---

Tracheostomy - Comprehensive ENT Review

---

1. DEFINITIONS

• Scott-Brown's Vol 3, p. 1083

---

2. TYPES OF STRIDOR

A. Inspiratory Stridor

• Obstruction at or above the vocal folds
• Most common causes: inhaled foreign body, acute epiglottitis
• Characteristic of supraglottic/glottic level pathology

B. Expiratory Stridor

• Originates from the lower respiratory tract
• Produces a prolonged expiratory wheeze
• Most common causes: acute asthma, acute infective tracheobronchitis

C. Biphasic Stridor

• Obstruction or disease of the tracheobronchial airway and distal lungs
• Occurs in both phases of respiration

Stridor in Children - Differential Diagnosis

• Laryngomalacia (most common; worsens with activity, crying, movement)
• Laryngeal web
• Subglottic stenosis
• Vocal cord palsy (weak cry)
• Vascular ring (worsens with feeding)
• Tracheoesophageal fistula

• Acute epiglottitis: inspiratory stridor + drooling (do NOT examine pharynx - risk of precipitating obstruction)
• Laryngotracheobronchitis (croup): biphasic stridor without drooling
• Bacterial tracheitis: croup non-responsive to steroids/adrenaline
• Retropharyngeal/peritonsillar abscess

• Associated with swallowing/crying/movement = laryngomalacia or subglottic stenosis
• Worsens with feeding (first 4 weeks) = vascular ring or TOF
• Weak/abnormal cry = vocal cord palsy
• Biphasic with URTI = congenital subglottic stenosis

---

3. TYPES OF TRACHEOSTOMY

A. By Duration/Intent

B. By Technique

---

4. INDICATIONS FOR TRACHEOSTOMY

1. Upper airway obstruction - ultimate form of airway control
2. Prolonged mechanical ventilation - most common indication in critically ill patients
3. Neurological condition preventing safe extubation - brain injury, spinal cord injury, severe agitation, altered mental status
4. Removal of secretions - inability to clear tracheobronchial secretions
5. As part of another procedure - major head/neck resection, laryngectomy

• Reduced sedation (no glottic stimulation)
• Reduced dead space
• Reduced tube resistance and work of breathing
• Improved mouth care
• Ongoing bronchial toilet during weaning

• Recent anterior neck surgery (<7 days)
• High ventilator settings (FiO2 >50%, PEEP >10 cmH2O)
• Elevated ICP
• Hemodynamic instability
• Significant coagulopathy/bleeding risk
• Local infection or malignancy at site
• Predicted early mortality (psychological and ethical consideration)

---

5. EFFECTS OF TRACHEOSTOMY

• Laryngeal bypass - loss of cough reflex and phonation
• Reduction in respiratory dead space (~150 mL reduction)
• Bypasses upper airway warming, humidification, and filtering function
• Tethers larynx, reducing laryngeal elevation during swallowing

---

6. HIGH VOLUME LOW PRESSURE (HVLP) CUFF

Concept

• Tracheal mucosal capillary perfusion pressure is approximately 25-30 mmHg
• When cuff pressure exceeds capillary perfusion pressure, ischemic necrosis and chondritis of underlying tracheal cartilages results, eventually leading to tracheal stenosis
• HVLP cuffs are designed to achieve an airtight seal at pressures below capillary perfusion pressure

Design and Function

• Large-volume, thin-walled balloon that conforms to the tracheal wall at low pressure
• Distributes pressure over a wider mucosal surface area, keeping pressure at any single point below ischemic threshold
• Recommended cuff pressure: 20-25 mmHg (or "minimal occlusive volume" technique)
• Prevents: mucosal ischemia, tracheomalacia, tracheal stenosis

Comparison

• Silicone TTS tubes must be filled with sterile water (not air) when cuff inflation is required, as air diffuses through the silicone cuff wall
• The overall rate of tracheal stenosis has markedly decreased since the 1960s due to the introduction of HVLP cuffs

Cuff Management

• Inflate cuff using a syringe via the Luer-Lok pilot balloon port
• Check cuff pressure with a handheld manometer
• Deflate once risk of aspiration has passed - in most cases no cuff inflation is needed after the first 12 hours
• Over-inflation is as harmful as under-inflation

---

7. TRACHEOSTOMY TUBE TYPES

A. Components of a Standard Tube

1. Outer cannula - permanent component; not removed unless complications arise or tube change needed; has flanges with eyelets for securing tapes
2. Inner cannula - removable for cleaning; reduces obstruction risk
3. Obturator - rounded/cone-shaped; inserted into outer cannula to facilitate insertion; extends a few mm beyond distal end; removed immediately after insertion

B. Materials

• Metal (silver/steel): low profile; no 15-mm connector; no cuff; NOT suitable for mechanical ventilation; used for long-term established tracheostomies
• Plastic (PVC/silicone): variety of shapes/sizes; can connect to ventilator circuits; most modern tubes

C. Sizing

• Sized by internal diameter (ID) at smallest dimension
• Rule of thumb: most women = OD 10 mm; most men = OD 11 mm
• Smallest ID that meets patient's needs should be selected (larger ID = lower resistance)
• Resistances (Shiley tubes): size 4 = 11.4 cmH2O/L/s; size 6 = 3.96; size 8 = 1.75; size 10 = 0.69

D. Special Designs

• Extra-proximal length (horizontal): for obese neck or anterior neck masses
• Extra-distal length (vertical): to bypass distal stenosis or malacia
• Adjustable flange / custom flexible tubes: for unusual anatomy
• Fenestrated tubes: fenestrations in superior posterior arch allow air past vocal cords enabling speech (use fenestrated inner cannula)
• Cuffless tubes: for patients not requiring mechanical ventilation; alert, adequate ventilatory effort, low aspiration risk
• Speaking valves (Passy-Muir, Shiley Phonate): one-way valves attached to 15-mm hub; allow inspiration through tube, expiration through vocal cords and mouth
• Tracheal buttons: maintain stoma patency during weaning; hollow outer cannula, solid inner cannula; useful if decannulation is not possible

---

8. SURGICAL STEPS: OPEN SURGICAL TRACHEOSTOMY

Pre-operative Preparation

1. Obtain informed consent - discuss risks including haemorrhage, infection, tracheal stenosis, tube obstruction, decannulation problems, voice changes
2. Coordinate with anaesthetist - discuss tube position, withdrawal plan, ventilator management
3. Check tracheostomy tube size and that cuff and all equipment function properly before opening the trachea
4. Position the patient

Patient Positioning

• Supine with neck extended - sandbag/roll placed under shoulders
• Patient square on the table with shoulders at the same level (ensures midline structures remain in midline)
• Under local anaesthesia: limit neck extension to avoid further airway restriction

Step-by-Step Procedure

• Horizontal incision midway between the sternal notch and the lower border of the cricoid cartilage
• Length: approximately 3-4 cm

• Incise through skin and subcutaneous fat
• Continue dissection to the strap muscles (sternohyoid and sternothyroid)

• Blunt dissection in the midline to separate strap muscles
• Retract strap muscles laterally with self-retaining retractors
• Thyroid isthmus should now be visible

• Clamp, divide, and transfix the isthmus (to avoid thyroid bleeding obscuring the field)
• Anterior tracheal wall is now exposed

• Identify the cricoid cartilage to plan the tracheotomy level
• Ideal level: between the 2nd and 4th tracheal rings
• Avoid the 1st ring (risk of subglottic stenosis) and very low placement (innominate artery risk)

• Give clear warning before entering the trachea
• Reduce FiO2 if possible (reduces airway fire risk with diathermy)

• Vertical slit between stay sutures placed on either side of the midline
• Guiding principle: cause as little disruption to the trachea as possible
• Maintain cartilage integrity; avoid damage to cricoid cartilage
• Bjork flap: an inferior-based tracheal flap (not universally used; increases risk of persistent tracheocutaneous fistula)

• Anaesthetist withdraws the endotracheal tube under surgeon's direct vision
• Stop withdrawal when ETT tip is immediately above the tracheotomy opening

• Insert the tracheostomy tube (with obturator in place)
• Remove obturator
• Inflate cuff
• Connect to ventilator
• Confirm position (breath sounds, ETCO2, capnography)

• Close wound loosely (tight closure risks subcutaneous emphysema)
• Secure tube with neck tapes, sutures, or both
• Dressings applied

---

9. PERCUTANEOUS DILATATIONAL TRACHEOSTOMY (PDT)

History

• First described by Ciaglia et al. in 1985; technique based on the Seldinger principle
• Ciaglia's serial dilator technique is the most common in the UK
• Variants: single tapered dilator (Ciaglia Blue Rhino), dilating forcep (Griggs), Blue Dolphin balloon dilation

Positioning

• Same as for open surgical tracheostomy (supine, neck extended, sandbag under shoulders)

Technique

1. Partially withdraw the endotracheal tube under GA and neuromuscular blockade (tube tip remains above carina)
2. Palpate and identify the trachea
3. Needle insertion just below the 1st tracheal cartilage ring using a needle and cannula with a saline-filled syringe (aspiration of air through saline confirms intratracheal position)
4. Withdraw needle and thread guidewire through cannula into trachea
5. Remove cannula
6. Pass either a single tapered dilator or serial dilators of increasing diameter over the guidewire to create a passage wide enough for the tracheostomy tube
7. Insert tracheostomy tube over the guidewire (with obturator in situ)
8. Remove guidewire and obturator
9. Inflate cuff, connect to ventilator, confirm position

PDT vs. Open Surgical: Key Comparisons

• PDT: less wound infection, similar overall complication rate, more cost-effective, periprocedural mortality <0.2%
• Open: preferred in obesity (appropriate PDT kit availability), anatomical variance (previous surgery, goitre), significant coagulopathy/bleeding diatheses

---

10. COMPLICATIONS OF TRACHEOSTOMY

A. IMMEDIATE (Intraoperative)

B. EARLY / INTERMEDIATE (Within first week)

C. LATE (After 1 week - weeks to months)

---

11. MANAGEMENT OF THE DIFFICULT AIRWAY IN OPERATIVE CASES

Definition

Pre-operative Airway Assessment (LEMON)

• L - Look externally (facial trauma, beard, obesity, short neck, high Mallampati)
• E - Evaluate 3-3-2 rule (3 finger mouth opening; 3 finger thyromental distance; 2 finger thyrohyoid distance)
• M - Mallampati score (I-IV)
• O - Obstruction/Obesity
• N - Neck mobility

ASA Difficult Airway Algorithm - Four Core Considerations

• Difficulty with patient cooperation/consent
• Difficult mask ventilation
• Difficult supraglottic airway placement
• Difficult laryngoscopy
• Difficult intubation
• Difficult surgical airway access

• Awake intubation vs. intubation after induction of GA
• Non-invasive vs. invasive techniques as the initial approach
• Video-assisted laryngoscopy as the initial approach
• Preservation vs. ablation of spontaneous ventilation

Key Decision: Awake vs. Asleep Intubation

• Significant anatomical airway difficulty anticipated
• Refractory hypoxemia, right heart failure, severe metabolic acidosis (brief laryngoscopy failure combined with rapid physiologic decline can cause arrest)
• Cervical spine instability
• Unable to open mouth adequately for direct laryngoscopy

• Awake fibreoptic intubation (AFI): gold standard; nasal or oral route; requires topical local anaesthesia (lidocaine 4% via mucosal atomiser, transtracheal injection, nerve blocks); patient cooperative and sedated but breathing
• Awake video laryngoscopy: increasingly used; C-MAC, McGrath, GlideScope
• Both are acceptable; choice depends on operator expertise and patient factors

Step-by-Step Approach in Theatre (Anticipated Difficult Airway)

• Standard: 100% O2 at 15 L/min via non-rebreather mask for 3 minutes (normal tidal volumes)
• Preferred: flush-rate oxygen (40-70 L/min) to outcompete room air entrainment, achieves higher FiO2
• Goal: denitrogenation to create an oxygen-rich alveolar reservoir
• Apnoeic oxygenation (ApOX): nasal cannula O2 at 5-15 L/min during laryngoscopy
• Time to safe apnoea: up to 6-8 minutes in healthy adults; shorter in obese, children, pregnant, critically ill
• Head-up positioning in obese patients extends safe apnoea time

• Have video laryngoscope, fibreoptic scope, LMA/iLMA, surgical airway equipment ready

• Repeated failed attempts cause progressive trauma, oedema, bleeding - making a "can manage" situation into a "cannot manage" situation
• Maximum 3 attempts with different techniques before declaring failure

• LMA (classic), i-gel, ProSeal LMA
• Second-generation devices (i-gel, ProSeal) have a good safety/efficacy profile and are replacing first-generation devices
• iLMA as conduit for blind or fibreoptic-guided intubation

• Once declared, proceed immediately to Front of Neck Airway (FONA)
• Do NOT repeat the same failed technique
• Scalpel-Bougie Cricothyroidotomy is the recommended technique (Difficult Airway Society UK guidelines):
  1. Stabilise the larynx
  2. Large horizontal stab incision through skin AND cricothyroid membrane
  3. Tracheal hook retracts inferior skin flap and keeps membrane open
  4. Bougie inserted caudally into trachea
  5. 6.0 cuffed ETT railroaded over bougie
  6. Inflate cuff, ventilate, confirm by capnography
• Needle cricothyroidotomy has been shown to be ineffective in altering outcome in CICO events and is NOT the DAS-recommended primary FONA technique

Special Situations in ENT/Head & Neck Surgery

• Options:
  1. Awake fibreoptic intubation (preferred if lumen is adequate)
  2. Tracheostomy under local anaesthesia (awake tracheostomy) - patient breathing spontaneously throughout
  3. Laser debulking prior to definitive airway - lower risk than tracheostomy, preserves incision planning, avoids stomal seeding of carcinoma, allows earlier definitive treatment
  4. GA induction with inhalational induction (sevoflurane) to maintain spontaneous ventilation
  5. Rigid bronchoscopy under jet ventilation

• For choice of anaesthesia: stable, intubated patients may require extubation for bronchoscopic inspection prior to tracheostomy
• Communication with surgical team paramount - ETT repositioning needed during procedure
• Once tracheostomy placed, attach to anaesthesia circuit via clean connector; confirm position
• In emergency/cannot-intubate patients: local anaesthesia + sedation, or GA via face mask/LMA

• Maintain spontaneous ventilation (controlled positive pressure ventilation may push object distally or cause ball-valve obstruction making ventilation impossible)
• Controlled vs. spontaneous ventilation is controversial but spontaneous is usually preferred

• After major head/neck surgery (thyroid, parotid, neck dissection): haematoma most common cause
• Immediate management: Open wound, evacuate haematoma at bedside if tension develops
• After tonsillectomy/adenoidectomy: blood, oedema, laryngospasm
• Steroid use (dexamethasone) reduces post-extubation stridor

---

12. POST-OPERATIVE TRACHEOSTOMY CARE

• Humidification is essential: inspired air bypasses upper airway warming/humidification; hot water bath humidifiers or nebulisers prevent tube obstruction by crust formation
• Suctioning: frequent in early post-op period; decreases as patient learns to clear secretions by coughing
• Tube security: tapes/sutures - must allow two fingers under the tapes
• Inner cannula: clean regularly; replace if obstructed
• Decannulation: stepwise downsizing, corking trials, speaking valve trials; multidisciplinary team (surgeon, speech therapist, respiratory therapist)

Multidisciplinary Tracheostomy Team

• Use of MDT protocols decreases tracheostomy-related morbidity, promotes earlier decannulation, and improves quality of life
• The American Academy of Otolaryngology-HNS consensus statement (2011) recommends standardisation of care

---

13. SUMMARY TABLE: COMPLICATIONS AND TREATMENT

---

Key Teaching Points from ENT Textbooks:

• Emergency tracheostomy is rare and often a sign of underestimated severity - most situations allow an urgent procedure under local anaesthesia with a spontaneously breathing patient.
• In CICO, the Scalpel-Bougie cricothyroidotomy is the DAS-recommended technique; needle cricothyroidotomy is ineffective as a definitive rescue.
• HVLP cuffs revolutionised tracheostomy safety by reducing tracheal stenosis - maintain pressure below 25 mmHg.
• The tracheotomy should be sited between the 2nd and 4th tracheal rings; damage to the cricoid is a serious complication that must be immediately recognised and repaired.
• Tracheoinnominate artery fistula carries ~50% operative mortality and is the most feared late haemorrhagic complication.