The purpose of this study is to compare the Total Face Mask™ (Respironics, Inc., Pittsburgh, PA) (covering whole face) and the standard oronasal facemask (covering nose and mouth) for the emergency treatment of patients with acute respiratory failure with the machine blowing air into the mask placed on the face (noninvasive positive pressure ventilation) (NPPV).

Despite its demonstrated efficacy in treating selected patients with acute respiratory failure, the application of NPPV is still plagued by a substantial failure rate, ranging from below 10% to above 40%. Mask intolerance ranks as one of the most common causes of failure. This is related to ill-fitting masks, mask discomfort (despite a properly fitted mask), excessively tightened straps, excessive air leaks around the mask or through the mouth, and claustrophobia.

The most commonly used masks in the acute care setting are either oronasal masks that cover the nose and mouth, or nasal masks that cover the nose alone. Both mask types usually consist of clear plastic dome-shaped mask with a soft silicon gasket to create an air seal with the skin. While this approach is usually successful, it may lead to patient discomfort and/or an air leak secondary to the difficulty in creating an effective seal over the bridge of the nose and over mobile structures such as the mandible. The Total Face Mask ™ (Respironics, Inc., Pittsburgh, PA) uses a different approach to avoid some of these limitations. Considerably larger than a standard oronasal mask, it covers the entire face and creates an air seal using a silicon gasket around the parameter of the face. In this way, gasket pressure is more evenly distributed, and discomfort over the bridge of the nose or chin is eliminated, and air leaking reduced. In addition, because one mask size fits virtually all patients, the Total Face Mask ™ facilitates the fitting process and permits more rapid initiation of ventilatory assistance. Clinical experience to date suggests that claustrophobia is not a common problem with the Total Face Mask ™ despite its size, and that its contribution to dead space is comparable to that of most oronasal masks.

The following protocol aims to compare use of the Total Face Mask ™ to the Comfort Full oronasal mask (also by Respironics, Inc., Pittsburgh, PA)or RT040 oronasal mask (Fisher&Paykel Inc., Wellington, NZ) in the acute care setting for patients meeting standard indications for NPPV.

Inclusion Criteria:

• Age>18
• Either A or B

A. Clinical Criteria: Moderate to severe respiratory distress as evidenced by tachypnea, use of accessory muscles for breathing, or abdominal paradox.

B. Blood Gas and Physiologic Criteria: Gas exchange abnormalities including PaCO2>45 with a pH<7.35, or a PaO2/FiO2 ratio<200.

Exclusion Criteria:

• The need for immediate intubation
• Medical instability such as hypotensive shock, uncontrolled cardiac ischemia or arrythmias, unstable myocardial infarction, uncontrolled upper gastrointestinal bleeding
• Agitation or uncooperativeness, unresponsive to small doses of sedatives
• Excretions or inability to protect the airway
• Inability to fit the mask
• Facial trauma
• Upper airway obstruction

Could not blind subjects or investigators