Effectiveness of assisted and unassisted cough capacity in amyotrophic lateral sclerosis patients

Abstract

Decreased cough capacity during a respiratory infection is one of the main causes of acute respiratory failure and hospitalisation in amyotrophic lateral sclerosis (ALS). Objective: To determine whether a respiratory measurement could identify the effectiveness of cough capacity in ALS during a respiratory infection. Methods: This was a prospective study of all ALS patients who were treated at a respiratory care unit due to a respiratory infection from 2012 to 2016. The effectiveness of unassisted and assisted coughing was evaluated and respiratory function tests were performed during the acute episode. Results: Forty-eight ALS patients were enrolled, with only four having an effective unassisted cough. The variable which predicted unassisted cough effectiveness was peak cough flow (PCF) (OR 4499.27; 95%CI 3.60–3219086.19; p = 0.022) with a cut-off point of 2.77 L/s (166 L/min). For manually assisted coughing, the predictor of cough effectiveness was manually assisted PCF (cut-off point of 2.82–169 L/min) (OR 2198.602; 95% CI 3.750–1351691.42; p = 0.019). Mechanically assisted PCF (cut-off point of 2.95–177 L/min) was found to be the predictor of mechanically assisted coughing effectiveness (OR 23.40; 95% CI 2.11–258.96; p = 0.010). Conclusions: During a respiratory infection in ALS patients, the effectiveness of assisted and unassisted cough capacity depends on the PCF generated.

Keywords:

• Cough effectiveness
• amyotrophic lateral sclerosis
• respiratory infection
• assisted coughing

Declaration of interest

JS, ES, PB and JM have no financial relationship with any commercial entity that has an interest in the subject of this manuscript.

Supplementary material available online