[Topical laryngo-tracheal anesthesia and intraocular pressure in anesthesia for ophthalmic surgery].
OBJECTIVE
The reflex response to orotracheal intubation provokes an increase of arterial pressure accompanied by an increase of chorioides volume and a consequent ocular hypertone. There are several methods to reduce the reflex response due to intubation. One of the most effective is topical anaesthesia of larynx and trachea. Experiments were directed to evaluate the efficacy of topical anaesthesia to reduce the intraocular hypertone due to orotracheal intubation.


METHODS
A prospective randomized mask study was conduct on patients undergoing ophthalmologic (anterior segment) surgery at the Eye Clinic of Florence University.


METHODS
Intraocular pressure was measured by a Goldman tonometer at four times: T0 = basal, T1 = 2' minutes after induction of general anaesthesia, T2 = 2' minutes after laryngoscopy, T3 = 2' minutes after orotracheal intubation. At the same moments, systolic blood pressure, heart rate, rate pressure pro duct were measured. Patients were randomly divided in two groups: Group L (n = 10) in which was evaluated the efficacy of laryngotracheal topical spray of lidocaine 4% (2 ml) and Group F (n = 10) in which saline was used instead of anesthetic. The filling of the LTA kit (Abbott) was made by a person not involved in the experiments.


METHODS
Student's t test for unpaired data.


RESULTS
Topical anaesthesia reduces the increase of intraocular pressure, hypertension and rate pressure product due to intubation. The intraocular pressure reduces to 13% less than basal value in Group L and increase to 50% more than basal value in Group F.


CONCLUSIONS
The topical anaesthesia of larynx and trachea is effective to reduce the intraocular hypertension due to the reflex response evoked by orotracheal intubation.
Giorgi
L
L
Instituto di Anestesia e Rianimazione, Università degli Studi di Firenze.
Di Filippo
A
A
Franchini
A
A
Rizzo
L
L
Benvenuti
S
S
Conti
M
M
Novelli
G P
GP
D000328:Adult; D000772:Anesthesia, Local; D000869:Anterior Eye Segment / Q000601:surgery; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D007830:Larynx; D008297:Male; D009798:Ocular Hypertension / Q000209:etiology / Q000517:prevention & control*; D011446:Prospective Studies; D014132:Trachea
Anestesia topica laringo-tracheale e pressione intraoculare in anestesia per la oftalmochirurgia.