In order to compare the effect of atropine and sodium chloride on the dynamic compliance of the respiratory system after tracheal intubation, we studied 20 patients allocated randomly into two groups to receive either: atropine after 5 min of steady state and sodium chloride after 10 min (group A) or in reverse order (group B) intravenously. The study was conducted in a randomized double-blinded manner. The patients were anaesthetized with thiopental 5 mg kg−1 followed by thiopental 50 mg intravenously, as required. Intubation was facilitated by atracurium 0.5mg kg−1 intravenously and fentanyl 200 μg intravenously. During fixed volume ventilation (100 mL kg−1, f=10), compliance and end-tidal carbon dioxide were measured every 10 s by a Datex AS/3-respiratory module connected to a portable IBM-pc. Five minutes was allowed to establish a steady state then either atropine or sodium chloride was administered according to the protocol. Respiratory dynamic compliance increased significantly after intravenous administration of atropine (P < 0.05). We conclude that atropine 1.0 mg given intravenously provides protection against an intubation-induced decline in respiratory dynamic compliance.

We evaluated the ability of inexperienced personnel in using a prototype illuminated flexible catheter to assist tracheal intubation through the intubating laryngeal mask in anaesthetised, paralysed patients. The device consists of a completely flexible thin plastic catheter, a bulb attached to its distal end and a 15-mm concentric adapter at its proximal end. The illuminated catheter is placed into a straight silicone tracheal tube in such a way that the bulb is placed at the distal end of the tracheal tube. Six nurses inexperienced in tracheal intubation followed a 2-hr training program by using the device through the intubating laryngeal mask in a mannequin and then intubated 10 patients each, with instruction from an anaesthetist. All patients (n = 60) were ASA 1–2, scheduled to undergo general anaesthesia for elective surgery. After fentanyl/propofol induction the intubating laryngeal mask was inserted. When an adequate airway was established, patients received atracurium and the endotracheal tube preloaded with the device was inserted through the intubating laryngeal mask and by observing the glow in the neck was advanced into the trachea. The final outcome and the duration of the procedure were recorded. The intubating laryngeal mask was inserted successfully in all patients. The success rate of intubation was 57/60 (95%); 38 patients at first attempt and 19 after two or three attempts. The mean (±SD) duration of the procedure in the first five patients in the series of each nurse was 74±40 s while in the last five patients it was diminished to 52±23 s (P= 0.01). We conclude that the described methodology has the potential for more widespread use of tracheal intubation through the intubating laryngeal mask even by inexperienced personnel.

We evaluated the efficacy of a newly developed prototype illuminated flexible catheter to facilitate tracheal intubation through the intubating laryngeal mask and compared this light-guided technique with the conventional blind tracheal intubation through the intubating laryngeal mask. The illuminated flexible catheter consists of a completely flexible thin plastic catheter, a bulb attached to its distal end, a 15-mm concentric adapter at its proximal end connected with a battery and a power switch. The device is placed into a silicone tracheal tube in such a way that the bulb protrudes from the distal end of the tracheal tube. One hundred adult patients, ASA I–III, scheduled to undergo propofol/fentanyl/atracurium anaesthesia for elective surgery were studied. All participants underwent a randomized double comparative cross over trial with respect to the tracheal intubation technique through the intubating laryngeal mask. The light guided tracheal intubation was performed as follows; the tracheal tube preloaded with the illuminated flexible catheter was inserted through the intubating laryngeal mask and by observing the glow in the neck was advanced into the trachea. Whenever resistance was felt during insertion, appropriate adjusting man oeuvres were performed. The intubating laryngeal mask was inserted successfully in all patients. The success rate for the blind and light-guided technique was 91% and 100%, respectively (P=0.003). The mean (±SD) duration including appropriate intubating laryngeal mask placement and tracheal intubation, was significantly lower in the light-guided tracheal intubation technique, than with the blind tracheal in-tubation (31±8s vs. 43±18s; P=0.0001). We conclude that the use of an illuminated flexible catheter carries advantages either in optimizing the intubating laryngeal mask position in the laryngopharynx or in achieving a quick and safe light-guided advancement from laryngopharynx into the trachea.