Lidocaine: the optimal timing of intravenous administration in attenuation of increase of intraocular pressure during tracheal intubation.
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.
Wang
Yi-Ming
YM
Department of Anesthesiology, Chang Gung Memorial Hospital, 123, TaPei Road, Niao Shung Hsiang, Kaohsiung, Hsien 833, Taiwan, R.O.C.
Chung
Kwan-Chi
KC
Lu
Hsiao-Feng
HF
Huang
Yu-Wei
YW
Lin
Kun-Chen
KC
Yang
Lin-Cheng
LC
Lin
Chung-Ren
CR
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*
D000779:Anesthetics, Local; D008012:Lidocaine