title: [Anesthesia and obstructive sleep apnea.].
abstract: METHODS
  Maintaining the patency of the upper airways is fundamental to anesthesia and patients with obstructive sleep apnea (OSA). During anesthesia and while a person is sleeping, the tonus of the pharyngeal muscles is reduced. It is important to identify patients with OSA to prevent risks in the perioperative period. The objective of this report was to present a revision of the relationship between OSA and anesthesia regarding planning of anesthesia, stressing the importance of identifying the obstructive sleep apnea hypopnea syndrome (OSAHS).
  
  
  BACKGROUND
  OSAHS is caused mainly by total or partial pharyngeal collapse, which may cause a reduction in hemoglobin saturation and cardiovascular complications. The main predisposing factors include male gender, obesity, and cranial and orofacial characteristics. It is diagnosis by its clinical and polysomnographic characteristics, which also determine its severity. Patients with severe OSAHS may present problems during tracheal intubation and sedation, and may be more susceptible to hypoxia and hypercapnia, even in the presence of normal lungs. The authors discuss the importance of diagnosing and treating OSAHS before surgeries in order to reduce the anesthetic risk.
  
  
  CONCLUSIONS
  Prior diagnosis and treatment of OSAHS with continuous positive pressure in the upper airways may reduce perioperative complications and influence the anesthetic and postanesthetic management.
authors.affiliation: UNIFESP.
authors.forename: Charles
authors.initials: C
authors.lastname: Machado
authors.forename: Américo Massafuni
authors.initials: AM
authors.lastname: Yamashita
authors.forename: Sonia Maria Guimarães Pereira
authors.initials: SM
authors.lastname: Togeiro
authors.forename: Dalva
authors.initials: D
authors.lastname: Poyares
authors.forename: Sérgio
authors.initials: S
authors.lastname: Tufik