Intrathoracic pressure variations in obese habitual snorers.

Six obese patients with complaints of snoring and daytime fatigue were monitored with polysomnography (PSG) and continuous recording of esophageal pressure (Pes) during 1 night. Nonapneic episodes in different sleep stages, with and without snoring, were selected and analysed. Peak to peak pressure was found to be significantly increased during snoring in sleep stages 2 and 3/4 with blood gas variations within the limits of normal unobstructed breathing, indicating increased respiratory effort. The present investigation supports the assumption that daytime tiredness in nonapneic patients can be linked to increased respiratory effort during sleep and that continuous esophageal pressure measuring may contribute to assessment of this condition.