title: Acute vision impairment: does it affect an anesthesiologist's ability to intubate the trachea?
abstract: The result of impaired vision on an anesthesiologist's ability to intubate the trachea is unknown. We studied 12 attending staff anesthesiologists as they intubated 2 anesthesia mannequins (A and B) under 6 conditions. The conditions were: 1) usual vision, 2) central-vision loss with 20/500 bilaterally and a 24 degrees central scotoma, 3) peripheral-field loss with 20/20 bilaterally and a 7 degrees visual field, 4) peripheral-field loss with 20/20 bilaterally and a 3.5 degrees visual field, 5) central-vision loss with 20/200 bilaterally and a 12 degrees central scotoma, and 6) right eye ocular media opacity and 20/70 left eye usual acuity. The time to intubation was recorded by stopwatch from gripping the laryngoscope until the anesthesiologist signaled that the endotracheal tube was properly placed in the trachea. The mean +/- SD times to intubation for Mannequins A and B were 16.0 +/- 3.3, 31.9 +/- 10.4, 26.4 +/- 9.0, 26.4 +/- 7.7, 22.4 +/- 5.1, 25.5 +/- 16.9 and 16.6 +/- 6.6, 26.9 +/- 10.0, 21.4 +/- 9.2, 21.4 +/- 5.8, 21.5 +/- 7.7, 17.7 +/- 5.1 s for the 6 conditions, respectively. Multiple analysis of variance revealed a highly significant difference for the time to successful intubation between the anesthesiologists' usual vision and the vision-impaired conditions. There was a significant improvement in time to successful intubation from the first to subsequent intubation attempts. There were also more esophageal intubations in the vision-impaired conditions. This implies that anesthesiologists who develop acute severe vision impairment might have more difficulty intubating the trachea, which could initiate more critical incidents. The results of this study cannot be applied to anesthesiologists with chronic vision impairment.
  
  
  CONCLUSIONS
  We found that acute severe vision impairment adversely affects the anesthesiologist's ability to intubate the trachea. This implies that anesthesiologists with acute onset of severe visual handicaps might have more difficulty intubating the trachea, which could initiate more critical incidents.
authors.affiliation: Department of Anesthesia, Sir Mortimer B. Davis Jewish General Hospital, 3755 Côte Ste. Catherine Road, Montreal, Quebec H3T 1E2, Canada. mtessler@ana.jgh.mcgill.ca
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Tessler
authors.forename: Stamatina T
authors.initials: ST
authors.lastname: Trihas
authors.forename: Olga
authors.initials: O
authors.lastname: Overbury
authors.forename: Thierry
authors.initials: T
authors.lastname: Ducruet
mesh_terms: D000208:Acute Disease; D000328:Adult; D000704:Analysis of Variance; D000769:Anesthesia, Inhalation; D000776:Anesthesiology; D002983:Clinical Competence; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal; D020704:Laryngoscopes; D007828:Laryngoscopy; D008297:Male; D008875:Middle Aged; D009719:Nurse Anesthetists; D014786:Vision Disorders; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology