Table 1

 Relevant papers

ReferenceStudyOutcomesKey resultsWeaknesses
15Randomised crossover study 25 electively anaesthetised patients with manual in-line stabilisation. LMA crossed over with ILMA. Randomised first device selection(1) Speed of placement(2) Ease of placement(3) Adequacy of ventilation based on chest movement, compliance and the presence of leak(1) Insertion of ILMA was significantly faster than LMA (p<0.001)(2) Insertion of ILMA was significantly easier than LMA (p<0.001)(3) Adequate ventilation achieved in 100% of ILMA insertions v 88% of LMA(1) Unblinded(2) Hospital based ASA 1–2 patients(3) Patients with neck/upper respiratory abnormality or at risk of aspiration excluded(4) Muscle relaxants used(5) Capnography/pulse oximetry not used
13Randomised crossover study. 55 electively anaesthetised patients. Randomised to use either LMA or ILMA(1) Speed of insertion(2) Successful ventilation as shown by positive end tidal CO2(1) No significant difference in mean insertion time(2) No significant difference in success of ventilation(1) Unblinded(2) Hospital based female patients only(3) Inexperienced operators(4) BMI >30/reduced mouth opening/reduced neck movements excluded
16Prospective study. 75 electively anaesthetised patients. 24 inexperienced operators. LMA crossed over with ILMA. Randomised first device selection(1) Speed of insertion(2) Adequacy of ventilation based on chest expansion and end tidal CO2>4kPa(3) Pressure at which leak developed around device(1) No significant difference in insertion time(2) No significant difference in success of insertion or ventilation(3) The ILMA was better at providing adequate ventilation without an audible leak p = 0.009(1) Unblinded(2) Hospital based ASA 1–2 patients(3) Inexperienced operators(4) Patients with risk factors for regurgitation excluded