SOE 558: Anatomy for Tracheostomy Insertion

Introduction

You review a man on the intensive care ward round who has been intubated for 3 weeks. He was admitted with a community-acquired pneumonia and has been difficult to wean from mechanical ventilation. You suggest the insertion of a percutaneous tracheostomy to aid weaning from the ventilator…

Question No. 2

Q: What is the preferred site of insertion for percutaneous tracheostomy and why?

Answer No. 2

Preferred site of tracheostomy is between the 2nd and 3rd tracheal rings in the midline
Tracheostomy above this site:
- Can lead to damage to the cricoid cartilage and first tracheal ring
- Results in increased risk of subglottic stenosis which is difficult to treat
Tracheostomy below this site:
- Can lead to damage to the thyroid and great vessels at the root of the neck
- Results in increased risk of significant bleeding

Question No. 3

Q: Which surface landmarks in the anterior neck are palpable and useful when determining the correct site for a percutaneous tracheostomy?

Answer No. 3

Question No. 4

Q: What is the structure and course of the trachea?

Answer No. 4

Tube of cartilage with a membranous lining continuous with the larynx
- Composed of 16–20 C-shaped cartilaginous rings
- Trachealis muscle completes the posterior wall
Around 10-12 cm in length
- Extends down from cricoid at C6
- Terminates at carina at T5-
Moves anteriorly to posteriorly from the cricoid distally
- Enters the chest behind the sternal notch

Question No. 5

Q: Which structures are in close relationship to the trachea?

Answer No. 5

Anterior Relations

Skin and fascia
Isthmus of thyroid
Sternothyroid and sternohyoid muscles
Manurbrium sternum
Thymus gland

Lateral Relations

Lobes of thyroid
Carotid sheath
Lungs and pleura
Arch of aorta, brachiocephalic and subclavian arteries

Posterior Relations

Oesophagus
Recurrent laryngeal nerve

Question No. 6

Q: Which vessels are at risk of damage during tracheostomy?

Answer No. 6

Anterior jugular veins:
- Run vertically close to the midline
Thyroid ima artery :
- Ima is 'lowest' in Latin
- Anatomical variant in 3–10% of the population
- More common British Asian populations
- Arises mainly from the brachiocephalic trunk and ascends along the front of the trachea
Inferior thyroid veins
Other vessels more lateral: internal jugular vein, carotid artery, external jugular vein

Question No. 7

Q: What are the indications for a tracheostomy?

Answer No. 7

Overcome Upper Airway Obstruction (Actual or Potential)

Tumour
Bilateral recurrent laryngeal paresis
Oral / facial trauma
Infection in oral cavity, pharynx or larynx
Burns
Following certain head and neck surgery

Facilitate Airway Protection and Secretion Management

Laryngeal incompetence due to critical illness, polyneuropathy, or bulbar dysfunction
Neurological disease
Traumatic brain injury

Facilitate Weaning from Mechanical Ventilation

Any reversible condition requiring ventilatory support

Provide Lifelong Ventilation

High C-spine injury

Question No. 8

Q: Is there any evidence to suggest early tracheostomy is superior to late tracheostomy to aid weaning from ventilation?

Answer No. 8

No high-quality studies have definitively answered the question of whether routine, early tracheostomy improves clinical outcomes:
- Studies are difficult to design
- Doctors are poor at predicting which patients may undergo successful extubation within the next few days, thereby avoiding unnecessary tracheostomy
Accumulated evidence and expert opinion suggest early tracheostomy does not improve survival or even shorten hospital stay
The largest trial to explore the question is the TRACMAN trial:

Population

Intervention

Conclusion

RCT: TRACMAN

Young et al
JAMA (2013)

View Paper

Intubated and ventilated patients expected to require at least seven further days of ventilation
Excluded those with potential indications for early tracheostomy (airway obstruction, neurological illness, TBI)

Early (within four days of admission) vs. late (on/after day 10) tracheostomy
Primary outcome 30-day mortality

No difference in mortality at any point over the two-year follow-up
Early group:
Non-significant trend towards shorter duration of mechanical ventilation
Significantly fewer days of sedation administration
Late group:
Only 43% of the patients in the late group went on to receive a tracheostomy (many not intubated)
6.3% complication rate for the tracheostomies that were performed

The Bottom Line Review

Meta-analysis: Cochrane Review

Andriola et al
Cochrane Database (2015)

View Paper

Eight RCTs with a total of 1,977 participants

Early tracheostomy (two to 10 days after intubation) vs. late tracheostomy (> 10 days after intubation) for critically ill adult patients

Results from seven RCTs (n = 1903) showed lower mortality rates in the early as compared with the late tracheostomy group (risk ratio (RR) 0.83, P value 0.03)
However due to low quality evidence review concluded results "no more than suggestive of the superiority of early over late tracheostomy"

Question No. 9

Q: What are the advantages of a tracheostomy?

Answer No. 9

Reduction in laryngeal and vocal cord trauma
- Prolonged intubation associated with injury such as pressure necrosis and mucosal abrasions
Reduced sedation requirement (better tolerated than ETT)
Facilitation of gradual weaning from mechanical ventilation:
- Reduced work of breathing
- Reduced resistance and dead space
Improved oral hygiene
Allows rehabilitation:
- Improved mobility, speaking, oral intake
- Improved patient communication (written or spoken)
Improved patient comfort
Reduced LOS in ICU
Reduced nursing care required

Question No. 10

Q: What are the different techniques for front of neck airway access?

Answer No. 10

Surgical Tracheostomy

An open surgical procedure that allows insertion of a tracheostomy tube into the trachea between cartilaginous rings.

Percutaneous Dilatational Tracheostomy

Refers to various procedures that have in common either a modified Seldinger technique for placing a modified tracheostomy tube or a forceps technique to cannulate and dilate tracheal tissue between cartilaginous rings
Used for over 90% of ICU tracheostomies with over two-thirds of all tracheostomy procedures are now performed by intensivists in ICUs rather than by surgeons

Cricothyroidotomy

Technique for placement of an airway into the trachea through the cricothyroid space
Can be performed as a surgical procedure through an incision, as a percutaneous procedure by a Seldinger technique, or as a needle cricothyroidotomy for emergency airway access.

Mini Tracheostomy

Allows percutaneous placement of a 7F cannula through the tracheal rings to allow suctioning for patients with difficulty clearing airway secretions

Question No. 11

Q: What are the advantages and disadvantages of surgical / percutaneous tracheostomies?

Answer No. 11

Percutaneous

Surgical

Advantages

Relatively quick in experienced hands
Avoids need for transfer of unstable patients
Does not require involvement of surgeons
Cheaper
Smaller scar
Tighter stoma that decreases stomal bleeding and provides better fit

Can be performed when percutaneous contraindicated:
- Short or thick neck, obese
- Coagulopathy
- Unstable spine
- Previous neck / thyroid surgery
- Abnormal vessels
Resources available to control bleeding
Potentially easier management in event of early tube dislodgment or tube exchange:
- Stoma stitched open
- May have stay sutures to elevate the trachea

Disadvantages

Suboptimal conditions for management of bleeding, especially if major vessel injured
Blind techniques can be incorrectly positioned
Tracheal ring fracture can occur
Late tracheal stenosis (as per surgical tracheostomy)
Lack of surgical dissection can increase risk of vascular or thyroid injury
Potentially more difficult management in event of early tube dislodgment or tube exchange:
- Tissues will tend to ‘spring’ closed when tube removed in first 7–10 days

Requires operating theatre leading to delays in insertion
Requires patient transfer
More expensive

Question No. 12

Q: What are the contraindications to tracheostomy?

Answer No. 12

Absolute Contraindications

Patient Refusal
Unstable fractures of the cervical spine
Severe local infection of the anterior neck
Uncontrollable coagulopathy

Relative Contraindications

Lack of need:
- Unlikely to survive >48 hours
- Unlikely to require >2 weeks ventilation
Controlled local infection
Coagulopathy:
- PT or APTT >1.5
- Platelets <50
High PEEP (>10) or FiO2 (>0.6) requirements
Difficult anatomy (contraindication to percutaneous tracheostomy, surgical tracheostomy advised):
- Abnormal or prominent vasculature at insertion site
- Morbid obesity
- Short thick neck
- Reduced neck extension
- Excessive goiter
- Tracheal deviation
- Previous radiotherapy
- Proximity to extensive burns or surgical wounds
Elevated intracranial pressure
Haemodynamic instability

Question No. 13

Q: What are the complications of percutaneous tracheostomy?

Answer No. 13

Immediate (During Insertion)

Arrest and Death (1/600)
Haemorrhage (minor or severe) - 4.8%
Misplacement (pre-tracheal tissues or to main bronchus)
Hypoxia
Injury to local structures:
- Pneumothorax and surgical emphysema
- Oesophageal perforation
- Vascular injury
- Thyroid injury
- Posterior tracheal wall injury
- Laryngeal nerve damage
- Tracheal ring fracture
Air embolism
Equipment issues:
- Incorrect tube / size
- Equipment malfunction

Delayed (Post Insertion)

Tube blockage with secretions (may be sudden or gradual)
Tube migration to pre-tracheal space
Accidental decannulation
Infection:
- Stoma site
- Bronchial tree
- VAP
Erosion related:
- Tracheal ulceration or necrosis
- Tracheo-oesophageal fistula formation
- Tracheo-innominate fistula

Late (Post Decannulation)

Tracheal injury / dysfunction:
- Tracheal stenosis at the cuff site
- Tracheomalacia
- Vocal cord dysfunction
- Persistent sinus at the tracheostomy site
Granulomata of the trachea
Tracheo-innominate fistula
Psychological impact related to stoma