A Preliminary Investigation of Relationships among Pharyngeal Acidity, Dysphagia, and Pneumonia in Acute Stroke

Individuals with acute stroke on nonoral feeding regimens frequently develop pneumonia, questioning the long-held belief that pneumonia in stroke patients is a caused by food and liquid aspiration alone. Refluxate and colonized oral secretions are thought to contribute to an acidic oropharyngeal environment. If aspirated, these colonized oral secretions with increased acidity, can result in increased risk to the respiratory system. This study aimed to investigate the relationship between pharyngeal acidity, dysphagia, and pneumonia in acute stroke patients. Twenty-one patients (mean age 67 years) admitted to a stroke unit were recruited into this study. We evaluated their stroke and dysphagia severity via clinical measures. Pharyngeal acidity was measured using a Restech Dx-pH measurement probe placed transnasally for 24 hours. Sixty two (62%) patients presented with moderate to severe stroke and 38% with dysphagia. Seven patients (33%) were positive for pharyngeal acidity. Two patients with pharyngeal acidity were diagnosed with chest infection. Pharyngeal acidity was significantly correlated with stroke severity (r = 0.487, P = 0.03) and significantly and inversely correlated to clinical swallow performance (rho = -0.626, p = 0.02). Additionally, pharyngeal acidity was significantly associated with categorical dysphagia scores (c2(3,21) = 10.5, p<0.01), functional oral intake (c2(3,21) = 15.7, p<0.001), presence of modified diets (χ2(1,21) = 14.0, p=0.0001), and tube feeding (χ2 (1,21) = 9.992, p = 0.002). Preliminary results suggest that acute stroke patients with dysphagia may present with increased risk for increased pharyngeal acidity. Pharyngeal acidity can result in negative sequelea, including respiratory complications. A better understanding of these potential relationships may lead to enhanced assessment and treatment approaches that limit pharyngeal acidity and resulting respiratory complications in acute stroke patients.