Efficacy of a New Full Face Mask for Noninvasive Positive Pressure Ventilation: Side Effects of the TFM
A representative tracing of airway pressure, airflow, and tidal volume for one patient while receiving NPPV is shown in Figure 4. Panel A shows the inability to maintain the preset pressure because of air leakage via the mouth during NPPV via a nasal mask. Accompanying this leak was a marked reduction in exhaled tidal volume. In panel B, the same patient is placed on NPPV with the same preset ventilatory support system (BiPAP) settings, but now using the TFM. During NPPV via the TFM, there is maintenance of the preset pressures, an absence of air leakage, and a greater expired tidal volume inhalers for asthma.
There was a significant and sustained improvement in oxygenation and ventilation during NPPV compared with spontaneous breathing. After daily NPPV, as an inpatient (7.1 ±1.5 h per night) for 22 ±26 days, patients had an increase in Pa02/FIc>2 (304 ±27 vs 241 ±14, p<0.05) with a simultaneous reduction in PaCC>2 (59 ± 3 mm Hg vs 79 ± 5, p<0.05) during daytime spontaneous breathing compared with hospital admission. After 6 ± 5 weeks following hospital discharge, using nightly NPPV as an outpatient for 6.7 ±1.5 h a night, the improvements in daytime gas exchange were maintained compared with hospital discharge (РаСОг, 58 ±3 mm Hg vs 59 ±3) and Pa02/FIo2 (304 ±18 vs 304±27).
Functional status before NPPV for the nine patients was 1.89 ± 1.45 (range, 1 to 7). Following nocturnal NPPV as an outpatient, the functional status increased to 5.38 ± 1.06 (p<0.05). There was no significant effect of NPPV via the TFM on spirometry (FEVi, 0.58±0.19 L; FVC, 0.95 ±0.53 L; vs FEVi, 0.60 ±0.21 [p=0.87]; FVC, 1.18 ±0.76 L[p=0.52]) or maximum inspiratory (40 ±12 vs 27 ±13 cm H2O [p=0.13]) and expiratory (58 ± 21 vs 38 ± 13 cm H2O [p>0.07]) mouth pressures compared with baseline.
The side effects of TFM ventilation were minor and included mild irritation over the chin due to improper padding of the inferior margin of the face mask, and overtightening of the TFM causing the anterior surface of the mask to compress the nose during expiration. No patient complained of eye or face irritation, no patient demonstrated gastric distention, and no patient developed rhinitis, claustrophobia, or panic.
Figure 4. Representative tracing in one patient showing mask pressure (Pm), tidal volume (Vt), and airflow (V). In panel A (top), arrows show the inability to maintain preset ventilatory support system (BiPAP) mask pressures and a reduction in expired tidal volume in NPPV via the nasal mask. Panel В (bottom) shows the maintenance of the preset ventilatory support system (BiPAP) mask pressures and consistently increased expired tidal volume.
Category: Respiratory Symptoms
Tags: face mask, hypercapnia, noninvasive ventilation, respiratory failure