Dysphagia occurs in approximately 55 percent of patients who have an acute stroke. Of these patients, 40 percent have aspiration identified during videofluoroscopy swallow studies (VSS). Silent aspiration, occurring in 40 to 70 percent of dysphagic patients, can present major problems, such as aspiration pneumonia. Six established clinical predictors may be used to identify patients at risk for aspiration after stroke. These include dysphonia, dysarthria, abnormal gag reflex, abnormal volitional cough, cough after swallow or voice change after swallow (see accompanying table). Daniels and associates studied the outcome of patients referred for VSS compared with the outcome in those who were not referred for VSS, based on a clinical evaluation using the six clinical predictors.
|Dysphonia||A voice disturbance in the parameters of vocal quality, pitch or intensity|
|Dysarthria||A speech disorder resulting from disturbances in muscular control affecting the areas of respiration, articulation, phonation, resonance or prosody|
|Abnormal gag reflex||Absent or weakened velar or pharyngeal wall contraction, unilaterally or bilaterally, in response to tactile stimulation of the posterior pharyngeal wall|
|Abnormal volitional cough||A weak response, a verbalized response or no response when given the command to cough|
|Cough after swallow||Cough immediately or within one minute of ingestion of calibrated volumes of water (5, 10 and 20 mL presented in duplicate)|
|Voice change after swallow||Alteration in vocal quality following ingestion of calibrated volumes of water|
A consecutive sample of patients who had an acute stroke and were referred to a speech pathology service were enrolled in the study. All were screened using the six clinical predictors for aspiration risk. Group 1 of the patients had two or more clinical predictors and were evaluated with VSS. Group 2 had one or none of the clinical predictors and were not evaluated with VSS. Both groups were evaluated before discharge with regard to dietary status and any aspiration pneumonia complications.
Sixty-eight percent of the patients with acute stroke had two or more clinical predictors, while 32 percent had one or none. In patients with two or more clinical predictors, a significant number were rated as having moderate or severe risk for aspiration by VSS. The clinical predictors were able to differentiate those who had moderate or severe dysphagia from those who had mild or no dysphagia. None of the patients in either group developed complications from aspiration pneumonia, and 93 percent returned to a regular diet by the time of discharge.
The authors conclude that clinical predictors of aspiration risk can be used to objectively differentiate patients with acute stroke who require further evaluation of swallow mechanics from patients who do not. This strategy could reduce the number of VSS examinations performed in acute stroke patients. In addition, the reduction in VSS use could reduce the cost of managing these patients.