Assessing fitness to fly : for healthcare professionals

Every year, over one billion people travel by air and that figure is predicted to double in the next two decades.
Health professionals may increasingly be asked to assess a patient’s fitness to fly. So , it's better you know it before you land in an awkward position.
Most patients will be able to fly safely, but some may require additional measures such as in-flight supplementary oxygen. Where necessary, even passengers who require specialist in-flight medical care up to intensive care level can usually be transported by air ambulance, although the cost of this can be prohibitive unless covered by the patient’s medical insurance.
It is important to note that although Cabin Crew are trained to render advanced first aid, they are not trained to administer medication. In addition, most airlines will assist passengers to reach the toilet accommodation on the aircraft but cannot render more personal hygiene or nursing care.
The majority of in-flight emergencies occur in situations when an individual's medical condition is unknown to the airline and it is therefore essential that the passenger’s physician sends adequate details well in advance of the flight to the carrier. Most airlines have medical advisors who provide advice and “clear” passengers as fit to fly. I am one of them.
The key information that they require is:
the nature of the individual’s condition and its severity/stability,
medication being taken, and
any pertinent information about mobility.
Basic physiology : In aircraft , there is
 fall of arterial oxygen saturation to around 90% and is well tolerated in healthy travellers.
So logic is Passengers with medical conditions associated with hypoxia or reduced oxygen-carrying capacity in the blood, such as respiratory and cardiac conditions or severe anaemia, may not tolerate the reduction in barometric pressure without additional support.
Humidity and hydration

The low humidity may result in drying of the mucous membranes of the lips and tongue, leading to a sensation of thirst, and can also cause problems for contact lens wearers due to corneal drying.Contrary to a widely held belief, the low humidity in the aircraft cabin does not result in dehydration. Research has shown that the additional insensible fluid loss amounts to approximately 150ml over an 8 hour flight, with no evidence of any change in plasma osmolality.  In patients with limited cardiac reserve, the use of supplemental oxygen (Table 1) may be required and most commercial airlines will supply this when requested in advance, although a charge may be levied. Some allow passengers to carry their own O2.

Cardiovascular indications for medical oxygen during commercial airline flights
Use of oxygen at baseline altitude CHF NYHA class III - IV or baseline PaO2 less than 70 mm Hg Angina CCS class III-IV Cyanotic congenital heart disease Primary pulmonary hypertension Other cardiovascular diseases associated with known baseline hypoxemia CHF - Congestive Heart Failure NYHA - York Heart Association CCS - Canadian Cardiovascular Society

Angina Pectoris, if stable, is usually not a problem in flight.

Patients with a recent myocardial infarction may travel after 7 to 10 days if there are no complications. If the patient has undergone an exercise test which shows no residual ischemia or symptoms, this may be helpful, but is not a mandatory requirement.

Coronary Artery Bypass Grafting (CABG) and other chest or thoracic surgery should prove no intrinsic risk in the aviation environment as long as the patient has fully recovered without complications. However, as air is transiently introduced into the thoracic cavity, there is a potential risk for barotrauma due to the gaseous expansion which occurs at altitude. It is therefore prudent that patients should wait until the air is reabsorbed, approximately 10 to 14 days before travelling by air.

Patients with uncomplicated Percutaneous Coronary Interventions such as angioplasty with stent placement may be fit to travel after 3 days, but individual assessment is essential.

Symptomatic valvular heart disease is a relative contraindication to airline travel. Individual assessment by the treating physician is essential, paying particular attention to the functional status, severity of symptoms and left ventricular function, in addition to the presence or absence of pulmonary hypertension.

There is no contraindication to air travel for patients with treated hypertension, as long as it is under satisfactory control and the patient is reminded to carry their medication with them on the flight.

Those with pacemakers and implantable cardioverter defibrillators may travel without problems by air once they are medically stable. Interaction with airline electronics or aviation security devices is highly unlikely for the most common bi-polar configuration.

Following a cerebrovascular accident, patients are advised to wait 10 days following an event, although if stable may be carried within 3 days of the event. For those with cerebral arterial insufficiency, supplementary oxygen may be advisable to prevent hypoxia.

Clinical judgement has an important role in the individual assessment of fitness to fly. 

Cardiovascular contraindications to commercial airline flight

Uncomplicated myocardial infarction within 7 days Complicated myocardial infarction within 4-6 weeks Unstable angina Decompensated congestive heart failure Uncontrolled hypertension CABG within 10 days CVA within 3 days Uncontrolled cardiac arrhythmia Severe symptomatic valvular heart disease Rest of the information is given in the previous blog. So far so much  Thanks! Source : https://www.caa.co.uk/Passengers/Before-you-fly/Am-I-fit-to-fly/Guidance-for-health-professionals/Contact-the-Aviation-Health-Unit/