A. G. Marfin

Use of the bougie in simulated difficult intubation. 2. Comparison of single-use bougie with multiple-use bougie*

Summary We studied the success rates for tracheal intubation in 32 healthy, anaesthetised patients during simulated grade IIIa laryngoscopy, randomised to either the multiple‐use or the single‐use bougie. Success rates (primary end‐point) and times taken (secondary end‐point) to achieve tracheal intubation were recorded. The multiple‐use bougie was more successful than the single‐use one (15/16 successful intubations vs. 9/16; p = 0.03). With either device, median [range] total tracheal intubation times for successful attempts were < 54 [24–84] s and there were no clinically important differences between these times. We conclude that the multiple‐use bougie is a more reliable aid to tracheal intubation than the single‐use introducer in grade IIIa laryngoscopy.

Determination of the site of tracheal tube impingement during nasotracheal fibreoptic intubation.

This study examines the incidence and site of tracheal tube impingement during nasotracheal fibreoptic intubation, and the efficacy of anticlockwise tube rotation to overcome the problem. Forty‐three patients underwent fibreoptic‐assisted nasotracheal intubation using a preformed nasal tube, and a second fibrescope was used to observe any obstruction to passage of the tracheal tube. Impingement occurred in 10 cases, with the most common site being the right arytenoid cartilage. Rotation resulted in successful intubation in all 10 cases, but proximal rotation did not always result in an equal degree of rotation at the tube tip. We conclude that the site of impingement for nasotracheal intubation with preformed nasal tubes is located at the posterior structures of the laryngeal inlet and that anticlockwise rotation is a simple and effective solution.

Use of the bougie in simulated difficult intubation. 1. Comparison of the single-use bougie with the fibrescope.

We studied the success rates for tracheal intubation in 64 healthy patients during simulated grade III laryngoscopy after induction of anaesthesia, using either the single‐use bougie or oral flexible intubating fibrescope, both in conjunction with conventional Macintosh laryngoscopy. Patients were randomly allocated to either simulated grade IIIa or grade IIIb laryngoscopy, and also to one of the two study devices. Success rates for tracheal intubation (primary outcome measure) and times taken to achieve intubation (secondary outcome measure) were recorded. For the simulated grade IIIa laryngoscopy group, the fibreoptic scope was more successful than the bougie (16/16 successful intubations vs. 8/16; p = 0.02). For the simulated grade IIIb laryngoscopy group, the fibreoptic scope was also more successful than the bougie (8/16 successful intubations vs. 1/16; p = 0.02), but clearly use of the fibreoptic scope was not as successful as it had been in simulated grade IIIa laryngoscopy (p = 0.04). With either device, median (range) total tracheal intubation times for successful attempts with either grade of laryngoscopy were less than 60 s (19–109) and there were no clinically important differences. We conclude that the fibrescope used in conjunction with Macintosh laryngoscopy is a more reliable method of tracheal intubation than the single‐use bougie in both types of grade III laryngoscopy. This finding has implications for the management of patients in whom grade III laryngoscopy is encountered unexpectedly after induction of anaesthesia, and also for the management of patients previously known to have grade III view at laryngoscopy.

A comparison of a flexometallic tracheal tube with the intubating laryngeal mask tracheal tube for nasotracheal fibreoptic intubation using the two-scope technique*

We compared the incidence and site of impingement of a flexometallic tracheal tube with those of the re‐usable intubating laryngeal mask (ILMA) tube in 60 anaesthetised patients undergoing nasotracheal fibreoptic intubation for oral surgery. A two‐scope technique was used, observing the site of impingement with one scope whilst intubating with the other. The tubes were 6.0‐mm in females and 6.5‐mm in males. Impingement occurred with 10 (33%) flexometallic and 2 (7%) ILMA tubes (p < 0.032). In all but one case, the impingement was posterior to the right arytenoid cartilage. When impingement was observed, a single disempaction with a 90° anticlockwise rotational manoeuvre overcame impingement in every case except one, allowing successful intubation. We conclude that the incidence of impingement of the tracheal tube, and therefore of potential laryngeal trauma from nasotracheal fibreoptic intubation, is significantly greater with the flexometallic tube than with the ILMA tube.

Ease of insertion of the laryngeal tube during manual-in-line neck stabilisation

The laryngeal tube has a potential role in airway management during anaesthesia or cardiopulmonary resuscitation. In patients with unstable necks, the head and neck may need to be stabilised manually (manual in‐line stabilisation), but it is not known whether this procedure affects the ease of insertion of the laryngeal tube. We studied, in a cross‐over study, 21 adult patients to compare the success rate of ventilation through the laryngeal tube between the Magill position (a pillow under the occiput and the head extended) or the manual in‐line position of the head and neck (without a pillow under the occiput). After induction of anaesthesia and neuromuscular blockade, the laryngeal tube was inserted in turn in the two positions. The ease of insertion was scored with four categories (easy, moderately difficult, difficult and impossible), and adequacy of ventilation through the device was assessed. Ventilation was adequate in all 21 patients in the Magill position, but only in two of 21 patients during manual in‐line positionin (p < 0.01; 95%CI for difference: 68–94%). In the Magill position, insertion of the laryngeal tube was easy in 16 patients and moderately difficult in the remaining five patients; in the manual in‐line stabilisation position, insertion was moderately difficult in two patients and impossible in the remaining 19 patients. Stabilisation of the patients head and neck by the manual in‐line method made insertion of the laryngeal tube either difficult or impossible.

Nasotracheal fibreoptic intubation: a randomised controlled trial comparing the GlideRite® (Parker-Flex® Tip) nasal tracheal tube with a standard pre-rotated nasal RAE™ tracheal tube.

In a randomised controlled study, we compared the ease of railroading a GlideRite® nasal tracheal tube over a fibrescope with that of a pre‐rotated RAE™ nasal tracheal tube. We studied 110 anaesthetised patients with no known airway difficulties undergoing elective dental or maxillofacial surgery. Impingement was more common with the GlideRite tubes (11/55 (20%)) compared with the pre‐rotated RAE tubes (3/55 (5%); p = 0.02). The median (IQR [range]) time to intubation (GlideRite 7.6 (4.7–10.8 [3.0–46.2]) s; RAE 8.0 (6.2–10.7 [2.4–30.0]) s) and postoperative sore throat numerical ratings (GlideRite 2 (0–3 [0–10]); RAE 2 (0–5 [0–8])) were similar. A 90° anticlockwise pre‐rotation of a standard nasal RAE tube has a higher initial rate of successful railroading at first attempt and is therefore superior to a GlideRite nasotracheal tube during nasal fibreoptic intubation.