A comparison of the use of Trachlight® and Eschmann multiple-use introducer in simulated difficult intubation:

A Comparison Between the Conventional and the Laryngoscope-Assisted Lightwand Intubation Techniques in Patients With Cervical Immobilization: A Prospective Randomized Study

BACKGROUND

Positioning of a lightwand in the midline of the oral cavity can be challenging in patients with cervical immobilization. Direct laryngoscopy may permit the lightwand tip to more easily access the glottic opening. We tested our hypothesis that a laryngoscope-assisted lightwand technique allows more successful endotracheal intubation than does a conventional lightwand approach.

METHODS

A total of 162 patients requiring cervical immobilization during intubation for cervical spine surgery were allocated randomly to 2 groups. The conventional lightwand technique (group C, n = 80) or the laryngoscope-assisted lightwand technique (group L, n = 82) was used for endotracheal intubation. In the group L, a Macintosh laryngoscope was inserted into the oral cavity, advanced until the epiglottis tip was visible, but not used to lift the epiglottis tip. The lightwand tip was placed below the epiglottis under direct view of the epiglottis tip. The primary outcome (the initial intubation success rate) and secondary outcomes (intubation time, hemodynamic changes, and postoperative airway complications) were evaluated.

RESULTS

The initial intubation success rate was significantly lower (75% vs 89%; relative risk [95% confidence interval]: 1.2 [1.0-1.4]; P = .034) in group C than group L. The intubation time (22 ± 13 vs 24 ± 12 seconds; mean difference [98.33% confidence interval]: 2.4 [-2.3 to 7.2]; P = .217) did not differ between groups. Postoperative sore throat score, incidences of hypertension and tachycardia, postoperative oral mucosal bleeding, and hoarseness also did not differ between groups.

CONCLUSIONS

Laryngoscope-assisted lightwand intubation did not increase intubation time, and it increased first attempt intubation rates compared with traditional lightwand intubation in patients requiring cervical immobilization for cervical spine surgery.

The difficult airway with recommendations for management--part 1--difficult tracheal intubation encountered in an unconscious/induced patient

Background

Previously active in the mid-1990s, the Canadian Airway Focus Group (CAFG) studied the unanticipated difficult airway and made recommendations on management in a 1998 publication. The CAFG has since reconvened to examine more recent scientific literature on airway management. The Focus Group’s mandate for this article was to arrive at updated practice recommendations for management of the unconscious/induced patient in whom difficult or failed tracheal intubation is encountered.

Methods

Nineteen clinicians with backgrounds in anesthesia, emergency medicine, and intensive care joined this iteration of the CAFG. Each member was assigned topics and conducted reviews of Medline, EMBASE, and Cochrane databases. Results were presented and discussed during multiple teleconferences and two face-to-face meetings. When appropriate, evidence- or consensus-based recommendations were made together with assigned levels of evidence modelled after previously published criteria.

Conclusions

The clinician must be aware of the potential for harm to the patient that can occur with multiple attempts at tracheal intubation. This likelihood can be minimized by moving early from an unsuccessful primary intubation technique to an alternative “Plan B” technique if oxygenation by face mask or ventilation using a supraglottic device is non-problematic. Irrespective of the technique(s) used, failure to achieve successful tracheal intubation in a maximum of three attempts defines failed tracheal intubation and signals the need to engage an exit strategy. Failure to oxygenate by face mask or supraglottic device ventilation occurring in conjunction with failed tracheal intubation defines a failed oxygenation, “cannot intubate, cannot oxygenate” situation. Cricothyrotomy must then be undertaken without delay, although if not already tried, an expedited and concurrent attempt can be made to place a supraglottic device.

A double bending lightwand can provide more successful endotracheal intubation in patients with a short thyromental distance: a prospective randomised study

BACKGROUND AND OBJECTIVE

This study assessed the efficacy of endotracheal intubation using a double bending lightwand in patients with an anticipated difficult airway because of a short thyromental distance.

METHODS

On the basis of the shape of the lightwand used, 68 patients with a thyromental distance of less than 65 mm undergoing general anaesthesia were randomly allocated to one of two groups. In the conventional bending group (n = 34), the lightwand was bent at 6.5 cm from the distal end to 90° angle. In the double bending group (n = 34), the lightwand was bent 30° at 15 cm from its tip in addition to the conventional bending. The ease of insertion was assessed by the lightwand search time and success rate at the first attempt. Post-operative complications, if any, were noted.

RESULTS

The success rate of intubation at the first attempt was higher for the double bending group (94 vs. 74%, P < 0.05). The search time was significantly shorter in the double bending group than the conventional bending group (10 ± 6 vs. 15 ± 8 s, P < 0.01). Mean blood pressure and heart rate increased after intubation in both groups (P < 0.05), but there were no significant differences between the groups. The incidence of post-operative sore throat and mucosal bleeding was not significantly different between the groups.

CONCLUSION

We conclude that the double bending lightwand is associated with a greater success rate of intubation in patients with an anticipated difficult airway because of a short thyromental distance.

Effect of cardiopulmonary resuscitation on intubation using a Macintosh laryngoscope, the AirWay Scope, and the gum elastic bougie: A manikin study

BACKGROUND

Physicians could encounter difficult intubation during cardiopulmonary resuscitation (CPR) in trauma patients due to the patient's movement from continuous chest compression and to cervical stabilisation. Therefore, first, we evaluated the impact of chest compression with or without cervical stabilisation on intubation with a Macintosh laryngoscope. Next, we compared difficulty in intubation among the Macintosh laryngoscope, AirWay Scope (AWS), and gum elastic bougie (GEB) with the Macintosh laryngoscope in three simulated CPR scenarios in a randomised, controlled, cross-over study design.

METHODS

Twenty-three anaesthetists intubated the trachea of a manikin (ALS Skill Master, Laerdal Medical Japan, Tokyo, Japan) using the Macintosh laryngoscope, AWS, and GEB in the control scenario, chest compression scenario, and chest compression with cervical stabilisation scenario. Difficulty in intubation was rated on a 5-point scale and the intubation time was measured.

RESULTS

Continuous chest compression increased difficulty in intubation with the Macintosh laryngoscope, compared with the control scenario. Concurrent application of cervical stabilisation further increased the difficulty, compared with application of chest compression alone. Of the three devices compared, the AWS facilitated the easiest intubation, and the GEB facilitated the second-easiest intubation in all scenarios, though the intubation time was slightly longer with the GEB than with other devices.

CONCLUSION

CPR employing continuous chest compression with or without cervical stabilisation caused difficult intubation with the Macintosh laryngoscope. The AWS and GEB facilitated the easiest and second-easiest intubation, respectively, even during CPR employing continuous chest compression with or without cervical stabilisation in a manikin.

Blind intubation device for nasotracheal intubation in 100 oral and maxillofacial surgery patients with anticipated difficult airways: a prospective evaluation

BACKGROUND AND OBJECTIVE

The blind intubation device is a newly developed light-guided intubation device for difficult nasotracheal intubation. The aim of this study was to evaluate its performance in adult patients with anticipated difficult airways.

METHODS

One hundred consecutive patients who required general anaesthesia with nasotracheal intubation for elective oral and maxillofacial surgery between March 2008 and August 2008 were recruited. In each case, the time for oesophagus airway successful placement, the attempts of the light-guiding catheter insertion into the trachea, the attempts of the endotracheal tube intubation over the light-guiding catheter and the time from the oesophagus airway placement to the completion of endotracheal intubation were recorded. The associated complications were also recorded.

RESULTS

Fifty-nine male and 41 female patients were studied. Each of the patients had at least temporomandibular joint ankylosis, maxillary and mandibular fracture, oral cancer, obstructive sleep apnoea syndrome, mandibular hypoplasia and micrognathia and cervical tumour. The oesophagus airway was directly inserted into the trachea in six patients. The placement of the oesophagus airway was successful in remaining 94 patients. The median (interquartile range) time for the oesophagus airway placement was 47 (25-178) s. The overall success rate of the light-guiding catheter insertion was 95.0%. The overall success rate of the ETT intubation over the light-guiding catheter was 95.0%. The median (interquartile range) time for complete tracheal intubation process was 194 (22-380) s. There was no episode of hypoxaemia during tracheal intubation. In 28 (29.5%) of our patients, there was a small amount of blood present in the tip of the oesophagus airways or around the inner wall of the endotracheal tubes. No serious epistaxis was found either.

CONCLUSION

We have demonstrated the safe and effective use of the blind intubation device in 100 adult patients with anticipated difficult airways. The overall success rates of the oesophagus airway placement, the light-guiding catheter insertion and nasotracheal intubation over the light-guiding catheter were really satisfied. This technique could improve the success of blind nasal intubation, especially in situations in which fibreoptic equipment was unavailable. However, further studies are still required.

A Comparison of a Fiberoptic Stylet and a Bougie as Adjuncts to Direct Laryngoscopy in a Manikin-Simulated Difficult Airway

STUDY OBJECTIVE

We compare the effectiveness of an endotracheal tube introducer ("bougie") with a new fiberoptic stylet as an adjunct to direct laryngoscopy in facilitating simulated difficult tracheal intubation in a manikin.

METHODS

Inexperienced laryngoscopists were recruited for this randomized, crossover study. After brief training, participants were randomized to first use either the bougie or fiberoptic stylet as an adjunct to direct laryngoscopy for attempted tracheal intubation of a manikin presenting a fixed, simulated, Cormack-Lehane grade IIIA view. Two attempts at tracheal intubation were allowed, each limited to 60 seconds. The participant then crossed over and used the other device. The same procedure was then repeated on a second manikin presenting a simulated Cormack-Lehane grade IIIB view. Primary outcomes were time to tracheal intubation and successful endotracheal tube placement.

RESULTS

One hundred three study participants performed a total of 533 tracheal intubations for evaluation. For the Cormack-Lehane grade IIIA view, correct placement of the endotracheal tube was achieved in 101 (98%) of the fiberoptic stylet-facilitated and all 103 (100%) of the bougie-facilitated tracheal intubations. The time to successful tracheal intubation was similar for both devices (difference in mean time 1.8 seconds; 95% confidence interval [CI] -2.5 to 6.1 seconds). In the Cormack-Lehane grade IIIB view manikin, use of the fiberoptic stylet significantly increased success rate (fiberoptic stylet 98% versus bougie 9%), and a trend was observed toward a decrease in the mean time required for successful tracheal intubation compared to the bougie (fiberoptic stylet 31.0 seconds versus bougie 45.6 seconds; difference in mean time -14.6 seconds; 95% CI -31.4 to 2.3 seconds).

CONCLUSION

In a manikin model, with inexperienced clinicians, both the bougie and the fiberoptic stylet were effective in facilitating tracheal intubation of a simulated Cormack-Lehane grade IIIA view. For a Cormack-Lehane IIIB view, the fiberoptic stylet was significantly more effective than the bougie in facilitating tracheal intubation. Because a manikin model eliminates some of the barriers to use of fiberoptics in patients, further validation of fiberoptic stylet use is required in human subjects with normal and difficult airways.