ABSTRACT
Dysphagia, or problems with swallowing, is common after acute stroke, and there is a risk of aspiration pneumonia and other complications. The early detection of dysphagia in such patients reduces such complications, hospital stay, and overall healthcare expenditures. The objective of this study was to detect and manage dysphagia in the first few days after stroke by formal swallowing assessments. A pre- and post-intervention study was performed using a standardised bedside swallowing assessment (SSA) at the neurology ward in King Khalid National Guard Hospital; Jeddah, Saudi Arabia. The ethical committee of the hospital approved the study. Pre-intervention is before administration of the SSA, and post-intervention is after the SSA.
The study involved forty consecutively admitted patients with acute stroke in the pre-intervention phase, and twenty in the post-intervention phase. The results mainly indicated that patients with dysphagia had a 6-fold higher risk of developing a chest infection compared to those without swallowing problems. The SSA was found to be a simple, safe, and effective procedure in the detection of dysphagia in the first few days after stroke. This study supports the use of the SSA by ward nurses as a screening tool for dysphagia in patients with acute stroke.
INTRODUCTION
Problem and its Background
Acute stroke is one of the leading conditions, afflicting at least 100,000 individuals in UK annually (Smithard et al., 1998, p.99). Stroke results in various impairments, including dysphagia, which is difficulty in swallowing. Dysphagia has been found to affect 43% of hemispheric stroked patients (Gordon, Langton-Hewer & Wade, 1987). Dysphagia has well-documented risks such as aspiration, which can lead to chest infections that may be life-threatening (Schmidt et al., 1994; Kidd, 1995), and dehydration and malnutrition appearing later on (Kidd, 1995; Barer, 1989).
There is considerable evidence to suggest that early detection of dysphagia in patients with acute stroke reduces such complications, reduces hospital stay and overall healthcare expenditures (e.g. Martino, Pron & Diamant, 2000). Clinical screening, specifically using the Standardized Swallowing Assessment (SSA; Perry & Love, 2001), has been one of the major breakthroughs of diagnostic procedures that endeavors swallowing-difficulty diagnosis. Several studies have described the utility and validity of the SSA (Smithard et al, 1997; Schmidt et al., 1994; Ellul & Barer 1993) compared with other methods of swallowing assessments as well as its inter-rater reliability (Smithard et al, 1997; Schmidt et al., 1994; Ellul & Barer 1993).
Setting of the Study
The study was conducted in the neurology ward of the King Khalid National Guard Hospital; Jeddah, Saudi Arabia. The study was performed after the approval of the ethical committee of the hospital. Medical and nursing team notes were assessed and the results were compared with independent assessment of swallowing safety made on days 1 and 7 by the speech language therapist using SSA.
Scope and Limitation
The objective of this study is the detection and management of dysphagia in the first few days after stroke by a pre- and post-intervention study using a standardized bedside swallowing assessment. Primarily, the study aims to validate the effectiveness of SSA in the detection of swallowing impairment, dysphagia. The following questions were addressed:
- Is SSA a valid diagnostic tool in the discovery of dysphagia in acute stroke patients? Provide validated evidences and specifications that clearly depict the effectiveness of such procedure.
- How are the research procedures done? Represent the methodology involved as well as the fundamental components, including statistics.
- What are the identified gaps and problems during the research processes, particularly data validation, statistical discrepancies and problems in methodology?
Health and Clinical Management
The occurrence of any chest infection was diagnosed and documented by the medical team. All nursing personnel in the neurology team have taken short courses in swallowing rehabilitation (rehabilitation with nasogastric tube or with gastronomy tube), although a qualified speech language therapist performed the swallowing assessment. The neurology team carried out standardized medical assessments (to classify the stroke and to estimate the severity). The Ear, Nose & Throat (ENT) team assessed the vocal cord movement and noted if there were any possible gaps in the vocal cord or paralyses. The Speech-Language Pathologists (SLP) performed the three stages of Standardized Bedside Swallowing Assessment and tongue movement assessment.
LITERATURE REVIEW
Acute stroke
Stroke is a common condition and it has been estimated to affect about 5 to 8 people in every 1000 who are over 25 years of age; and 47 in every 1000 over 55 years of age (Perry, 2001). Stroke can produce a wide variety of neurological impairments in the acute stages, including swallowing disorders, lack of postural control; upper-limb dysfunction; visual, cognitive, perceptual, and communication impairments; and dyspraxia (Perry, 2001). These problems can occur by themselves or in combination, leading to malnutrition; prolonged hospital inpatient stay and increased complications and mortality rates (Perry, 2001).
Although brain stem strokes are less common than cortical lesions, they cause the greatest swallowing difficulties by affecting the sensations of the mouth, tongue, and cheek; timing in the trigger of the pharyngeal swallow; laryngeal elevation; glottic closure; and cricopharyngeal relaxation (Ertekin, 2000; Martino, 2001). Whatever the location of the lesion, stroke occurs more commonly in the elderly (Devroey, 2003), and the normal age-related swallowing changes worsens the dysphagia due to stroke.
Risks of Dysphagia
Aspiration may occur before, during, or after the swallow. Some of the factors that contribute to aspiration include: reduced consciousness, immobility, tube feeding, trachea tube or ventilation, stroke location, reduced pharyngeal sensation, and abnormal voluntary cough. There are six clinical features to identify those patients at increased risk of aspiration after acute stroke, and these are dysphonia, dysarthria, abnormal volitional cough, abnormal gag reflex, cough after swallow, and voice change after swallow (Smithard et al 1998).
Aspiration pneumonia is an important cause of mortality after stroke and accounts for about 6% of deaths. The clinical presentation of aspiration pneumonia may be in the form of a febrile illness (lasting for 24 to 72 hours), and there may be no respiratory symptoms with only fleeting infiltrates in the chest radiograph. There is an 8% to 40% chance of developing malnutrition following stroke. There is also an increased risk of dehydration in patients with dysphagia due to stroke, which can lead to death from azotemia, hypernatraemia, hyperkalaemia, and hypercalcaemia (Smithard et al 1998).
Assessment of swallowing
Given the high prevalence of swallowing difficulties present at the time of admission and the consequent risk of aspiration, an assessment needs to be done at the bedside at the time of admission by non-specialists (doctors and nurses). A full assessment consists of a clinical bedside assessment (BSA; Smithard et al 1996) and, where indicated, more complex investigative techniques.
The Clinical Bedside Assessment (BSA)
A speech-language therapist who performs an accurate and timely BSA can help detect patients with dysphagia who are at risk of aspiration. The BSA includes examination of the anatomy and neurology of swallowing and the swallowing mechanism, which can be done by different methods. In many studies, a simple swallow test of a fixed volume of water was used to assess the ability to swallow (timed or untimed) and has been correlated to videofluoroscopy findings.
Some common signs which suggest the presence of aspiration are reduced level of consciousness, weak cough, dysphonia, wet/gurgly voice, choking/coughing on swallowing 5 ml water and an increased time taken to swallow a fixed volume (50–90 ml) of water. However, none of these signs by themselves have been shown to be sensitive or specific enough to predict the presence of aspiration (Ramsey, Smithard, Kalra, 2002).
Gag reflex
Historically, the gag reflex was used as an assessment method to know the ability to swallow safely. This was based on studies of patients many months after the onset of stroke (Ramsey, Smithard, Kalra, 2002). However, such procedure has been proven unreliable at some instances, such as unconscious clients, etc. (Tohara et al., 2003).
Nasal endoscopy
Nasal endoscopy has been used in recent years to also study swallowing. It can be used at the bedside, and does not expose the patient to radiation. The presence of aspiration can be indirectly assessed by residue seen in the larynx and pharynx (Ramsey, Smithard, Kalra, 2002).
Fluoroscopy
Videofluoroscopy, a modified barium swallow, is considered to be the gold standard in the assessment of the swallowing mechanism. Videofluoroscopy allows the study of all three phases of the swallow in one examination.
The examination is performed in both the lateral and anteroposterior projection views; this allows imaging of the oral, pharyngeal and oesophageal phase. In order to ensure that aspiration is not missed, swallows are required in bedside assessment. Videofluoroscopy provides a dynamic image of the swallow, which helps to increase the diagnostic accuracy of swallowing difficulties and improve the treatment of dysphagia. Since small volumes of high-density barium are used, videofluoroscopy helps in the detection of even the smallest amount of aspiration (Ramsey, Smithard, Kalra, 2002).
Pulse oximetry
Pulse oximetry is a noninvasive method of investigating bedside swallow (Ramsey, Smithard, Kalra, 2002). Some have proposed that aspiration causes reflex bronchoconstriction and a subsequent ventilation-perfusion imbalance, which leads to hypoxia and desaturation. Others have suggested that abnormal swallowing leads to poor breathing and ventilation perfusion mismatching because of reduced inspiratory volumes (Ramsey, Smithard, Kalra, 2002).
More recent studies have shown that pulse oximetry is not as accurate as once thought; original studies contained numerous design flaws, and the results yielded a high rate of false positives (Bateman et al 2007).
Fiberoptic endoscopic examination of swallowing (FEES)
FEES is a highly sensitive method for the detection of aspiration. FEES can provide information on the anatomy, the swallowing process, pharyngeal motility, and presence of any sensory deficits. Although FEES does not allow the direct visualization of aspiration, the presence of aspiration is confirmed by noting the presence of residue left after swallowing or by noting the ejection of material out of the trachea after coughing. The FEES assessment can be conducted at the bedside, and can even be videotaped if required. The procedure is generally safe and well tolerated by the patient (Ramsey, Smithard, Kalra, 2002).
Water swallow test
Early water swallow tests used small (5–10 ml) volumes of water, which may not have been adequate to identify the presence of any swallowing dysfunction. In contrast, the use of large (50–150 ml) volumes of water may improve the diagnostic accuracy in identifying swallowing dysfunction but it has its complications (Daniels et al., 1997).
The combination of the water swallow and oxygen desaturation tests into one test of “bedside aspiration,” resulted in a highly significant value, with a sensitivity of 100%, a specificity of 70.8%, a positive predictive value 78.8%, and negative predictive value 100%, respectively. The combined test also enabled the detection of four silent aspirators, which was missed in the 50-ml water swallow test.
Other methods
Cervical auscultation of the mechanical and/or respiratory components of swallowing, combined with bedside testing, has been compared with VF and revealed significant agreement for detection of aspiration. Lateral cervical soft tissue radiographs have been used after swallowing contrast. Ultrasonography is safe and moderately portable. Pharyngeal or esophageal manometry can provide useful information, particularly when combined with VF. Other methods include scintigraphy and electromyography (Ramsey, Smithard, Kalra, 2002).
Drawbacks of swallowing assessment methods
BSA takes time, and even then may not detect all cases of aspiration. Although nasal endoscopy gives good three-dimensional views of the pharynx and larynx, it does not offer much information with regard to the oral stage, the function of the upper oesophageal sphincter, or pharyngeal motility (Tohara et al., 2003).
Tests like water-swallowing test and Repetitive Saliva Swallowing Test (RSST) are either not accurate or require skilled examiners (Tohara et al., 2003). In addition, in the water-swallowing test, the use of large volumes of water can potentially lead to the aspiration of large amounts of water, and therefore may result in medical complications (Daniels et al., 1997).
Fiberoptic Endoscopic Examination of Swallowing (FEES) is highly sensitive for detecting aspiration but cannot provide all the details of swallow physiology. FEES also requires sophisticated instrumentation and a skilled examiner (Tohara et al., 2003).
There are issues of transportation and radiation with the videofluoroscopic swallowing test (VFSE) (Tohara et al., 2003). . VFSE requires coaching (Tohara et al., 2003), and has other issues, including lack of standardization of volumes, consistencies or textures of food/fluids used, or anatomical landmark movements or motion duration used as criteria of normal swallowing (Perry, 2001). The inter-rater reliability of reporting is poor and the relationship between abnormalities identified on VFSE and patient outcomes is unclear (Perry, 2001). Both FEES and VFSE are also expensive (Tohara et al., 2003).
SSA
Currently, SSA is the only screening tool which has published reliability data using nurses, and it has shown good results with minimal training (Perry & Love, 2001). A comparison of various screening tools (SSA, BSA, and timed test) in consecutively admitted stroke patients has shown that SSA has the lowest percentage of un-assessable patients, which may indicate the relative clinical utility of SSA (Perry, L, Love, 2001).
Perry (2001) conducted a longitudinal prospective survey to review the evidence for dysphagia screening methods in patients with acute stroke and identify, implement and establish the sensitivity and specificity of SSA by nurses.
Swallowing function was screened within 24 hours of admission. A total of 123 patients were screened. For 33 patients, details on the method of screening were not available. For 64 patients, the principle method of screening was the Standardized Swallowing assessment-based tool. Gag reflex alone was used for six patients; two patients used the gag plus water; 18 cited ‘checking the ability to swallow water.’ While judgments about the ability to swallow water were made by both doctors and nurses (with one supervised episode excepted), the SSA was used only by the nurses. The results revealed a sensitivity of 0.97 and specificity of 0.9 for detection of dysphagia, with positive and negative predictive values of 0.92 and 0.96.
Ellul, Watkins, Barer (n.d) studied the frequency, clinical course, complications and functional consequences of dysphagia in the acute stages of stroke in 676 consecutively admitted patients with acute stroke. They used a standardised bedside swallowing assessment (SSA). Chest infections were diagnosed in 10% of those with safe and 39% of those with unsafe swallowing, on day one of the hospital stay (without knowledge of the SSA findings).
It was found that a higher fatality, worse functional outcome and a longer hospital stay was associated with the presence of dysphagia. This was found in almost all subgroups. However, the effect was most marked in those without other adverse prognostic factors. From these findings, the authors concluded that the SSA can be recommended as a standard tool for both observational and intervention studies of dysphagia. They also recommended SSA to be adapted as a screening tool to be used in routine practice by nonspecialist clinical staff. They also felt that coordinated interdisciplinary policies could improve the detection and management of dysphagia after stroke.
METHODS
Patient selection
The study was carried out in the neurology ward in King Khalid National Guard Hospital, Jeddah, Saudi Arabia. A register was kept of all adults admitted with acute stroke to the hospital. The exclusion criteria for the study included patients with reduced consciousness level or poor postural head control who could not be considered for oral feeding and patients who were admitted 48 hours after the onset of stroke.
60 patients were selected for this study by completing some initial assessments, which are detailed below; 40 were in the pre-intervention stage, and 20 were in the post-intervention stage. 30 patients were male, and 30 were female. The median age was 79, with a range from 43 to 90. Although more than 60 patients were initially identified as possible participants in this study (153), several were excluded due to unconsciousness, co-existing or pre-existing conditions, or could/would not undergo an initial VF examination. The remaining patients were considered healthy enough to participate in the study, and gave informed consent.
Clinical Assessments
The investigator carried out a standardised clinical and neurological examination in all study patients on day 1, and a Standardised Bedside Swallowing Assessment (SSA) within 48 hours of stroke onset (89% within 24 hours), and repeated on day 7 after admission. The doctor in charge was convinced of the need to retain the patients for at least 14 days in order to complete the study.
A simple version of the SSA, which can be used by the clinical staff, was developed for the study (see Figure 1). The SSA consists of three stages:
Stage I. An initial assessment of whether the patient is alert enough for the study is made. This includes checking to see if the patient is conscious, aware of his surroundings, able to sit up and understand any instructions he is given. In addition, an evaluation of other general factors, which are likely to affect swallowing safety including: lip and tongue movements, gag reflex, voluntary cough and voice quality, are made. After ensuring that all these assessment criteria are met, the patient continues in the study.
Stage II. The patient is made to sit upright and given 3 teaspoonfuls of water. After each spoonful, careful observations are made of swallowing attempts, leakage of water out of the mouth, laryngeal movement, signs of pooling of fluid around the laryngeal opening (“wet” or “gurgly” voice), or signs of aspiration (coughing, choking, respiratory distress). If the patient makes some attempt to swallow or if there are no problems, the patient proceeds to Stage III.
Stage III. This stage involves drinking 60 ml of water from a glass. Observations are made similarly to stage II, as well as an overall judgment on whether the patient’s swallowing is “safe,” “possibly unsafe,” or “definitely unsafe.” If the swallowing is “safe,” then free diet/fluids are given to the patient and the patient is observed when eating solid food. Another observation is made with a glass of water before the next meal. If the patient deteriorates, the assessment can be repeated.
All three stages were carried out by an SP (Speech Pathologist), who assessed the patients’ responses to the tests carefully. The tests were also carried out by a physician to check if the results would match. The details of this are covered in the statistics section.
Patients who, in Stage III, were found to have “possibly unsafe” or “definitely unsafe” swallowing were placed on restrictive diets. This diet included liquids and other easy to swallow foods, and required the patients to be observed when eating. VF, or videofluoroscopy, was also used as an assessment test. VF was used within three days of the stroke occurrence, barring medical complications. VF was also used again on day 7. SSA assessments were carried out on days 1 and 7.
Analysis and Implication:
The reduction table illustrates the patient decrease as due to various reasons encountered during the whole time span. Such condition portrayed the methodological, variant, and situational characteristics that led to the trimming down of participants. Analyzing the figure, it significantly implies non-modifiable rationales of participant-reduction etiology; hence, enhancement of participant count is deemed unnecessary. In addition, the reduction rationale mainly satisfies the exclusion criteria, which is appropriately validated.
Clinical and Related Professional Involved
The research procedure involves independent procedurals of two physicians, both of whom are both in dysphagia management. On the other hand, two speech pathologists, both trained in the management of dysphagia are included to conduct tests and validate research outcomes.
This research is about the need for a new procedure for stroke patients. A dysphagia management policy (DMP) was developed and implemented in some of the medical wards. The detection and management of dysphagia in these wards were then compared with the “conventional” management provided on the control wards.
RESULTS
The results of the study have significantly compared outcomes from both bedside assessments and VF procedure. In addition, the primary subjects assessed are with varying total of final participant count obtained from the 3-month gathering procedures. However, PHYSICIAN-X has included the logistically excluded participants for SSA implementation.
The data illustrated portrays the higher obtained results of SP1 compared to predictives except for NPV. The predictives are the predicted value of how many people would aspirate. On the other hand, PHYSICIAN-X had obtained data that are significantly lower than the expected outcomes; although the data obtained are higher than the data of SP1, particularly NPV but the opposite in terms of sensitivity. Such data implies incongruencies on both implemented results, which endeavors possible inaccuracy as manifested by the discrepancy particularly on NPV. However, significantly, sensitivity plays the major prime results.
Unsafe Swallow
Data shows that day 1 and day 7 outcomes provided significant results comparable to other table results, which is mainly the increase of Safe swallow category. SSA has provided an assessment of higher results in day 7 as validated by VF results. The results on day 1 are comparably more on unsafe swallowing; however, on day 7, there are significantly increased results.
Pre-intervention Phase
During a 2-month period in the pre-intervention phase, 15 (38%) of the 40 patients included in the study were referred to SLTs for assessment of swallowing, communication, or both by the patient’s medical team. Of the 25 patients who were not referred for SLT assessment, 3 (12%) had some degree of dysphagia on day 1. None of these patients was referred during their hospital stay, although none had recovered safe swallowing by the end of the first week.
Of all the patients well enough to be assessed with the SSA on day 1, 10 (25%) had “unsafe swallowing.” During this preliminary phase of the study, 6 (15%) of patients who were well enough to be assessed on day 1 suffered at least one episode of chest infection, which was diagnosed and documented by the admitting medical team. Patients with dysphagia had a 6-fold higher risk of developing a chest infection compared to those without swallowing problems.
During the post-intervention phase, 13 patients in the control wards were assessed by the SSA on day 1; 7 in the intervention wards. The proportion of patients found to have dysphagia in the intervention wards (57%) was considerably higher than that on the control wards (46%), and that on all the wards during the pre-intervention phase. On the other hand, the proportion of patients with unsafe swallowing on day 1 who were able to swallow safely by day 7, was almost identical on the intervention and control wards.
The incidence of chest infections during the hospital stay on the intervention wards was low (14%), despite the higher proportion of patients with dysphagia and with “severe strokes.” On the other hand, the incidence of chest infections on the control wards was higher (23%) than it had been during the pre-intervention phase (15%).
The incidence of chest infection did not differ significantly between patients with or without dysphagia on the intervention wards, whereas on the control wards, the risks of chest infection were markedly increased in those with swallowing problems.
DISCUSSION
In this study, the version of the SSA used by the ward staff as an initial screening test is a simple step-by-step procedure, and retains only the most important items of the original SSA. This version of the simplified SSA was designed in such a manner as to ensure maximum safety for the patients.
An initial assessment of whether the patient is alert enough for the study and an evaluation of other general factors which are likely to affect swallowing safety are made first. Further study is carried out only after ensuring that all these assessment criteria is met. A decision on proceeding to stage III is made only if the patient makes some attempt to swallow or if there are no problems.
In the analysis of the study directed in table 3, the SSA trained SP have evidently provided more accurate results compared to the doctors. The results obtained were not influenced by external or internal factors as validated by the same inference of both pairs. As for these outcomes, implications suggest the need for health care staffs, such as speech pathologists and physicians, to undergo significant training for the grant of implementation for the procedure.
In terms of SSA effectiveness as a diagnostic procedure in swallowing difficulties, overall data suggests 70% sensitivity reports from medical bedside assessment, and 90% for trained speech pathologists. Such results contradict the standard of 100% sensitivity protocol that needs to be achieved in order to validate claims of effectiveness. However, with the ratings of 90% with the trained SP compared to 70% of the untrained physicians, the sensitivity results justify the effectiveness of such procedure.
The aspiration predictives have been negated with rates of 30% from medical perspectives and 10% from speech pathologists. According to bedside results, the majority of the patients with ….[A1] progress to safe swallowing at day 7, and with further evaluation of aspiration probabilities, the test reveals significantly high effective results. Evidently, more than half of the patients are at a lesser risk of aspiration as provided by both SSA test and aspiration predictives. Conflicts arise from non-agreement of data results between medical and speech pathologists; however, the importance of SSA methodology has provided a different perspective.
The data on day 1 has shown majority results of unsafe swallowing, which connotes increased risk of aspiration; however, on day 7, tests revealed that safe swallowing is already present. The test results by SSA are validated further by the complex radiologic exam, VF, and has proven almost similar results.
Radiological examinations are complex and most of the time inapplicable especially in variant urgencies, and with a simple test, such as SSA, further diagnostics and prevention can be acquired. Moreover, aspiration predictives are of different nature than dysphagia; although, these conditions are most of the time related especially in swallowing complications. The importance and significance provided by SSA is the diagnosis of unsafe and safe swallowing, which entails appropriate diagnostic especially for individuals with unsafe swallowing capacity. It is essential, however, to note further validations for safe swallow individuals before having intake. Meanwhile, inability to swallow is validated to confirm negation of swallowing inductors.
CONCLUSION
In conclusion of the study, it has been found that the SSA procedure is a very crucial yet validating diagnostic approach. There are numerous drawbacks of current swallowing assessment methods like gag reflex, FEES, videofluoroscopy, water swallow test, pulse oximetry etc. Currently, SSA is the only screening tool with good reliability data and good results in terms of determining unsafe swallowing criterion. Furthermore, validation is essential for those individuals categorized in safe swallowing groups; since, evidently on this research, safe swallow outnumbered the unsafe swallow groups, but later on with aspirating predictives different results came up.
SSA is proven to be a beneficial complex procedure in detecting swallowing safety, and it provides significant results in the obtainment of patients with risk of swallowing. The procedure is reliable for this type of scenario, which significantly diminishes the stress load of problem diagnostics. Speech pathologists and other administrators of such procedures should be taught well in order to implement such tests accurately and appropriately. Aspiration after stroke may occur before, during, or after the swallow. It is therefore very important to identify at an early stage those patients who are at an increased risk of aspirating, since it is associated with a high fatality rate.
The SSA was found to be a simple, safe, and effective procedure in the detection of dysphagia in the first few days after stroke as validated by swallowing safety results. This study supports the use of the SSA by speech pathologists at the Neurology and ENT Departments of King Khalid National Guard Hospital, as a screening tool for dysphagia in all patients admitted with acute stroke.
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