IMPACT OF OROTRACHEAL INTUBATION ON A POST STROKE INDIVIDUAL ’ S SWALLOWING AFTER CARDIAC SURGERY

(1) Seção de Fonoaudiologia do Instituto Dante Pazzanese de Cardiologia, São Paulo, SP, Brasil. (2) Faculdade de Medicina na Universidade de Marília UNIMAR-Marilia, SP, Brasil. (3) Setor de Nutrologia e Fonoaudiologia do Instituto Dante Pazzanese de Cardiologia IDPCSão Paulo, SP, Brasil. (4) Laboratório de Epidemiologia e Estatística (LEE) do Instituto Dante Pazzanese de Cardiologia IDPC São Paulo, SP, Brasil. (5) Instituto Dante Pazzanese de Cardiologia, São Paulo, SP, Brasil. (6) Departamento de Fonoaudiologia e do Programa de Pós-Graduação em Fonoaudiologia da Faculdade de Filosofia e Ciências da Universidade Estadual Paulista Júlio de Mesquita Filho-FFC/UNESP-Marília, SP, Brasil. Conflict of interest: non-existent  INTRODUCTION


INTRODUCTION
Cardiovascular disease (CVD) is considered to be the most frequent cause of death worldwide and according to the projections for 2020, will remain as the main cause 1 .The improvement of operative techniques allowed the reduction in the rate of mortality and morbidity, however, neurological complications in intra and postoperative remain being a common problem 2,3 .The most common neurological deficit is stroke 4 and represents the second most frequent cause of perioperative mortality 5 .The causes of stroke in the peri and postoperative periods are multiple.Among these ABSTRACT Purpose: to associate the degree of oropharyngeal dysphagia and orotracheal intubation time in post stroke individuals after cardiac surgery.Methods: a cross-sectional retrospective discriptive clinical study carried out by means of protocols data collection and chart records during six months in a public hospital of reference in cardiology.We analyzed 25 protocols and medical records of individuals undergoing cardiac surgery who evolved with stroke and were assisted by a team of speech language therapists.The subjects were divided into two groups.Group1 (G1) consisted of 10 individuals with orotracheal intubation less than 24 hours and Group 2 (GII) of 15 individuals with orotracheal intubation more than 24hours.After performing swallowing clinical evaluation and analyzing the association between the clinical classification of degree of commitment for dysphagia and orotracheal intubation time.Results: it was found that40% of the individuals in group 1 presented mild dysphagia, 30% moderate and 20% severe.In Group II, 13.3 % presented mild dysphagia, 33.3% moderate and 53.33% severe.There was a significant linear association between the degree of dysphagia and OTI.(p=0,031) indicating that the number of individuals with moderate and severe dysphagia was higher in the group with a longer intubation Conclusions: we could observe that time of orotracheal intubation more than 24 hours increases the degree of oropharyngeal dysphagia in this population.

KEYWORDS: Deglutition Disorders ; Stroke; Thoracic Surgery
The time of speech assessment after neurological damage ranged from 1 to 67 days.
The subjects were divided into two groups.Group 1 (GI) consisted of individuals with OTI time less than 24 hours (n=10) and group 2 (GII) individuals with OTI time more than 24 hours (n=15).Collection of the information in the database was performed by the researchers.For the clinical speech therapy assessment protocol data was collected with clinical classification of oropharyngeal dysphagia commitment proposed by Silva 13 , applied during the acute phase of stroke.For the clinical classification of dysphagia framework it was considered mild dysphagia when there was the presence of records of labial sphincter alterations, lack of tongue coordination, language delay to trigger the pharyngeal response, absence of cough, absence of sharp reduction of the elevation of the larynx, absence of alteration of the vocal quality after swallowing and cervical auscultation without alteration.For the classification of moderate dysphagia we considered labial alteration, lack of tongue coordination, pharyngeal response delay, absence of cough or cough presence before, during or after swallowing.Severe dysphagia was classified in the presence of delay or absence of pharyngeal response, reduction in the elevation of the larynx, absence of cough, presence of cough before, during or after swallowing, change in vocal quality after swallowing, evident respiratory alteration, incomplete swallowing and altered cervical auscultation.
Categorical variables were described by absolute frequency and relative frequency.Chi-square test and linear association test wre used for statistical analysis.
The statistical significance adopted was 5%.

RESULTS
We analyzed 25 charts, 56% males and 44% female gender aged 44 to 80 years, with a median of 62 years.Of these 14 subjects had coronary artery disease (cad) and were submitted to myocardial revascularization surgery, 9 individuals submitted to valvular surgery, one individual was submitted to myocardial revascularization and valve replacement in the same surgical procedure and only one subject was submitted to endarterectomy .All individuals featured at least one of the personal history of risk such as: diabetes mellitus, obesity, smoking or atrial fibrillation.The ones with a previous history of sroke were excluded.All the strokes were ischemic and located in cortical region.In the period investigated, of the 25 individuals who have evolved with stroke evaluated in the acute phase, 24 individuals are the use of extra corporeal circulation (ECC) 2,4 , atrial fibrillation (AF) 6,7 , presence of atherosclerosis in the aorta and carotid arteries 2 , old age 2,4,6 , global or local hypoperfusion or haematological alterations, microembolization in intraoperative 2 , prolonged clamping time 5 .The risk of developing stroke also increases the associated risk factors such as obesity, smoking, dyslipidemia, hypertension and diabetes mellitus 1,8 .
Stroke can bring numerous sequels, including oropharyngeal dysphagia, 9 swallowing disorder which can lead to aspiration pneumonia, dehydration, malnutrition and death 10 .
However, in the population who underwent cardiac surgery, neurological injury cannot be considered isolated factor of cause for dysphagia, since these individuals can present intraoperative complications as important reduction of lung volumes, losses on respiratory mechanics, decrease in pulmonary compliance and increased respiratory work and require an extended period of mechanical ventilation, evolving in some cases for tracheostomy for difficult weaning 11 .Orotracheal intubation (OTI), defined as a prolonged period of more than 24 hours of intubation may impact directly the swallowing dynamics increasing the risk of laringotracheal aspiration 12 .
Considering that the population who underwent cardiac surgery evolving with stroke presents besides the neurological damage other predictive factors for oropharyngeal dysphagia.This study aimed to associate the degree of oropharyngeal dysphagia and orotracheal intubation in a poststroke individual after cardiac surgery.

METHODS
This study was approved by the ethics and research committee of the institution (protocol #4129).This is a cross-sectional retrospective observational descriptive clinical study accomplished through data collection from assessment protocols and medical record evolution at institute of cardiology of the state of São Paulo, Brazil.The medical records of all individuals who have undergone cardiac surgery and evolved with postoperative stroke, within six months, between 2010 and 2011, and were assisted by a speech-language pathology team specialized in dysphagia after medical request were analyzed .We analyzed the medical records of all the individuals who have undergone cardiac surgery and evolved with postoperative stroke, within six months, between 2010 and 2011, and were assisted by a speech-language pathology team specialized in dysphagia after medical request.
Analysing the association between the groups GI and GII and the degree of oropharyngeal dysphagia, no statistical significance was found (p=0.164).But when analyzing the linear association a significant value of (p=0.031), was found, indicating that the number of individuals with moderate and severe dysphagia was higher in the group with a longer intubation.(Graphical 1).
In the analysis of the groups we observed a higher number of patients with mild dysphagia in Group I (40%) followed by moderate (30%) and severe (20%).The only patient of this study with functional swallowing belonged to Group I. A higher number of individuals in Group II presented severe oropharyngeal dysphagia (53.33%), followed by moderate (33.33%) and mild (13.33%).

DISCUSSION
The population who underwent cardiac surgery and evolved with stroke features numerous risk factors for the development of oropharyngeal dysphagia, besides neurological injury.Therefore it is extremely important the integration of teams in the screening and diagnosis of dysphagia symptoms in this population.
As for the impact of OTI on this population's swallowing it was found that the group submitted to the prolonged OTI showed higher frequency of severe oropharyngeal dysphagia.It is known that OTI causes alterations in oral and pharyngeal phase of swallowing with tracheal aspiration risks and which may be an independent predictor of oropharyngeal dysphagia after extubation 12 .
In the current study it was possible to observe that the only patient with functional swallowing belonged to the group of patients with OTI less than 24 hours and that in this group there was a higher frequency of patients with mild dysphagia.Whereas in the group of patients with OTI more than 24 hours there was a higher number of patients with severe oropharyngeal dysphagia, followed by moderate dysphagia.
Linear association was found when analyzing the degree of dysphagia of group 1 in relation to group ii (p=0.031),thus, OTI for long periods was an aggravation for dysphagia in the present study, as reported by other authors who observed that the patients with neurological injury that showed worse deficits in swallowing were those who were previously submitted to a longer period of mechanical ventilation 12 .
Another relevant fact is that 96% of individuals of the entire sample had oropharyngeal dysphagia.Although the occurrence of dysphagia in post-stroke population is quite variable in literature [14][15][16][17] .Little do we know about dysphagia in individuals with stroke after cardiac surgery.The wide range of variation on the occurrence of dysphagia in individuals with stroke must be analyzed considering the methodological differences proposed in the investigations, the number of individuals, the site of the injury, the time of assessment in relation to the ictus, among other differences 17 .
As regards the classification of oropharyngeal dysphagia impairment degree found in our sample, it was observed that this degree ranged from mild to severe, with higher frequency of severe dysphagia.Severe dysphagia are described in the literature as those which in addiction to altering the swallowing oral phase provoke laryngotracheal aspiration 18 .However, although there are disagreements among authors about what would be the ideal parameters for classifying as severe dysphagia, concordance point to the entry of food in lower airway, and in the case of the population studied, this can occur due to a number of predictive factors found in neurological and cardiac population 18 .
Therefore, there is a possibility that the prolonged time of orotracheal intubation is also the cause of high prevalence and severity of oropharyngeal dysphagia in an individual who evolved with stroke after cardiac surgery.
diagnosis and proper treatment, possibly reducing the risks of complications, mainly respiratory ones.
In this way, it is apparent the need for teams to use screening tools that can map this population and forward early diagnosis and the rehabilitation of oropharyngeal dysphagia.

CONCLUSION
It was observed that prolonged orotracheal intubation interfered on swallowing dynamics, specifically on the degree of oropharyngeal dysphagia in this population.
Considering the limitations of our study, size of the sample and the absence of an objective research swallowing method that could measure the accuracy of dysphagia impairment degree used here it is necessary to continue in this line of research.
Due to the numerous predictive factors of dysphagia which this population presents, the specialized speech therapist activities with oropharyngeal dysphagia should be included within the specific intervention of tertiary cardiovascular prevention since dysphagia is a limiting consequence and the presence of a professional specialized in dysphagia is essential for early