Clinical validation of the nursing diagnosis Risk for Aspiration among patients who experienced a cerebrovascular accident 1

OBJECTIVE
the study's objective was the clinical validation of the nursing diagnosis Risk for Aspiration among patients who experienced cerebrovascular accidents (CVA).


METHOD
a prospective cohort study was conducted with 24 patients hospitalized due to a CVA. The instrument used to collect the data addressed the risk factors for respiratory aspiration, validated by concept analysis and by experts.


RESULTS
the most frequent risk factors for respiratory aspiration were: dysphagia (54.2%) and impaired physical mobility (41.7%). The prevalence of the nursing diagnosis Risk for Aspiration was 58.3% and the prevalence of respiratory aspiration over the span of 48 hours (monitoring period) was 37.5%. Risk factors for dysphagia and impaired physical mobility were significantly associated with respiratory aspiration.


CONCLUSION
the risk factors dysphagia and impaired physical mobility are good predictors of the nursing diagnosis Risk for Aspiration. This study contributed to improving the NANDA-I Taxonomy and the systematization of the nursing process.

We kept the factors "the use of gastrointestinal tubes" and "endotracheal intubation/tracheostomy", even though they may seem redundant, because the literature differentiates them both.This study's objective was to clinically validate the nursing diagnosis Risk for Aspiration in patients who had a cerebrovascular accident (CVA).An earlier study (1) presented an analysis of its concept and specialists validated the risk factors for the nursing diagnosis Risk for Aspiration in patients who had a CVA (stroke).The study reported that the risk factors for respiratory aspiration include: dysphagia, altered level of consciousness, impaired or absent cough reflex, other neurological disorders (e.g.brain injury or Alzheimer's www.eerp.usp.br/rlae Rev. Latino-Am.Enfermagem 2013 Jan.-Feb.;21(Spec):250-8.
Knowledge concerning risk factors for respiratory aspiration in patients with a CVA is essential for nurses because the key element in the treatment of patients who have experienced a CVA in the acute and sub-acute phase is based on the prevention of complications, reduced hospitalization, mortality and hospital costs (2)(3) .
The literature (4) , however, reports that clinical predictors for the nursing diagnosis Risk for Aspiration are not well defined, while there are few studies addressing the clinical validation of this nursing diagnosis.
Given this context, studies performing the clinical validation of risk factors for the nursing diagnosis Risk for Aspiration in patients who had a CVA are needed.
It is important to note that the main objective of this validation process is to increase the validity of this diagnosis in NANDA-I Taxonomy II and provide tools for nurses to evaluate patients who have had a CVA and are at risk for aspiration.

Methods
This observational study was conducted in the CVA unit of a public general tertiary hospital, a referral center for the treatment of people with this pathology in the Northeast, Fortaleza, CE, Brazil.A convenience sample was selected.The patients were allocated in the study at the time they were admitted in the cerebrovascular accident unit (initial assessment) and reassessed 48 hours after the first assessment.This period between the two assessments was established in accordance with the recommendations of researchers (2,(5)(6) , who stated that respiratory aspiration is a clinical condition that occurs within five days of the first signs and symptoms of a CVA during hospitalization.to a lack of specialized personnel and the equipment required to perform videofluoroscopy, we checked the clinical signs proposed in two studies (7)(8) : dysphonia, dysarthria, abnormal gag reflex, abnormal voluntary cough, cough after swallowing, and voice change after swallowing.Two or more of six of these signs indicate respiratory aspiration.The studies (7)(8) supporting these clinical signs present specificity of 89% for the detection of respiratory aspiration when compared to the gold standard (videofluoroscopy).
After the patients were identified, the study's objectives were explained to the patients and/or their respective companions.After signing free and informed consent forms, a preliminary assessment was performed to see whether the patients had the respiratory aspiration condition or related complications (e.g.Consultation of the patients' medical charts enabled the researcher to read medical assessments looking for medical diagnoses (aspiration pneumonia, pneumonitis and pulmonary embolism), as well as readings of X-rays.
After this preliminary assessment, those who met all the inclusion criteria were assessed in terms of socio-demographic, clinical and predictor variables (risk factors) by means of interviews, physical assessments, and consultation of their medical charts.After 48 hours from the first evaluation, the patients were assessed again to see whether respiratory aspiration had occurred.
As already mentioned, the researcher performed this second assessment checking for any of the six clinical signs (7)(8) .
An expert, who met the system's specific scores criteria (9) , that is, she had an academic and professional research involving human beings (10) , this study was submitted to and approved by the Ethics Research Committee at the Federal University of Ceará (Process No. 262/10).

Results
A total of 24 patients who had experienced a CVA were monitored and their socio-demographic profiles are presented in Table 1.

Discussion
The analysis of the three first causes of death in 2009, according to the report Situação de Saúde no Estado do Ceará [Health Situation in the Ceará State] published in 2011 (11) , showed that diseases of the circulatory system were the primary cause of death, accounting for 30.2% (13,333) of all deaths, mainly among elderly individuals (82%/10,891), of both genders.Cerebrovascular diseases accounted for the highest number of deaths due to diseases in the circulatory system, followed by ischemic heart diseases and hypertensive diseases, in both genders.
In regard to gender, men were more prevalent in this study.Studies (12)(13)(14) report a slightly greater predominance of CVAs among the male population.
The average age of this study's individuals was 63.17 years old (SD=13.34).A similar result was found in another study (15) .We note that, even though CVA is a disease that can occur at any age, its incidence increases as age advances and approximately doubles with each decade of life (16) .
It is opportune, however, to consider the increased prevalence of cerebrovascular disease in the younger population, greatly affecting their social and economic spheres.In Brazil, the increase of hospitalizations due to CVAs among young individuals, between 15 and 34 years old, was 64% in men and 41% among women, from 1998 to 2007.Data from Brazilian Ministry of Health show that there were almost 8,000 hospitalizations in 2007 among individuals in this age group (17) .
The median number of years of schooling was 4.50 years; the median monthly family income was one times the minimum wage; and most patients were retired.
Hence, the studied participants presented unfavorable socioeconomic conditions.Another study (12) showed that most participants were either illiterate (39.1%) or attended school for up to three years (20%).Many researchers (18) believe that the increased incidence of CVAs is related to a decreased socioeconomic level.The causes for such a relationship include: higher frequency of risk factors for cerebrovascular diseases, unfavorable psychosocial factors, and limited access to health services.
In relation to the prevalence of subtypes of CVAs, different results were found in another study (15) , because there was a balanced proportion between the ischemic type (42.9%) and the hemorrhagic type (38.5%).
The frequency of CVAs in the Brazilian population, according to different statistics, ranges from 53% to 85% of cases (16) .It is important to note, however, that the high prevalence of the ischemic type compared to the hemorrhagic type found in this study may be explained, in part, by the established inclusion criteria (being conscious and capable of following commands) because the condition of patients with hemorrhagic CVA is more severe and they generally present an impaired level of consciousness.
Specifically in relation to the prevalence of dysphagia, this study was in agreement with data from various studies (6,8,(19)(20) .The incidence of the nursing diagnosis Risk for Aspiration was similar to the one found in another study (15) .In regard to respiratory aspiration, its incidence in patients who experienced a CVA is around 50% and approximately half of these patients experience silent aspiration (5) .
Because this study did not evaluate the presence of silent aspiration, the prevalence of respiratory aspiration presented by the assessed patients may Introduction disease), presbyphagia, use of gastrointestinal tubes, gastroesophageal reflux disease, impaired physical mobility, impaired or absent gag reflex, invasive procedures, such as advanced digestive endoscopy and videofluoroscopy, endotracheal intubation/ tracheostomy, and low headboard.
The population was composed of patients with a diagnosis of a CVA hospitalized in the aforementioned unit.A total of 24 individuals were included in the study, based on the following criteria: a) being older than 18 years of age; b) having a medical diagnosis of a CVA; c) being in the acute phase of the CVA (up to 72 hours after the first symptoms); d) being sufficiently conscious and able to follow commands.Those who, in the first assessment, presented respiratory aspiration or related complications, such as aspiration pneumonia, pneumonitis, obstructed airways, or pulmonary embolism, as well as those who, at the time of data collection, presented some clinical life-threatening condition, were excluded.
aspiration pneumonia, pneumonitis, obstructed airways, and pulmonary embolism).Data were collected through physical assessment and consultation of the patients' medical files.The physical assessment focused on the patient's airway tract, searching for signs indicating complications related to respiratory aspiration.
background in the field of nursing diagnoses and care delivered to patients who experienced CVA, verified whether the studied patients presented the diagnosis Risk for Aspiration.The expert received, after the first assessment, a summary of the case of each patient with his/her socio-demographic data, clinical variables and risk factors for respiratory aspiration but was not informed whether the outcome (respiratory aspiration) was confirmed or not.The purpose of having the participation of an expert in providing the diagnosis (Nursing diagnosis Risk for Aspiration) was to make sure data would not be biased by the researcher who collected data, since she would be aware of those patients who had suffered respiratory aspiration during hospitalization.Excel 2007 spreadsheets were used while statistical analysis was performed by the Statistical Package for the Social Sciences (SPSS).The numerical variables were presented as central tendency and dispersion and the Shapiro-Wilks' test was used to verify the normality/ symmetry of the numerical data.The binomial test was used to analyze the association of nominal data.Odds Ratio (OR) was used to verify the magnitude of association.Tests of sensitivity and specificity, positive predictive value and predictive negative value were performed, considering p< 0.05 for statistical significance, in the analysis of accuracy of risk factors for respiratory aspiration.In accordance with the guidelines from Resolution 196/96, Brazilian National Council of Health concerning

Figure 1 -
Figure 1 -Presentation of false positive and negative values of risk factors for respiratory aspiration when compared to the risk factor impaired or absent gag reflex.Fortaleza, CE, Brazil, 2011 be underestimated.It is a red flag to the health staff, especially the nursing staff, which needs to act early and efficiently to prevent this clinical condition.Even though the risk factor impaired physical mobility, measured through Brunnstrom's Motor Recovery Stages, is not considered a risk factor for the nursing diagnosis Risk for Aspiration by the NANDA-I Taxonomy, it was found in almost 45% of the assessed patients and showed statistically significant association with respiratory aspiration.In relation to the accuracy of clinical indicators for the nursing diagnosis Risk for Aspiration in patients who experienced a CVA, knowledge of the conditional probability of the presence or absence of the nursing diagnosis, based on clinical indicators, can help the nurses to infer and accurately diagnosis it.In this Cavalcante TF, Araujo TL, Moreira RP, Guedes NG, Lopes MVO, Silva VM. context, the study of the sensitivity and specificity of risk factors of the nursing diagnosis Risk for Aspiration permitted the evaluation of the importance of each risk factor for predicting Risk for Aspiration presented by patients who experienced a CVA.In summary, the risk factors dysphagia and impaired physical mobility were good positive predictors of the nursing diagnosis Risk for Aspiration and also presented considerably high values of specificity for the studied diagnosis.In turn, the risk factors for the presence of gastroesophageal reflux, presbyphagia, and invasive procedures, such as advanced digestive endoscopy and videofluoroscopy, were not considered important risk factors for the nursing diagnosis Risk for Aspiration in patients who had a CVA.Conclusion The results indicated in the clinical validation showed that the risk factors dysphagia and impaired physical mobility are good predictors of the nursing diagnosis Risk for Aspiration among patients who had a CVA.The risk factors presbyphagia, gastroesophageal reflux, and invasive procedures, such as advanced digestive endoscopy and videofluoroscopy, were not specific and predictive of the studied diagnosis.Hence, further research addressing large populations in other contexts may confirm such a fact.The risk factors for the nursing diagnosis Risk for Aspiration presented by patients who have experienced a CVA are: dysphagia, impaired or absent cough reflex, neurological disorders, gastrointestinal tubes, impaired physical mobility, impaired or absent gag reflex, and low headboard.Limitations were faced during this study such as the fact that a single researcher collected data for clinical validation; the literature recommends a pair of researchers.Additionally, two risk factors "impaired consciousness" and "endotracheal intubation/ tracheostomy" were not verified because the assessment of six clinical signs indicating respiratory aspiration requires that the patient is alert.Finally, a reduced number of patients participated in the study (n=24).This study contributed to refining the nursing diagnosis Risk for Aspiration for individuals who experienced a CVA presented in the NANDA-I Taxonomy.The validation of this nursing diagnosis can ease the care phases: nursing history, nursing diagnosis, and intervention planning, in a specific and accurate manner to search for and analyze the Risk for Aspiration in patients who experienced a CVA.In this context, nurses with knowledge of all the risk factors for respiratory aspiration, can devise clinical protocols to prevent respiratory aspiration and more efficiently intervene with patients, whether independently or together with a multidisciplinary team.

Table 1 -
Characterization of socio-demographic data Rev. Latino-Am.Enfermagem 2013 Jan.-Feb.;21(Spec):250-8.evaluated 72 hours (median) from the beginning of the first signs and symptoms.The distribution of risk factors for the nursing diagnosis Risk for Aspiration and the nursing diagnosis per se among the studied patients are presented below.
*SD -Standard Deviation.†P25-Percentile25.‡P75 -Percentile 75.§Shapiro-Wilks test As shown in Table1, most individuals who suffered income of up to one times the minimum wage (median).In terms of clinical characteristics, most of the group had the ischemic type of the disease (91.7%) and it was the first episode (75%).The patients were

Table 2 -
Distribution of risk factors for the nursing Therefore, except for the risk factors of endoscopy and videofluoroscopy, all other risk factors were observed in clinical practice, less than 50% in the sample, except for the first factor.The risk factors most frequently presented by those with the nursing diagnosis Risk for Aspiration were dysphagia and impaired physical mobility.

Table 3
respectively).The patients who were exposed to the risk of dysphagia had a 16 times greater chance of developing respiratory aspiration when compared to those who did www.eerp.usp.br/rlaeCavalcante TF, Araujo TL, Moreira RP, Guedes NG, Lopes MVO, Silva VM.

Table 4 and
Figure 1 present the accuracy measures of risk factors evaluated for the nursing diagnosis Risk for Aspiration.

Table 4 -
Distribution of accuracy measures of risk factors for the nursing diagnosis Risk for Aspiration in patients who experienced a CVA.Fortaleza, CE, Brazil, 2011The analysis of data presented in Table4revealed that most of the risk factors (impaired or absent cough reflex, neurological disorders, presbyphagia, the use of gastrointestinal tubes, impaired or absent gag reflex, and low headboard) obtained high sensitivity values (above 80%) with, however, low specificity values (below 60%).The reduced number of studied patients (n=24) may partially explain this fact.Even thought the risk factor dysphagia presented an average sensitivity value (66.6%), it was a risk factor of high specificity for the nursing diagnosis Risk for Aspiration (88.8%), with a positive predictive value of 90.9%.The risk factor impaired physical mobility was the only risk factor for respiratory aspiration that presented high sensitivity, specificity, and positive and negative predictive values for the nursing diagnosis Risk for Aspiration.