The Laryngeal Mask Airway for Intraocular Surgery: Effects on Intraocular Pressure and Stress Responses

Abstract

Tracheal intubation, performed routinely during general anaesthesia in patients undergoing intraocular surgery, may have adverse effects on cardiovascular function and intraocular pressure. This study assessed the suitability of the laryngeal mask airway (LMA) as a substitute for tracheal intubation. Intraocular and systemic pressor effects, heart rate changes and catecholamine concentrations were measured in two groups of 10 patients receiving standardized anaesthesia with either a tracheal tube (TT) or a LMA. There were significantly smaller changes in the pressor responses to insertion and in concentrations of catecholamines at critical times in the anaesthetic sequence in the LMA group. Mean (SEM) rate-pressure product was significantly smaller in the LMA group compared with the TT group after both insertion (8276 (730) vs 13307 (1348), P < 0.01) and removal (10152 (595) vs 14137 (1044), P < 0.01) of the airway device. The change in intraocular pressure was significantly less in the LMA group at all time points after airway instrumentation than that in the TT group, with the greatest difference after extubation (-2.3 (2.4) mm Hg vs 14.5 (3.4) mm Hg, P < 0.01).

Changes in intra–ocular pressure during general anaesthesia

“…The transient hypotension in these three patients did not cause a significant reduction in the IOP. Our finding of a higher systolic arterial pressure and heart rate following tracheal extubation compared with removal of the laryngeal mask agrees with the findings of Lamb and others [6]. The cardiovascular response in the tracheal intubation group may be related to the use of neostigmine and glycopyrrolate to reverse the action of vecuronium.…”

“…Some authors have shown increases after tracheal intubation [5,9,161 whereas others have shown a reduction [7]. Many authors [5,6,9,161 have shown significantly lower IOPs after insertion of a laryngeal mask compared to tracheal intubation. Our present results showed a significant reduction in IOP after intubation in both groups compared to baseline.…”

“…In recent studies where controlled ventilation only was employed , the laryngeal mask was compared to tracheal intubation for intra-ocular surgery. Although Akhtar and others [7] found that the laryngeal mask did not offer any advantages over tracheal intubation in the control of IOP, other investigators [5,6,9] have concluded that the change in IOP was less with the former device than the latter. Payne and Edwards [ 101 used fibreoptic laryngoscopy to confirm the position of the laryngeal mask; they reported that the oesophagus was clearly visible through the laryngeal mask aperture in 6% of the patients and emphasised that, in their view, this type of airway could not provide effective protection against aspiration of gastric contents.…”

“Comparison of Cuff Pressure Changes Between Air with Oxygen or Nitrous Oxide with Oxygen During General Anaesthesia Using Proseal LMA for Laproscopic Surgery”

“…These findings are similar to those of previous studies . [6,7,8,9,11 ]. In Our study there was no difference in both the groups A and group N in terms of pulse rate, mean arterial blood pressure , SpO2, EtCO2 and peak airway pressures.…”

Comparison of Hemodynamic Responses and Postoperative Airway Complications between ET Tube and LMA in Pediatric Short Surgical Procedures

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ABSTRACT 9%, 11.9%, 7.9%, 2.1% above baseline in group T and 3.6%, 5.2%, 5.3%, 5.4% below baseline for group L. The DBP were 11.2%, 8.9%, 5.6%, 2.1% above baseline in group T and in 3.2%, 5.1%, 5.6%,6.2% below baseline for group L. The incidence of post operative sore throat was 8% in group L and in 20% in group T. Conclusions: Laryngeal mask airway is a valuable and better alternative to endotracheal intubation in securing the airway, especially in pediatric patients in whom pressor response to endotracheal intubation is detrimental.

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