Prediction of Cough Effectiveness in Amyotrophic Lateral Sclerosis (ALS) patients assessed by Ultrasuond of the Diaphragm during the Cough Expiration phase

<bold>Background:</bold> Cough effectiveness, assessed by measuring Cough Peak Flow (CPF), is important, especially for patients with Amyotrophic Lateral Sclerosis (ALS). We hypothesized Diaphragmatic Cough Expiratory Excursion (DCEE), assessed during the cough expiratory phase, might predict CPF in ALS patients. Aim of the study is to value the association between these two parameters, in order to investigate if the ultrasonographic (US) index can be used to ascertain CPF in ALS. <bold>Methods:</bold> Twenty-two ALS patients were enrolled. The DCEE was measured with US during voluntary cough expiration and CPF was simultaneously measured. A multivariable linear regression model was built to quantify the association between CPF and DCEE. Age, height, and sex were used as adjustment variables. <bold>Results:</bold> There is significative association between CPF and DCEE with a coefficient of 0.86 observed in the ALS group. Multiple linear regression analysis for CPF (Adjusted R2 = 0.86) revealed significant associations with DCEE (adjusted β-coefficient: 64.78, 95% CI: 51.50 to 78.07, p<0.001), subject group (adjusted β-coefficient: -93.84, 95% CI: -138.04 to -49.65, p<0.001) and sex (adjusted β-coefficient: -69.06; 95% CI: -109.98 to -28.15, p=0.001). <bold>Conclusions:</bold> This study shows a strong relationship between DCEE, detected by ultrasound, and CPF during the expiratory phase of cough in ALS patients. Our results predict the cough effectiveness by using M-mode diaphragmatic sonography with a potentially significant impact on therapeutic choices, preventing pulmonary complication in patient at high risk of respiratory failure.