Conceptual and operational definitions of the defining characteristics of the nursing diagnosis Disturbed Sleep Pattern*

Objective to present the knowledge produced about sleep and Acute Coronary Syndrome in order to assist in the elaboration of the operational and conceptual definitions of the defining characteristics of the nursing diagnosis Disturbed Sleep Pattern (00198). Method integrative review in the following databases: COCHRANE; SCOPUS; MEDLINE (Medical Literature Analysis and Retrieval System Online) via Pubmed; LILACS (Latin American and Caribbean Health Science Literature Database); CINAHL (Cumulative Index to Nursing and Allied Health Literature) and EMBASE (The Excerpta Medical Database). At the end of the search, 2827 studies were found, 43 were selected for reading, and 10 were included in the review. The gray literature was also included. Results important findings related to clinical evidence and contributing factors of sleep were found in the review. However, in order to build definitions of the defining characteristics, it was necessary to use gray literature, such as a Portuguese dictionary and two textbooks about sleep. Conclusion the definitions will help nurses in their practice in the collection of information, in the determination of the nursing diagnosis studied here, and in directing care measures with respect to quantity and quality of sleep of Acute Coronary Syndrome inpatients. They will also assist in the next steps of the validation of this diagnosis to the referred population.


Introduction
Sleep is a physiological condition and has two essential patterns: Non-Rapid Eye Movement (NREM) sleep, divided into three stages -N1, N2 and N3, being the latter the deeper stage, when heart rate and blood pressure decrease; and Rapid Eye Movement (REM) sleep, when rapid eye movements, muscular hypotonia or atonia are present. These two patterns ared interspersed during the night. On a typical night of sleep, four to six NREM-REM cycles occur (1) .
Good sleep health with adequate quantity and quality is recognized as an indicator of vitality, mental health, and physiological, emotional, cognitive and physical well-being that leads to a good quality of life (2)(3) . On the other hand, recurrent lack of sleep health can contribute changes in physical health, leading to serious conditions and even death (4)(5) .
Assessing sleep health is extremely complex, but the literature (6) proposes five more appropriate and relevant dimensions for measuring and defining it: duration; efficiency/continuity; sleep time in 24 hours; alertness and drowsiness; and satisfaction/quality of sleep.
Objective instruments can be used to measure sleep, including Polysomnography (PSG), the gold standard in sleep evaluation, as well as subjective instruments as self-reports and questionnaires (7)(8) . In nursing practice, observation and reports of patients are usually useful to subjectively evaluate the patients' sleep patterns.
In the hospital environment, several factors can disturb sleep, such as diagnostic and therapeutic procedures, the noise and illumination of the environment, and also the nursing care routine (9)(10) . The literature has demonstrated the poor quality and quantity of sleep in ACS patients. A study used PSG to demonstrate that the architecture and microarchitecture of the sleep of patients in the acute phase after ACS were negatively affected and that the quality and amount of sleep was related to their quality of life in the short and long term (11) . Another study used a specific questionnaire and observed poor sleep quality in 71.7% of infarcted patients (12) .
Still in a study that sought to identify the profile of nursing diagnoses in infarcted patients, it was evidenced that the Nursing Diagnosis (ND) of Disturbed Sleep Pattern (00198) was present in 85% of participants (13) .
Thus, the nursing team should be sensitized on the importance of promoting quality and quantity of sleep, its contributing factors and how to promote adequate sleep for ACS patients who are hospitalized. In this way, nursing should provide care measures that evaluate, promote and maintain adequate quantity and quality of sleep in these patients (9)(10)14) .
To this end, nurses should use tools to support an effective, rapid, direct, low-cost, and accessible bedside assessment for all patients in the hospital environment, taking into consideration also the patient's own opinion.
In this context, the Nursing Process (NP) emerges as an alternative to sleep assessment. The NP is divided into five stages (15) . The second stage is the ND and serves as basis to the others; it is used by nurses to evaluate human responses after clinical judgment, with the focus on specific problems, in a state of health promotion or potential risk. There are ND taxonomies that assist in the classification and categorization of areas that concern Nursing, such as the NANDA-International Taxonomy (NANDA-I) (15) .
In order to determine a ND, nurses should know their indicators, which include the Defining Characteristics (DC) and their contributing factors, corresponding to the Related Factors (RF) (15) .
The DC are clinical manifestations, evidences, signs and symptoms or inferences that can be observed in the individuals to determine a given ND. However, in clinical practice, nurses may face lack of clarity regarding what and how to evaluate.
Thus, validation studies of ND have been proposed in order to contribute to lessen the variability present in clinical situations and to help in the accurate identification of ND that corresponds to the clinical condition presented by the patient (16)(17) .
In order to carry out the validation of a ND, a first step is proposed, namely, the construction of conceptual definitions (CD) and operational definitions (OD) of the DC of a given ND for a specific population (16) . CD correspond to the theoretical meaning of the DC. On the other hand, the OD should assign a meaning capable of communicating how a given concept is applied, that is, they should elucidate the practical meaning of the CD of each DC and specify what practical activities or Manzoli JPB, Correia MDL, Duran ECM.
procedures are necessary for the evaluation of such characteristics (18)(19) . Therefore, the present study proposed to carry out an Integrative Review with the objective of presenting the knowledge produced about sleep and acute coronary syndrome in order to assist in the elaboration of the The descriptors used in the various databases were: "disorders of sleep onset and maintenance"; "sleep deprivation"; "sleep disorders by excessive sleepiness"; "circadian rhythm sleep disorders"; "sleep-wake disorders"; "intrinsic sleep disorders"; "dyssomnias"; "sleep-wake transition disorders"; "sleep waking disorders"; "REM sleep behavior disorder"; "sleep apnea syndromes"; "sleep pattern disorders"; "coronary disease"; "acute coronary syndrome"; "coronary care units"; "unstable angina" and "myocardial infarction". The Boolean operators "OR" and "AND" were used to cross the descriptors and keywords. An instrument created and validated in Brazil was used to extract data from the selected articles, including identification data, study institution, journal characteristics, study methodology and methodological rigor (21) .
After reading and extracting the data, two tables with information of the articles were created.
The information was the title, journal of publication, country of origin of the study, language and year of publication, methodological delineation, level of evidence and objectives.
The level of evidence was classified in seven levels, namely, level I -evidence from systematic review or meta-analysis covering all relevant randomized controlled trials, or from systematic reviews whose clinical trials had been subjected to randomization and control; level II -evidence from at least one well delimited randomized controlled trial; level IIIevidence from a designed and controlled, but not randomized study; level IV -evidence from cohort studies or case-control studies; level V -evidence from systematic review of descriptive and qualitative studies; level VI -evidence from a descriptive or qualitative study; level VII -evidence from authoritative opinion or expert reports (22) .
A total of 2827 results were found in the search.
Articles were pre-selected by evaluation of the titles and, when necessary, the abstracts. Sixty-one articles were Rev. Latino-Am. Enfermagem 2018;26:e3105.
kept after pre-selection. Of these, 18 were duplicated in other databases and were therefore excluded. There were still 43 articles, which were reevaluated after a quick reading to ensure compliance with the established criteria. Articles that did not meet the inclusion criteria were excluded. Other reasons for non-selection were lack of specification in the study whether the patients had ACS, and lack of relevant content of clinical evidence and/ or contributing factors to Disturbed Sleep Pattern (00198) in these patients. Due to these reasons, 33 articles were excluded, leaving a final sample of 10 articles.  (23) .
At the end of IR, the gray literature was also explored, since it was not possible to construct the conceptual and operational definitions with the articles of the IR.

Results
The final sample consisted of ten studies. The main characteristics of the articles are described in Regarding the main results of the articles included in the IR, they identified that patients with recent AMI had worse quality and quantity of sleep (11,24,32) and that a high angina score and length of stay in intensive care unit were predictors of poor sleep quality (24) . They also pointed out that during the hospitalization more than one third of the ACS patients had insomnia (29) . And patients with angina had disturbed sleep pattern due to pain (31) . Sleepiness Scale and that 29.2% of the patients presented daytime sleepiness (25) .

Another study identified that infarcted patients
Studies on non-pharmacological interventions such as aromatherapy (28) and use of eye masks (30) and pharmacological interventions such as the use of Escitalopram (27) showed positive results, in which there was a significant improvement in the sleep of the study patients.
The study that sought to evaluate sleep through a specific questionnaire and compare it to PSG findings identified a correlation with sleep efficiency, REM sleep and excitation index, but the minority of the patients were classified as poor sleepers (26) .
Important findings related to sleep and ACS were evident in the present IR. However, they were not sufficient for the construction of the CD and OD of the DC of Disturbed Sleep Pattern (00198), which justified the use of gray literature. Thus, other sources were searched, including a dictionary of the Portuguese language and two textbooks on sleep (33)(34)(35) and an article (36) found that was not included and analyzed in the IR. The OD were developed by the authors based on the information identified in the gray literature. The Figure 4 below presents the CD and OD of the DC Disturbed Sleep Pattern (00198).

Title Journal Country of origin Language Year
Angina severity predicts worse sleep quality after coronary artery by-pass grafting (24) Perfusion Turkey English 2016 Excessive daytime sleepiness in patients with acute myocardial infarction (25) Acta Paulista Enfermagem Brazil Portuguese 2015 Validation of a novel sleep-quality questionnaire to assess sleep in the coronary care unit: a polysomnography study (26) Sleep Medicine Brazil English 2015 Correlates and escitalopram treatment effects on sleep disturbance in patients with acute coronary syndrome: K-DEPACS* and EsDEPACS † (27) Sleep

South Korea English 2015
Effect of Rosa damascene aromatherapy on sleep quality in cardiac patients: A randomized controlled trial (28) Complementary Therapies in Clinical Practice

Iran English 2014
Clinical correlates of insomnia in patients with Acute Coronary Syndrome (29) International Heart Journal United States English 2013 The effect of eye mask on sleep quality in patients of coronary care unit (  Angina severity predicts worse sleep quality after coronary artery by-pass grafting (24) Cohort study/Level IV To determine the effect of angina on sleep quality in patients with myocardial revascularization.
Excessive daytime sleepiness in patients with acute myocardial infarction (25) Cross-sectional study/ Level VI To identify sociodemographic and clinical attributes associated with daytime sleepiness in AMI* patients.
Validation of a novel sleep-quality questionnaire to assess sleep in the coronary care unit: a polysomnography study (26) Cross-sectional study/ Level VI (the Figure 3 continue in the next page...) Rev. Latino-Am. Enfermagem 2018;26:e3105.

Methodological Design Objective
Effect of Rosa damascene aromatherapy on sleep quality in cardiac patients: a randomized controlled trial (28) Randomized controlled trial/Level II To investigate the effect of aromatherapy with Rosa damasceno on the sleep quality of patients hospitalized in coronary care units.

Clinical correlates of insomnia in patients with
Acute Coronary Syndrome (29) Cross-sectional study/ Level VI To examine the prevalence of insomnia and its association with depression, anxiety, and comorbidities after ACS § .
The effect of eye mask on sleep quality in patients of coronary care unit (30)

Randomized controlled trial/Level II
To investigate the effects of the use of eye mask on the sleep quality of patients hospitalized in coronary care units.
Sleep patterns in patients with acute coronary syndromes (11) Longitudinal study/ Level IV To evaluate nocturnal sleep in patients with ACS § far from the environment of coronary care units and evaluate potential connections with the disease process.
Physiologic adaptation problems in people with angina (31) Cross-sectional study/ Level VI To present common physiological problems in patients with UA || using the Roy Adaptation Model.
Sleep quality of patients with acute myocardial infarction outside the CCU ¶ environment: a preliminar study (32) Longitudinal study/ Level IV To assess the quality of sleep in patients with AMI* hospitalized in a coronary care unit and six months after the episode.

Alteration in sleep pattern
Conceptual definition: change in the normal state of sleep defined by the predetermined "sleeping models", based on alterations of the quantitative and qualitative dimensions. Adults need an average of seven to eight hours of sleep in 24 hours, with up to 5% of nocturnal awakenings, for an optimal state of wakefulness and, therefore, to obtain quality sleep (33)(34)36) .
Operational definition: patient reports that he did not sleep quantitatively enough and did not wake up rested (qualitative evaluation).

Unintentional awakening
Conceptual definition: stop sleeping spontaneously or due to external factors without intention (34) .
Operational definition: Patient reports that she woke up during the night, unintentionally.

Difficulty in daily functioning
Conceptual definition: patient considers it difficult to carry out functions, engage in exercises, in activities, have a good and regular performance, and satisfactorily perform movements in the daily routine (34) .
Operational definition: patient reports difficulty in carrying out functions, engage in exercise, in activities, having a good and regular performance, satisfactorily performing movements in the daily routine.

Difficulty initiating sleep
Conceptual definition: patient considers it difficult or impeded to initiate sleep. Difficulty to initiate sleep happens when the individual presents the perception of taking more than 30 minutes between preparing to sleep and falling asleep (sleep latency), regardles clock time, since this is a subjective symptom (34)(35)(36) .
Operational definition: patient reports difficulty in initiating sleep and the perception that he took a long time to sleep.

Dissatisfaction with sleep
Conceptual definition: lack of satisfaction, discontent, displeasure related to the physiological state of sleep (34) .
Operational definition: patient reports not feeling satisfied with the sleep of the previous night.

Feeling unrested
Conceptual definition: perception of feeling unrested in relation to the sensation of rest, that is, he has the perception of being tired, fatigued (34) .
Operational Definition: patient reports that he woke up tired and reports tiredness during the day. Intensive Care Unit were found (24) .
There was a correlation of poor sleep quality with UA in another study, showing that sleep apnea, daytime sleepiness, tiredness, lethargy, nocturnal awakenings, difficulty sleeping and superficial sleep were associated with the use of sedative drugs, tension due to illness, fear and anxiety (31) .
Pain was also identified as a factor that disturbs sleep in a study with hospitalized patients. Other factors such as excessive lighting, nursing care, and organic disorders such as fatigue were also highlighted (9) .
In that the major cause of sleep disorders was the underlying acute disease (11) .
On the other hand, a study that examined the prevalence of insomnia in ACS patients, hospitalized and after hospitalization, and its association with depression, anxiety and comorbidities found that 37% of the patients who reported moderate or severe insomnia during hospitalization presented 76 minutes more of wakefulness after the onset of sleep at home. For this evaluation, the patients were submitted to questionnaires to assess insomnia, sleepiness, depression and anxiety at admission, and weeks later, outpatient PSG. Other findings were that patients with insomnia presented higher scores in depression and anxiety questionnaires (p < 0.01) when compared to non-insomniacs, but no evidence was related to the sleepiness scale, and the scores on the sleepiness scale were positively correlated with depression scores (p = 0.024) (29) . Patients in the control and experimental groups presented alterations related to latency, duration, and habitual efficiency of sleep and to the domains of sleep disorders, which decreased significantly after the intervention (p < 0.05) (28) .
Other study evaluated the effect of the use of eye promote improved sleep quality of inpatients (37) .
A study created a tool to evaluate the sleep of ACS patients hospitalized in coronary units. This tool was compared to PSG. The main finding was related to the contributing factors of poor sleep quality, namely exposure to light and concern with the disease in the nighttime, conversation of hospitals workers, and poor bed quality during daytime sleep. Overall results showed that patients admitted to Coronary Care Units were classified as "poor sleepers" (22%); "regular sleepers" (43%) and "good sleepers" (35%) (26) .
Other clinical evidence was found in a study that characterized daytime sleepiness and identified clinical and sociodemographic characteristics in AMI patients using the Epworth Sleepiness Scale. The study identified excessive daytime sleepiness in 29.2% of the patients.
As contributing factors, the age group (60 years or older presented a 3.43-fold higher chance than individuals under 60 years); marital status (separate individuals presented a 9.23-fold higher chance than those of another civil state) and BMI (individuals with BMI greater than 30 kg/m 2 had a 5.9-fold higher chance than individuals with BMI equal to or less than 30 kg/m 2 ) (25) .
Age is the factor that most influences the sleepwake rhythm. Age determines the time of each sleep state. This variable must be considered whenever reference is made to the temporal dimension of sleep.
There is evidence that the sleep of the elderly has distinct characteristics compared to young adults. In the elderly, the REM stage decreases, stage changes are frequent with alternations between superficial and deep sleep, and the waking times increase (33) .
Although the findings of this IR were important, the gray literature had to be used to achieve the objectives of the study. This was due to the fact that the articles did not present enough information for the construction of the CD and OD of the ND in question. However, all the phases proposed by the literature for the conceptualization of DC were followed, which made the study feasible.
This was seen as an obstacle to the realization of the IR as the first step in validation studies. Most of the scientific articles on original researches did not address clinical evidences and contributing factors so as to conceptualize them; it is, therefore, difficult to gather quantitative and qualitative material to review a particular ND (38) .

Conclusion
After reviewing the articles that evaluated the Further studies addressing the determinants of this ND are therefore recommended.