A novel way to assured, direct wire-guided tracheal intubation.
The unique design offers access to the unoccupied main lumen of the tracheal tube throughout the intubation process making concurrent, safe delivery of oxygen and ETCO2 monitoring possible, using familiar equipment.
The tube and the guidewire are hybrid in nature and matched, to facilitate efficient guided intubation and to prevent device-related trauma to the airway structures.
One system to accomplish anterograde or retrograde intubation.
The guided tracheal intubation by advancing a tracheal tube over a guidewire inside the trachea is an essential technique, published almost fifty years back [1]. Tracheal tubes of smaller diameter as used in paediatric applications, can be directly railroaded over the guidewire but for the larger tubes, a hollow catheter or flexible scope, as an introducer, over the guidewire is common to accomplish the guided intubation. The technique is universally used to manage difficult tracheal intubations endotracheal tube exchange, intubation during 'staged extubation’ procedure, and retrograde intubation. The incidence of difficulties, failures, and complications associated with the technique are similar to those without a guidewire at the core [2-8]:
Impingement of the tube at the glottic inlet/peri-glottic area [9.]
Misplacement of the tube into pharyngeal recess or intothe oesophagus [9, 10].
**Difficult railroading of the tube [4, 11, 12, 13].
**Iatrogenic trauma to the airway structures.
Failed intubation, repeated attempts to intubate, worsening hypoxia - 'cannot intubate, cannot oxygenate' scenario; demands immediate oxygen delivery into the lungs to avoid deaths and disabilities [14]
Objectives to achieve, therefore, are -
Can the technique be made more consistent?
Can Oxygen be delivered simultaneously with guided intubation?
Can the tissue-trauma be reduced/avoided?**
The 'deformation' or 'change in shape' is essential for the airway, the introducer, and the tracheal tube for the dynamic railroading process. We have little or no control over the consistency of the airway, but the devices used are open to modifications for enhanced capabilities.
To change ‘shape’ during its transit through the tortuous airway, rigidity, flexibility, and elasticity are essential for the devices to support each other in a complementary way by repeated bending and prompt recovery during the railroading. Only hybrid structures of the introducer and the tracheal tube can deliver the required ‘deformation’, as adopted in the NagaTM tracheal intubation system [15, 16, 17].
In current practice, tracheal intubation, and concurrent delivery of oxygen into the lungs is available with Supra Glottic Airway- based sequential technique [18]. However, the success with the technique is difficult due to the dimensional incompatibilities between the devices getting in the way to achieve guided intubation [19].
Is safe delivery of oxygen possible during railroading?
The Naga Intubation System** has achieved it in an innovative way.
- A novel 'guide channel in the wall of the tube accomodates the guidewire in situ to railroad the tube. The unoccupied central lumen becomes available for familiar applications as; oxygen delivery, respiratory gas monitoring, and a port to introduce flexible viewing scope, throughout the railroading.
- Utilisation of the mutual complementary deformation between the kink-resistant tube and the introducer accomplish assured guided intubation with greatly reduced frictional resistance during railroading.
The Naga Tracheal Intubation system is born. (15)
The system has two components:
• a reinforced silicon tracheal tube with a dedicated guide-channel built into its wall and an extended, soft, non-reinforced section at the tip, and
2. a Nitinol core guidewire matched with the tube for dimensions and deformation, as the introducer.
Naga" is the word for a snake in Sanskrit. The Naga tracheal tube's entry into and progress inside the airway mimics a snake's movement from the ground surface into a burrow.
For the publications on the Naga tracheal intubation system, please go to references 15, 16, 19, 24.
References
1. Stiles CM. A flexible bronchoscope for endotracheal intubation of infants. Anesth Analg 1974; 53:1017-9.
2. Joffe AM, Aziz MF, Posner KL, Duggan L, Mincer MSW, Domino KB. Management of Difficult Tracheal Intubation, S Closed Claims Analysis. Anesthesiology 2019;131: 818-29.
3. Cook TM, MacDougall-Davis. Complications and failures of airway management. Br. J Anaesth 2012;109: i68- i85.
3. Mushambi MC, Ali P, Dyson L, Malik D. A national survey of tracheal tube introducers and associated complications. Anaesthesia 2016; 71: 853-4.
4. Asai T, Shingu K. Difficulty in advancing a tracheal tube over a fibreoptic bronchoscope: incidence, causes, and solutions. Br J Anaesth 2004; 92: 870-81.
5. McLean S, Lanam CR, Benedict W, et al. Airway exchange failure and complications with the use of the cook airway exchange catheter®: a single-center cohort study of 1177 patients. Anesth Analg. 2013;117: 1325–7.
6. Cavallone LF, Vannucci. Extubation of the difficult airway and extubation failure. Anesth Analg 2013; 116: 368-383.
7. C. Furyk, M. L. Walsh, I. Kaliaperumal, S. Bentley, C. Hattingh. Assessment of the reliability of intubation and ease of use of the Cook Staged Extubation Set—an observational study. Anaesth Intensive Care 2017; 45:6: 695-99.
8. Lenfant F, Benkhadra M, Trouilloud P, Freysz M. Comparison of two techniques for retrograde tracheal intubation in human fresh cadavers. Anesthesiology 2006;104: 48-51.
9. Jackson AH, Orr B, Yeo C, Parker C, Craven R, Greenberg SL. Multiple sites of impingement of a tracheal tube as it is advanced over a fibreoptic bronchoscope or tracheal tube introducer in anaesthetised, paralysed patients. Anaesth Intensive Care 2006; 34: 444- 9
10. Mort TC, Braffett BH. Conventional versus video laryngoscopy for tracheal tube exchange: glottic visualization, success rate, complications, and rescue alternatives in the high-risk difficult airway patient. Anesth Analg 2015; 121: 440–8.
11. Jackson GNB, Bartlett R, Yentis SM. Forces required to remove bougies from tracheal tubes. Anaesthesia 2009; 64: 320-322.
12. Arya VK, Makker S. Impacted gum elastic bougie in ETT after intubation of a difficult airway. Journal of Clinical Anesthesia 2007; 19: 566.
13. Prasad MMV, Lim KS, Kumar CM. Tracheal injury using a gum elastic bougie within a RAE endotracheal tube. Anaesth Intensive Care 2016; 44: 428.
14. Karen B Domino. Death and brain damage from difficult airway management: a “never event”. Can J Anesth 2021; 68; 169-174.
15. Dhara SS, McGlone DJ, Skinner MW. Development of a new system for guidewire-assisted tracheal intubation: manikin and cadaver evaluation. Anaesthesia. 2016;71: 44-9.
16. SS Dhara, P Kundra. Complementary deformation of tracheal tubes and flexible introducers: a prerequisite to a secured guided tracheal intubation. J C Monit Comp 2019, 34, 381-383.
17. Ponnusamy T, Kundra P, Rudingwa P, Gopalakrishnan S. Comparison of laryngeal morbidities with modified reinforced silicone tube intubation guided over a bougie vs. a guidewire: novel assessment with voice analysis. Anaesthesia 2018; 73: 730-7.
18. 1. Cooper J R Jr. Use of a LMATM and a sequential technique for unanticipated difficult intubations. Anesthesiology 2002; 97: 1326.
19. Moser B, Kemper M, Kline Brueggegney M, Gasteiger L, Weiss M. Dimensional compatibility and limitations of tracheal intubation through supraglottic airway devices: a manikin based in vitro study. Can J Anesth 2021; 68: 1337-1348.