**8. Follow up**

80 Sleep Disorders

Periods of high esophageal pressure swings with associated

Lack of increase in airflow despite increasing respiratory effort.

Flattening of the normal bell-shaped curve of normal breath with a drop in the amplitude of the curve by 2–29% compared to the

Abnormal inspiratory air flow shape during partialupper airway

Abnormal contour in the nasal/presure transducer signal waveform

Presence of an inspiratory plateau or reduction in inspiratory flow

Pressure waveflattening<30% is associated with a physiological

Two or more breaths (10 sec) without sinusoidal appearance and without hypopnea criteria, end abruptly, taking on the sinuidal flow

simultaneously with the development of an inspiratory plateau (loss

independent of any increase in inspiratory efforts.

event (arousal, CAP complex, variabilidad RR, etc)

At least four successive breaths reduction in amplitude

of a sinusoidal inspiratory waveform)

Table 2. Inspiratory flow limitation: Definitions.

 Pneumotachygraphy Nasal cannula pressure

 Pulse Transit Time Neural network

 Forced oscillation technique Suprasternal pressure transducer Presence ofalteringcyclicpattern(EEG) Forehead venous pressure signal

Resistive Inductance Plethismography

EMG signals

Snore signals

obstruction

aspect

Table 1. Techniques to assess respiratory effort.

inspiratory flow limitation

normal breaths immediately preceding

Te long time evolution of UARS patients, within the overall spectrum of sleep disordered breathing disorders, is an area of interest. RERA may be intermediate event between snoring and hypopnea. RERA predominate in younger and thinner people than apnea and hypopnea episodes. Hypopneas becoming true apneas with increasing age and weight. Few existing studies on the matter. In a five years follow-up study of untreated UARS patients, Guilleminault report that only 10% developed a OSAS and always in the context of weight gain (Guilleminault 2006b). Jonzak, in a retrospective study,also report that obesity as an aggravating factor of severity in follow up six years (Jonzak 2009).
