A comparison of blind and lightwand-guided tracheal intubation through theintubating laryngeal mask

We have tested the hypothesis that intubation success rates, haemodynamic c hanges, airway complications and postoperative pharyngolaryngeal morbidity differ between blind and lightwand-guided intubation through the intubating laryngeal mask airway. One hundred and twenty paralysed anaesthetised adul t patients (ASA I-II, no known or predicted difficult airways) were assigne d in a random manner to one of two equal-sized groups. In the blind group, patients were intubated blindly through the intubating laryngeal mask airwa y. In the lightwand group, patients were intubated through the intubating l aryngeal mask airway assisted by transillumination of the neck with a light wand. A standard sequence of adjusting manoeuvres was followed if resistanc e occurred during intubation or if transillumination was incorrect. The num ber of adjusting manoeuvres, time to intubation. intubation success rates, haemodynamic changes (pre-induction, pre-intubation, postintubation), oesop hageal intubation, mucosal trauma (blood detected), hypoxia (oxygen saturat ion < 95%) and postoperative pharyngolaryngeal morbidity (double-blinded) w ere documented. Overall intubation success was similar (blind. 93%; lightwa nd, 100%), but time to successful intubation was significantly shorter (67 vs. 46 s, p = 0.027) and the number of adjusting manoeuvres was significant ly fewer (p = 0.024) in the lightwand group. There were no significant diff erences in blood pressure or heart rate between the groups at any time. Oes ophageal intubation occurred more frequently in the blind group (18 vs. 0%, p = 0.002). The incidence and severity of mucosal injury, sore throat and hoarseness were similar between the groups. We conclude that lightwand-guid ed intubation through the intubating laryngeal mask is superior to the blin d technique.