Cough Strength Is an Indicator of Aspiration Risk When Restarting Food Intake in Elderly Subjects With Community-Acquired Pneumonia

BACKGROUND: The incidence of community-acquired pneumonia (CAP) is relatively high in elderly subjects. Cough peak flow (CPF) is an objective indicator of cough strength, and CPF evaluation might be useful to assess whether food intake can be restarted. We aimed to examine whether cough strength assessed with CPF can be used as an indicator of the aspiration risk when restarting food intake in elderly subjects with CAP.

METHODS: This cross-sectional study included 82 elderly subjects with CAP between August 2016 and March 2018. CPF was measured using a peak flow meter, and we performed the repetitive saliva-swallowing test (RSST), which is a videoendoscopic evaluation of swallowing and is used to assess dysphagia and aspiration. Receiver operating characteristic (ROC) curve analysis was performed. The cutoff value was determined, and the area under the ROC was calculated.

RESULTS: The areas under the RSST and CPF curves were 0.87 and 0.83, respectively. The RSST value for identifying the aspiration risk was 2.5 swallows. The sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were 70.0%, 71.7%, 2.5, and 0.42, respectively. The CPF for identifying the aspiration risk was 190 L/min. The sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were 82.6%, 69.4%, 2.7, and 0.25, respectively.

CONCLUSION: Our findings suggest that cough strength assessed with CPF can be used as an indicator of the aspiration risk when restarting food intake in elderly subjects with CAP and that CPF evaluation is not inferior to the RSST. However, CPF evaluation should be performed together with swallowing screening tests to determine the aspiration risk.