Laryngeal tube versus laryngeal mask airway in anaesthetised non-paralysed patients. A comparison of handling and postoperative morbidity

Background. The purpose of this study was to compare the classical laryngeal mask airway (LMA) with the laryngeal tube (LT) in anaesthetised non-paralysed patients. Patients and methods. A total of 100 patients scheduled for minor elective surgery were included. After standardised induction and maintenance of anaesthesia with propofol and remifentanil, patients were randomly allocated to receive either a LMA or LT, muscle relaxants were not applied. Selection of the appropriate size and the initial inflation volume were chosen according to the manufacturers instructions. Ease of insertion, initial intra-cuff pressure, oropharyngeal leak pressure at an intra-cuff pressure of 60 cmH(2)O and incidence and severity of complications during and after anaesthesia were compared. Results. The LT was inserted significantly quicker than the LMA (35.1 +/- 15.9 s vs. 56.6 +/- 42.5 s; mean +/- SD). Insertion of the LT was successful within 1 attempt in 90% and within 2 or 3 attempts in another 4% of patients for the LT compared with 68% and 20% of patients for the LMA, respectively. For the LT the initial cuff pressure was significantly lower (75,1 +/- 16.2 cmH(2)O) and the oropharyngeal leak pressure after adjustment of the intra-cuff pressure to 60 cmH(2)O was significantly higher (27.2 +/- 6.9 mbar) compared with the LMA (109.5 +/- 25.7 cmH(2)O and 19.9 +/- 4.0 mbar, respectively), Incidence of postoperative laryngeal complications in the LT group (31%) was lower compared with the LMA group (54%). Conclusion. In anaesthetised non-paralysed patients the J compares favourably to the LMA in terms of ease of insertion and postoperative morbidity.