title: Lightwand intubation does not reduce the increase in intraocular pressure associated with tracheal intubation.
abstract: OBJECTIVE
  To evaluate the changes in hemodynamic variables and intraocular pressure (IOP) after tracheal intubation using either lightwand or direct-vision laryngoscopy techniques.
  
  
  METHODS
  Prospective, randomized study.
  
  
  METHODS
  Inpatient anesthesia at a University Anesthesia Department.
  
  
  METHODS
  50 normotensive, ASA physical status I and II patients, without ocular or cardiovascular diseases, and with a Mallampati score no greater than 2.
  
  
  METHODS
  After intravenous (i.v.) midazolam premedication (0.05 mg.kg-1), general anesthesia was induced with fentanyl (1 microgram.g-1) and thiopental sodium (5 mg.g-1) followed by vecuronium bromide (0.1 mg.g-1), then patients were randomly allocated to receive either the lightwand (Trachlight, n = 25) or direct-vision laryngoscopy (Laryngoscopy, n = 25) intubating techniques. General anesthesia was maintained with 1% isoflurane and 60% nitrous oxide in oxygen mixture for 5 minutes.
  
  
  RESULTS
  Baseline hemodynamic variables were recorded 10 minutes after i.v. premedication, and then every minute after tracheal intubation. Intraocular pressure measurements were performed by means of a computerized indentation tonometer after general anesthesia induction and then 1 and 5 minutes after tracheal intubation. In both groups, mean arterial blood pressure and heart rate increased from baseline, without differences between the two groups. One minute after intubation, IOP increased in both groups: the mean percentage increase was 32% in the Laryngoscopy group and 16% in the Trachlight group. However, this difference was not statistically significant. Five minutes after intubation, IOP decreased to baseline values in both groups.
  
  
  CONCLUSIONS
  We conclude that in healthy patients without ocular disease, using a lightwand intubating technique does not reduce the hemodynamic responses and increase in IOP associated with tracheal intubation as compared with conventional direct-vision laryngoscopy.
authors.affiliation: Department of Anesthesiology, University of Milan, Italy. casati.andrea@hsr.it
authors.forename: A
authors.initials: A
authors.lastname: Casati
authors.forename: G
authors.initials: G
authors.lastname: Aldegheri
authors.forename: G
authors.initials: G
authors.lastname: Fanelli
authors.forename: L
authors.initials: L
authors.lastname: Gioia
authors.forename: E
authors.initials: E
authors.lastname: Colnaghi
authors.forename: L
authors.initials: L
authors.lastname: Magistris
authors.forename: G
authors.initials: G
authors.lastname: Torri
mesh_terms: D000768:Anesthesia, General; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007429:Intraocular Pressure; D007442:Intubation, Intratracheal / Q000379:methods*; D007828:Laryngoscopy / Q000379:methods*; D014172:Transillumination / Q000295:instrumentation*