Q: What is Asthma?
Asthma is a long-term (chronic) allergic inflammatory disease of the small airways (bronchioles) that convey air in & out of the lungs, and is characterised by attacks (episodes) of airway narrowing that obstruct normal airflow. It is a very common condition, affecting 1 in 10 Australian adults and is often associated with other allergic conditions like hay-fever or eczema. Asthma can be classified into types based on Severity or Triggers into:
Severity: Intermittent, Mild persistent, Moderate persistent & Severe Asthma
Triggers: allergic or non-allergic asthma, seasonal or perennial asthma, exercise-induced or occupational asthma, childhood or adult-onset asthma.
For example: Intermittent exercise induced asthma.
Q: Why is Asthma relevant to pilots & aviation safety?
Asthma can cause either subtle impairment or total incapacitation of a pilot due to a lack of oxygen (hypoxia) or the symptoms of an acute asthma attack. Further, inherent aspects of aviation, such as: cold or dry air, dust & fumes or physical stress (for example: during high G-force manoeuvres) can trigger an asthma attack. If this occurs in flight, the air that is trapped within a pilot’s lungs will expand during the climb to higher altitude. This can cause damage (barotrauma) to, or rupture (pneumothorax) & collapse (atelectasis) of the lung, which can be fatal. Finally, some medications used to treat asthma are not compatible with flying.
By way of an aviation analogy, asthma would be like piloting an aircraft that is highly susceptible to carburettor icing, that occludes both the air-intake & exhaust systems in cold dry air at altitude. The engine performance would initially decline, then it would begin to run rough before coughing, spluttering & then failing! Would you want to pilot THAT aircraft before corrective maintenance? The same applies to pilots with asthma.
Q: What are the symptoms of asthma & how is it diagnosed?
The classic symptoms of asthma are cough, wheeze, chest-tightness & shortness of breath (dyspnoea) typically at night or early in the morning. Asthma is diagnosed on lung function (spirometry) testing, by comparing Peak Expiratory Flow (PEF) rate before and after airway dilatation (bronchodilation) with Ventolin (salbutamol). Normally there is no change in PEF rate with Ventolin, while those with asthma will show an improved PEF rate.
Q: What causes asthma & triggers attacks?
While the exact cause of asthma is not known, it is associated with allergies (atopy) & is essentially caused by the abnormal function of the immune system in the small airways (bronchioles) of the lungs. This results in chronic airway inflammation & hypersensitivity of the airways to environmental triggers, such as: mould, dust or dust-mites, pollen, smoke, fumes or air pollution, respiratory viruses, exercise, stress or cold/dry air.
Did you know?...Asthma is also associated with poor diet & obesity - yet another reason pilots need to maintain a healthy diet & weight!
Q: Can pilots fly with Asthma?
In general, pilots with stable & well-controlled asthma, using inhaled preventer therapy (such as Fluticasone) & carrying a reliever (like Ventolin) in the cockpit are eligible for any class of medical certificate. In contrast, poorly controlled or moderate to severe asthma, triggered by dry air or controlled with high dose oral steroids (like prednisone) may not qualify for a medical certificate to fly. Fortunatley, for the majority of aspiring & active pilots asthma can be well-controlled making medical certification likely.
This is why it is essential for pilots to work closely with their GP to ensure their asthma is well managed.
Q: Why does CASA care about a history of childhood asthma?
While approximately 50% of kids with childhood asthma “outgrow” their asthma once they pass adolescence, their respiratory tract remains sensitive to asthma triggers for life. Further, in half of those kids (so 25%), some asthma symptoms will return in their late 30’s or early 40’s. Finally, new triggers may cause symptoms to appear at any time in people with a childhood history of asthma.
For all these reasons, CASA requires a baseline pre & post bronchodilator spirometry test in all pilots with a history of asthma.
Q: How is Asthma treated in pilots?
It is very important that pilots with asthma take it seriously & work closely with their GP to ensure their asthma is treated, well-controlled & stable to ensure both good lung health & ongoing medical certification to fly. Asthma is treated in 3 ways:
Management plan - a written-plan developed in consultation with a pilot’s GP is provides the foundation of well-controlled asthma & medical certification to fly
Preventers - (Flixotide, Symbicort or Trimbow) are daily inhaled medicines that reduce both airway inflammation & airway sensitivity to asthma triggers
Relievers - (Ventolin or Bricanyl) are used during an acute asthma attack to dilate the small airways, permit the inflow/outflow of air & alleviate symptoms
Finally, it is essential that pilots with asthma actually use their preventer daily (as prescribed), even in the absence of symptoms. In much the same way that we dip & drain the tanks before EVERY flight…even if the fuel was “fine & free of water” on the last flight.
Q: What can pilots do about asthma?
Just as we employ countermeasures to minimise threats, errors & undesired aircraft states in aviation, pilots can take countermeasures to minimise the threat asthma poses to their health & medical certification, such as:
Regular GP review - annually to semi-annually
Asthma Management plan - stored on your mobile
Awareness - of your asthma symptoms, triggers & when to seek help
Monitoring PEF rate - successively low numbers can provide an early warning
Healthy Habits - maintaining healthy weight, regular sleep, exercise & eating fresh (unprocessed) foods help to reduce asthma severity
Observing these countermeasures will almost certainly ensure stable, well-controlled asthma & ongoing medical certification to fly both now & into the future!
Got more questions?
Contact us: info@aerokare.com.au
References & links to more information:
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