Haemodynamic responses to the intubating laryngeal mask and timing of removal

Tracheal intubation in morbidly obese patients: a comparison of the Intubating Laryngeal Mask Airway™ and Laryngeal Mask Airway CTrach™

The aim of this study was to evaluate the efficacy of the Intubating Laryngeal Mask Airway™ (ILMA) and Laryngeal Mask Airway CTrach™ (LMA CTrach) in facilitating tracheal intubation in morbidly obese patients. Eighty patients (body mass index >40 kg x m(-2)) were randomly allocated to the ILMA or the LMA CTrach. The median (IQR [range]) total time taken for tracheal intubation was shorter with the ILMA than with the LMA CTrach (78 (63-105 [40-265]) s vs 128 (98-221 [60-423]) s, respectively; p<0.001). Significantly more manoeuvres were applied for the satisfactory ventilation and viewing of the glottis with the LMA CTrach (25% vs 55% with the ILMA; p=0.006). During the postoperative period, there was more sore throat with the LMA CTrach (p<0.02). We conclude that the ILMA results in shorter intubation times with fewer manoeuvres and sore throat compared with the LMA CTrach in the morbidly obese.

Intubating condition, hemodynamic parameters and upper airway morbidity: A comparison of intubating laryngeal mask airway with standard direct laryngoscopy

Background:

Intubating Laryngeal Mask Airway (ILMA) is a relatively new device designed to have better intubating characteristics than the standard Laryngeal Mask Airway. This study was designed to compare Intubating Laryngeal Mask with standard Direct Laryngoscopy (DLS), taking into account ease of intubation, time taken for intubation, success rate of intubation, hemodynamic responses and upper airway morbidity.

Materials and Methods:

Sixty patients, ASA I or II, of age between 20 and 60 years, were enrolled in this prospective and randomized study. They were randomly allocated to one of the two groups: group ILMA, Intubating Laryngeal Mask Airway; group DLS, Direct Laryngoscopy. The patients were intubated orally using either equipment after induction of general anesthesia.

Results and Conclusions:

DLS is comparatively a faster method to secure tracheal intubation than Intubating Laryngeal Mask. ILMA offers no advantage in attenuating the hemodynamic responses compared to direct laryngoscope. The success rate of intubation through Intubating Laryngeal Mask is comparable with that of DLS. The upper airway morbidity and mean oxygen saturation are comparable in both the groups.

Comparison of the intubating laryngeal mask airway and laryngeal tube placement during manual in-line stabilisation of the neck

We compared the placement of the laryngeal tube (LT) with the intubating laryngeal mask airway (ILMA) in 51 patients whose necks were stabilised by manual in-line traction. Following induction of anaesthesia and neuromuscular blockade, the LT and ILMA were inserted consecutively in a randomised, crossover design. Using pressure-controlled ventilation (20 cmH(2)O inspiratory pressure), we measured insertion attempts, time to establish positive-pressure ventilation, tidal volume, gastric insufflation, and minimum airway pressure at which gas leaked around the cuff. Data were compared using Wilcoxon signed-rank tests; p < 0.05 was considered significant. Insertion was found to be more difficult with the LT (successful at first attempt in 16 patients) than with the ILMA (successful at first attempt in 42 patients, p < 0.0001). Time required for insertion was longer for the LT (28 [23-35] s, median [interquartile range]) than for the ILMA (20 [15-25] s, p = 0.0009). Tidal volume was less for the LT (440 [290-670] ml) than for the ILMA (630 [440-750] ml, p = 0.013). Minimum airway pressure at which gas leak occurred and incidence of gastric insufflation were similar with two devices. In patients whose necks were stabilised with manual in-line traction, insertion of the ILMA was easier and quicker than insertion of the LT and tidal volume was greater with the ILMA than the LT.