Prospective randomized comparison of the new Laryngeal Tube Suction LTS II and the LMA-ProSeal for elective surgical interventions

Background and aim: The Laryngeal Tube Suction (LTS) has recently undergone considerable changes in design. The new LTS II was compared with the LMA-ProSeal to determine device performance during general anaesthesia and controlled ventilation. Methods: After Institutional Review Board approval, 100 elective surgical patients were randomized to be ventilated with LTS II or LMA-ProSeal. The number of attempts (maximum of two, and then other device tested) and time until first tidal volume were recorded. Ventilation was standardized (tidal volume, 7 ml/kg; respiratory rate, 12 breaths/min) and the resulting end-tidal CO2 was recorded. The airway leak pressure (maximum of 40 cmH(2)O) was measured at cuff pressures of 60 cmH(2)O. The ease of gastric tube insertion was evaluated. The devices were inspected for traces of blood after removal. Patients were questioned regarding post-operative complaints. The Mann-Whitney U-test was used to compare the groups. Results: The demographic data, American Society of Anesthesiologists' group, Mallampati score, and haemodynamic and respiratory variables were comparable for both groups of 50 patients. Insertion was successful in the first/second attempts in 44/4 patients for LTS II and in 43/6 patients for LMA-ProSeal. After two failed attempts, the other device was successfully used in one patient for LMA-ProSeal and in two patients for LTS II. The times until first tidal volume for LTS II and LMA-ProSeal were 25.0 +/- 10.1 and 25.5 +/- 11.5 s, respectively. The airway leak pressures were comparable: 33.1 (15-40) and 32.0 cmH(2)O (18-40 cmH(2)O) for LTS II and LMA-ProSeal, respectively. Gastric tube insertion failed in two patients in each group. Traces of blood were found in two patients with LTS II and in three patients with LMA-ProSeal. In both groups, post-operative complaints were mild and infrequent. Conclusion: In this prospective randomized trial, LMA-ProSeal and LTS II were comparable in all respects.