Sleep disruption in patients with sleep apnea and end-stage renal disease.

Objectives: Sleep apnea (SA) is common in patients with end-stage renal disease (ESRD) and such patients are likely to suffer additional sleep disruption associated with restless legs syndrome (RLS) and periodic leg movements (PLM). Our objective was to evaluate sleep quality in ESRD patients who are newly diagnosed with SAand determine the additional contribution of PLM to sleep disruption.

Methods: Two groups of patients with SA (apnea-hypopnea index (AHI) > 15) were compared, one with ESRD (n = 12) and the other with normal renal function (n = 18), using a sleep history questionnaire, sleep diary, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, polysomnography (1 night) and actigraphy (6 nights).

Mechanisms of breathing instability in patients with obstructive sleep apnea.

The response to chemical stimuli (chemical responsiveness) and the increases in respiratory drive required for arousal (arousal threshold) and for opening the airway without arousal (effective recruitment threshold) are important determinants of ventilatory instability and, hence, severity of obstructive apnea. We measured these variables in 21 obstructive apnea patients (apnea-hypopnea index 91 +/- 24 h(-1)) while on continuous-positive-airway pressure. During sleep, pressure was intermittently reduced (dial down) to induce severe hypopneas.