Table 2

Nocturnal ventilation, oxygen saturation and heart rate (n=34)

Zurich 490 mDavos Schatzalp 1860 mDavos Jakobshorn 2590 m
1st day1st day2nd day1st day2nd day
Spo2, entire night (%)94 (93–95)90* (88–91)90* (88–91)86* (84–89)87* (84–89)
Spo2 during REM (%)94§ (93–95)89* § (88–91)90* § (88–91)85* § (83–89)86* § (84–89)
Spo2 during REM (%)94 (90–95)87* (84–91)88* (85–91)83* (78–88)84* (81–87)
Ptcco2, entire night (mm Hg)49 (44–50)39* (36–41)39* (37–41)37* (33–42)37* (33–39)
Ptcco2 during NREM (mm Hg)49 (46–50)40* § (37–44)39* § (36–42)38* (35–42)39* (34–40)
Ptcco2 during REM (mm Hg)51 (48–51)41* (37–44)43* (37–44)40* (36–42)39* (34–42)
Oxygen desaturation index (1/h)37.3 (14.6–52.7)67.6* (37.6–88.2)57.4* (32.1–86.1)80.6* (52.4–103.4)71.5* (43.4–98.6)
Total AHI (events/h)51.2 (31.7–74.4)85.1* (53.9–94.3)68.5* (51.3–95.7)90.0* (64.2–103.2)88.6* (62.4–108.4)
Obstructive AHI (events/h)39.4 (24.1–65.8)32.1 (21.3–71.8)33.0 (15.3–60.0)32.0 (3.3–54.6)25.2 (6.5–58.8)
Central AHI (events/h)2.4 (0.4–8.8)25.4* (17.0–55.9)32.7* (14.2–43.7)51.3* (32.8–75.5)49.4* (22.6–57.8)
Obstructive apnoea duration (s)21.0 (16.4–24.9)22.8 (17.7–26.6)22.6 (18.5–27.8)18.8 (13.3–22.8)18.5 (15.4–24.1)
Central apnoea duration (s)11.6 (8.9–18.2)15.5* (13.2–19.3)15.1 (12.7–19.4)14.2 (12.5–16.7)15.3 (12.2–18.3)
Heart rate (1/min)57.2 (54.7–61.8)61.1* (57.2–66.4)61.5* (57.4–69.2)66.5* (58.4–72.0)62.6* (57.7–68.8)
Premature beats, entire night (1/h)3.2 (0.6–11.2)6.7 (1.2–33.6)9.8* (3.0–31.0)7.2 (2.2–29.6)6.1 (1.2–30.4)
  • Values are median (IQR).

  • * p<0.01 vs 490 m.

  • p<0.005 vs 1860 m, day 1.

  • p<0.005 vs 1860 m, day 2.

  • § p<0.005 vs REM.

  • AHI, apnoea/hypopnoea index; Ptcco2, transcutaneous carbon dioxide tension; Spo2, oxygen saturation.