Guidance for medical examiners when assessing a patient for either a general topic or condition – Deep vein thrombosis.
Aeromedical implications
Effect of aviation on condition
- Long periods of immobility
- Dehydration (dependent on operations)
Effect of condition on aviation
- Overt incapacitation
- Sudden death
- Distracting pain.
Effect of treatment on aviation
- Risk of distraction due to bleeding
- Risk of incapacitation secondary to bleeding
Approach to medical certification
Based on the condition
- confirmed diagnosis of deep vein thrombosis
- exclusion of other diagnoses
- clinically evident pulmonary embolus
- predisposing disease pro-thrombotic malignancy, pro-thrombotic haematological disease
- Acceptable prognosis - risk of recurrence, risk of incapacitation.
Based on treatment
- Acceptable, stable treatment without significant side effects
- Demonstration of adherence
- If commencing warfarin, a minimum of three INRs are required at least one week apart and must be within the therapeutic range (see guidelines for Anticoagulation – Warfarin)
- If commencing NOAC then confirmation of adherence to medication (see guideline for Anticoagulation - NOACs).
Demonstrated stability
- Absence of symptoms e.g. distracting calf pain, chest pain and shortness of breath
- Interval ultrasound evidence of thrombus stabilisation
Risk assessment protocol - information required
New cases
- Confirmed diagnosis
- Provoked or Unprovoked DVT
- Exclusion of PE (see guidelines on Pulmonary Embolus)
- Pre-disposing co-morbidities
- Clinical status
- history of condition
- details of any symptoms
- Investigations conducted
- procoagulant screen (conducted before or after anticoagulant treatment)
- ultrasound or CT scans
- Management
- treatment: response to treatment and side effects
- monitoring regimen including adherence with and stability of
- anticoagulant medication
- (ie, serial INR results (or proof of NOAC adherence)
- any side-effects
- Underlying cause of thrombosis
- Estimate of annualised percentage risk of recurrence
- Estimate of annualised percentage risk of incapacitation
- Follow-up plan.
Interval assessment at 6 – 12 months
- Clinical status
- history of condition
- details of any symptoms
- Investigations conducted
- pro-coagulant screen (if not done prior)
- ultrasound or CT scans
- Management
- treatment: response to treatment and side effects
- monitoring regimen including adherence with and stability of
- anticoagulant medication
- (ie, serial INR results (or proof of NOAC adherence)
- regimenany side-effects
- Underlying cause of thrombosis
- Estimate of annualised percentage risk of recurrence
- Estimate of annualised percentage risk of incapacitation
- Follow-up plan.
Renewal
DAME comments. (Additional reports may be needed for long-term treatment.)
Indicative outcomes
- Initial notification to CASA and grounding required pending diagnosis
- Clearance by CASA required before exercising privileges
- Interval assessment at 6 months
- Audit will be required with review at 12 months
- Both due to the risk of recurrent DVT/PE and anticoagulation treatment, certificates may be subject to long term multi-crew/proximity restriction (Class 1 and 3)
- See guidelines for Anticoagulation – Warfarin and Anticoagulation - NOACs
Favourable
- Successful treatment of deep vein thrombosis
- Absence of co-morbid conditions
- Acceptable recurrence risk
Unfavourable
- Clexane (other than initial treatment for DVT during grounding period)
- Poor adherence to anticoagulation treatment
- Unstable or out of target range INR
- Side effects of treatment (e.g. epistaxis, gastrointestinal haemorrhage, stroke)
- Recurrent thrombosis or pulmonary embolus
- Positive procoagulant screen
- Presence of co-morbid conditions
Pilot and controller information
- DVT is an aero-medically significant medical condition because blood clots can move and affect the lungs heart or brain
- Pilots and controllers who have been diagnosed with DVT are required to ground themselves and notify this condition to their DAME or CASA.
- Anticoagulant medication is associated with well recognised hazards (e.g. bleeding) which must be considered as a separate risk to aviation safety
- Effective and stable treatment is critical in reducing these risks
- If cleared to exercise the privileges of a medical certificate, long term multi-crew/proximity restriction and audit may be required (Class 1 and 3)
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Disclaimer
The clinical practice guidelines is provided by way of guidance only and subject to the clinical practice guidelines disclaimer.