Many studies have been performed in order to evaluate intraocular pressure changes during induction and maintenance of anesthesia in ocular surgery. Use of the laryngeal mask airway permits the maintenance of a clear airway without laryngoscopy.
To
evaluate the effect of laryngeal mask airway placement with/without laryngoscopy on intraocular pressure, sixty patients were randomly allocated to one of three groups: a tracheal intubation group with laryngoscopy (TI, n=20); a laryngeal mask
airway
placement group with laryngoscopy (LMA-L, n=20); a laryngeal mask airway placement group with blind technique (LMA, n=2). The authors compared the intraocular pressure and hemodynamic responses to the laryngeal mask airway insertion with (LMA-L
group)
and without (LMA group) laryngoscope to those of tracheal intubation (TI group) in 60 patients during a standardized anesthetic pratice. Baseline measurements of intraocular pressure, heart rate, and arterial blood pressures were recorded and
repeated
at one minute after insertion of the airway device in each group. Insertion of the laryngeal mask airway required significantly more time (LMA-L group, 15.5 sec; LMA group, 14.3 sec) in comparison with that for the tracheal intubation (9.1 sec).
The
laryngeal mask airway placemen did not increase intraocular pressure, or arterial blood pressures except for heart rate above baseline values. However, tracheal intubation was associated with significant increases of intraocular pressure, heart
rate,
and arterial blood pressure at one minute compared to the baseline values. The mean intraocular pressures at one minute after airway instrumentation in TI group were significantly different form those of LMA or LMA-L group. The authors suggest
that
a
laryngeal mask airway may be a good alternative to tracheal intubation in intraocular surgery if a laryngeal mask airway is not contraindicated.
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