Silent Aspiration: What Do We Know?

Silent aspiration risk is volume-dependent

Clinical swallow protocols cannot detect silent aspiration due to absence of overt behavioral signs, but screening with a much larger bolus volume, i.e., 90 cc vs. 1-10 cc, may elicit a reflexive cough in individuals who might otherwise exhibit silent aspiration. A swallow screen that maintains high sensitivity to identify aspiration risk while simultaneously reducing the false-negative rate for silent aspiration would be beneficial. The purpose of this study was to investigate whether silent aspiration risk was volume-dependent by using a 3-oz. (90-cc) water swallow challenge to elicit a reflexive cough when silent aspiration occurred on smaller bolus volumes. A prospective, consecutive, referral-based sample of 4102 inpatients from the acute-care setting of a large urban tertiary-care teaching hospital participated. Silent aspiration was determined first by fiberoptic endoscopy and then each participant was instructed to drink 3 oz. of water completely and without interruption. Criteria for challenge failure were inability to drink the entire amount, stopping and starting, or coughing and choking during or immediately after completion. Improved identification of aspiration risk status occurred for 58% of participants who exhibited silent aspiration on smaller volumes, i.e., an additional 48% of liquid silent aspirators and 65.6% of puree silent aspirators coughed when attempting the 3-oz. water swallow challenge. A low false-negative rate was observed for the entire population sample, i.e., ≤2.0%. A combined false-negative rate for participants who silently aspirated was 6.9%, i.e., 7.8% if silently aspirated liquid and 6.1% if silently aspirated puree consistency. Determination of silent aspiration risk was shown to be volume-dependent, with a larger volume eliciting a reflexive cough in individuals who previously silently aspirated on smaller volumes. A 3-oz. water swallow challenge's previously reported high sensitivity for identification of aspiration risk combined with the newly reported low false-negative rate mitigates the issue of silent aspiration risk during clinical swallow screening.

Pneumonia and in-hospital mortality in the context of neurogenic oropharyngeal dysphagia (NOD) in stroke and a new NOD step-wise concept

The aim of our work was to develop a step-wise concept for investigating neurogenic oropharyngeal dysphagia (NOD) that could be used by both trained nursing staff as well as swallowing therapists and physicians to identify patients with NOD at an early stage and so enable an appropriate therapy to be started. To achieve this objective, we assessed uniform terminology and standard operating procedures (SOP) in a new NOD step-wise concept. In-house stroke mortality rates and rates of pneumonia were measured over time (2003–2009) in order to show improvements in quality of care. In addition, outcome measures in a stroke-unit monitoring system were studied after neurorehabilitation (day 90) assessing quality of life (QL) and patient feedback. An investigation that was carried out in the context of internal and external quality assurance stroke projects revealed a significant correlation between the NOD step-wise concept and low rates of pneumonia and in-house mortality. The quality of life measures show a delta value that can contribute to “post-stroke” depression. The NOD step-wise concept (NSC) should, on the one hand, be capable of being routinely used in clinical care and, on the other, being able to fulfil the requirements of being scientifically based for investigating different stages of swallowing disorders. The value of our NSC relates to the effective management of clinical resources and the provision of adequate diagnostic and therapeutic options for different grades of dysphagia. We anticipate that our concept will provide substantial support to physicians, as well as swallowing therapists, in clinical settings and rehabilitation facilities, thereby promoting better guidance and understanding of neurogenic dysphagia as a concept in acute and rehabilitation care, especially stroke-unit settings.

Dysphagia and aspiration pneumonia in older adults

PURPOSE

To review the risks, diagnosis, management, and prevention of aspiration pneumonia in adults over age 65, and discuss the major role of dysphagia as a risk factor in this population.

DATA SOURCES

A comprehensive search of the literature using PubMed (MedLine) and CINAHL.

CONCLUSIONS

Aspiration pneumonia is a common diagnosis in older adults and is associated with significant morbidity and mortality. Oropharyngeal and esophageal dysphagia, often related to stroke, dementia, poor oral hygiene, or multiple chronic illnesses, increases the risk of aspiration. Nurse practitioners (NPs) need to be aware that frequent episodes of pneumonia may be caused by aspiration: therefore it is prudent to identify dysphagia and implement precautions.

IMPLICATIONS FOR PRACTICE

Numerous physical, cognitive, or environmental factors have been identified as predictors of aspiration pneumonia. Knowledge of clinical features, treatments, and prevention will help NPs improve outcomes in older adults with aspiration pneumonia; especially those in long-term care.

Gastroesophageal reflux disease and graft failure after lung transplantation

In spite of advances in lung transplantation, the median survival after lung transplant remains less than 5 years, an outcome that is significantly worse than other solid organ transplants. Efforts to understand the unique hurdles faced in lung transplant have revealed gastroesophageal reflux disease (GERD) as a risk factor for ultimate graft failure. The link between GERD and chronic lung rejection parallels the association between GERD and other forms of lung disease such as idiopathic pulmonary fibrosis. Understanding how GERD predisposes to graft failure is an important issue as it may lead to therapies such as surgical correction that aim to lessen the exposure of the pulmonary epithelium to gastric contents. Here, we review the link between GERD and lung disease and discuss the preclinical and clinical studies that are starting to elucidate a mechanism for this association.

Oropharyngeal dysphagia after stroke: incidence, diagnosis, and clinical predictors in patients admitted to a neurorehabilitation unit

OBJECTIVE

We analyzed patients with stroke in a neurorehabilitation unit to define incidence of dysphagia, compare clinical bedside assessment and videofluoroscopy (VFS), and define any correlation between dysphagia and clinical characteristic of patients.

METHODS

In all, 151 consecutive inpatients with recent ischemic or hemorrhagic stroke were enrolled.

RESULTS

Dysphagia was clinically diagnosed in 62 of 151 patients (41%). A total of 49 patients (79% of clinically dysphagic patients) underwent VFS. Six patients clinically suggested to be dysphagic had a normal VFS finding. The correlation between clinical and VFS diagnosis of dysphagia was significant (r = 0.6505). Penetrations and aspirations were observed, respectively, in 42.8% and 26.5% of patients with dysphagia, with 12.2% classified as silent. Lower respiratory tract infections were observed in 5.9%, more frequently in patients with dysphagia (30%). Dysphagia was not influenced by type of stroke. Cortical stroke of nondominant side was associated with dysphagia (P = .0322) and subcortical nondominant stroke showed a reduced frequency of dysphagia (P = .0008). Previous cerebrovascular disease resulted associated to dysphagia (P = .0399). Patients with dysphagia had significantly lower functional independence measurement (FIM) and level of cognitive functioning on admission and lower FIM on discharge, longer hospital stay, and more frequent malnutrition, and they were more frequently aphasic and dysarthric. Percutaneous endoscopic gastrostomy was used in 18 of 151 patients (11.9%) (41.8% of patients with VFS-proved dysphagia).

CONCLUSIONS

Dysphagia occurs in more than a third of patients with stroke admitted to rehabilitation. Clinical assessment demonstrates good correlation with VFS. The grade of dysphagia correlates with dysarthria, aphasia, low FIM, and level of cognitive functioning. Large cortical strokes of nondominant side are associated with dysphagia.

Novel preventive and therapuetic strategy for post-stroke pneumonia

Pneumonia is a significant complication of ischemic stroke that increases mortality. Post-stroke pneumonia is defined as newly developed pneumonia following stroke onset. Clinically and chronologically, post-stroke pneumonia is divided into two types of aspiration pneumonia. First, acute-onset post-stroke pneumonia occurs within 1 month after stroke. Second, insidious or chronic-onset post-stroke pneumonia occurs 1 month after the stroke. The mechanisms of pneumonia are apparent aspiration and dysphagia-associated microaspiration. Stroke and the post-stroke state are the most significant risk factors for aspiration pneumonia. The preventive and therapeutic strategies have been developed thoroughly and appropriate antibiotic use, and both pharmacological and nonpharmacological approaches for the treatment of post-stroke pneumonia have been studied rigorously. Increases in substance P levels, oral care, and swallowing rehabilitation are necessary to improve swallowing function in post-stroke patients, resulting in a reduction in the incidence of post-stroke pneumonia in a chronic stage. The stroke must be a cause of aspiration pneumonia.

Abnormal swallowing reflex and COPD exacerbations

BACKGROUND

It is unclear whether an abnormal swallowing reflex affects COPD exacerbations. This study investigated the prevalence of abnormal swallowing reflexes and its relationship with COPD exacerbation prospectively. We also clarified its association with gastroesophageal reflux disease (GERD) and airway bacterial colonization.

METHODS

Swallowing reflex and serum C-reactive protein (CRP) levels were examined in subjects with stable COPD and in control subjects. Concurrently, GERD symptoms were assessed using a self-reported questionnaire, and sputum bacterial cultures were investigated in the same subjects. Exacerbations were counted prospectively during the following 12 months.

RESULTS

The study group comprised 67 subjects with COPD and 19 controls. The prevalence of abnormal swallowing reflex was significantly higher in subjects with COPD (22/67) than controls (1/19; P = .02). Among subjects with COPD, the serum CRP level, GERD symptoms, isolation of sputum bacteria, and the frequency of exacerbations were significantly increased in those with abnormal swallowing reflexes compared with controls (2.72 vs 1.04 mg/L, P = .04, for serum CRP level; 6.75 vs 4.10 points, P = .04, for GERD symptoms; 5/11 vs 3/22, P = .04, for the isolation of sputum bacteria; and 2.82 vs 1.56/y, P = .007, for the annual frequency of exacerbations). Multivariable analysis confirmed that abnormal swallowing reflex was significantly associated with frequent exacerbations (>or= 3/y; P = 0.01).

CONCLUSIONS

Abnormal swallowing reflexes frequently occurred in subjects with COPD and predisposed them to exacerbations. Abnormal swallowing reflexes in COPD might be affected by the comorbidity of GERD, and cause bacterial colonization.

Bedside screening tests vs. videofluoroscopy or fibreoptic endoscopic evaluation of swallowing to detect dysphagia in patients with neurological disorders: systematic review

AIM

This paper is a report of a systematic review conducted to determine the effectiveness and feasibility of bedside screening methods for detecting dysphagia in patients with neurological disorders.

BACKGROUND

Dyspaghia affects 22-65% of patients with neurological conditions. Although there is a large variety of bedside tests to detect dysphagia, it is unknown which have the best psychometric properties and are feasible for nurses to use.

DATA SOURCES AND REVIEW METHODS

An electronic database search was carried out using Medline (PubMed), Embase, CINAHL, and PsychLit, including all hits up to July 2008. The search terms were dysphagia, sensitivity, specificity, diagnosis, and screening. The methodological quality of included studies was assessed.

RESULTS

Thirty-five out of 407 studies were included in the review. Eleven studies with sufficient methodological quality revealed that trial swallow tests using water had sensitivities between 27% and 85% and specificities between 63% and 88%. Trial swallow tests with different viscosities led to sensitivities ranging from 41% to 100% and specificities of 57% to 82%. Combining water tests with oxygen desaturation led to sensitivities between 73% and 98% and specificities between 63% and 76%. Single clinical features, such as abnormal gag, generally had low sensitivity and specificity.

CONCLUSION

A water test combined with pulse oximetry using coughing, choking and voice alteration as endpoints is currently the best method to screen patients with neurological disorders for dysphagia. Further research is needed to establish the most effective standardized administration procedure for such a water test, and to assess the value of pulse oximetry, in addition to a trial swallow to detect silent aspiration.

Hypoxaemia and stroke

The topic of hypoxaemia after stroke was last reviewed in this journal in 2001. Since then a lot of new information on the subject has been published, and while some questions have been resolved, new problems have emerged. This article discusses new research in the light of what is already known and outlines areas of persisting uncertainty.

The clinical significance of gastrointestinal changes with aging

PURPOSE OF REVIEW

With the graying of the world's population, there is an increased interest in the physiological effects of aging. This review examines the physiological changes of the gut with aging and their clinical significance.

RECENT FINDINGS

Changes with aging in the gastrointestinal tract are variable, but in some cases they are responsible for a variety of symptoms. Thus, alterations in taste and smell, gastric motility, intestinal overgrowth and changes in gastrointestinal hormone release are the basis of the physiological anorexia of aging. Alterations in swallowing lead to silent aspiration. Changes in gastric emptying play a role in postprandial hypotension. Changes in gastrointestinal function can lead to constipation and fecal incontinence. Weakening of the colonic muscular wall produces diverticula. Achlorhydria is associated with malabsorption of some forms of iron and calcium. Vitamin D malabsorption aggravates the hypovitaminosis D that is so common in older persons. Changes in probiotics can lead to diarrhea and altered immune system. In the liver, aging is associated with delayed drug metabolism.

SUMMARY

Changes in the physiology of the gut play a role in the anorexia of aging, aspiration pneumonia, postprandial hypotension, constipation and fecal incontinence.

Preventing aspiration in older adults with dysphagia

Dysphagia, the impairment of any part of the swallowing process, increases the risk of aspiration. Dysphagia and aspiration are associated with the development of aspiration pneumonia. While some changes in swallowing may be a natural result of aging, dysphagia is especially prevalent among older adults with neurologic impairment or dementia, leading to an increased risk of aspiration and aspiration pneumonia. This article discusses best practices for assessment and prevention of aspiration among older adults who are being hand-fed or fed by tube. To view an accompanying online video, go to http://links.lww.com/A226.

Digital cineradiographic study of swallowing in patients with amyotrophic lateral sclerosis

PURPOSE

This study was performed to evaluate the usefulness of digital cineradiography in detecting swallowing disorders in dysphagic patients affected by amyotrophic lateral sclerosis (ALS) with a view to planning an adequate therapeutic approach.

MATERIAL AND METHODS

From January 2005 to September 2006, 23 patients (10 men and 13 women; mean age 41.3+/-8.6 years) affected by ALS were evaluated with digital cineradiography to assess the grade of dysphagia. All patients were classified using the Hillel ALS Severity Scale (ALSSS). All examinations were performed with radiocontrolled equipment provided with a digital C-arm.

RESULTS

The cineradiographic technique enabled us to differentiate patients with disorders of the oral (17/23) and/or pharyngeal (19/23) swallowing phase from those without swallowing dysfunction (4/23). In 14/23 patients, passage of contrast medium into the upper airways was observed during swallowing, whereas in 5/23 cases, aspiration of contrast medium into the lower airways was recorded.

CONCLUSIONS

The videofluoroscopic swallowing study has high diagnostic capabilities in the evaluation of swallowing disorders, as it is able to identify the degree and causes of impairment. In addition, the study proved useful for planning speech therapy and for follow-up in patients with ALS.

Centres of Excellence for the care of people with progressive ataxias

This article provides a description of the progressive ataxias and how such a diagnosis impacts on a person's life. The nurse's role in helping these patients, who can face numerous difficulties in everyday life, is highlighted. Moreover, the authors discuss the development of Ataxia Specialist Centres of Excellence for the diagnosis and management of people with ataxia, and the benefits believe these centres will bring to the care of these patients.

Substance P and swallowing after stroke

In the field of digestive tract surgery, QOL can be significantly decreased in patients who experience recurrence or metastasis of a cancer, not only by digestive tract disorders that prevent the patient from taking a meal, but also by installation of gastric or ileus tubes. For such patients, surgical procedures aimed to palliate their symptoms are necessary, rather than radical surgeries. We examined 24 cases at our department, for which operations were performed with the aim of palliating their symptoms, during the 4-year period from October 2001 to December 2005. Sixteen (89%) out of 18 symptomatic cases (i.e. patients who could not take a meal, or who had undergone tracheal intubation) exhibited confirmed improvement in their symptoms after the operations. On the other hand, we also experienced one case in which installation of an ileus tube was necessary after the operation (1 case, 5.5%). Five patients (20.9%) died after the operation, before they were discharged from the hospital. For such patients, additional minimally invasive procedures should have been taken into consideration.