A simple technique for pulmonary function testing in patients with permanent tracheostomies

In patients with permanent tracheostomies, the clinician can encounter difficulty in creating a satisfactory seal between the patient and pulmonary function testing (PFT) equipment. We have developed a simple apparatus and procedure for effecting a tight seal during testing.

The seal around the tracheostomy is made with a newborn-size resuscitation mask, the hole of which is larger than the tracheal stoma. A sealing lubricant is applied to the soft rim of the mask and around the tracheostomy site, and adapters enable connection of the resuscitation mask and the large-bore PFT-equipment tubing. After affixing the adapters to the mask, we check that the seal is tight; if airleak is evident, more lubricant or a mask of different size or style may be necessary. Once a tight seal is achieved without airway compromise, the mask is attached to the PFT equipment and testing can begin. During testing, the patient should wear nose clips to prevent volume loss through the upper airway.

This equipment is simple, inexpensive, and readily available. Further, it permits pulmonary function testing whether or not a tracheostomy tube is in place, an advantage if variable extrathoracic upper airway obstruction is a consideration. If the patient has a cuffed tracheostomy tube in place, the PFT equipment can be connected directly to the tube. We have found that this apparatus and technique are well tolerated and that test results are reproducible.