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. 2018 Aug 22;41(11):zsy160. doi: 10.1093/sleep/zsy160

Figure 5.

Figure 5.

Respiratory timing and ventilatory parameters for inspiratory (Insp) arousals (closed symbols) and expiratory (Exp) arousals (open symbols) for the first two breaths following CPAP reduction (Breaths 1 and 2), and the three breaths prior to arousal during the CPAP reduction (Breaths −3 to −1; Breath −1 is immediately prior to arousal), expressed as a change (∆) from baseline therapeutic CPAP (Breath 0; average of 60 s immediately prior to CPAP reduction). (A) Inspiratory time (Ti), (B) expiratory time (Te), (C) duty cycle (Ti/Ttot; Ttot = Ti + Te), (D) respiratory rate (RR), (E) peak inspiratory flow (PIF), (F) minute ventilation (Vi), and (G) nadir epiglottic pressure (NadirPepi). Data are estimated marginal mean (confidence interval). *p < 0.05 for Insp vs. Exp arousals. Between breath comparisons are shown for Insp and Exp arousals: # p < 0.05 vs. Breath 0, + p < 0.05 vs. Breath 1, ^ p < 0.05 vs. Breath 2, ϕ p < 0.05 vs. Breath −3, – p < 0.05 vs. Breath −2. For the breath immediately prior to arousal following CPAP reduction (Breath −1), Exp arousals have lower increases in Ti and Ti/Ttot and lower reductions in Te compared with Insp arousals. RR increases are immediate following CPAP reduction for both Insp and Exp arousals and are mostly maintained at that level for the duration of the CPAP drop. PIF and Vi return to baseline levels on Breath −1 for Exp arousals, though remain reduced for Insp arousals. There were no differences between Insp and Exp arousals on Breaths 1 and 2 for any of the parameters. Negative NadirPepi progressively increases from Breaths 1 to -1. There are no differences in NadirPepi changes between Insp and Exp arousals for all analyzed breaths (G).