Anesth Pain Med.  2022 Jan;17(1):104-111. 10.17085/apm.21095.

Comparison between GlideRite® rigid stylet and Parker Flex-It™ stylet to facilitate GlideScope intubation in simulated difficult intubation: a randomized controlled study

• Bak JW
• Noh Y
• Kim J
• Hwang B
• Kang S
• Son H
• Kim M

• KMID: 2526535
• DOI: http://doi.org/10.17085/apm.21095

Abstract

Background
The GlideScope® videolaryngoscope (GVL) is widely used in patients with difficult airways and provides a good glottic view. However, the acute angle of the blade can make insertion and advancement of an endotracheal tube (ETT) more difficult than direct laryngoscopy, and the use of a stylet is recommended. This randomized controlled trial compared Parker Flex-It™ stylet (PFS) with GlideRite® rigid stylet (GRS) to facilitate intubation with the GVL in simulated difficult intubations. Methods: Fifty-four patients were randomly allocated to undergo GVL intubation using either GRS (GRS group) or PFS (PFS group). The total intubation time (TIT), 100-mm visual analog scale (VAS) for ease of intubation, success rate at the first attempt, use of laryngeal manipulation, tube advancement rate by assistant, and complications were recorded. Results: There was no significant difference between the GRS and PFS groups regarding TIT (50.3 ± 12.0 s in the GRS group and 57.8 ± 18.8 s in the PFS group, P = 0.108). However, intubation was more difficult in the PFS group than in the GRS group according to VAS score (P = 0.011). Cases in which the ETT was advanced from the stylet by an assistant, were more frequent in the GRS group than in the PFS group (P = 0.002). The overall incidence of possible complications was not significantly different. Conclusions: In patients with a simulated difficult airway, there was no difference in TIT using either the PFS or GRS. However, endotracheal intubation with PFS is more difficult to perform than GRS.

Keyword

Airway management; General anesthesia; Intubation; Laryngoscopes

Figure

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  Fig. 1. The GlideRite® rigid stylet (GRS, Verathon, USA), a dedicated stylet provided by the manufacturer.

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  Fig. 2. The Parker Flex-It™ stylet (PFS, Parker Medical, USA), shown individually and inserted into an endotracheal tube.

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  Fig. 3. CONSORT flow chart for the study patients. GRS group: GlideRite® rigid stylet (Verathon, USA) group, PFS group: Parker-Flex-It™ stylet (Parker Medical, USA) group.

Reference

1. Doyle DJ. The GlideScope video laryngoscope: a narrative review. Open Anesth J. 2017; 11:48–67.

2. Verathon. Gliderite rigid stylet: operations & maintenance manual. [serial on the Internet]. 2019 Apr [cited 2019 Apr]. Available from https://www.verathon.com/sites/default/files/2021-07/0900-4686-xx-60.pdf.

3. Jones PM, Turkstra TP, Armstrong KP, Armstrong PM, Cherry RA, Hoogstra J, et al. Effect of stylet angulation and endotracheal tube camber on time to intubation with the GlideScope. Can J Anaesth. 2007; 54:21–7.

4. Bader SO, Heitz JW, Audu PB. Tracheal intubation with the GlidesScope videolaryngoscope, using a "J" shaped endotracheal tube. Can J Anaesth. 2006; 53:634–5.

5. Turkstra TP, Jones PM, Ower KM, Gros ML. The Flex-It stylet is less effective than a malleable stylet for orotracheal intubation using the GlideScope. Anesth Analg. 2009; 109:1856–9.

6. Parker Medical. Parker medical innovation in intubation. Parker intubating stylets. [Internet]. 2015 Feb [cited 2019 Feb]. Available from https://www.salterlabs.com/catalog/product/view/id/913/s/intubating-stylets/category/4/#.

7. Malik MA, Maharaj CH, Harte BH, Laffey JG. Comparison of Macintosh, Truview EVO₂, Glidescope, and Airwayscope laryngoscope use in patients with cervical spine immobilization. Br J Anaesth. 2008; 101:723–30.

8. Smith CE, Pinchak AB, Sidhu TS, Radesic BP, Pinchak AC, Hagen JF. Evaluation of tracheal intubation difficulty in patients with cervical spine immobilization: fiberoptic (WuScope) versus conventional laryngoscopy. Anesthesiology. 1999; 91:1253–9.

9. Bathory I, Frascarolo P, Kern C, Schoettker P. Evaluation of the GlideScope for tracheal intubation in patients with cervical spine immobilisation by a semi-rigid collar. Anaesthesia. 2009; 64:1337–41.

10. Theiler LG, Kleine-Brueggeney M, Kaiser D, Urwyler N, Luyet C, Vogt A, et al. Crossover comparison of the laryngeal mask supreme and the i-gel in simulated difficult airway scenario in anesthetized patients. Anesthesiology. 2009; 111:55–62.

11. Phua DS, Mah CL, Wang CF. The Shikani optical stylet as an alternative to the GlideScope^® videolaryngoscope in simulated difficult intubations--a randomised controlled trial. Anaesthesia. 2012; 67:402–6.

12. Malik MA, O'Donoghue C, Carney J, Maharaj CH, Harte BH, Laffey JG. Comparison of the Glidescope, the Pentax AWS, and the Truview EVO₂ with the Macintosh laryngoscope in experienced anaesthetists: a manikin study. Br J Anaesth. 2009; 102:128–34.

13. Jeon WJ, Shim JH, Cho SY, Baek SJ. Stylet- or forceps-guided tube exchanger to facilitate GlideScope intubation in simulated difficult intubations--a randomised controlled trial. Anaesthesia. 2013; 68:585–90.

14. MacQuarrie K, Hung OR, Law JA. Tracheal intubation using Bullard laryngoscope for patients with a simulated difficult airway. Can J Anaesth. 1999; 46:760–5.

15. Goutcher CM, Lochhead V. Reduction in mouth opening with semi-rigid cervical collars. Br J Anaesth. 2005; 95:344–8.

16. Sheta SA, Abdelhalim AA, ElZoughari IA, AlZahrani TA, Al-Saeed AH. Parker Flex-It stylet is as effective as GlideRite Rigid stylet for orotracheal intubation by Glidescope. Saudi Med J. 2015; 36:1446–52.

17. Malik AM, Frogel JK. Anterior tonsillar pillar perforation during GlideScope video laryngoscopy. Anesth Analg. 2007; 104:1610–1. discussion 1611.

18. Dow WA, Parsons DG. 'Reverse loading' to facilitate Glidescope intubation. Can J Anaesth. 2007; 54:161–2.

19. Cooper RM. Complications associated with the use of the GlideScope videolaryngoscope. Can J Anaesth. 2007; 54:54–7.

20. Leong WL, Lim Y, Sia AT. Palatopharyngeal wall perforation during Glidescope intubation. Anaesth Intensive Care. 2008; 36:870–4.