title: Pulse oximetry using a disposable finger sensor placed on the forehead in hypoxic patients.
abstract: BACKGROUND
  Disposable pulse oximetry sensors designed for the finger are sometimes placed on the forehead. Although finger sensors have not been designed to accurately measure arterial oxygen saturation when placed on other body parts, they are used on the forehead when an oximetry waveform cannot be obtained from the finger.
  
  
  OBJECTIVE
  The purpose of this prospective observational study was to measure the agreement between disposable transmittal sensors placed on the finger and the same sensors placed on the forehead.
  
  
  METHODS
  We used a convenience sample of hypoxic emergency department patients. Patients were attached to three oximeters: 1) a non-disposable finger sensor (reference); 2) a disposable finger sensor placed on the finger; and 3) a disposable finger sensor placed on the forehead. Data were analyzed using the Bland-Altman method. A difference of 5% was considered clinically significant.
  
  
  RESULTS
  Twenty-five patients were approached, and 20 were enrolled. Eleven of the patients had an absolute difference between the disposable finger sensor placed on the finger compared to the forehead > or = 5%.
  
  
  CONCLUSIONS
  Pulse oximetry measurements taken on the forehead using a disposable finger sensor were inaccurate in over half of the subjects. Therefore, disposable finger oximetry sensors should not be placed on the forehead.
authors.affiliation: Department of Emergency Medicine, Baystate Medical Center, Springfield, Massachusetts 01199, USA.
authors.forename: Howard A
authors.initials: HA
authors.lastname: Smithline
authors.forename: Ned
authors.initials: N
authors.lastname: Rudnitzky
authors.forename: Sandy
authors.initials: S
authors.lastname: Macomber
authors.forename: Fidela S J
authors.initials: FS
authors.lastname: Blank
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004209:Disposable Equipment; D004636:Emergency Service, Hospital; D005260:Female; D005546:Forehead; D006801:Humans; D000860:Hypoxia / Q000175:diagnosis*; D008297:Male; D010092:Oximetry / Q000295:instrumentation / Q000379:methods*; D011446:Prospective Studies; D015203:Reproducibility of Results