2007

Spring Meeting:   24th February 2007, London.

Theme:   Promoting Safe Practice in Aviation and Medicine

Venue:  The Royal College of General Practitioners, 14 Princes Gate, Hyde Park, London.

A big thank you to Peter Anderson for all the hard work he has put into this excellent detailed report of all the lectures at the Spring Meeting.

Report:

The 2007 Spring Clinical Meeting of The British Medical Pilots Association was on Saturday 24th February at The Royal College of General Practitioners, London.  The meeting was masterminded by Norena McAdam and Raj Bansal did excellent work in organizing the programme. President, Stephen Gibson, opened the meeting with a welcome, then cheekily suggested we should bring some younger members as those present were looking a bit ancient!

Unfortunately there were two deaths to report: Prof. Robert Kerwin and Dr Hettlich.

The meeting went off very well, and was followed in the evening by a very pleasant Association Dinner at the same venue.

  • “London Heathrow and a District General Hospital”, Mr John Belstead
  • “Common Arrhythmias and their Certificatory Implications”, Professor Michael Joy, Consultant Advisor in Cardiology to the CAA
  • “An Accidental Traveller”, Mr. David Roberts, freelance writer
  • “Aviation Health, Fact or Fiction?”, Dr. Raymond Johnston, Head of Aviation Health Department, CAA

“London Heathrow and a District General Hospital”,  Mr John Belstead.

Mr John Belstead, recently retired from Ashford Hospital, told of his 20 years as A&E consultant.  Though warned to expect a major aviation incident every seven years none happened, though standby for perceived emergency was not rare.

Heathrow is a giant industrial area with 60,000 or more on site, and handles 60 million passengers per year.  BA handles 25,000 hazardous cargoes per month, though no explosive or highly radioactive substances. There were only three significant incidents, involving fumes, some admissions required but no serious outcomes.

Passenger problems have included 75 Japanese with food poisoning, and treatment-seeking “tourists” often with cancer.  Fitness to fly issues varied from BA – “if you can climb stairs your are OK” to Quantas, six sides of A4.  The “worried well” included a journalist demanding, but not receiving, unnecessary rabies vaccination, who went on to misrepresent him in the newspaper.

There were plenty of industrial accidents including a man who fell off a BM hangar.  The Health and Safety people demanded a safety rail, and two men fell off fitting it.  There were also plenty of road accidents at Heathrow.

Concerning terrorism.  Terminal 4 was a worry, with no open spaces, so ideal for causing gun or bomb chaos.  The fuel farm was between the hospital and Heathrow, and the clearance (three quarters of a mile), was half that recommended by the Fire Service.

Immigration related procedures were a nightmare, no matter whom they phoned it was always the wrong number.  The Quarantine Centre handled 10,000 animals per month, some venomous, yet only one bite in 20-year history.  Pulmonary embolus cases were around ten per year, but in quiet news time one case would make the headlines and Mr. Belstead was involved in numerous TV and newspaper interviews.

Exercises for major incidents were carried out regularly, much influenced by weather, communications and military assistance.  To get help from the RAF one had to go through a large chain of command, yet the Army could produce a Chinook in half an hour.  The exercises were enlivened by overhearing remarks like “if you are dead, go over there”

An informative and entertaining talk.

Peter Anderson

“Common Arrhythmias and their Certificatory Implications”,
Professor Michael Joy, Consultant Advisor in Cardiology to the CAA.

Prof Joy learnt to fly on Tiger Moths, going solo at 7 hours 20 minutes and doing solo aerobatics at 20 hours.  His Instrument Rating of thirty years is still current.  He reminded us that 80% of accidents are due to human error, mainly CFIT (Controlled Flight into Terrain).  The most common incapacitating event is acute diarrhoea, which appears to becoming slightly less common, maybe due to improvement in food hygiene.  Cardiovascular events in pilots are rare and are related to pilot age as well as to conventional risk factors such as hypertension, hypercholesterolemia, smoking and diabetes. The regulatory process contributes but the upturn, including that from central review of electrocardiograms is small.  The legal basis of the incoming EASA regulations is likely to make the process more rather than less rigid.

Arrhythmias can be supra-ventricular, junctional, or ventricular.  They may be paroxysmal, persisting or permanent.

Atrial ectopic (premature beats) are common.  If occasional, they are not predictive in an intact heart.  If they are frequent (>2% of normal heartbeats) there is a risk of atrial fibrillation.  A search should be made for possible alcohol abuse and frequent atrial ectopy investigated with echocardiography and Holter monitoring.  Medical treatment is not normally indicated.  The licensing implications are governed by the presence or absence of atrial fibrillation.

Atrio-ventricular re-entrant tachycardias (Wolff-Parkinson-White syndrome, for example), are best managed by radiofrequency ablation of the accessory pathway.  This is carried out by the transvenous approach and unrestricted class I certification is to be expected if there is no other disqualifying circumstance and successful ablation of the pathway is demonstrated either by adenosine or EP study.

Atrial flutter, which normally arises in the right atrium and is usually at a rate of 300 beats a minute, denies certification.  The reason is that 1:1 AV conduction can be associated with a significant fall in blood pressure due to excessive heart rate.  Furthermore although conduction is normal 2:1, 3:1, etc., heart rate changes can be abrupt.  This too can be managed with radio frequency ablation of the isthmus at the lower end of the christa terminalis. Unrestricted certification can be achieved provided this is successful.

Atrial fibrillation affects 0.4% of the population below the age of 60, 4% below the age of 70 and 10 or more percent of 80 years and beyond.  It can be provoked in the normal heart by excessive alcohol, caffeine excess, illicit drugs and in thyrotoxicosis.  It may be asymptomatic, be associated with awareness of the heart, or, at the onset of an attack, may cause dizziness or faintness due to a fall in the blood pressure.  Paroxysmal atrial fibrillation is self-limiting, two thirds reverting to sinus rhythm inside 24 hours, but one third will become permanent within 3 years.  Certification is permitted if the subject is asymptomatic and the rhythm is either suppressed by drugs or the rate controlled by them.  The need for warfarin, which is usually indicated in structural abnormality of the heart, hypertension or diabetes in addition to the atrial fibrillation, is disqualifying.  Permitted drugs include digoxin, beta-blocking agents and Sotalol. Class I C agents such as flecainide usually are not permitted because of side effects, but may be reviewed centrally, as with any difficult case.

The risk of thromboembolic stroke rises during the sixth decade and is unusual in the intact heart in atrial fibrillation below the age of 65.  The risk is reduced by two thirds with warfarin and by one fifth by aspirin.  The bleeding risk of warfarin is of the order of 0.7-1.7%.  Permanent atrial fibrillation is not disbarring but the above rigorous criteria had to be met. Electrophysiological techniques to ablate foci of enhanced automaticity usually in the pulmonary veins are not particularly successful.

Ventricular ectopic beats if unifocal but infrequent in the intact heart are not predictive of outcome.  Even complex forms up to and including non-sustained ventricular tachycardia is not premonitory.  When the VPB count is > 2% of the total QRS count, investigation is justified which would include exercise electrocardiography, echocardiography and Holter monitoring.  Although the patient is commonly asymptomatic it maybe desirable to attempt to suppress very frequent VPB’s (i.e. >5% of total).  If there is a bundle branch aberration with right axis deviation in the aberrant, the origin is likely to be in the right ventricular outflow tract.  In this case the possibility of arrhythmogenic right ventricular cardiomyopathy should be sought (AVRC) with MRI scanning.  If that diagnosis is made then the pilot is unfit for all forms of certification.

The standards for unrestricted class I certification permit little or no departure from normal.  When the risk is perceived to be increased – following coronary revascularization, for example, or following a myocardial infarction, the class I certificate will be restricted and bear an OML (operational multi-crew limitation) endorsement upon it.  This is approximately equivalent to the JAA class II for unrestricted private flying.

In conclusion arrhythmias cause as many problems in certification as the various presentations of the coronary syndromes.  The anti-arrhythmic armamentarium is not a large one and not an effective one.  Nevertheless the commonest arrhythmia of all – atrial fibrillation is often consistent with certification provided the rate can be managed, the pilot is asymptomatic and there is no other disqualifying condition or factor.

Peter Anderson

“An Accidental Traveller”,  Mr. David Roberts, freelance writer.

David Roberts, a pilot, skydiver and freelance writer, gave an entertaining review of his philosophy of life, starting with the suggestion that journalism was the poor man’s substitute for income!  Proof of this?  How else would he recently have been in the hills in Mongolia, looking at Russia and China,  all courtesy of testing a 4 x 4 for a magazine.

David’s preference is for getting through life and travel without too much premeditated planning.  He felt that in the 30s flying was likely a mixture of camaraderie and freedom, coming and going as you liked.  Now it was often an occupation of sitting staring at lots of instruments, taking much of the adventure from it all.

He praised Geoffrey de Havilland for his achievement of creating wonderful aeroplanes for all, from a baseline of free thinking aided by not much money.  Amongst the many adventurous types that he would have loved to have known, he mentioned Johnny Johnson, Amy Johnson and Beryl Markham.

An entertaining and unusual talk.

Peter Anderson

“Aviation Health, Fact or Fiction?”,  Dr. Raymond Johnston, Head of Aviation Health Department, CAA.

Ray Johnston moved to Occupational Health in 1990 and since April 2006 specifically in Aviation Health, investigating the effects of air travel on health, and the effects of health on air travel.  This involves much cooperation with professionals and passengers.  There is involvement with industry (crew and management), Unions [BALPA.and TGWU], the public (business and leisure), pressure groups (especially Cabin Air and DVT), the CAA, and the Department of Transport (Government).

Dr Johnston reviewed three main areas of challenge: Cabin Air; Deep Vein Thrombosis; Defibrillators.

CABIN AIR: Does it at present have adverse effects?  There is at present plenty of opinion but not much solid fact.  It is likely that a definitive answer will come from the review currently being undertaken by the Committee on Toxicity (CoT), a part of the Food Standards Agency.  This is in progress in the UK, though no FAA airline has taken it up.

There is active research for the Ideal Cabin Environment (ICE), a six million Euro project with thirteen members acquiring data over the period 2005 – 2008.  The need for defining the ICE is driven by changing passenger demographics and increasing ultra-long haul flights.  Boeing is experimenting with 6000 ft. cabin pressure, not from bleed air from the turbine compressors, which could be contaminated.  Airbus has variable pressure and humidity devices to study “well being” and physiological effects.

DEEP VEIN THROMBOSIS (DVT): In the 1940s it was noted that DVT incidence lessened with a change from deckchairs to bunks.  In the mid 50s an association was observed between DVT and prolonged sitting in aircraft, cars and theatre.  In the late 80s there were reports of the poorly named “economy class syndrome” type of DVT.

There is an estimate of five DVTs per million passengers, the incidence increasing with distance.  Crew fly more than passengers, but are at less risk, perhaps a healthy worker effect?  The risk of DVT increases with all modes of travel, plus the effect of obesity the contraceptive pill and HRT. There is no activation of coagulation in a controlled cabin environment.

Mobility helps, a good seat pitch (26″), leg exercises and walking about. Proper TED compression stockings help, but “bargain” ones in airport shops can be useless or worse, being “marketing by fear.”  Low molecular weight heparin can help in suitable cases with low risk of bleeding.  Aspirin is of no value on the venous side of clotting.

DEFIBRILLATORS:  Are they of use in aircraft?  Previously older people with significant heart disease would not have travelled, but increasingly they are now doing so.  The FAA have made on-board defibrillators mandatory, but not the JAA.  Clearly there is political and legal push for this, but very little from hard data.  In 1997 Quantas had 27 incidents in 30 million passengers, with 2 successful defibrillations.  American Airlines, over 71 million passengers had 6 survivors from 14 incidents.

The problem needs a cooperative approach from many organization and government to ascertain facts and not to manufacture opinion. For interest the approximate cost and practical implications per aircraft are £2,500 per item, £10,000 for crew training, needed even though the item is automatic, engineering backup, legal risk assessment, and crew rostering problems.

Peter Anderson. 

7th-10th June 2007.

Several of our members joined with our European counterparts at the “Rassemblement International Médecins-Pilotes, at Quimper in Brittany.

We enjoyed a full programme of visits that included;  A walking tour of Quimper and its cathedral, A gastronomic meal on board a boat on the river l’Odet,  Concarneau, Pointe de Raz (westernmost part of France), Locronan, and a Gala Dinner.

July 2007, Shenington.

The usual summer gliding meeting at Shenington.

Autumn Meeting:  31st August-2nd September 2007, Winchester.

This included a Friday evening meal at the Winchester Royal Hotel, an architectural tour of Winchester Cathedral, lunch at “The Old Vine”, a Gala Dinner, a walking tour of the city and a visit to City Mill (National Trust).