Interruptions of nurses' activities and patient safety: an integrative literature review

OBJECTIVES: to identify characteristics related to the interruption of nurses in professional practice, as well as to assess the implications of interruptions for patient safety. METHOD: integrative literature review. The following databases were searched: Pubmed/Medline, LILACS, SciELO and Cochrane Library, using the descriptors interruptions and patient safety. An initial date was not established, but the final date was December 31, 2013. A total of 29 papers met the inclusion criteria. RESULTS: all the papers included describe interruptions as a harmful factor for patient safety. Data analysis revealed three relevant categories: characteristics of interruptions, implications for patient safety, and interventions to minimize interruptions. CONCLUSION: interruptions favor the occurrence of errors in the health field. Therefore, there is a need for further studies to understand such a phenomenon and its effects on clinical practice.


Introduction
Patient safety is a problem faced in the health field around the world. A study conducted in the United States of America (USA) identified the occurrence of adverse events during healthcare delivery as the 8th leading cause of death in the country (1) . A significant number of these adverse events is avoidable because they accrue from human errors of systemic origins (2) . Additionally, most of these errors occur due to the complexity of the care involved, considerable variation in the qualification and quantity of available healthcare providers, diversity of procedures, deficiencies in infrastructure and management, and mainly arise from failures in activity systems that disregard the human factor in the design and conception of actions (1)(2) .
The nursing staff plays a key role in insuring the safety of patients because it provides direct assistance and care to the patient and family, composing the largest group of professionals in the health field in the world (3) .
Because these professionals have direct participation in the safety of patients, it is essential to understand the conditions and complexities of the working environment in which nurses work and that may compromise the quality of care delivery, especially in regard to interruptions of the activities performed by nurses.
According to the report To Err is Human: Building a Safer Health System, developed by the Institute of Medicine (IOM) (1) , interruptions contribute to the occurrence of errors and are the main cause of failures related to the work environment, very common in hospital facilities (4)(5) .
Interruptions occur when the main task is suspended so that a secondary activity receives attention (6) .

Interruptions can be classified into: intrusions
(unexpected encounters with someone who temporarily interrupts the main activity), distractions (psychological responses triggered by external or environmental stimuli, or by secondary activities that break one's concentration on the primary task), breaks (planned or spontaneous pauses in a task), and disagreements (uncertainty perceived by the professional according to his/her knowledge, expectations and/or observations that are relevant for the work being performed) (7) .
Additionally, such interruptions can be a disturbing factor, affecting the professionals' concentration and delaying care delivery, impeding the professional from successfully finishing tasks, potentially favoring the occurrence of errors and putting patients at risk, in addition to wasting the resources of the healthcare system (8) . A task's cognitive load also influences the impact of interruptions on care delivery; human memory has limitations hindering the simultaneous assimilation of multiple inputs of information.
Some interruptions are, however, essential in the process of care delivery and enable the transmission of important information (4) .
Nurses constantly perform multiple activities and need to develop cognitive mechanisms to keep their focus on clinical rationale, which is necessary to providing care. This dynamic environment in which tasks are performed requires reflection and complex psychomotor and cognitive skills to ensure quality and safe care delivery. Interruptions during practice may compromise the attention of workers, leading to distractions, and therefore, may represent a risk to the safety of patients.
These distractions may be more related to failure in the systems than to individual performance (9)(10) .
Note that patient safety is a result of the quality of interactions among all the components of the care system, not uniquely determined by one individual, type of activity, infrastructure or technology (11) . Therefore, to achieve good results it is essential to conceive and design environments and working processes in health and nursing, the fundamental principles of which are guided by the needs of patients and their families, comprising the causes and consequences of interruptions.
In the face of evidence that interruptions increase the likelihood of errors during care delivery and because of there being few international studies and no Brazilian studies characterizing such occurrences or describing their impact on clinical practice, this study's aim was to perform a literature review to understand the characteristics of interruptions and the factors contributing to this phenomenon, so as to implement strategies that enable reducing the occurrences of such events and improving quality of care.
Hence, this study's guiding question was defined interpretation of results and presentations of review (12) .
The descriptors used for the search were First, we read the title of the publication followed by a careful reading of abstracts to verify whether the inclusion criteria were met. In cases in which the title and abstract were not sufficient to define the topic addressed, we sought the full-text so that all the criteria would be applied and papers answering the study's guiding question would be included.

Authors Type of study and sample Objective Results
Type of study: observational. Sample: eight nurses.
To identify and classify the types of interruptions experienced by nurses.
The organizational structure contributed to the occurrence of interruptions in the workflow. A greater number of interruptions was identified as being caused by environmental factors (face-to-face, technology, lack of supplies, patient's needs).
Type of study: exploratory. Sample: three nurses.
To identify the cognitive effect of interruptions on the performance of nursing workers.
The dynamics of work and interruptions may harm the professional's assessment and clinical decision-making, consequently increasing the number of omissions and errors. In this study, 47% of the interruptions occurred when direct care was being provided to patients.
To develop a method to categorize interruptions.
The study resulted in the development of an instrument to categorize activities and interruptions. Interruptions were named and categorized into eight distinct taxonomies. (16) Type of study: observational. Sample: 38 healthcare providers (physicians, nurses, physical therapists and occupational therapists).
To characterize and analyze interruptions and distractions experienced by professionals using an electronic information system.
Nurses experienced five distractions per hour and, consequently, their primary activity was interrupted (62.5%), multitasks (25.0%), and tasks were postponed (12.5%). Additionally, such distractions led to the occurrence of memory lapses, incomplete tasks and change in the workflow.
To analyze the relationship between interruptions during cardiac surgeries and the occurrence of errors.
Interruptions occurred due to failures in staff communication and failures in equipment. In addition to external interruptions, there were distractions related to the activity and access to resources. Surgical errors occurred regularly and increased significantly with the occurrence of interruptions in the staff's work. (18) Type of study: observational and exploratory. Sample: 16 surgeons, 26 nurses and 20 anesthetists.
To develop a tool to assess the perceptions of professionals working in surgical environments, concerning interruptions they and their coworkers experience.
All the professionals reported that individual issues, the surgical environment and communication problems affect other professionals more frequently and more severely them themselves. Surgeons reported a significantly lower number of interruptions than nurses and anesthetists.
To observe activities and interruptions experienced by physicians and nurses.
Nurses experienced 12 interruptions/hour. Main sources of interruptions: telephone; pager; other people; self-interruption; physical environment and lack of supplies. The professionals resumed their primary activity after performing eight activities. (20) Type of study: observational, prospective. Sample: 38 times of administration of medication.
To analyze the occurrence, type and duration of interruptions experienced by nurses during times when medications were administered.
In activities concerning the administration of medication, nurses spent 11% of their time managing interruptions. There was an average of 2.6 interruptions per administration; interruptions lasted one minute on average. Main sources: physicians, nurses, patients, telephone, family members, and selfinterruption. Interruptions that lasted the longest included patients and telephone. (21) Type of study: observational, descriptive. Sample: 102 times when medication was being administered.
To assess the characteristics of interruptions experienced by nurses during the administration of medications.
Main sources: nursing staff and lack of supplies. Causes of interruptions varied according to the time in which it occurred (preparation or administration). Most of the time, nurses immediately attended to the interruption.
To analyze aspects related to interruptions experienced by pediatric nurses in clinical practice.
The environment and nursing staff were the main sources of interruptions and the most frequent were intrusions and distractions. In regard to causes, the communication of patientrelated issues, pumps/monitors and the need to provide assistance, were the most frequent. Care directed to patients and documentation activities were the activities most frequently interrupted and most of the interruptions negatively impacted care delivery.   (25) Type of study: literature review.
To analyze the difficulties presented in the study of interruptions in the health field.
The complexity of studying interruptions and measuring their impact on clinical practice due to the study method and variables used is one of the reasons there are gaps in the knowledge of consequences accruing from such events.
To verify the difficulty of researching interruptions in the health field.
Interruptions are influenced by various factors that compromise patient safety and workflow, such as: characteristics of the primary task; time and duration of interruptions; the individual's cognition; type of interruption; environment; other aspects.
To understand how nurses deal with interruptions during the administration of medication and design strategies to avoid errors.
Three of the strategies used allow interruptions and the fourth strategy does not (block) in order to maintain attention on the primary task. Factors related to the activity and professional experience influence control over interruptions.
To assess interruptions during the administration of medication before and after the implementation of a program of interventions with the use of visual signs and an interruptionfree area.
There was an increase of interruptions after the intervention, mainly on the part of staff members, though interruptions were of shorter duration.
To identify the occurrence of interruptions during activities of medication administration, causes, avoidable interruptions, and develop a project to decrease such interruptions.
A total of 1,170 interruptions were observed during 3,000 hours of observation; 14 causes of interruption were observed, nine of which were avoidable. The authors propose a form for a multidisciplinary recording of the prescription, preparation and administration of medication, including the occurrence of incidents.
Li SYW et al./ China, 2012 (29) Type of study: systematic literature. To understand the effects of interruptions on healthcare services.
The main factors impacting the effects of interruptions are: the work's cognitive load; time the interruption occurred; similarity between primary and secondary activity; the same sensory stimulus is used in the primary and secondary tasks; practice and experience of the professional being interrupted; and management of interruptions.  To implement strategies used in the aviation field (sterile cockpit) to decrease interruptions and distractions during the administration of medication, as well as to reduce errors of administration of medication.
The number of interruptions decreased during the administration of medication, especially when the sources were the health staff and patients. Errors of administration of medication also decreased after the use of aviation principles, identifying a positive impact of patient safety.
To analyze evidence obtained in studies addressing interruptions in intensive care units.
Interruptions occur during all the nurse activities and studies should not focus only on specific activities. Additionally, interventions may be implemented to decrease such events, however, further studies are needed to provide evidence on the impact of interruptions.
To develop strategies to prevent distractions and interruptions in surgical units. Type of study: systematic literature review.
Assess the efficiency of strategies to decrease interruptions during the administration of medication and error rates.
There is little evidence on the efficiency of interventions to significantly decrease interruptions and errors of medication administration . Therefore, further studies are needed.
To describe the interruptions of nurses in hospital units and consequences for practice.
Nurses were interrupted by brief questions and the exchange of information among professionals. Interruptions most frequently occurred during the preparation of medication and in a room specific for this activity. Some interruptions were considered to integrate different parts of the work, though some were considered unnecessary and led to frustration.
Berg LM et al./ Sweden, 2013 (36) Type of study: observational and descriptive. Sample: six clinical nurses, six nurses and six physicians.
To analyze interruptions of professionals working in emergency rooms.
Most interruptions occurred during the exchange of information among professionals. When computing the percentage of activities performed and interruptions experienced during activities, the preparation of medication was shown to be the activity most frequently interrupted. The places most common for the occurrence of interruptions were: nursing stations and the physicians' rooms. Professionals often do not consider interruptions to be negative, except when they are unnecessary or disturbed the work processes.
To observe the occurrence of interruptions during the intra-operative and assess the impact on the staff.
The staff was interrupted 9.8 times per hour and the most frequent interruptions were entry and exit of people from the surgical room, telephone and pagers. There was a greater number of interruptions in a procedure's initial phase. The nurses suffered the lowest level of impact from these interruptions among the professionals observed.
To develop a methodology to identify and classify interruptions in the workflow inside a cardiac surgery room.
Interruptions were grouped into six categories; the main categories experienced by nurses were: general interruptions; problems in the use of objects; and miscommunication. The physical layout of the surgical room and failure of equipment impact workflow. Monteiro C, Avelar AFM, Pedreira MLG.

Characteristics of interruptions
The number of interruptions experienced by nurses ranged from 0.4 to 13.9 interruptions per hour, according to the type of unit under observation (5,9,(13)(14)16,(18)(19)(23)(24)28,(35)(36)(37)39) . Interruptions were most frequent in pediatric units, a fact that may be explained by the peculiar care environment of pediatric units due to the physiological characteristics and complex development of this population. It is also a dynamic unit with a high transit of family members, companions and workers (5) .
Additionally, the study showed that nurses are rarely able to complete an activity without being interrupted, which may be related to the tasks they constantly perform involving managing the unit, care delivery, and care directly provided to patients, in addition to being the most requested professional to provide information to patients, families and other healthcare providers (39).
Among the professionals in the surgical staff, surgeons are the professionals most frequently interrupted, followed by nurses (30,37) . One study, however, assessed the perceptions of professionals concerning this phenomenon and verified that surgeons reported being interrupted significantly less frequently than did nurses or anesthetists (18) . Additionally, there is a positive and significant linear correlation between interruptions in the workflow of surgical procedures and the occurrence of errors (p<0.001) (17) .
Only three studies classified interruptions according to type, while the most frequent interruptions resulted from intrusion and distraction, and less frequently, from disagreements and breaks (5,(23)(24) .
The main sources of the interruption of nurses were other healthcare providers, members of the nursing staff, telephones, pagers, patients, family members, visitors, and self-interruption (5,(13)(14)18,20,(22)(23)(24)27,30,35,37) . There are also the environment's physical characteristics (5,13,38) and a lack of supplies or a failure of equipment necessary for care delivery (13,21,30,38) , which lead to interruptions in the workflow. Researchers report that nurses were more frequently interrupted to answer questions concerning professional issues and due to the need to provide patient-related information (35) . In regard to places where interruptions occur, research shows there is greater occurrence in nursing stations, followed by rooms dedicated to storing and preparing medication , medical staff rooms, areas near beds and corridors (35)(36) .
One study reports that one nurse was interrupted 43 times in a period of 10 hours; 23% of these occurrences accrued from operational failures such as lack of supplies, equipment or personnel (40) . These interruptions caused by failures in the system are avoidable, therefore, working processes in healthcare facilities should be improved to minimize such occurrences. Where these failures are corrected, nurses spend less time resolving institutional failures and have more time to provide direct care to patients (41) .
A characteristic observed in one study assessing interruptions during the administration of medication was that among the 14 causes of interruptions, nine (64.3%) were avoidable. The most frequent reasons were: illegible or incomplete medical prescriptions; the need to address the requests of physicians or other providers; and alarms. All of these are avoidable interruptions (28) . lack of supplies -interruption originated from a need to seek materials or equipment not available in the work area; and initiator -the person who caused the interruption (15) .

Implications of Interruptions for Patient Safety
Interruptions directly affect the performance of activities and may compromise decision-making processes and the efficiency of workers when they occur during the performance of more complex activities that require greater concentration (7) . These occurrences are common in the practice of nurses and impact the quality and safety of care delivered to patients by interfering in staff member's cognitive processes, potentially resulting in a great number of errors (4)(5)(6)(13)(14)(16)(17)(22)(23)(24)(26)(27)(29)(30)35) .
Studies identified that 88.9% to 90% of interruptions resulted in negative consequences, such as delay in treatment and loss of concentration (5,(23)(24) .
Other studies related interruptions to a greater chance of errors in the administration of medication (6,27) .
The literature shows that interruptions do not always lead to adverse events and some may have a positive impact on a professional's performance and care delivery because some interruptions may contribute to increased safety, increased comfort of patients, and help nurses to be more accurate in their tasks (5) .
Therefore, further studies addressing this topic with methodology appropriate to the study's objective (25)(26) are needed to assess the impact of interruptions on care delivery, since some interruptions are actually necessary to quality care (4)(5)32,(35)(36) .   (27) . After such interventions, however, an increased number of interruptions were observed, especially during the time when medication was being prepared, mainly by staff members. Nonetheless, interruptions were or shorter duration and the time nurses dedicated to the performance of direct care increased, enabling the supply of care to a greater number of patients (27) . Another study, however, which implemented strategies used in the aviation field (sterile cockpit), showed a decreased number of interruptions during the administration of medication, especially when the sources were the health staff and patients (31) .

Interventions to Minimize Interruptions
Interruptions, however, may still occur, even after instructing the staff and adopting strategies to decrease the number of interruptions, depending on patient needs and staff adherence to recommendations.
Therefore, it is necessary for nurses to be able to deal with the occurrence of interruptions. One study aiming to understand how nurses manage interruptions during the administration of medications reports four strategies. Three of these allow interruptions: when the Monteiro C, Avelar AFM, Pedreira MLG.
primary task is discontinued and can be resumed after a secondary task that has greater priority is performed; when the professional shares attention between the primary and secondary tasks, as both have similar priority; and when an interruption is mediated with an action that allows the primary task to be resumed (prospective memory). The fourth intervention, however, called "blocking", occurs when the primary task has greater importance and the interruption must be blocked, so that the professional is able to maintain attention to this primary task. Note that these strategies depend on staff workload and clinical assessments and are influenced by factors related to the activities involved and professional experience (6) .

Conclusion
The

Final considerations
Studies presented in this review show a scarcity of papers addressing interruptions during the practice of nurses, which may be related to the absence of a descriptor for this topic that is used worldwide.
Additionally, no study addressing this topic was found in Brazil, which hinders comparisons with the Brazilian context in which nurses often have to correct failures in the system and the nursing staff is mostly composed of professionals without a bachelor's degree.