What criteria determine if a patient is fit to fly?

Determining Fitness to Fly

Patients should be assessed for fitness to fly based on specific medical criteria, with medical clearance required for those with conditions that may be worsened by the aircraft environment or pose risks during travel. 1

General Assessment Criteria

The following patient groups require pre-flight assessment:

• Patients with severe respiratory conditions (COPD, asthma, restrictive lung disease) 1
• Individuals with cognitive impairment, especially those with history of agitation in unfamiliar environments 1
• Patients with recent hospitalization for acute respiratory illness (within 6 weeks) 1
• Those with recent pneumothorax or thoracic surgery 1
• Patients with pre-existing oxygen requirements 1
• Individuals with conditions worsened by hypoxemia (cerebrovascular disease, coronary artery disease, heart failure) 1
• Patients with infectious diseases, particularly tuberculosis 1

Physiological Challenges of Air Travel

• Modern aircraft cabins are pressurized to altitudes of up to 2438m (8000 ft), resulting in reduced oxygen partial pressure equivalent to breathing 15.1% oxygen at sea level 1
• This reduced pressure causes arterial oxygen tension to fall to 7.0-8.5 kPa in healthy individuals 1
• Cabin humidity is extremely low (5-25%), which can exacerbate respiratory symptoms 1
• These environmental changes can trigger symptoms ranging from mild discomfort to severe complications, particularly in vulnerable populations 1

Assessment Algorithm for Respiratory Conditions

1. Initial screening with pulse oximetry:

   • SpO₂ >95% with no risk factors: Fit to fly without further assessment 2
   • SpO₂ 92-95% with risk factors: Perform hypoxic challenge testing 1
   • SpO₂ <92%: Supplemental oxygen recommended for flight 2

2. Exercise capacity assessment:

   • Inability to walk 50m suggests high risk and air travel should be avoided 3
   • Exercise desaturation test (6-minute walk test) with SpO₂ falling below 84% indicates need for in-flight oxygen 2

3. Hypoxia Altitude Simulation Test (HAST):

   • Recommended when resting SpO₂ is 92-95% with additional risk factors 1
   • PaO₂ <6.6 kPa during HAST indicates need for supplemental oxygen 2

Assessment for Patients with Cognitive Impairment

1. Pre-travel risk assessment:

   • Evaluate type and severity of cognitive impairment 1
   • Review history of agitation or delirium in unfamiliar environments 1
   • Consider recent hospitalizations which may increase risk 1

2. Determining fitness to fly:

   • Cognitive impairment alone is not a contraindication to air travel 1
   • Presence of a capable caregiver is essential for moderate to severe impairment 1
   • Risk of behavioral disturbances should be evaluated based on past history 1

3. Medical clearance requirements:

   • Medical clearance from airline required if patient:
     • Is likely to be a hazard to other passengers due to behavioral condition 1
     • Is considered a potential risk to flight safety 1
     • Is incapable of self-care and requires special assistance 1
     • Has a medical condition that may be adversely affected by the flight environment 1

Absolute Contraindications to Air Travel

• Active infectious tuberculosis 1
• Current closed pneumothorax 1
• Oxygen requirements exceeding 4 L/minute 3
• Major thoracic surgery within 6 weeks (unless essential travel with medical assessment) 1
• Severe uncontrolled psychiatric conditions with risk of agitation 1

Preparation Recommendations for Approved Travel

• For patients with cognitive impairment:

  • Book direct flights whenever possible 1
  • Schedule flights in late morning or early afternoon to maintain routine 1
  • Request special assistance and early boarding 1
  • Secure aisle seats near lavatories 1
  • Inform cabin crew about the patient's condition 1

• For patients with respiratory conditions:

  • Carry all medications in original containers 3
  • Adjust medication timing based on time zone changes 3
  • For long-haul flights with supplemental oxygen, complete Special Assistance Form (SAF) and Medical Information Form (MEDIF) 1
  • Consider applying for Frequent Traveller's Medical Card (FREMEC) for those with stable conditions requiring regular travel 1

Common Pitfalls and Caveats

• Failure to recognize that moderate hypoxia can significantly worsen existing medical conditions 1
• Underestimating the stress of air travel on patients with cognitive impairment 1
• Not accounting for the combined effects of hypoxia, dehydration, and immobility 1
• Inadequate preparation for medication adjustments across time zones 1
• Overlooking the need for airline medical clearance, which can result in denied boarding 1

By following this structured approach to assessing fitness to fly, clinicians can help ensure safe air travel for patients with various medical conditions while minimizing the risk of in-flight emergencies.