Efficacy of a New Full Face Mask for Noninvasive Positive Pressure Ventilation: Statistical Analysis
After initial titration of pressure (BiPAP) or volume (PLV-102), to achieve ventilation goals as previously outlined, levels of ventilation remained identical during each trial with the three different face masks. At the end of each trial, arterial blood gas analysis was performed and the patients were queried with regard to their level of comfort with the mask, and their perception of dyspnea when using each of the masks. In addition, a semiquantitative analysis of air leaks during NPPV with each mask was determined.
Long-term Efficacy of NPPV via the TFM: In nine patients, NPPV was delivered via the TFM as an inpatient for 22 ± 26 days, 7.1 ± 1.5 h a night, and as an outpatient for 6±5 weeks, 6.7± 1.5 h a night. Arterial blood gases and functional status were measured at admission, discharge from the hospital, and at follow-up. Respiratory mechanics (spirometry and respiratory muscle pressures) were also obtained in follow-up Reading here.
An analysis of variance was used to compare ventilatory variables, arterial blood gases, mask leaks, discomfort with the face mask and level of dyspnea between eupnea, and NPPV via the various masks. The Student’s t test was used to determine whether a significant relationship existed between the values for arterial blood gases, respiratory mechanics, and functional status at baseline, hospital discharge, and follow-up. A p value <0.05 was considered statistically significant.
Patient characteristics are shown in Table 2. Three patients had severe obstructive lung disease, and six patients had severe restrictive disorders. The patients’ ages ranged from 44 to 81 years. Three of the nine patients suffered from acute superimposed on chronic respiratory failure that had necessitated recent (within 6 months of the study) endotracheal intubation and mechanical ventilation. The remaining patients had a more gradual, progressive worsening of their respiratory status. Five patients had evidence of cor pulmonale with a right-sided third heart sound, elevation in the pulmonic component of the second heart sound, peripheral edema, and evidence of right ventricular dysfunction by two-dimension echocardiography. All patients had severe derangements in lung mechanics with an FVC (mean±SD) of 0.95 ±0.44 L, and FEVi of 0.57 ±0.18 L.
Table 2—Patient Characteristics
|PatientNo.||Disease Causing Respiratory Failure||Age, yr||History of Acute Respiratory Failure||Presence of Cor Pulmonale||FVC, L,% Predicted||FEVi, L (% Predicted)|
|2||Severe kyphoscoliosis||44||No||No||0.75 (22)||0.72 (26)|
|3||Thoracoplasty, kyphoscoliosis||81||No||Yes||0.90 (33)||0.64 (34)|
|4||Severe kyphoscoliosis||55||No||No||0.43 (16)||0.32 (16)|
|5||Diaphragm paralysis||68||Yes||Yes||0.74 (28)||0.72 (36)|
|6||Severe kyphoscoliosis, postpolio syndrome||72||No||Yes||0.69 (41)||0.52 (38)|
|7||Severe kyphoscoliosis, postpolio syndrome||56||No||No||0.93 (27)||0.81 (31)|
|8||COPD||78||Yes||Yes||1.88 (48)||0.36 (14)|
|9||COPD||62||No||No||1.26 (36)||0.45 (17)|
Category: Respiratory Symptoms
Tags: face mask, hypercapnia, noninvasive ventilation, respiratory failure