Behavioural intervention for dysphagia in acute stroke: a randomised controlled trial

Summary

Background

Swallowing dysfunction after stroke is common, but there is little reliable evidence for how the disorder should be managed. This study compared standard low-intensity and high-intensity behavioural interventions with usual care for dysphagia.

Methods

306 patients with clinical dysphagia admitted to hospital with acute stroke were randomly assigned to receive usual care (n=102), prescribed by the attending physician; standard low-intensity intervention (n=102), comprising swallowing compensation strategies and diet prescription three times weekly for up to a month; or standard high-intensity intervention and dietary prescription (n=102), at least daily for up to a month. The primary outcome measure was survival free of an abnormal diet at 6 months. Analysis was done by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00257764.

Findings

60 patients died and three patients were lost to follow up before the 6-month analysis. Of patients randomly allocated usual care, 56% (57/102) survived at 6 months free of an abnormal diet compared with 67% (136/204) allocated standard swallowing therapy (relative risk 1·19, 95% CI 0·98–1·45). Standard swallowing therapy was associated with a non-significant trend toward a reduction in death (0·80, 0·5–1·3), institutionalisation (0·69, 0·4–1·1), and dependency (1·05, 0·8–1·3); a significant reduction in swallowing-related medical complications (0·73, 0·6–0·9), chest infection (0·56, 0·4–0·8), and death or institutionalisation (0·73, 0·55–0·97); and a significant rise in the proportion of patients regaining swallowing function (1·41, 1·03–1·94) by 6 months. Compared with usual care and low-intensity therapy, high-intensity therapy was associated with an increased proportion of patients who returned to a normal diet (p=0·04) and recovered swallowing (p=0·02) by 6 months.

Interpretation

These data show a consistent trend towards more favourable outcomes in dysphagic stroke patients who are assigned a standard programme of early behavioural swallowing intervention, including active therapeutic approaches and dietary modification.

Introduction

Swallowing disorders (dysphagia with or without aspiration) are present in about 27–50% of patients with acute stroke,1, 2, 3, 4, 5 and are associated with an increased risk of complications, such as aspiration pneumonia, dehydration, and malnutrition, in a fifth to a third of patients.1, 6, 7 These complications are theoretically preventable by prompt and accurate diagnosis of the swallowing disorder and appropriate intervention. The possible interventions include indirect behavioural strategies (eg, modification of food consistency),⁸ direct behavioural strategies (eg, stimulation of oral and pharyngeal structures),⁹ and enteral feeding by means of a nasogastric tube or by percutaneous endoscopic gastrostomy.10, 11, 12, 13

Feeding by percutaneous endoscopic gastrostomy is associated with an increased rate of death or a poor outcome compared with feeding by nasogastric tube.11, 12 The effectiveness of behavioural interventions for swallowing disorders after stroke, however, is uncertain. Kasprisin and colleagues¹⁴ did a non-randomised, uncontrolled study of swallowing therapy in patients with stroke and mixed neurogenic causes (n=69). The main outcome of this study was pneumonia development as reported from chart review. Despite the inclusion of unmatched comparison groups with mixed causes, the authors concluded that swallowing therapy was efficacious. Rosenbek and co-workers¹⁵ undertook a controlled, multiple crossover design assessment of the effect of thermal stimulation of the fauces on swallowing in seven patients with multiple previous strokes. They identified initial change in duration and descriptive measures of swallowing; however, these changes were not maintained a month after treatment. From a different focus, Sukthankar and colleagues¹⁶ did a randomised controlled trial of nine patients with dysphagia secondary to stroke or head injury. Patients were randomised to receive treatment with oral exercises or oral exercises with visual and audio biofeedback. These authors concluded that oral exercises combined with biofeedback methods improved swallowing recovery, despite including only lip and tongue force measures as outcomes. DePippo and co-workers¹⁷ studied 115 orally fed patients with subacute stroke, mild dysphagia, and absent or minimum aspiration on videofluoroscopy. Patients were randomly assigned to one of three graded levels of treatment, including dietary modification and swallowing therapy. However, the study did not include a non-treatment control group. Outcome measures included pneumonia, dehydration, calorie-nitrogen deficit, and death. The authors concluded that outcome did not differ among the three groups. Furthermore, only 15% of patients reached one or more of these endpoints within the 12-month study period.

Taken together these studies suggest positive outcomes from behavioural interventions for dysphagia. However, significant design issues make it impossible to conclude efficacy for this form of intervention; specifically, small sample sizes,14, 15, 16, 17 restriction to patients with a narrow spectrum¹⁷ or multiple causes of dysphagia,14, 16 and limitation by delayed intervention¹⁵ or lack of a control group.15, 17

The primary aim of this study was to ascertain whether a standard behavioural intervention for swallowing dysfunction after stroke, given by a speech pathologist for up to a month after stroke, could improve swallowing function, as measured by the proportion of patients returning to a normal (prestroke) diet by 6 months after stroke, compared with usual care in hospital. Secondary aims were to determine a) whether the intervention could increase the proportion of patients who recovered swallowing function and reduce the proportion who developed dysphagic-related complications, died, were institutionalised, or dependent in activities of daily living by 6 months after stroke; and b) whether there was a dose-dependent effect associated with high-intensity and low-intensity standard behavioural interventions.