Laryngeal mask airway or endotracheal tube for ocular surgery; effects on intraocular pressure

ABSTRACT

This study was done to evaluate the intraocular pressure [IOP] and haemodynamic changes [heart rate [HR], mean arterial pressure [MAP]] subsequent to insertion and removal of laryngeal mask airway [LMA] and tracheal tube [TT]. The study was coducted on 40 patients divided into two equal groups, they received standarized general anaesthesia with either LMA [group I] or TT [group II]. IOP, HR and MAP were measured at preinduction of anaesthesia and pre removal of LMA or TT. Also one and two minutes after insertion and removal of LMA or TT. A statistically significant rise in heart rate, mean arterial pressure and intraocular pressure was seen in both the groups subsequent to insertion of laryngeal mask airway or tracheal tube, but after 2 minutes HR and MAP decreased significantly throughout the study in LMA group. However, IOP decreased after two minutes and become significantly lower at preremoval and after removal of LMA. Mean maximum increase was statistically more after endotracheal intubation than after laryngeal mask airway insertion. The duration of statistically significant pressure responses was also longer after tracheal intubation. Cough and breath holding ocured more significantly in TT group compared with LMA group. [LMA] is an acceptable alternative technique in intraocular surgery, offering advantages in cases of perforated globe, glucomatous patients and hemodynamically unstable cardiovascular or cardiac patients compared to tracheal intubation