Comparison of the laryngeal mask (LMA) and laryngeal tube (LT) with the new perilaryngeal airway (CobraPLA) in short surgical procedures.

BACKGROUND AND OBJECTIVE: We compared the laryngeal mask airway (LMA) and the laryngeal tube (LT) with the newly introduced perilaryngeal airway (CobraPLA, PLA) with regard to haemodynamic responses induced by airway insertion, clinical performance and occurrence of postoperative sore throat after short surgical procedures.

METHODS: After premedication, 90 ASA I-II patients awaiting short surgical procedures were randomized to receive, LMA, LT or PLA. Anaesthesia was induced with intravenous propofol (2.5 mg kg(-1)) and mivacurium (0.2 mg kg(-1)). Number of attempts, time of insertion of the device, any other unwanted effect, mean aterial pressure, heart rate, oxygen saturation and end-tidal carbon dioxide were recorded. At the end of surgery, the cuff of the device was immediately deflated and the airway device was removed. The device was examined and noted for the presence of visible blood. Patients were asked to rate their throat soreness, dysphonia and dysphagia 1 and 24 h postoperatively.

RESULTS: There were no differences in haemodynamic variables. Insertion times for the devices were similar (LMA: 20 +/- 11 s, LT: 19 +/- 14 s and PLA: 21 +/- 12 s.) The success rates at first insertion were lower in the (LMA group (57%) when compared with the PLA (97%, P < 0.05). The number and type of airway interventions for achieving an effective airway were similar. When the airways were removed 50% of the PLA devices had positive blood traces, while only 17% of the LMA and LT devices had positive blood traces (P < 0.01). Fifty percent of the patients suffered from a sore throat in the PLA group, which was significantly higher than in the LMA and LT groups (P < 0.05).

CONCLUSION: We conclude that haemodynamic, ventilation and oxygenation variables throughout the surgery were similar with, LMA, LT and PLA, but LT and PLA were easier to insert; LMA and LT caused less mucosal trauma.