title: Time course of postoperative hypoxaemia.
abstract: OBJECTIVE
  To study the time course of nocturnal episodic and constant hypoxaemia during the first five nights after a major abdominal operation in patients not given supplementary oxygen.
  
  
  METHODS
  Open study.
  
  
  METHODS
  17 patients undergoing major elective operations and with no recognised risk factors.
  
  
  METHODS
  Arterial oxygen saturation measured by pulse oximetry.
  
  
  RESULTS
  The level of constant hypoxaemia was lowest during night 2 (p < 0.01) as was the time spent below 90% saturation (p < 0.01) compared with the other four postoperative nights. Episodic hypoxaemia was most common during night 3 (p < 0.05). It was not possible to predict the postoperative occurrence of hypoxaemia from the preoperative spirometric measurements. Preoperative awake arterial oxygen saturation correlated significantly with mean constant hypoxaemia on postoperative nights 1, 3, 4, and 5, but not with episodes of sudden desaturation after operation. Preoperative overnight oximetry correlated significantly with constant hypoxaemia on all five postoperative nights and with episodic hypoxaemia on nights 3 and 4.
  
  
  CONCLUSIONS
  In the light of these results which show the natural history of postoperative hypoxaemia without supplementary oxygen, and because postoperative hypoxaemia may be associated with dysfunction of organ systems after major operations, controlled studies of supplementary oxygen in the late postoperative period are warranted.
authors.affiliation: Department of Surgical Gastroenterology, Hvidovre University Hospital, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Rosenberg
authors.forename: T
authors.initials: T
authors.lastname: Ullstad
authors.forename: J
authors.initials: J
authors.lastname: Rasmussen
authors.forename: F P
authors.initials: FP
authors.lastname: Hjørne
authors.forename: N J
authors.initials: NJ
authors.lastname: Poulsen
authors.forename: M D
authors.initials: MD
authors.lastname: Goldman
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000368:Aged; D000369:Aged, 80 and over; D002245:Carbon Dioxide / Q000097:blood; D003624:Darkness; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D000860:Hypoxia / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D010100:Oxygen / Q000097:blood; D010366:Peak Expiratory Flow Rate / Q000502:physiology; D011183:Postoperative Complications; D011184:Postoperative Period; D011300:Preoperative Care; D013997:Time Factors; D014797:Vital Capacity / Q000502:physiology
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen