Table 2.
Polysomnographic Findings and Treatment of Patients With Obstructive Sleep Apnea (N = 596), Cincinnati Veterans Affairs Medical Center, 2005-2007
| Findings/Treatment | Obstructive Sleep Apnea Severitya | P Valueb | |||
|---|---|---|---|---|---|
|
| |||||
| None (n = 144) | Mild (n = 136) | Moderate (n = 105) | Severe (n = 211) | ||
| Polysomnographic findings | |||||
| Pretreatment AHI, mean (SD), events/h | 1.5 (1.9) | 9.2 (2.9) | 21.3 (4.3) | 66.9 (27.5) | NA |
| Pretreatment REM-related AHI, mean (SD), events/h | 5.5 (13.2) | 29.7 (22.9) | 44.0 (32) | 54.1 (34.5) | <.001c |
| Minimum SpO2, mean (SD), % | 88.4 (4.5) | 83.4 (6.3) | 81.9 (8.1) | 78.4 (9.3) | <.001d |
| Treatment | |||||
| Patients receiving CPAP treatment, n (%) | NAe | 82 (60.3) | 56 (53.3) | 129 (61.1) | .60 |
| CPAP pressure, mean (SD), cm H2O | NAe | 8.2 (2.3) | 8.3 (1.9) | 9.9 (2.5) | <.001d |
| Patients receiving bilevel treatment, n (%) | NAe | 21 (15.4) | 21 (20.0) | 59 (28.0) | .02f |
| Bilevel pressure inspiration, mean (SD), cm H2O | NAe | 12.0 (2.5) | 13.3 (2.7) | 14.5(3.2) | .002f |
| Bilevel pressure expiration, mean (SD), cm H2O | NAe | 7.8 (2.5) | 9.2 (2.6) | 10.2 (3.0) | .003f |
| Did not tolerate CPAP or bilevel treatment, n (%) | NAe | 13 (9.6) | 17 (16.2) | 17 (8.0) | .08 |
| REM rebound, n (%) (n = 435)g | NAe | 12 (8.8) | 21 (20.0) | 64 (33.0) | <.001f |
| Posttreatment AHI, mean (SD), events/h | NAe | 3.0 (5.1) | 3.6 (4.7) | 5.6 (9.5) | .04f |
Abbreviations: AHI, apnea-hypopnea index; SD, standard deviation; NA, not applicable; REM, rapid eye movement; SpO2, pulse oximetry oxygen saturation; CPAP, continuous positive airway pressure.
None, AHI <5; mild, AHI 5-14; moderate, AHI 15-30; severe, AHI >30.
ANOVA with Bonferonni correction was used to compare continuous values, and χ2 test with Marasculio procedure was used to compare proportional variables.
Mild vs moderate and severe.
Mild vs severe, moderate vs severe.
Treatment data are only for patients with OSA.
Mild vs severe.
REM rebound was defined as 20% of sleep time in REM; no. is the number of patients with data concerning REM rebound. Data were not available for all patients; n = number of patients with this information.