title: Lidocaine: the optimal timing of intravenous administration in attenuation of increase of intraocular pressure during tracheal intubation.
abstract: BACKGROUND
  This study was designed to examine the optimal timing of intravenous lidocaine in attenuation of increase of intraocular pressure in response to laryngoscopy and tracheal intubation during induction of anesthesia.
  
  
  METHODS
  One hundred and thirty five adult patients of ASA class I, aged between 20-35 years, undergoing surgical procedures irrelevant to ophthalmology were enrolled for study. Patients were randomly assigned to one of five groups. In group II, III, IV and V the patients received intravenous injection of lidocaine (2 mg/kg), 1, 3, 5, 10 min before tracheal intubation, respectively. Group I in which patients did not receive lidocaine served as the control group.
  
  
  RESULTS
  In patients of groups I, IV and V, the intraocular pressure increased significantly after intubation, whereas in those of groups II and III, the intraocular pressure did not. All patients in the five groups showed concomitantly a surge of blood pressure, but the magnitude of increase was smallest in group III in comparison with the other groups. The values of systolic and diastolic pressures 1 min after intubation were significantly less in groups III and IV than in the control group.
  
  
  CONCLUSIONS
  In healthy patients aged between 20 and 35 the most optimal time of administration of intravenous lidocaine to attenuate the increase of intraocular pressure seemed to be the space between 1 to 3 min before laryngoscopy and tracheal intubation.
authors.affiliation: Department of Anesthesiology, Chang Gung Memorial Hospital, 123, TaPei Road, Niao Shung Hsiang, Kaohsiung, Hsien 833, Taiwan, R.O.C.
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Wang
authors.forename: Kwan-Chi
authors.initials: KC
authors.lastname: Chung
authors.forename: Hsiao-Feng
authors.initials: HF
authors.lastname: Lu
authors.forename: Yu-Wei
authors.initials: YW
authors.lastname: Huang
authors.forename: Kun-Chen
authors.initials: KC
authors.lastname: Lin
authors.forename: Lin-Cheng
authors.initials: LC
authors.lastname: Yang
authors.forename: Chung-Ren
authors.initials: CR
authors.lastname: Lin
mesh_terms: D000328:Adult; D000779:Anesthetics, Local / Q000008:administration & dosage*; D006801:Humans; D007275:Injections, Intravenous; D007429:Intraocular Pressure / Q000187:drug effects*; D007442:Intubation, Intratracheal; D007828:Laryngoscopy; D008012:Lidocaine / Q000008:administration & dosage*
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine