Results
Patients with OSA-I and OSA-II represented 6% (n=84, 71% males) and 10% (n=144, 72% males) of the national cohort (n=1449) respectively. OSA-II patients were older at CPAP/NIV initiation (mean age 11.0 ± 4.0 vs 6.8 ± 4.5 years, p<0.001) (Table 1). OSA-II patients were treated with CPAP/NIV for a longer time than OSA-I patients (mean duration 2.3 ± 2.6 vs 1.3 ±1.5 years, p=0.008). A minority of patients were treated with NIV as compared to CPAP, with no difference between patients with OSA-I and OSA-II (6% of OSA-I vs 13% of OSA-II patients, p=0.142). For both groups, the overall duration of ventilatory support was greater for patients treated with NIV as compared to patients treated with CPAP (4.0 ± 3.0 vs 1.7 ± 2.1 years, p<0.001) (Table 1). The objective adherence was similar for both groups (mean adherence 6.8 ± 2.6 hours/night and 5.9 ± 3.0 hours/night for OSA-I and OSA-II patients, respectively, p=0.054). However, in both groups, the objective adherence was greater with NIV as compared to CPAP (Table 1). The 5 OSA-I patients treated with NIV were younger at NIV initiation as compared to those treated with CPAP, they were treated with NIV for a longer time, and were also more adherent to treatment as compared to patients treated with CPAP. The 19 OSA-II patients treated with NIV were also treated for a longer time than those treated with CPAP.
Nearly all the patients had a polysomnography (PSG) or a respiratory polygraphy (PG) prior to CPAP/NIV initiation (Table 2), with approximately half of the patients having a simultaneous recording of transcutaneous carbon dioxide pressure (PtcCO2), with no difference between patients with OSA-I and OSA-II. Only a minority of patients (4%) had only a nocturnal recording of pulse oximetry (SpO2) and PtcCO2 without a PSG or a PG.
CPAP/NIV was initiated on a high AHI in 68% of the patients, and on a high AHI with an abnormal SpO2 and PtcCO2 value in 24% of the patients, with no difference between patients with OSA-I and OSA-II (Table 2). CPAP/NIV was initiated on an abnormal SpO2 and PtcCO2 alone in only 4% of the patients. On note, the 5 patients with OSA-I who were treated with NIV had all a PtcCO2 recording, whereas the 44 patients who did not have a PtcCO2 recording were all treated with CPAP. Of the 19 patients with OSA-II who were treated with NIV, only 2 had no PtcCO2 recording.
Patients with OSA-II were treated more often with a standard device, and less often with an intermediate and life support device, as compared to patients with OSA-I (Table 3). Patients treated with a standard device were older than those treated with an intermediate or life support device, with a greater age difference for patients with OSA-I as compared to patients with OSA-II (Table 4). The mean age of the patients treated with an auto-titrated CPAP was 11.4 ± 3.6 and 14.4 ± 3.3 years for patients with OSA-I and OSA-II, respectively. Both groups used most often a nasal interface with around 20% of patients in both groups using a nasobuccal interface. Patients with OSA-II were treated with a higher CPAP level in case of CPAP, while the inspiratory and expiratory pressures were not different between sub-groups in case of NIV even though they tended to be higher in patients with OSA-II (Table 5).