Category: Obstructive Sleep Apnea

sleep apneaThis study shows that a large majority of patients with sleep apnea and associated hypoxemia have cognitive impairment. In addition, this study demonstrates that patients with sleep apnea and associated hypoxemia have poorer cognitive functioning than such patients without hypoxemia. The hypoxemic patients with sleep apnea had a significantly greater number of performance scores in the impaired range than patients without hypoxemia. Finally, the degree of hypoxemia during the awake and sleeping states was significantly correlated with the degree of cognitive impairment in patients with sleep apnea.

Hypoxemia during both wakefulness and sleep may cause a disruption in the biochemical and hemodynamic state of the central nervous system. Hypoxemia markedly affects central neurotransmitter function and brain adenosine levels in animals. Hypoxemia and hypercapnia also significantly increase cerebral blood flow in humans. Given such disruptions in the central nervous system, it is not surprising that previous investigators have found an association of hypoxemia with cognitive dysfunction in humans at high altitudes and in patients with severe COPD.

…Read the rest of this article

disordered breathingTable 2 gives the total time in apnea as a percentage of total sleep time, the number of episodes of apnea per hour of sleep, and the decrements in Sa02 during apnea for each patient before, during, and after treatment. Table 3 gives the same information for episodes of disordered breathing. All patients continued to have apneic episodes during and following treatment. There were no significant differences among the group means before, during, and after treatment for either apneic or disordered breathing episodes. Examination of Tables 2 and 3 reveals that there was no consistent pattern of responses to medroxyprogesterone over all variables among the different patients.

The total times spent in apnea and disordered breathing episodes, expressed as percentages of total sleep time, are shown in Figure 1. There were no significant differences in mean percentage of time in apnea before (20.8±3.5 percent [±SE]), during (18.6 ±4.3 percent), and after (16.9 ±4.5 percent) medroxyprogesterone. Likewise, there were no differences in the mean percentages of disordered breathing time before (17.0±6.1 percent), during (17.4±5.3 percent), or after (21.6 ±6.8 percent) the drug. The mean durations of apneic and disordered breathing episodes for all patients are shown in Figure 2. There were no significant changes associated with administration of medroxyprogesterone. The distribution for the number of apneic episodes by duration is given in Figure 3. Again, there was no difference in mean values resulting from treatment.

…Read the rest of this article