Tachypnea Seen During Positive Airway Pressure Titration Studies: A Case Series of Four Patients.

We report a case series of four patients where tachypnea was observed during positive airway titration studies, double the baseline breathing rate (tachypnea range 46-68 breaths/min). It happened mainly during non-rapid eye movement to rapid eye movement sleep transitions without significant changes in oxygen saturation or signs of autonomic hyperactivity such as an increased heart rate. The increased respiratory rate may be a normal physiological extreme outlier seen during phasic rapid eye movement sleep triggered by high pressure ventilation and it may also indicate underlying ventilatory instability, making patients predisposed to central sleep apnea.

Shift work sleep disorder is associated with an attenuated brain response of sensory memory and an increased brain response to novelty: an ERP study.

Study Objective: To study the neurophysiological changes in attention and memory functions in shift work sleep disorder (SWSD), using event-related brain potentials (ERPs).

Participants: 9 healthy night workers (NW) (mean age = 40 y; SD +/- 8.9 y); 8 night workers meeting diagnostic criteria for SWSD (mean age = 37 y +/- 9.