Use of Noninvasive Ventilation with Volume-Assured Pressure Support to Avoid Tracheostomy in Severe Obstructive Sleep Apnea
Table 1
Polysomnography parameters at baseline and on CPAP and AVAPS-AE.
Parameter
Baseline
CPAP titration
AVAPS-AE titration
Total sleep time (min)
323.5
358.0
429.0
Sleep efficiency (%)
78.5
82.3
97.1
Sleep latency (min)
0.5
3.0
3.0
R latency (min)
175.5
238.8
132.5
Wake (min) (%)
88.5 (21.5)
77.0 (17.7)
13.0 (2.9)
N1 (min) (%)
1.0 (0.2)
0.0 (0.0)
0.0 (0.0)
N2 (min) (%)
238.5 (57.9)
175.5 (40.3)
268.0 (60.6)
N3 (min) (%)
63.5 (15.4)
127.0 (29.2)
72.5 (16.4)
R (min) (%)
20.5 (5.0)
55.5 (12.8)
88.5 (20.0)
Arousals index (arousals/h)
72.3
39.7
12.3
Periodic limb movement index (events/h)
0.0
0.0
0.0
Apnea-hypopnea index (events/h)
138.2
57.5
9.7
Obstructive apnea index (events/h)
122.0
44.1
0.1
Mean SpO2 (%)
92
94
97
Minimum SpO2 (%)
59
72
93
Time SpO2 ≤ 90% (min)
111.7
55.9
0.0
Baseline ETCO2 (mm Hg)
50
36
47
Maximum ETCO2 (mm Hg)
60
48
51
Time ETCO2 ≥ 50 (mm Hg) (min)
123.3
0.0
0.7
Note. On diagnostic (baseline) polysomnography, oxygen at 0.25 L/min via nasal cannula was added 40 min after sleep onset due to severe hypoxemia without rebound and maintained for the remainder of the study. CPAP and AVAPS-AE studies were done in room air. AVAPS-AE, average volume-assured pressure support with autotitrating expiratory positive airway pressure; CPAP, continuous positive airway pressure; R, rapid eye movement sleep; N, nonrapid eye movement sleep; SpO2, oxygen saturation by pulse oximetry; ETCO2, end-tidal carbon dioxide.
