Risk factors for the onset of aspiration pneumonia among stroke patients in the recovery stage

Abstract

Post-stroke aspiration pneumonia is one of the most common complications among stroke patients. Although the onset of aspiration pneumonia is caused by a disruption of the balance between invasion (the type and amount of oral flora and aspiration) and host resistance (the protective airway reflex and immune function), several previous studies have focused on invasion, such as aspiration and dysphagia. In this study, we examined the importance of the host resistance to aspiration pneumonia among stroke patients with dysphagia. The study subjects included 76 stroke patients (mean age, 74.7±8.4 years) with dysphagia chosen from 175 stroke patients who were newly admitted to four rehabilitation hospitals. We divided the subjects into two groups based on the onset of pneumonia during the period of admission and compared their status. Ten patients (13.2%) developed pneumonia at the hospital, and all of the affected patients were over 65 years old. Significant differences existed between the two groups with respect to the gender, activity level, albumin level, nutrition method and severity of dysphagia (p<0.05). Our study revealed that recumbency, malnutrition, tube feeding, severe dysphagia and female sex were risk factors for pneumonia. In particular, dysphagia was closely associated with aspiration pneumonia. Moreover, host resistance factors, such as recumbency and malnutrition, also play important roles in the development of aspiration pneumonia.