The Burke dysphagia screening test: validation of its use in patients with stroke.

The objective of this study was to validate a dysphagia screening test to identify patients in the rehabilitation phase post stroke at risk for pneumonia, recurrent upper airway obstruction, and death. The setting was an inpatient stroke rehabilitation unit. One hundred thirty-nine consecutive patients met the following criteria: stroke confirmed by clinical history and neurological exam with compatible computed tomography (CT) or magnetic resonance imaging (MRI) scan; ages 20 to 90 years inclusive; and no known history of significant oral or pharyngeal anomaly. The main outcome measures were pneumonia, recurrent upper airway obstruction, and death. The Burke Dysphagia Screening Test (BDST) identified 11 of 12 patients who subsequently developed pneumonia, recurrent upper airway obstruction, or death (Fisher's exact test: p = .03). The relative risk for the occurrence of any of these complications was 7.65 times greater for those failing versus passing the BDST. The BDST identified 9 of 9 patients who developed pneumonia (Fisher's exact test: p = .01). We concluded that the BDST is of value in identifying patients in the rehabilitation phase poststroke at risk for pneumonia, recurrent upper airway obstruction, and death.

Aspiration and relative risk of medical complications following stroke.

OBJECTIVE: To determine the relative risk of pneumonia, dehydration, and death associated with videofluoroscopic evidence of aspiration, silent aspiration, aspiration of 10% or greater on one or more barium test swallows, and aspiration of thick liquid or more solid consistencies in the subacute phase after stroke. DESIGN: Prospective, longitudinal cohort study. SETTING: Inpatient stroke rehabilitation unit. PATIENTS: There were 114 consecutive patients who met the following criteria: (1) stroke as defined by clinical history and neurological examination with compatible computed tomographic or magnetic resonance imaging scan; (2) age 20 to 90 years, inclusive; (3) no known history of significant oropharyngeal anomaly; and (4) videofluoroscopic evidence of dysphagia. Of 122 eligible patients, eight refused participation. MAIN OUTCOME MEASURES: Development of pneumonia, dehydration, and death. RESULTS: The relative risk for developing pneumonia was 6.95 times greater (P = .027) for those patients who aspirated compared with those who did not, 5.57 times greater (P = .012) for those who aspirated silently compared with those who coughed when aspirating or who did not aspirate, and 8.36 times greater (P = .002) for those who aspirated 10% or greater on one or more barium test swallows compared with those who aspirated less than 10% or did not aspirate. CONCLUSION: Aspiration, silent aspiration, and aspiration of 10% or greater on one or more barium test swallows during videofluoroscopic evaluation are associated with an increased risk of pneumonia, but not dehydration or death, during the subacute phase after stroke.

Dysphagia therapy following stroke: a controlled trial.

OBJECTIVE: To determine the effect of graded levels of intervention by a dysphagia therapist on the occurrence of pneumonia, dehydration, calorie-nitrogen deficit, recurrent upper airway obstruction, and death following stroke. DESIGN: A randomized control trial. SETTING: Inpatient stroke rehabilitation unit. PATIENTS: All patients met the following eligibility criteria: (1) stroke defined by clinical history and neurologic examination with compatible CT or MRI, (2) ages 20 to 90 years inclusive, (3) no known history of significant oral or pharyngeal anomaly, (4) laboratory values below end point criteria, (5) failure on the Burke Dysphagia Screening Test, and (6) modified barium swallow evaluation evidence of dysphagia (patients who aspirated > or = 50% of all consistencies presented, even using compensatory swallowing techniques, were excluded). Of 123 eligible patients, eight refused study participation. One hundred fifteen patients were randomized. INTERVENTIONS: Three graded levels of dysphagia therapist control of diet consistency and reinforcement of compensatory swallowing techniques were provided during the inpatient rehabilitation stay. MAIN OUTCOME MEASURES: Pneumonia, dehydration, calorie-nitrogen deficit, recurrent upper airway obstruction, and death. RESULTS: The log rank statistic showed no significant difference between the three treatment groups for the distribution of time until end point during the inpatient stay or to 1 year post-stroke. CONCLUSION: Limited patient and family instruction regarding use of diet modification and compensatory swallowing techniques during inpatient rehabilitation is as effective as therapist control of diet consistency and daily rehearsal of compensatory swallowing techniques for the prevention of medical complications associated with dysphagia following stroke.

Videofluoroscopic evidence of aspiration predicts pneumonia and death but not dehydration following stroke.

In order to assess the risk of pneumonia, dehydration, and death associated with videofluoroscopic evidence of aspiration following stroke, the clinical records of 26 patients with aspiration and 33 randomly selected, case-matched, dysphagic controls without videofluoroscopic evidence of aspiration were reviewed. The videofluoroscopic modified barium swallow technique included 5 ml-thin and thick liquid barium, 5 ml barium pudding, and 1/4 cookie coated with barium, plus additional 20 and 30 ml of thin liquid barium. Patients were assessed a mean of 2 +/- 1 SD months poststroke and were followed for a mean of 16 +/- 8 SD months poststroke. The odds ratio for developing pneumonia was 7.6 times greater for those who aspirated any amount of barium irrespective of its consistency (p = 0.05). The odds ratio for developing pneumonia was 5.6 times greater for those who aspirated thickened liquids or more solid consistencies compared with those who did not aspirate, or who aspirated thin liquids only (p = 0.06). Dehydration was unrelated to the presence or absence of aspiration. The odds ratio for death was 9.2 times greater for those aspirating thickened liquids or more solid consistencies compared with those who did not aspirate or who aspirated thin liquids only (p = 0.01). Aspiration documented by modified videofluoroscopic barium swallow technique is associated with a significant increase in risk of pneumonia and death but not dehydration following stroke.

Validation of the 3-oz water swallow test for aspiration following stroke.

A 3-oz water swallow test identified 80% (16/20) of patients aspirating during a subsequent videofluoroscopic modified barium swallow examination (sensitivity, 76%; specificity, 59%). It also identified patients with more severe dysphagia aspirating larger amounts (sensitivity, 94%; specificity, 26%) or thicker consistencies (sensitivity, 94%; specificity, 30%) of test material. The 3-oz water swallow test is a sensitive screening tool for identifying patients at risk for clinically significant aspiration who need referral for more definitive modified barium swallow evaluation.

Do hormonal (stress) and vascular (ischaemia) factors contribute to reflex muscle atrophy induced by chronic nociceptive stimulation in rats?

1. Reflex muscle atrophy was induced in rats by fracturing the metatarsal bones of one hind paw and injecting 0.02 ml turpentine oil into the planta under shortlasting ether anaesthesia. The atrophy thus evoked in the soleus and extensor digitorum longus (EDL) was compared with the contralateral muscles. 2. There was a twelvefold increase of plasma corticosteroid levels one hour after application of the above nociceptive stimulus and the levels were still somewhat enhanced at 3 days. Neither bilateral adrenalectomy nor administration of corticosteroid hormones or cold stress affected the development of reflex atrophy. 3. Restriction of the arterial blood supply (ligature of the common iliac artery) led to a slowly progressing atrophy with a maximum 10 days after the ligature. Reflex atrophy introduced at different times after ligature was not enhanced. 4. These results are interpreted as evidence that neither general stress (and the effect of catabolic hormones) nor local restriction of muscle blood flow (by reflex vasospasm, for example) are likely to play any appreciable role in the mechanism of reflex muscle atrophy.

Work-induced potassium changes in skeletal muscle and effluent venous blood assessed by liquid ion-exchanger microelectrodes.

Using liquid ion-exchanger semimicroelectrodes with a side pore, we measured changes of extracellular potassium concentration (Ke+) in adult rabbit and cat gastrocnemius muscles and in venous effluent blood flowing from the cat gastrocnemius muscle during various bouts of activity induced by sciatic nerve stimulation. 1. Isometric tetanic contractions (at 50 Hz) of various durations caused transient accumulation of Ke+ which was non-linearly related to the duration of muscle activity. The peak values of Ke+ in response to muscle stimulation were analogous in rabbits and cats, attaining values, e.g. after a 20-sisometric tetanus, between 8-9 mEq/1K+ in both species. 2. Potassium concentration in venous effleunt blood (K+ven) was transiently increased after isometric tetani. Since blood flow was measured at the same time, it was possible to calculate the amount of K+ lost by the muscle after tetani of various durations. A 32 g gastrocnemius muscle of the cat, for example, loses 9.36 +/- 1.52 muEqK+ after a 20-s isometric tetanus, which corresponds roughly to 0.5% of the total muscle potassium content. The loss of K+ in this muscle was 29.3 pEq K+ /impulse/100 g fresh muscle tissue. 3. There was no evident difference between the amount of K+ released during isometric tetani, or tetanic contractions performed under isotonic conditions. Single twitches evoked by indirect stimulation at 1 HZ for several minutes also induced a small rise in K+ven. 4. If the loss of K+ from the muscle into the blood stream is transiently prevented by arterio-venous occlusion installed immediately before a 10-s isometric tetanus, most K+ is released subsequently when blood flow is renewed, if the occlusion lasts for 20-25 s. It is not until blood flow is occuded for 40-60 s that most K+ is apparently resorbed and only a minor portion is released and is to be found in the venous blood. 5. The transient accumulation of muscle extra-cellular potassium may locally affect nerve endings, skeletal and smooth muscle cells.