Two head positions for orotracheal intubation with the trachway videolight intubating stylet with manual in-line stabilization: A randomized controlled trial

BACKGROUND

The Trachway Videolight Intubating Stylet is a video-assisted system with a rigid but malleable intubating stylet that facilitates endotracheal intubation. Minimizing cervical spine movement with manual in-line stabilization is essential for patients with cervical spine injuries such as multiple trauma. However, the intubation time of the Trachway Videolight Intubating Stylet and complications associated with intubation in patients with manual in-line stabilization in the neutral-head and head-lift positions remain unclear.

METHODS

Patients (20-80 years old) who were scheduled to undergo surgery that required general anesthesia with tracheal intubation were randomly allocated to either a neutral-head (n = 62) or a head-lift position (n = 62) group. Manual in-line stabilization was performed to limit cervical spine mobility. We aimed to evaluate orotracheal intubation time and success rate in these 2 positions with the Trachway Videolight Intubating Stylet.

RESULTS

Intubation was faster in the head-lift than in the neutral-head position (20 ± 10 and 25 ± 13 seconds, respectively, P = .000); intubation was equally successful in the 2 positions (96.8% vs 96.8%). Responses to intubation did not differ between positions (heart rate, P = .142; visual analog scale scores for throat soreness, P = .54). The only significant predictor of intubation time was the body mass index in the head-lift position group (P = .005).

CONCLUSIONS

Intubation using the Trachway Videolight Intubating Stylet with manual in-line stabilization is faster in the head-lift position, and therefore preferable. However, if the head-lift position is not suitable, the neutral-head position is a sensible alternative, with comparable intubation success rate, heart rate change, and postoperative throat soreness.

Removal methods of rigid stylets to minimise adverse force and tracheal tube movement: a mathematical and in-vitro analysis in manikins

This study investigated displacement of the tracheal tube caused by different methods of intubating stylet removal, using in-vitro experiments and mathematical analysis. In the first in-vitro experiment, we measured the distance travelled by the tube tip during stylet extraction. Then, we investigated the ideal technique for stylet extraction using mathematical analysis, which would cause minimal tube displacement. Then, using a training manikin, we measured the force applied to the vocal cords and stylet extraction force during tracheal intubation. When the stylet was extracted along a straight path towards the stylet end, the distance travelled by the tube tip significantly increased as the bending angle increased. Mathematical analysis revealed that the stylet should be diagonally extracted (in the sagittal plane) at an appropriate angle, rather than along a straight path towards the direction of the stylet end. In simulated tracheal intubation, extraction force and force applied to the vocal cords both significantly increased as the bending angle increased. Compared with the 'hockey stick'-shaped stylet, the arcuate-shaped stylet resulted in reduced force. Our results indicate the potential risk for vocal cord injury when using hockey stick-shaped stylets with large bending angles.

A prospective cohort study of awake fibreoptic intubation practice at a tertiary centre

Contemporary data are lacking for procedural practice, training provision and outcomes for awake fibreoptic intubation in the UK. We performed a prospective cohort study of awake fibreoptic intubations at a tertiary centre to assess current practice. Data from 600 elective or emergency awake fibreoptic intubations were collected to include information on patient and operator demographics, technical performance and complications. This comprised 1.71% of patients presenting for surgery requiring a general anaesthetic, with the majority occurring in patients presenting for head and neck surgery. The most common indication was reduced mouth opening (26.8%), followed by previous airway surgery or head and neck radiotherapy (22.5% each). Only five awake fibreoptic intubations were performed with no sedation, but the most common sedative technique was combined target-controlled infusions of remifentanil and propofol. Oxygenation was achieved with high-flow, heated and humidified oxygen via nasal cannula in 49.0% of patients. Most operators had performed awake fibreoptic intubation more than 20 times previously, but trainees were the primary operator in 78.6% of awake fibreoptic intubations, of which 86.8% were directly supervised by a consultant. The failure rate was 1.0%, and 11.0% of awake fibreoptic intubations were complicated, most commonly by multiple attempts (4.2%), over-sedation (2.2%) or desaturation (1.5%). The only significant association with complications was the number of previous awake fibreoptic intubations performed, with fewer complications occurring in the hands of operators with more awake fibreoptic intubation experience. Our data demonstrate that awake fibreoptic intubation is a safe procedure with a high success rate. Institutional awake fibreoptic intubation training can both develop and maintain trainee competence in performing awake fibreoptic intubation, with a similar incidence of complications and success compared with consultants.

Evaluation of simple pre-determined length insertion technique (SPLIT) with conventional method for oral fibreoptic intubation: A randomised cross-over study

BACKGROUND AND AIMS

The difficulty during flexible fiber-optic bronchoscopy (FOB) guided tracheal intubation could be because of inability in visualising glottis, advancing and railroading of endotracheal tube. Several methods are available for visualising glottis, but none is ideal. Hence, this randomised controlled study was designed to evaluate the simple pre-determined length insertion technique (SPLIT) during oral FOB.

METHODS

Fifty-eight patients were randomised into Group C and Group P. General anaesthesia was maintained with sevoflurane and oxygen in spontaneous respiration. In Group C, conventional flexible fiberoptic laryngoscopy was done followed by SPLIT and vice versa in Group P. The time to visualise the glottis (T₁), from glottic visualisation to pass beyond glottis (T₂) and from incisors to pass beyond the glottis (T₃) were noted from the recorded video. The time interval was analysed using Wilcoxon matched pairs test and Mann-Whitney U-test.

RESULTS

The T₁ was significantly less in SPLIT as compared to conventional technique (13 [10, 20.25] vs. 33 [22, 48] s). The T₃ was significantly less in SPLIT (24.5 [19.75, 30] vs. 44 [34, 61.25] s). The T₁ by SPLIT was comparable between residents and consultants (P = 0.09), whereas it was significantly more among residents than the conventional technique. The SPLIT was preferred by 91.3% anaesthesiologists.

CONCLUSION

The SPLIT significantly lessened the time to visualise the glottis than conventional technique for FOB. The SPLIT was the preferred technique. Hence, we suggest using the SPLIT to secure the airway at the earliest and also as an alternative to conventional technique.