2.1 Airway Management

AM 1.6 Discuss the clinical features, possible causes and management of perioperative airway obstruction

Clinical Features

1. Signs of Obstruction:

   • Stridor, wheezing, or gurgling.

   • Paradoxical chest and abdominal movement (increased effort without airflow).

   • Reduced or absent breath sounds on auscultation.

   • Cyanosis or hypoxemia (SpO₂ drop).

   • Hypercapnia (increased EtCO₂) or loss of capnographic waveform.

2. Hemodynamic Changes:

   • Tachycardia or bradycardia.

   • Hypotension in severe cases due to hypoxemia.

3. Visualization:

   • Visible swelling, hematoma, or foreign body in the oropharynx.

   • Airway collapse or obstruction on bronchoscopy or laryngoscopy.

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Possible Causes

1. Anatomical Obstruction:

   • Tongue or soft tissue obstruction (e.g., in sedated patients).

   • Laryngospasm.

   • Foreign body or secretions (e.g., blood, vomit, mucus).

2. Pathological:

   • Airway swelling (e.g., anaphylaxis, angioedema).

   • Trauma or hematoma (e.g., post-intubation injury).

   • Airway masses (e.g., tumors, goiter, epiglottitis).

3. Mechanical Issues:

   • Endotracheal tube (ETT) kinking, dislodgement, or blockage.

   • Equipment malfunction (e.g., valve failure in ventilators).

4. Neuromuscular Issues:

   • Incomplete reversal of neuromuscular blockade.

   • Vocal cord paralysis or dysfunction.

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Management

1. Immediate Action:

   • Call for Help: Engage experienced colleagues and prepare for advanced airway intervention.

   • Oxygenation: Administer 100% oxygen via facemask, bag-valve mask, or supraglottic airway device.

   • Clear Obstruction:

     • Suction secretions or remove foreign bodies.

     • Reposition the head (e.g., chin lift, jaw thrust).

2. Specific Interventions:

   1. Laryngospasm:

      • Apply continuous positive airway pressure (CPAP) with 100% oxygen.

      • Administer small doses of IV muscle relaxants (e.g., succinylcholine).

   2. Swelling/Anaphylaxis:

      • Administer adrenaline, corticosteroids, and antihistamines.

      • Prepare for surgical airway if swelling progresses.

   3. ETT Issues:

      • Check for kinks or obstruction; replace tube if necessary.

3. Advanced Airway Management:

   • Perform laryngoscopy, fiberoptic intubation, or cricothyroidotomy in extreme cases.

4. Post-Event Care:

   • Monitor closely for recurrence or complications.

   • Investigate underlying causes (e.g., imaging, allergy testing).

   • Document and debrief with the team.

AM 1.7 Outline an appropriate ventilation strategy, including different modes of ventilation, suitable for elective and emergency patients

Principles of Ventilation:

• Goals: Ensure adequate oxygenation and ventilation while minimizing lung injury.

• Assess patient-specific factors: age, comorbidities, surgical procedure, and urgency of intervention.

• Use protective ventilation strategies: low tidal volumes (4-8 mL/kg predicted body weight) and appropriate PEEP levels.

Modes of Ventilation:

• Volume-Controlled Ventilation (VCV):

  • Delivers a preset tidal volume.

  • Suitable for controlled environments like elective surgery.

  • Risks: potential barotrauma in patients with poor compliance.

• Pressure-Controlled Ventilation (PCV):

  • Delivers a preset pressure; tidal volume varies.

  • Useful for patients with variable lung compliance (e.g., obesity, ARDS).

• Pressure-Support Ventilation (PSV):

  • Patient-triggered; supports spontaneous breaths.

  • Ideal for awake or recovering patients and during emergence.

• SIMV (Synchronized Intermittent Mandatory Ventilation):

  • Combines mandatory breaths with patient-initiated breaths.

  • Useful in transitioning between controlled and spontaneous ventilation.

Ventilation in Elective Patients:

• Preoperative considerations: optimise pulmonary function, especially in patients with respiratory comorbidities.

• Tailor ventilation to surgical needs (e.g., laparoscopic surgeries may require higher PEEP to counteract pneumoperitoneum effects).

• Use neuromuscular blockade to ensure synchrony in controlled modes if necessary.

Ventilation in Emergency Patients:

• Rapid assessment of airway and respiratory function.

• Prioritise oxygenation and ventilation in critically ill patients.

• Use rapid sequence induction (RSI) for patients at risk of aspiration, with immediate initiation of controlled ventilation.

• In trauma or ARDS, consider PCV or lung-protective strategies to prevent ventilator-induced lung injury (VILI).

Special Situations:

• ARDS: Low tidal volumes, higher PEEP, permissive hypercapnia, and prone ventilation as appropriate.

• Obese Patients: PCV with higher PEEP to optimise oxygenation and prevent atelectasis.

• Neurosurgical Patients: Maintain normocapnia to avoid intracranial pressure fluctuations.

• Pregnancy: Avoid hyperventilation; maintain normal PaCO₂ to ensure uteroplacental perfusion.

Monitoring and Adjustments:

• Use capnography, pulse oximetry, and arterial blood gases to guide ventilation settings.

• Regularly reassess lung mechanics and compliance to optimise ventilatory parameters.

• Be vigilant for complications such as barotrauma, volutrauma, and atelectrauma.

AM_1.9 Describe a ‘can’t intubate, can’t oxygenate’ drill, including equipment required to be immediately available and the technique for performing an emergency surgical airway Refer to ANZCA professional document: PG61(A) Guideline for the management of evolving airway obstruction: transition to the Can’t Intubate Can’t Oxygenate airway emergency 2017

Can’t Intubate, Can’t Oxygenate (CICO) Drill: ANZCA Guidelines Summary

Overview

The PG61(A) Guideline for the Management of Evolving Airway Obstruction: Transition to CICO 2017 outlines the principles for managing airway emergencies when both intubation and oxygenation have failed. This involves transitioning to infraglottic rescue techniques (Front of Neck Access, FONA) and using a structured approach to mitigate risks.

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1. Key Components of a CICO Drill

A. Phases Leading to CICO Declaration

1. Supraglottic Rescue Pathways:

   • Bag Mask Ventilation (BMV): Ensure two-person technique, optimize head position, and use oro/nasopharyngeal airways.

   • Supraglottic Airway Device (SGA): Attempt two devices of different types or sizes.

   • Endotracheal Tube (ETT): Maximize up to three attempts using adjuncts (e.g., stylet, bougie) or alternative blades (e.g., video laryngoscope).

2. Criteria for CICO Declaration:

   • Failed BMV, SGA, and ETT despite optimized techniques.

   • Oxygen saturation ≤90% or imminent desaturation.

   • Waking the patient is not feasible.

3. Team Preparation:

   • Mobilize resources for FONA.

   • Brief team members and encourage assertive communication.

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B. Transition to FONA

1. Verbal Declaration: Clearly state: “This is a CICO situation.”

2. Method Selection:

   • Scalpel-Bougie Technique: The primary method recommended for surgical airway access.

   • Cannula-Based Technique: Alternate technique if resources or expertise support it.

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2. Equipment Required

Immediate Availability

1. Airway Devices:

   • Bag-mask ventilation equipment.

   • SGAs of various sizes and types.

   • Endotracheal tubes, stylets, and bougies.

2. FONA Equipment:

   • Scalpel (#10 blade).

   • Bougie (15 Fr or equivalent).

   • Endotracheal tube (size 6.0–7.0 mm).

3. Additional Tools:

   • Suction devices.

   • Supplemental oxygen sources.

   • Monitoring equipment (e.g., pulse oximetry).

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3. Technique for Surgical Airway (Scalpel-Bougie)

Steps:

1. Prepare the Neck:

   • Identify cricothyroid membrane through palpation.

   • Position the neck optimally (extension).

2. Incision:

   • Make a horizontal incision through the skin and cricothyroid membrane.

3. Introduce the Bougie:

   • Insert bougie into the trachea through the incision.

4. Secure the Airway:

   • Pass an endotracheal tube over the bougie into the trachea.

   • Confirm placement with capnography and auscultation.

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4. Human Factors and Teamwork

A. Effective Communication:

• Use cognitive aids to ensure adherence to best practices.

• Maintain clear and concise instructions, employing closed-loop communication.

B. Team Coordination:

• Assign roles (e.g., airway operator, assistant, oxygenation support).

• Regularly update the team on patient status.

C. Training and Simulation:

• Conduct regular CICO drills to reinforce technical skills and teamwork.

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5. Post-Event Management

• Documentation: Record all interventions and outcomes.

• Patient Notification: Provide an airway alert letter for future anaesthetic care.

• Debriefing: Conduct team debrief to identify improvement opportunities.

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Conclusion

A structured approach to managing CICO, supported by proper equipment, skilled execution of the FONA technique, and effective team communication, is critical to patient safety during airway emergencies.

AM 1.10 Outline the important patient, staff and facility factors in determining the suitability of a patient for transfer to, and then discharge from the post anaesthesia care unit

1. Patient Factors

• Airway and Breathing:

  • Patent airway without significant obstruction or risk (e.g., no excessive secretions or swelling).

  • Stable respiratory parameters (adequate oxygen saturation, respiratory rate, and absence of apnea or stridor).

  • Ability to maintain oxygenation on room air or low supplemental oxygen.

• Circulation:

  • Hemodynamically stable (normal blood pressure, heart rate, and no ongoing bleeding or signs of shock).

  • Adequate perfusion (warm extremities, good capillary refill).

• Neurological Status:

  • Responsive to stimuli and oriented (or returning to preoperative baseline if altered consciousness is expected).

  • Adequate recovery from neuromuscular blockade (sustained head lift, handgrip strength, or negative inspiratory force test).

• Pain and Comfort:

  • Adequate pain control (manageable with appropriate medication).

  • No severe nausea or vomiting (or adequately managed with antiemetics).

• Surgical Site:

  • Stable wound with no active bleeding.

  • Drains or catheters functioning properly with acceptable output.

• Co-morbidities:

  • Addressed pre-existing conditions (e.g., glucose control in diabetics, stable cardiovascular disease).

2. Staff Factors

• Training and Expertise:

  • PACU staff trained in managing airway, hemodynamic instability, and postoperative complications.

  • Adequate staff-to-patient ratio for monitoring and interventions.

• Communication and Handover:

  • Comprehensive handover from the anaesthetist to PACU staff using structured formats (e.g., SBAR).

  • Clear documentation of medications administered, surgical events, and anticipated complications.

• Decision-Making Authority:

  • Presence of senior clinicians to make transfer and discharge decisions for high-risk patients.

3. Facility Factors

• Equipment and Monitoring:

  • Availability of appropriate monitoring (ECG, pulse oximetry, capnography) and emergency equipment (defibrillator, airway management tools).

  • Access to medications (analgesics, antiemetics, vasopressors).

• Space and Resources:

  • Adequate physical space to accommodate patient needs.

  • Resources for specific requirements (e.g., heated blankets, oxygen therapy, suction).

• Escalation Pathways:

  • Clear protocols for managing emergencies (e.g., code blue, ICU transfer).

  • Ability to perform point-of-care testing (e.g., blood gases, glucose).

• Patient Flow and Discharge Criteria:

  • Standardized discharge criteria ensuring safety for transfer to wards or home (e.g., Aldrete score ≥ 9).

  • Availability of beds in the next stage of care (e.g., ward, ICU).

Considerations for Discharge from PACU

• Patient meets criteria for transfer to the next care setting.

• Staff confidence in the patient’s stability and clear post-PACU care instructions.

• Ward readiness to accept the patient, with appropriate follow-up monitoring and interventions in place.

AM 1.11 Discuss nasal intubation indications and contraindications

• Surgical Access:

  • Oral and maxillofacial surgeries (e.g., mandibular or maxillary fractures).

  • Dental procedures requiring a clear oral cavity.

  • ENT surgeries needing unimpeded oral access.

• Oral Obstruction:

  • Limited mouth opening (e.g., trismus from trauma, infection, or tetanus).

  • Tumors or foreign bodies obstructing the oral airway.

• Prolonged Intubation:

  • Prevents oral pressure sores or ulcers from prolonged use of an oral tube.

  • Allows better patient comfort for alert or semi-conscious patients.

• Specific Situations:

  • Patients in whom oral intubation is technically challenging (e.g., congenital anomalies, postoperative changes).

  • Situations requiring stable tube fixation (e.g., awake fibre-optic intubation).

Contraindications

• Absolute Contraindications:

  • Basal skull fractures (risk of intracranial placement and cerebrospinal fluid leakage).

  • Coagulopathy or anticoagulation therapy (increased risk of epistaxis).

• Relative Contraindications:

  • Nasal trauma or deformities (e.g., septal deviations or fractures).

  • Nasal polyps or tumours (risk of bleeding or obstruction).

  • Recent nasal or sinus surgery (risk of disrupting healing tissue).

  • Active sinus or nasal infections (risk of spreading infection).

• Other Considerations:

  • Pediatric patients with small nasal passages (higher risk of trauma).

  • Pre-existing severe airway swelling or stridor (may exacerbate obstruction).

Pre-procedure Preparation

• Nasal Assessment:

  • Test nasal patency with airflow check or mirror fogging.

  • Visual inspection for obstructions, deformities, or infections.

• Medication Use:

  • Vasoconstrictors (e.g., phenylephrine or oxymetazoline) to minimize bleeding.

  • Local anaesthetics (e.g., lidocaine spray) for patient comfort.

• Lubrication and Equipment:

  • Use water-soluble lubricant on the tube.

  • Select an appropriately sized nasal tube (smaller than oral intubation tubes).

Complications

• Common Risks:

  • Epistaxis due to trauma to nasal mucosa.

  • Nasal trauma (abrasions, ulceration, or turbinate injury).

• Rare Risks:

  • Tube misplacement (e.g., esophageal or intracranial).

  • Sinusitis or nasal infections from prolonged intubation.

• Mitigation:

  • Ensure proper technique and gentle handling.

  • Use a guide (e.g., fibre-optic scope) for difficult cases.

A 1.12 Discuss the issues involved with a shared airway

Shared Airway Definition

• A shared airway occurs when both the anaesthetist and surgeon need simultaneous access to the patient’s airway, often during head, neck, or thoracic procedures.

Key Issues

Patient Safety

• Airway Obstruction:

  • Surgical instruments or retraction can compromise ventilation or intubation tube patency.

  • Risk of dislodgement of airway devices during surgical manipulation.

• Oxygenation and Ventilation:

  • Limited access may restrict effective mask ventilation or intubation.

  • Risk of hypoxia or hypercapnia if ventilation is compromised.

Surgical and Anaesthetic Coordination

• Limited Access for Anaesthetist:

  • Difficulty in adjusting or re-securing the airway.

  • Restricted ability to troubleshoot airway issues promptly.

• Positioning Challenges:

  • Patient may be in unconventional positions (e.g., prone, lateral, or head turned), complicating airway management.

Communication

• Clear communication is essential to balance surgical and anaesthetic needs:

  • Timing of surgical interruptions for airway interventions.

  • Surgeons notifying the anaesthetist of impending airway manipulations or risks.

Equipment Issues

• Choice of Airway Device:

  • Endotracheal tubes with reinforced or flexible designs may reduce risk of kinking or obstruction.

  • Use of specialized equipment such as a laser tube for laser surgeries or a microlaryngeal tube for laryngeal procedures.

• Airway Securing:

  • Ensuring secure fixation of the tube to prevent displacement during surgery.

• Shared Use of Instruments:

  • Fibre-optic scopes or jet ventilation equipment may be required, adding complexity.

Surgical Considerations

• Operative Field Visibility:

  • The airway device and anaesthetic circuit can obstruct the surgeon’s view.

  • Shared airway techniques like pharyngeal packing or adjusting tube positioning may be necessary.

• Risk of Contamination or Damage:

  • Surgical debris or fluids entering the airway.

  • Risk of thermal or mechanical damage to the tube during procedures like cautery or laser use.

Anaesthetic Management

• Optimizing the Airway:

  • Preoperative planning to select the most suitable device and technique (e.g., awake fibre-optic intubation if difficult airway is anticipated).

• Ventilation Strategies:

  • Apneic oxygenation, high-flow nasal oxygen, or jet ventilation may be employed during brief interruptions of ventilation.

• Monitoring:

  • Continuous vigilance through capnography, pulse oximetry, and careful auscultation to detect early signs of airway compromise.

Complications

• Surgical Delay:

  • Frequent anaesthetic interruptions to address airway issues can prolong the procedure.

• Airway Compromise:

  • Hypoxia, aspiration, or trauma from tube displacement or shared manipulation.

• Postoperative Concerns:

  • Edema or trauma to the airway requiring extended postoperative monitoring or interventions.

Strategies for Mitigation

• Detailed preoperative planning and multidisciplinary discussion.

• Ensuring the availability of advanced airway management equipment and expertise.

• Clear contingency plans for airway emergencies."