1. High airway obstruction
Congenital
Craniofacial dimorphism
Paralysis of the vocal chords
Subglottic hemangioma
Subglottic membrane
Upper subglottic or tracheal stenosis
Pharyngeal collapse
Severe laryngomalacia
Acquired
Secondary subglottic stenosis
Severe obstructive sleep apneas
Papillomatosis
Burn injuries
Tumors
2. Prolonged need of MV
Congenital
Neuromuscular disorders
Central hypoventilation
Diaphragmatic hernia
Severe bronchopulmonary dysplasia
Acquired
Traumatic chest injuries
CNS tumors
Severe chronic lungs damage
Severe scoliosis
3. Lung hygiene
Classification of degree of subglottic obstruction
From | To | |
|---|---|---|
I degree |
No obstruction |
50% of lumen obstruction |
II degree |
51% of lumen obstruction |
70% of lumen obstruction |
III degree |
71% of lumen obstruction |
99% of lumen obstruction |
IV degree | No detectable lumen |
Most instances of stenosis in children happen as a result of endotracheal intubation, because the sub glottis, contained by the cricoid cartilage —a full ring that cannot dilate nor accommodate— becomes swollen at the epithelium by the mechanical injury of the tube, reducing the caliber of the airway. When these scars narrow, the result is subglottic stenosis. Grade IV stenosis by Myer–Cotton’s system has an absolute indication of tracheotomy, but for grade II and III stenosis it will depend on the degree of respiratory compromise.
For patients with respiratory failure caused by severe lung disease or by neuromuscular, neurological, or heart diseases, who also depend on mechanical ventilation for over 12 hours a day, tracheotomy is considered. In the case of acute respiratory failure requiring mechanical ventilation for over 21 days, tracheotomy may also be considered. The benefit of prolonged mechanical ventilation through tracheotomy lies in the reduction of laryngeal damage, improving the level of comfort for the patient, and improving their daily activities like mobility, speech, and oral feeding.
Tube Selection
Once the tracheotomy has been performed, it is necessary to insert a tube in order to keep the airway open and permeable. This tube is the tracheotomy cannula. There are different kinds of tubes designed to adjust to the appropriate needs of each patient.
Metal (stainless steel, silver): rigid tubes
PVC (polyvinyl chloride): may be rigid or flexible
Polyurethane
Silicone: these tubes are preferred for their flexibility, as they adapt to the size and shape of the patient’s trachea
Simple or double tube
With cuff or balloon: there is an inflatable device on the distal end of the tube. These tubes may be: high volume/low pressure, low volume/high pressure, and foam balloon. High volume/low pressure is the preferred option given their lower injury risk to the airway. Indications for using balloon are given mainly to lower the risk of aspiration, need of mechanical ventilation at high pressure, night ventilation, and for patients with chronic aspiration.
Fenestrations: they improve trans-laryngeal flux and phonation, while also improving the handling of discharges. However, different studies have shown that these promote the emergence of granulomas on the fenestration area, so the use of the technique has been limited.
Internal cannula: these tubes are indicated for patients with abundant thick discharges that stick to the walls of the tube. In this way, it is only necessary to remove the internal cannula during the cleaning procedure, thus avoiding frequent tracheotomy tube switching.
Age: patients under 1 year must use cannulas that are specially designed for newborns.
Reason for tracheotomy: in case of upper airway obstruction or if prolonged mechanical ventilation is needed.
Diameter and curvature of the tube: the size of tracheotomy tubes is based on internal diameter, much like the selection of endotracheal tubes. When choosing the right diameter, many factors must be considered, including lung mechanics, upper airway resistance, need for ventilation/union, and procedure indications. The diameter must be wide enough to avoid damage to the wall of the trachea, minimize respiratory work, and promote laryngeal airflow. It should not exceed two thirds of the diameter of the trachea, thus avoiding damage to the wall of the trachea and allowing trans-laryngeal flow. Its curvature must be such that the distal portion of the cannula becomes aligned and concentric toward the trachea. It is recommended to confirm both position and adequate size of the cannula the first time it is placed in the larynx through a neck X-ray or a fibrobronchoscopy.
Length of the cannula: the length of the cannula must be at least 2 cm beyond the stoma and remain 1–2 cm over the carina.
Characteristic of tracheotomy cannulas
Age | PT-1 m | 1–6 m | 6–18 m | 18 m -3a | 3–6 a | 6–9 a | 9–12 a | 12–14 a | |
|---|---|---|---|---|---|---|---|---|---|
Trachea | Diameter (mm) | 5 | 5–6 | 6–7 | 7–8 | 8–9 | 9–10 | 10–13 | 13 |
Shiley | Size | 3.0 | 3.5 | 4.0 | 4.5 | 5.0 | 5.5 | 6.0 | 6.5 |
ID (mm) | 3.0 | 3.5 | 4.0 | 4.5 | 5.0 | 5.5 | 6.0 | 6.5 | |
ED (mm) | 4.5 | 5.2 | 5.9 | 6.5 | 7.1 | 7.7 | 8.3 | 9.0 | |
Length NB (mm) | 30 | 32 | 34 | 36 | – | – | – | – | |
Length PED (mm) | 39 | 40 | 41 | 42 | 44∗ | 46∗ | – | – | |
Length PDL (mm) | – | – | – | – | 50∗ | 52∗ | 54∗ | 56∗ | |
Portex | Size | 2.5 | 3.0 | 3.5 | 4.0 | 4.5 | 5.0 | 5.5 | – |
ID (mm) | 2.5 | 3.0 | 3.5 | 4.0 | 4.5 | 5.0 | 5.5 | – | |
ED (mm) | 4.5 | 5.2 | 5.8 | 6.5 | 7.1 | 7.7 | 8.3 | – | |
Length NB (mm) | 30 | 32 | 34 | 36 | – | – | – | – | |
Length PED (mm) | 30 | 36 | 40 | 44 | 48 | 50 | 52 | – | |
Tracoe | Size | 2.5–3.0 | 3.5 | 4.0 | 4.5 | 5.5 | 5.5 | 6.0 | – |
ID (mm) | 2.5–3.0 | 3.5 | 4.0 | 4.5 | 5.5 | 5.5 | 6.0 | – | |
ED (mm) | 3.6–4.3 | 5.0 | 5.6 | 6.3 | 7.0 | 7.6 | 8.4 | – | |
Length NB (mm) | 30 32 | 34 | 36 | – | – | – | – | – | |
Length PED (mm) | 32 36 | 40 | 44 | 48 | 50 | 55 | 62 | – | |
Rüsch | Size | – | 3.0 | 4.0 | – | 5.0 | – | 6.0 | – |
ID (mm) | – | 3.0 | 4.0 | – | 5.0 | – | 6.0 | – | |
ED (mm) | – | 4.8 | 6.0 | – | 7.0 | – | 8.2 | – |
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