title: [Nocturnal hypoxemia after abdominal surgery: associated factors and usefulness of oxygen therapy].
abstract: BACKGROUND
  Postoperative nocturnal hypoxemia (PONH) is a main factor in the genesis of respiratory, cardiac and neurologic complications after surgery.
  
  
  OBJECTIVE
  To describe the phenomenon of PONH after elective laparoscopy and laparotomy, and to evaluate the usefulness of oxygen therapy in its prevention.
  
  
  METHODS
  Fifteen elective patients (6 M, 9 F, 51 +/- 8 years old) scheduled for laparotomy (n = 8) or laparoscopy (n = 7) were studied. Ventilatory parameters and pulse oximetry were measured pre and postoperatively. Patients were randomly assigned to receive oxygen by nasal cannula either during the first or the second postoperative night.
  
  
  RESULTS
  PONH (SatO2 < 85) developed in seven patients (47%), of which four had undergone laparoscopic surgery. PONH was more frequent in mildly obese patients and those presenting preoperative hypoxemia (p = 0.03). Peak Flow was lower in patients presenting PONH (p = 0.04). In five patients, PONH was associated with significant tachycardia. Oxygen administration was associated with a higher SatO2 and prevented PONH in 6/7 patients.
  
  
  CONCLUSIONS
  PONH is a common event in patients older than 40 years scheduled for open or laparoscopic abdominal surgery, and develops more frequently in those with preoperative nocturnal hypoxemia and greater ventilatory impairment. PONH can be prevented, most of the time, with oxygen administration.
authors.affiliation: Departamento de Anestesiología, Facultad de Medicina, Hospital Clínico Pontificia Universidad Católica de Chile.
authors.forename: G
authors.initials: G
authors.lastname: Bugedo
authors.forename: J
authors.initials: J
authors.lastname: González
authors.forename: J C
authors.initials: JC
authors.lastname: de la Cuadra
authors.forename: C
authors.initials: C
authors.lastname: Asenjo
authors.forename: A
authors.initials: A
authors.lastname: Gajardo
authors.forename: I
authors.initials: I
authors.lastname: Huenchullán
authors.forename: R
authors.initials: R
authors.lastname: Añazco
authors.forename: S
authors.initials: S
authors.lastname: Torregrosa
authors.forename: J
authors.initials: J
authors.lastname: Dagnino
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000328:Adult; D001662:Biliary Tract Surgical Procedures / Q000009:adverse effects; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000209:etiology* / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D010102:Oxygen Inhalation Therapy; D011183:Postoperative Complications / Q000209:etiology* / Q000517:prevention & control*; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors
vernacular_title: Hipoxemia nocturna después de cirugía abdominal: factores asociados y rol de la oxigenoterapia.