Abstrakt: |
It is generally accepted that the ventilatory sensitivity to CO2 is decreased during non-rapid eye-movement (NREM) sleep, although the degree of this reduction has varied considerably among studies[1],[2]. In all these studies, the ventilatory response to hypercapnia (HCVR) was measured under steady-state conditions in quiet wakefulness and, subsequently, in one or more stable stages of NREM sleep. In sleep-disordered breathing, however, sleep is constantly punctuated by transient arousals, which are generally associated with brief periods of hyperpnea[3],[4]. Thus, the standard procedures of estimating steady-state chemoresponsiveness may not produce measures that appropriately capture the changes in chemoreflex control that accompany such abrupt state changes. This may partially account for the lack of any consistent relationship between the steady-state HCVR and breathing pattern stability or instability[5]. [ABSTRACT FROM AUTHOR] |