By Sean R. Muldoon, M.D., M.P.H., F.C.C.P.
Senior Vice President and Chief Medical Officer
Kindred Healthcare Hospital Division

An intervention known as noninvasive ventilation is being increasingly studied and used in patients with chronic respiratory failure. An article in a recent issue of the journal Respiratory Care, which followed a national symposium dedicated to the care of the chronically critically ill patient, examined its use in several patient populations. Noninvasive ventilation, or NIV, does not require an artificial airway, in contrast to tracheostomy (surgical creation of an airway through the neck) or the placement of a breathing tube through the nose or mouth. NIV is achieved most often through the delivery of pressure and flow to the normal airway through the nose and/or mouth.

The benefits of NIV therapy include reduced re-hospitalizations of out-patients and a reduction in potential complications such as infection that can occur with invasive ventilation techniques.

There have been many studies looking at the use of NIV. Some of the studies had limitations and the results of some were at odds with others, so it is fair to say that the use of NIV still bears further consideration and study. But it does show promise for certain conditions, particularly acute exacerbations of chronic obstructive pulmonary disease (COPD) and CHF decompensations presenting to the Emergency Department.

 Desireable Characteristics of an Interface for NIV from: Hess DR. The Growing Role of Noninvasive Ventilation in Patients Requiring Prolonged Mechanical Ventilation. Respir Care. 2012 Jun;57(6):908 Desireable Characteristics of an Interface for NIV from: Hess DR. The Growing Role of Noninvasive Ventilation in Patients Requiring Prolonged Mechanical Ventilation. Respir Care. 2012 Jun;57(6):908

In out-patients with restrictive thoracic disorders, including chest wall deformity, which can happen after certain illnesses such as tuberculosis, the patients receiving NIV had better survival rates than those who were receiving oxygen therapy alone.

Likewise, patients with obesity hypoventilation syndrome (patients with obesity, slow or shallow breathing during the day and sleep-disordered breathing at night) experienced an improved quality of life and enhanced response to oxygen therapy as well. NIV also has been shown to prolong life in patients with chronic neuromuscular disease, which causes respiratory muscle weakness and insufficient ventilation.

NIV seems to show particular promise in patients who require ventilation part-time, in whom the costs, morbidity and complication risks of invasive ventilation are not avoidable.

The treatment potential for NIV in patients with obstructive lung disease, such as cystic fibrosis, is less conclusive.

There are NIV equipment challenges that can affect the success of the therapy. The “interface,” or the “mask” that connects the patient to the ventilator, can be problematic; certain masks, for instance, can cause facial skin breakdown particularly at the bridge of the nose. Leaks through the mouth can occur with nasal delivery of therapy, and this can lead to discomfort, including dry mouth. These complications can be addressed by trying and rotating different interface designs throughout therapy. Improvements in ventilator software and valve design can compensate for some of the leaks.

Since NIV shows such promise in certain situations – typically patients who require intermittent vent support, but who are neither vent dependent nor chronically critically ill – more research would be beneficial as would continued improvement to interface mechanisms.

References:

Hess DR. The Growing Role of Noninvasive Ventilation in Patients Requiring Prolonged Mechanical Ventilation. Respir Care. 2012 Jun;57(6):900-18; discussion 918-20.

Desireable Characteristics of an Interface for NIV from: Hess DR. The Growing Role of Noninvasive Ventilation in Patients Requiring Prolonged Mechanical Ventilation. Respir Care. 2012 Jun;57(6):908