RESUMO
Cough is a natural reflex that protects respiratory airways against infections or mucus retention. Cough maintains an adequate cleaning of the airways and is a mainstay of respiratory therapy. It can be triggered voluntarily by the patient or by a specific cough device. Peak cough flow (PCF) is used to assess the effectiveness of the cough. When this value is below 160 L/min, cough is considered inefficient and becomes a risk factor for respiratory problems. Patients with weak cough, especially those with neuromuscular disease, have in common a low tidal volume and a decreased maximum insufflation capacity. Both factors directly affect the inspiratory phase previous to cough, which is considered vital to obtain the optimum flow for a productive cough. Different therapeutic measures may help to increase cough efficiency among patients with cough weakness. These interventions may be performed using manual techniques or by mechanical devices. The aim of this review is to analyze the different techniques available for cough assistance, set a hierarchy of use and establish a scientific basis for their application in clinical practice.