventions adapted to the specific characteristics of each situation, estimated after a previous assessment.^4,17 The high specificity of this service, nonetheless, does not always correspond to regulated training of professionals, and it is still possible to access the emergency ambulance unit with just a university nursing degree in some locations. For instance, in Spain, the Emergency Nurse must have a university degree in Nursing, but the Master’s Degree in Emergency Nursing, or nursing specialties in community nursing or medical-surgical nursing are not mandatory requirements.^17,18 Nevertheless, in other countries such as Sweden,¹⁹ Finland, Belgium, Thailand, Malaysia, Indonesia, or Brazil,²⁰ nurses provide prehospital services and define a new field for the university nursing practice and training.^21,22 Indeed, in Sweden, national regulations require an ambulance to be staffed with at least one registered nurse and, depending on local requirements, this nurse is often required to hold an additional one-year post-graduate specialist nursing diploma.^23,24 In Croatia, Estonia, and Lithuania this training is ongoing, while in the Czech Republic, Germany, Ireland, Latvia, the Netherlands, and the United Kingdom nurses are required to attend courses on a yearly basis. In Belgium, skills are evaluated once in five years.^25,26 However, in other countries such as Iran emergency medical technicians (EMTs) are the most common providers of prehospital emergency care²⁷ and, due to the insufficient number of EMTs, nurses are included among prehospital care providers.²¹ The complexity of the practice and its prerequisites may explain why nursing professionals working in the ambulance service express the need for periodic renewal training based on the belief that the job requires a specialised level of education, including psycho-emotional competencies and tools.²⁴

Inadequate training means that most ambulance nurses do not have the adequate knowledge to evaluate or initiate appropriate treatment, or to deal with situations where the patient is seriously affected and it is necessary to inform family members and, at the same time, offer emotional support.²⁸ This has been associated with the idea that nurses with a longer career (greater experience) will experience lower levels of stress.²⁹

Previous studies have also highlighted the influence of the paediatric patient as the most stressful factor, stating that such associated critical incidents account for up to 41% of the stress experienced by prehospital emergency professionals.^30–32 Other notable aspects related to stress have been working overtime and the existence (or not) of a support network of co-workers and superiors.^31,33 Regarding violence, as a stressor perceived by prehospital emergency nurses, a review carried out in 2018 included 25 studies that highlighted the frequent presence of this factor in daily work.³⁴ A significant link has been found between exposure to violence, emotional exhaustion, depersonalisation, and lower personal accomplishment levels, noting that increased exposure to verbal abuse leads to staff fatigue, loss of productivity and, eventually, turnover.³⁵ In this sense, cases of verbal and physical violence stand out,³⁶ amounting to 34.5% of professionals who had been physically assaulted as evidenced by a study conducted in Spain.³⁷ It has also been suggested that being female was a risk factor only for ambulance staff and emergency nurses,³⁸ which increases the likelihood of suffering some form of violence, thus making the possibility of intimidation, sexual harassment, or sexual assault more relevant.³⁴

Occupational health services play a major role in achieving the highest possible level of biopsychosocial well-being for workers.^39–42 However, there is still a notable lack of knowledge about the multiple stress factors that nurses in the prehospital emergency service face on a daily basis. So, it is relevant to address this issue in order to achieve a favourable and optimal environment to work safely so as to offer higher quality of care.^6,43 In this sense, the concept of coping with stress,⁷ defined as the effort to handle specific demands that require an effort, a challenge, or a price on the part of the person, is useful for ameliorating stressful situations.^44,45

To our knowledge, there are no previous reviews on the stress levels of ambulance emergency nurses. Therefore, the general objective of this research was to assess the personal and work-related factors influencing the stress levels of nurses during prehospital care. As specific objectives, the first was to identify the association between the level of perceived stress, the degree of professional experience, and the level of knowledge. Secondly, it was to examine the relationship between stress levels and violence in the work environment. And third, to investigate the main protective factors against work-related stress during prehospital care.

Methods

Study Design

A systematic review of the available literature on prehospital nursing stressors and how they affect the work of nurses working in the ambulance service was carried out following the PRISMA methodology.⁴⁶ A pre-established search and review protocol minimised the risk of selection and publication bias. This protocol was registered in PROSPERO with code CRD42023446080. First, the PECO question was formulated for an adequate literature review (Table 1). For this, the following research question was developed: What factors affect the stress levels of prehospital emergency nurses?

Table 1 PECO Question

Databases and Search Strategy

The search was carried out in the PubMed, WOS, Enfispo, Cochrane, and LILACS databases during July and August, 2023. Last searched on 08/08/23. MeSH descriptors related to the topic were identified to define the search equation and were combined using parentheses and Boolean operators. The resulting search strategy was: “occupational stress” AND nurs* AND (“prehospital care” OR emergenc* OR ambulance OR “first aid” OR “work experience”) (Table 2). A reverse search was also conducted to collect suitable research studies from the reference lists of other pre-selected studies.

Table 2 Search Strategies

Study Selection

The inclusion and exclusion criteria have been identified in Table 3. Two researchers performed the review using the aforementioned database search strategy, executing an initial screening of articles by title and abstract. After this, the same two researchers analysed the full text of the articles and agreed on those studies that were potentially suitable for inclusion in the review. Any discrepancies that arose were resolved by a third researcher.

Table 3 Inclusion and Exclusion Criteria

Initially, the search equation, once the criteria had been applied, yielded a total of 2241 articles of which n=1449 were assessed after removal of duplicates (n=756) and other records due to exclusion criteria (n=36). A first reading was performed by title and abstract of each study in order to obtain a first screening, eliminating those whose who did not met the expectations (n=1301). Next, the articles that had not been eliminated in the previous phase were sought for retrieval and read (n = 148). Finally, each study was full text reviewed to select those that could adequately meet the study objectives. Twenty-two studies were ruled out for analyzing PTSD, n=28 for treating compassion fatigue, and n=60 for treating burnout. Twenty-seven studies were excluded for not specifying that the sample consisted of nurses. A total of n=14 articles were finally selected, of which n=3 articles had been selected by reverse search (Figure 1).

Figure 1 PRISMA flow chart. Adapted from Page MJ, McKenzie JE, Bossuyt PM et al The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:n71. Creative Commons.46

Data Collection and Extraction

For a peer-review purpose, a template was created to allow the researchers to review and collect the main characteristics of each study. All relevant data was synthesized and categorized according to the PECO framework and compared to resolve any possible discrepancies.

Risk of Study Bias and Methodological Quality Assessment

Once the articles on which this work would be based had been selected, a bias assessment was carried out on each of them in order to know the reliability and relevance of the studies and, therefore, their eligibility. For this, the critical appraisal tool of the Joanna Briggs Institute (JBI)⁴⁷ was used, which allowed identifying the possible biases of each study in terms of design, conduct, and analysis, thus showing their methodological quality. The data obtained in this process were placed in tables according to the specific type of study.

The methodological quality assessment was performed independently by both reviewers. For the selected studies, a cut-off point was established for scores equal to or greater than half of their maximum value: analytical cross-sectional studies (Table S1) were measured through 8 items,⁴⁸ and scores of 4/8 or higher were accepted; randomised controlled trials were measured through 13 items⁴⁹ (Table S2), and scores of 7/13 or higher were accepted; for qualitative research, 10 items were assessed (Table S3),⁵⁰ and scores of 5/10 or higher were accepted. In this study, no studies were ruled out by the investigators as all exceeded the minimum required scores.

Management of Data and Synthesis methods

Finally, both authors made a narrative synthesis of the data obtained and organized them into categories. This synthesis was aimed at explaining the results of the selected studies according to the objectives of this study. In addition to this, the quality of the evidence was evaluated using GRADE system for the assessment of quality of evidence and degree of recommendation.

Results

Descriptive Analysis of Study Characteristics

A total of 14 articles focusing on the factors that generate work-related stress in prehospital services were selected for this study.^{5,21,23,27,28,36,43,51–57} Half of these articles approached their research from a qualitative perspective (n = 7),^{21,23,28,36,43,51,52} and the others did so from a quantitative perspective (n = 7);^5,27,53–57 the oldest articles selected were from 2014^36,56 and the most recent ones, from 2022.²⁷ These studies were carried out in 8 different countries: 5 in Iran;^{21,27,43,54,55} 2 in Sweden^23,28 and Brazil;^5,53 and 1 in Ireland,⁵¹ USA,⁵² Switzerland,⁵⁶ Spain,³⁶ and Poland.⁵⁷ The total sample was n=2475 participants from various healthcare professions; in the specific case of nursing specialised in prehospital emergencies, n=855 (34.5%) were nurses. Table 4 shows the characteristics of each of the 14 final articles for this review. These characteristics were categorised by authors and year of publication, geographical context, objective, type of study, interventions, variables, measurement instrument(s), participants, and main findings.

Table 4 Summary of the Selected Articles

Results for the general objective: factors influencing the level of stress of nurses during prehospital emergencies.

In order to classify the results obtained in a homogeneous and practical format, the results were organised into 5 categories, based on the classification of 7 categories defined by Aisling et al⁵¹ in their study of mixed methods on prehospital nursing professionals. These categories were: 1) The management of the health service, comprising the personnel in charge of managing the material, economic, and human resources (also offering psychological support) within the prehospital emergency service, the aim of which is to offer an adequate service to meet the needs of the population; 2) Patient care, referring to the types of emergencies and interventions derived from prehospital clinical care; 3) Interpersonal stressors, including relationships with peers, both in the work team and in the work environment; 4) Environmental factors, related to the work context and risk scenes. 5) Personal factors, derived from personal experience, training, health status, or behavioural characteristics of nurses. A summary of the findings is shown in Table 5.

Table 5 Description of the Main Findings

Management

The very nature of the service (ambulance and prehospital environment) is conducive to not having all the material resources (p=0.002; OR=2.88), nor the necessary personnel.⁵³ This deficit is exacerbated in critical situations, where the demand for care is much higher, so managers must strive to equip ambulances with everything necessary to facilitate interventions and reduce the likelihood of developing stress among their staff members.²⁸

In addition, the support received from those in charge is an aspect to highlight within this category. Several studies have reported on the low level of occupational care that nurses generally had, which also led to stress, cardiovascular problems, and both physical and emotional exhaustion.^5,28 Managing bodies are also responsible for indicating the role of each of the team members who assist in any health emergency, which will allow for cooperation at all times, thus avoiding working in an unstructured team that can act as a stressor.²⁷

On the other hand, as evidenced, the lack of autonomy in the nurses’ practice did significantly affect the level of perceived stress (p=0.001; OR=2.86).⁵³ This fact seems to generate a passive profile in the worker who, due to the lack of a relevant role within the emergency team, was less involved, which resulted in decreased ability for problem solving.^5,53

The workload has also been presented as a factor capable of generating work stress, and this is derived from the type and level of organisation of the work of health professionals. The authors Mirzaei et al²⁷ found a higher level of occupational stress caused by workload (β=0.163, p = 0.012 β). However, Mahdizadeh et al classified this factor as being as stressful as the lack of autonomy (p < 0.05).⁵⁴

Patient Care

Cardiovascular emergencies were classified as the most demanding and those that generated the need to act at a faster pace, thus limiting the possibility of fully using nurses’ competencies.^23,55

Gynaecological emergencies (specifically if the nurse was a male), airway obstruction, and paediatric emergencies^{23,28,51,52,55} were also highly stressful, especially if the results obtained were considered negative.^23,28,55 This feeling of stress is magnified if the patient eventually dies, and several studies have determined that this situation was the most stressful one faced by nursing professionals working in prehospital emergencies since, in addition to assimilating the death of the cared-for person, it is necessary to deal with the emotional responses of the relatives.^51,54

Traumatology accidents, respiratory distress, and heart problems were revealed as the paediatric emergency situations that led to the highest level of occupational stress.⁵² In these cases, stress was associated with assuring patient safety at all times, the psychological trauma of seeing an injured child, lack of experience in these types of emergencies, responses from family members, as well as children’s reactions and knowing that the situation could worsen rapidly.⁵²

The situations in which the behaviour, mainly of the patient or their companions, are out of control, thus becoming a danger for professionals, were described by the participants of the sample of M. Mahdizadeh et al⁵⁴ and the research by A. Afshari et al⁴³ as one of the most stressful factors. Bohström et al²⁸ mentioned increased perceived danger by health professionals during prehospital emergencies, mainly due to violent or threatening behaviours from both patients and their companions who see their expectations unmet, both in priority and rapid care and as regards the results of the clinical assistance. This danger generates a high level of stress that continues to affect nurses even during holiday periods, due to memories of previously experienced incidents.

Interpersonal Stressors

Prehospital emergencies require multidisciplinary care, so it is essential, especially for nursing, to have a good working relationship with the staff who assist in the ambulance. This will make it possible to act in a coordinated manner seeking at all times the benefit of the patient and reducing the impact of stress on the work team.⁵¹

As assessed in the studies included, this adequate feedback with peers, especially among experienced professionals, led to a greater development of personal skills and safety in each intervention, while a poor interpersonal relationship with peers or a lack of trust between them was perceived by the professionals of three studies as one of the factors with the most significant impact on the generation of work stress.^23,51,54

Environmental Stressors

Working in an unhealthy environment or inadequate facilities may increase the stress levels perceived by healthcare professionals.⁵³ Likewise, highly complex scenes and high risk for the physical safety of the health team force nurses to be very attentive to the dangers, which generates a great feeling of stress and anxiety. The possibility of suffering a musculoskeletal injury when mobilising a patient, being involved in an accident inside the ambulance, or the possibility of exposure to different diseases transmitted by the patient have also been highlighted.⁴³ As for work schedules, working the night shift also turned out to be an environmental factor that revealed a significant influence in the generation of stress.²⁷ Despite this, environmental emergencies were recognised as one of the least stressful for prehospital care nurses,⁵⁵ and the differences between hospital nurses and prehospital nursing teams were notable (t = −4.719; p=0.000).²⁷

Personal Factors

Bohström et al focused their study on two main topics: inadequacy related to the ability to cope; and uncertainty about the context and final outcome of the health intervention.²⁸ In this study in Sweden, it was reported that, since the emergency alert call is received, a series of stressors are activated, to which it is sometimes added the fact of not knowing all the patient’s information or the exact location of the incident.²⁸ As shown in the study, when patient data were expanded, practitioners greatly relaxed. Other factors are related to the abilities of each professional to adapt to the situations they face. Many nurses claimed not to have the adequate knowledge for both evaluating the situation and initiating an adequate treatment, and above all they affirmed that situations where the patient was seriously affected and they had to inform their relatives and at the same time offer emotional support generated a great feeling of stress that was aggravated even more so when they were acquaintances of the patient they had to assist.²⁸ Low personal mood, poor sleep quality, and emotional fatigue (an element that doubled the presence of stress in health workers) also obtained significant evidence as determinants of the generation of work stress perceived by ambulance emergency nurses in countries such as Ireland or Brazil.^51,53

Results for the Specific Objective: Relationship Between Violence and Stress

Violence is a frequent problem for nurses during prehospital care due, mainly, to the false expectations of both the relatives and the patient, even in cases where there has been drug abuse. The emergency respondents’ perception of the most threatening situation would be, first, the interaction with patients who have taken designer drugs, followed by drunk patients and those with mental disorders.⁵⁷

From the total selected research, it has been observed that prehospital nursing professionals do not define their profession as completely safe. For example, 572 health workers of the Polish emergency service indicated on a scale of 1 to 5 the level of perceived danger, obtaining a mean of 3.6, being valued by 40% as a high level of danger (level on the scale: 4/5). Multivariate regression has shown that staff with a career length > 5 years assessed the level of danger as 1.132 times higher (p < 0.001, R2 = 0.181).⁵⁷

The above said contrasts with the results obtained in a Spanish study where it was found that 18.1% had never been exposed to any type of aggression. However, 47.6% had been exposed to verbal violence and 34.3% had also been physically assaulted.³⁶ This study also mentions waiting times of both the patient and their environment as one of the most frequent reasons for aggression.³⁶ In contrast, participants in an Iranian study were more likely to experience violence when they attended crowded scenes, with people with a high level of stress in high-severity incidents, which were aggravated if they had not arrived promptly at the scene.²¹ Also, feelings of anger are generated, mostly, in serious situations that can lead to the death of the patient.^28,43

Results for the Specific Objective: Protective Factors Against Work-Related Stress

The importance of work experience and the level of knowledge of the nursing professionals has offered inconclusive results as regards the level of perceived stress. Some studies highlight that an optimal level of experience extends the stress-reducing capacity and point out statistically significant differences that confirm that younger professionals and with less prehospital experience are more vulnerable when facing complex situations such as, for example, those involving children (especially if the result of the intervention is not positive), so their perception of work stress rises, affecting their overall perception of health.^23,57 Lack of experience is also a determining risk factor for numerous physical injuries caused by violent acts through direct confrontation with patients or relatives, resulting in obvious sources of stress.^21,43 Being youth has been postulated as a facilitating factor for both physical and verbal violence that also increases the sense of danger.³⁶

The professional experience of peers has been found to affect the level of stress of ambulance staff. It has been shown how nurses working in ambulances stated that the fact of working alongside an experienced peer allowed them, through feedback, to develop their own skills with a greater degree of confidence when performing the interventions, resulting in benefits on perceived stress. On the contrary, working with inexperienced peers or with whom one had a bad working relationship generated a high level of stress.^23,28

On the other hand, there are some detractors who claim that the level of experience plays a relevant role as a stressor. The study by Mirzaei et al²⁷ established a statistically significant relationship between both age and work experience and work-related stress. The results obtained suggest that, as the age and work experience of nurses increased, their ability to adapt and resistance to the stressful situations of the prehospital emergency service were minimised. Stress increased more significantly in those who had been working longer in the profession, since they had greater emotional exhaustion due to years of work and less physical capacity to perform activities. Afshari et al⁴³ highlighted work injuries as the main source of stress, categorising them into physical injuries and psychological stress. Following this line, the results obtained by Carvalho et al showed a lower stress level among those who had worked less time in this service, being the time frame worked from 6 to 10 years as a prehospital nurse the most affected, with 35.2% of respondents declaring stress.⁵³

The application of protective measures within the prehospital emergency service is mainly derived from the following two categories:

The Support Received from Colleagues

Prehospital nursing is a fundamentally collaborative profession, with the need for a fluid working relationship and an adequate level of trust in the rest of the colleagues, since this decreases the level of perception of stress, even when faced with a highly complex event.^23,28 As shown by the results, the benefit of informal talks between peers should also be highlighted, which allowed to expose common experiences among the staff. This enabled regular feedback on healthcare outcomes, where professionals could maintain an open discussion about the stressful situations encountered during their practice in a self-evaluative and reflective way, sharing how they felt and coped with similar situations.^23,28,51

Management

The role of the manager is also fundamental in reducing the feeling of stress on the part of health professionals, as among the functions of managing staff is to ensure the specific training of nurses in the field of prehospital emergency care, as well as to implement adequate and sufficient resources to allow the team to perform their tasks in an optimal way. In addition, as the person in charge of regulating working conditions and supporting professionals, the manager must address the perceived need for structured schedules and breaks.⁵¹ Other authors also highlighted increasing autonomy, creative work capacity, and humour as factors to be taken into account for protection against stress.⁵

Discussion

Occupational stress is a problem that professionals must cope with on a daily basis and, within the different professions that deal with prehospital emergencies, nursing is among the most affected by the level of perceived stress.⁵¹ The severity of this issue is made evident by the frequency with which this condition manifests itself in this professional group, with numerous studies declaring a prevalence of between 25% and 65%, the vast majority of which with stress in the resistance phase and with a high percentage in the exhaustion phase.^27,51,53 To answer the first objective of this review, 14 studies were analysed and stressors felt by prehospital nurses were grouped into five categories: management, patient care, interpersonal stressors, environmental stressors, and personal factors. The violence perceived by professionals has also been a remarkable element in this review, being one of the factors that precipitates stress and the perception of danger. On the other hand, the main protective factors derive from peer support and provision from health service managers,^23,28,51 although certain individual interventions have also been effective, such as mindfulness^52,56 or positive coping therapies.²⁷ The results from this review provide useful information for prehospital nurses and allow these factors to be mapped against other nursing specialties in the hospital setting.⁵⁸

Regarding health services’ management, the shortage of resources outside a clinical centre has been considered one of the most relevant factors affecting stress, even having the capacity to double the stress levels.^51,59 The incidence of psychological distress in ambulance personnel is not just a matter of exposure to traumatic incidents, but is also a result of the way in which the organisation responds, at managerial and organisational level.⁵⁹ Likewise, a significant influence of the low level of support perceived by nurses from their superiors during the performance of their duties has also been observed.⁵³ In this sense, it has been suggested that the effects of stress, especially those of a psychological nature, or cases of perceived violence, may have a relevant effect on the work engagement of nurses, and closer attention by occupational health services may help to reduce the negative consequences of these adverse events by favouring high levels of self-efficacy;^38,60 for example, by facilitating access to formal paths of psychological attention, ambulance personnel could receive appropriate care against stress, lack of confidentiality, use of inappropriate therapies, poor return-to-work mechanisms, isolation, or stigmatisation of work.⁵⁹

The personalised care of each patient, the patient’s state of health, and closeness to death are the patient-centred factors that most influence stress levels in nurses. In this sense, cardiovascular, gynaecological, and paediatric emergencies are the most demanding situations, highlighting musculoskeletal trauma, respiratory distress, and cardiac problems among the events involving children.^23,51,55 The level of stress is also interrelated with decreased patient safety, mainly due to identification with the patient, lack of experience, responses from family members, and knowing that the situation could worsen at any time.⁵⁵ Some studies already showed that ambulance nurses need more knowledge and education as regards the care of children.^61,62

Similarly, dealing with special patients, suicide events, workplace violence, and other traumatic events have been pointed as the direct causes of stress in emergency nurses.⁶³ Situations of violence are aggravated, according to some studies, when the patient and/or their companions are intoxicated or when the perception of the patient’s injuries differs between health workers and family members, and it is reinforced if the ambulance does not arrive promptly.^21,54 In those situations, in which the patient gets out of control (becomes verbally and/or physically aggressive), professionals feel insecure, and there is debate about whether the age and experience of the professional can act as protective agents or censors in these situations.^23,28,38 For example, problems with superiors have been positively associated with repeated confrontations, ie verbal aggression, being on guard, and/or any form of aggression, and could be seen as factors related to interpersonal conflict and inability to prevent violence escalations.²⁶

The environmental factor comprises working in unhealthy environments, in inadequate physical facilities, or in scenes of high risk to the physical safety of the health provider, in addition to working the night shift.^53,56 In a previous review,⁵⁸ the work environment was pointed as a factor that contributes to increased stress levels, impacting on nurse retention rates in the emergency departments. These environmental stressors included inadequate staffing levels, very high responsibility, excessive workload, and overcrowding.⁶⁴ On the other hand, the stressful role that night work plays in nursing has also been highlighted,⁶⁴ being a possible cause of cancer⁶⁵ and work-family conflicts.⁶⁶

In terms of personal health, low mood and poor sleep quality stand out as stressors. Studies on the effects of long-term stress among nurses very often show sleep problems and insomnia.⁶⁴ On the other hand, emotional fatigue, not knowing exactly the patient’s information, and not having adequate knowledge to evaluate a patient or perform the appropriate interventions aggravate the level of stress of prehospital nurses, especially in complex situations, thus increasing the probability of suffering both physical and psychological problems such as anxiety, physical pain, deterioration of personal relationships, or increased cardiovascular problems.^28,53 In this sense, promoting ongoing training is essential, since nurses with less advanced training in the ambulance system may encounter greater complications during health care than those with a higher level of competence. A curriculum for a specialist nurse should reflect the actual knowledge, expertise, and skills required in the profession-specific environment.⁶⁷ Treatment guidelines and working protocols, as well as contact with more competent colleagues, are workplace-based strategies that contribute to safe patient care and strengthen the ability to successfully deal with critical incidents.⁴⁵

Finally, the main protective agents for stress reduction highlighted in this review are interventions carried out jointly with both managers and peers working in the service. However, these are not fully effective, so professionals suffering from stress should seek support in practices such as mindfulness, spiritual coping, massage, and psychological therapies.^{27,51,52,54,56,68}

Psychological Therapies

Comprehensive psychiatric evaluations should include assessment of long working hours and high levels of strain and stress at work, in particular when there have been work-family conflicts, health issues, emotional problems, suicidal ideation, and previous psychological treatment. Marital status, perceived family and social support, and sense of coherence should also be assessed. Additionally, it is important to consider other factors such as age at the start of the profession, years of service, or rank.⁶⁹ Similarly, a comprehensive psychiatric evaluation, including a clinical interview and administration of validated assessment measures, should be done on a regular basis to help the person to correctly perceive external threatening factors of stress.^44,45 In this regard, the lack of accessibility described by nurses should be noted, since in very few cases this type of intervention is promoted by managers.⁵¹

Mindfulness

It has been proven that mindfulness therapies favourably affect the reduction of stress perceived by nurses, especially in cases of conflict with peers and with a great number of interventions during the workday. It is also worth noting the improvement obtained in the specific case of prehospital emergency care involving children.^52,54,56

Positive spiritual coping was associated with decreased occupational stress (β = 0.373).²⁷ This type of intervention has obtained significant statistical evidence as for reducing occupational stress in all its subscales, obtaining higher self-awareness and increasing the search for peace and internal harmony. It mainly consists of religious help, coping with difficult situations, and the use of cognitive and behavioural work through a positive attitude to overcome weaknesses.²⁷

Massages

Although it has been mainly used in pain management, it has also been highlighted in the treatment of stress given its ability to promote patients’ relaxation as well as to increase the ability to concentrate and stabilise the immune system (p = 0.001).⁵⁴ However, although massage was beneficial against some stressors (patient death and conflict with managers and peers), it did not obtain significant evidence when dealing with stress in general. Therefore, although this intervention should be considered when dealing with stress in prehospital care based the results obtained in various studies, where it was studied as a single intervention, it should be recommended as a complementary procedure, just like other means such as music therapy.⁵⁴

The main limitation of the present study has been the low prevalence of previous studies that focus on work-related stress from the perspective of prehospital emergency nurses. Indeed, only one of the selected studies was a clinical trial, and the others were observational and qualitative studies. To this it must be added that some research was excluded because it did not offer data disaggregated by health professions, thus making it difficult to obtain a clear vision of the problem in the field of nursing. For future research it is convenient to analyse the stress factors exclusively from the nurses’ point of view, separating the nursing profession from the other professions that act within the ambulance service.

According to the selected studies, it should be mentioned that the information in this review has been extracted from a heterogeneous international context, so some variability in these factors may be found in each national health system. In this sense, a limitation of this study is that due to the low volume of articles, the variables analyzed, and the different measurement scales, the researchers did not consider it applicable to perform a meta-analysis as a synthesis of the evidence.

The investigators performed a review protocol to minimise bias during research and used the GRADE tool to assess the quality of the evidence to avoid potential publication bias, and consequent overestimation of the data. A selection bias must also be acknowledged, given that some studies in the research may not have been identified or were excluded as they did not fit the established criteria. Nonetheless, all identified research was retrieved, and any study was excluded due to methodological bias. Finally, note a possible researcher bias since expectations and opinions may have conditioned the conclusions.

The main contributions of this study are based on the description of the main factors that act in prehospital emergency systems that increase the stress perceived by nurses, with the aim of reducing these risks and acting to promote the mental health of healthcare professionals. The optimal strategy to follow parts from a collaborative effort between health services managers and the nurses who work in them, so as to correctly cope with these stressors, according to Lazarus’ theory.^7,8 However, a review on this topic showed that most studies only measure some work stressors and some outcomes, without taking into account the perception of the stressor by the emergency nurse.⁷⁰ According to Lazarus,⁷¹ coping strategies may be used to change the stressful situation for the better, either by modifying the person’s actions or by changing the environment. Seeking information or planning alternatives and direct actions are useful strategies for active coping.⁷² Nursing managers need to be aware of those situations when nurses’ usual strategies are no longer adequate for effective coping, and it is essential to understand that they might be key figures in helping them to cope.^44,45

The organisation can assist through a number of strategies and processes that can be divided between cultural shifts and organisational re-design. Cultural action is required to remove the stigma associated to seeking help for work-related stress. This may mean that the service needs to organise staff to allow that fatigue and emotional processes can be addressed. Therefore, hospital and prehospital emergency managers can reduce their staff’s stress levels by reducing workplace demands and improving the work environment. By reducing stress, the health of staff members is maintained and improved, and the quality of care provided to patients increases.^59,73

Conclusions

Due to the characteristics of the prehospital emergency, it is inevitable that nurses will be exposed to multiple potentially dangerous and stressful factors. Mainly, 5 categories have been highlighted based on personal characteristics of nurses, environmental stressors, management, interpersonal stressors, and patient characteristics. It was also possible to associate the increase in the perception of work-related stress with the violence received during the service. On the contrary, the level of experience and knowledge presented a diversity of opinions about their role in stress levels.

Against aggressions, there are multiple strategies to deal with it, being the control of the patient’s clinical situation and the control of their social environment the most effective, as well as implementing national strategies in order to minimise violence towards healthcare workers. To improve safety in the different interventions performed by the emergency team, the relationship of trust between colleagues is also relevant as well as working with professionals with a higher degree of experience and knowledge when nursing staff are poorly trained.

Finally, providing the necessary resources to ambulances and workers, so that professionals do not have a feeling of lack of control, especially when it comes to a complex intervention, is essential to control the environmental factor. To this can be added the establishment of adequate rest periods and the adequacy of the workload.

This study promotes that interventions for stress management in health workers could have a greater weight in health policies by managing resources and environmental factors that can influence stress levels among members of staff. In addition, providing workers with psychosocial skills to increase self-knowledge and self-care also places on them the responsibility of coping with stress. This allows collective awareness to be, finally, the main element that reduces the incidence of stress.