Assessment of Cough Strength in Patients With Tracheostomies

When a patient has recovered from the initial respiratory insult which precipitated respiratory failure, the patient may need a prolonged period of time to wean completely from mechanical ventilation.

One method of weaning from mechanical ventilation involves having the patient breath spontaneously without the assistance of the ventilator. This is referred to as a spontaneous breathing trial. Over time, the duration of spontaneous breathing is gradually increased until the patient is able to breathe entirely on their own. Traditionally, the tracheostomy cuff has been kept inflated until the patient can breathe entirely on their own (2,3).

A recent study has assessed the effect of deflating the tracheostomy tube cuff on weaning from mechanical ventilation (4). Patients, who required prolonged mechanical ventilation and had a tracheostomy, were weaned using a T piece trial. They were randomized to two groups: the control group had the tracheostomy cuff kept inflated; the study group had the tracheostomy cuff deflated. The study group, with the cuff deflated, had a shorter time to weaning from the ventilator, fewer respiratory infections and improved swallowing. This was attributed to an increase in the effective airway diameter, which would decrease the resistive work of breathing. The authors did not comment on the effect cuff deflation may have on coughing and clearance of secretions.

It is postulated that patients can cough more effectively when he/she can use their vocal cords to generate a cough as opposed to coughing through a tracheostomy tube where the vocal cords are bypassed. It has been previously demonstrated that patients have a stronger cough after the tracheostomy tube has been removed as compared to when the tracheostomy tube is in place (5).

Patient population