ECONOMY CLASS SYNDROME

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ECONOMY CLASS SYNDROME A COMMON RISK OF
TRAVELLING FARROL KAHN, DIRECTOR AVIATION HEALTH
INSTITUTE Bayer Lunch Satellite Symposium 4th
European Conference on Travel Medicine Rome,
Italy, 29-31st March 2004
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Aviation Health Institute
INTRODUCTION
The Aviation Health Institute is a medical
research charity that

• Promotes passenger health world-wide
• Researches links between flying and health
• Provides education and prevention programmes

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Aviation Health Institute
The main issues we are concerned with

• DVT
• Air Quality Inflight - Disease transmission
• Cosmic Radiation
• Inflight Medical Incidents
• Leakage of Organo-phosphates

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Aviation Health Institute
Sudden natural deaths associated with commercial
air travel Sarvesvaran R Med. Sci. Law 26
35-38 (1986)

• 104 deaths at Heathrow Airport (London) in the
  period from February 1979 to January 1982
• 11 of 51 (18) cases of sudden death in
  passengers arriving at the airport were due to
  pulmonary embolism
• Duration of flight in the 11 cases of fatal
  pulmonary embolism in passengers
• 0-6 hours 0 cases.
• 6-12 hours 1 case.
• 12-18 hours 10 cases.
• Although no statistically significant
  conclusions can be drawn from this study it is
  reasonable to conclude that even apparently
  health air passengers who are confined for
  prolonged periods of time are at a greater risk
  of developing deep vein thrombosis that could
  result in a fatal embolic episode.

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Aviation Health Institute
Economy class syndrome Cruickshank JM et al.
Lancet ii 497-498 (1988)

• Describes six cases of thromboembolism
• Affluence, cheap travel package holidays and
  international business ensure that long distance
  air travel has become commonplace
• Long trips are associated with profound inertia
  and apathy in the passengers
• The subject should be aware of the possible
  dangers and the airlines should be responsible
  for this

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Aviation Health Institute
World Health Organisation Conference On 12-13
March 2001

• A link probably exists between air travel and
  venous thromboembolism
• Such a link is likely to be small Risk factors
  for individuals have been identified
• Research programmes proposed
• Multi-centre international epidemiological
  studies
• Cabin environmental risk factors
• Preventive measures

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Aviation Health Institute
Medical Guidelines for Air Travel ( October,
1996) Aerospace Environmental Medical Association

• Medical Guidelines for Air Travel published by
  Aerospace Medical Association. Authors of paper
  included doctors from Lufthansa (Dr Lutz Bergau),
  B.A. (Dr Neville Byrne), Air Canada (Dr Claude
  Thibault). Recognised the occurrence in economy
  and business/first.
• According to Virchow, there are three
  underlying conditions which cause a
  predisposition for DVT (Statis, endotheluim and
  coagulability).
• All three of these conditions are associated
  with air travel, particularly long-distance
  flights.

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Aviation Health Institute
Risk Factors Extrinsic

• People with a history of blood clots
• People who have recently undergone surgery
• People who have had recent severe leg injuries
• Women on the contraceptive pill or HRT
• Women who are pregnant and postnatal

• Passengers on flights of four hours or more
• People over 40 years of age
• Thrombophilic abnormalities
• People with severe varicose veins
• People with heart disease
• People suffering from cancer

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Aviation Health Institute

• LONFLIT STUDES 1 TO 5
• Prevention of venous thrombosis in long-haul with
  Flite Tabs, elastic stockings, aspirin v
  low-molecular-weight heparin (LMWH) in high risk
  patients. Belcaro et al 2001-2003. Various
  journals including Angiology.
• Several thousand subjects
• Incidence in high risk is between 4 to 6
• Long-haul flights gt 7 hours
• Stockings decrease incidence by 18.75 times.
  (Scholl compression level 14-17mmHg)
• 4.3 of short-haul high risk passengers
  developed DVT. Preliminary results on 500 out
  of 900 passengers.

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Aviation Health Institute

• Frequency of venous thromboembolism in low to
  moderate risk long distance air travellers The
  New Zealand Air Travellers Thrombosis (NZATT)
  Study (2003) Hughes RJ et al. Lancet Dec 20/27.
• 878 subjects in study
• Average travel duration of 39h.
• Ages between 18 and 70 years.
• Incidence of 1, 1 in 100 at risk
• 9 cases included, 5 DVT and 4 PE.

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Aviation Health Institute

• 6 cases had pre-existing risk factors such as
  HRT, the pill, obesity, strong family history and
  genetic defect.
• Preventive measures, 17 wore compression hose,
  31 (some 270 passengers) took aspirin.
• Our results suggest an association between
  multiple long distance air flights and venous
  thromboembolism even in individuals at low to
  moderate risk.

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Aviation Health Institute
Risk Factors Intrinsic

• Immobility
• Cramped position
• Dehydration due to excessive use of alcohol
• Compressions of popliteal vein by edge of seat
• Seated posture (especially when sleeping)
• Tall and short individuals

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Aviation Health Institute
AHI SURVEY OF AIR-RELATED DVT DEATHS (2003)
Analysis of risk factors of air-related DVT mild
and severe outcomes Gravenor M, Kahn F

• 49 males v 51 females out of 554 incidents
• 31 were under 40, youngest 19
• 19 short haul compared to 81 long haul
• 15 in business/first, 85 economy

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Aviation Health Institute

• Prospective Registry of 5,451 patients with
  ultrasound confirmed Deep Vein Thrombosis
  (2004) Goldhaber SZ, Tapson VF. American Journal
  of Cardiology.
• Patients included 2,892 women and 2,559 men
• 5 frequent co-morbidities were hypertension
  (50) surgery within 3 months, (38) immobility
  within 30 days (34), cancer (32), and obesity
  (27)
• Symptoms 82 swelling, 70 Extremity
  discomfort, 13 Dysphea, 17 Erythema, 13
  Difficulty walking, 6 chest pain, 3 cough, 2
  none.

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Aviation Health Institute
Guidelines for advice to passengers

• Leg Oedema
• Exercise legs
• Keep hydrated
• Avoid excessive alcohol
• Avoid sleeping in uncomfortable position
• Compression stockings (U.K. standard e.g.
  Scholl flight socks)
• Aspirin

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Aviation Health Institute
Guidelines for advice to passengers

• History of venous thrombosis and/thrombophilia
• Aspirin
• Bilateral stockings
• Low molecular weight heparin
• Recent surgery/injury to lower limbs
• Avoid journey
• Prophylaxis

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Aviation Health Institute
CONTACT INFORMATION

• Director Farrol Kahn
• Medical Director Professor Nicholas Peters,
• Imperial College, London
• Web site http\\www.aviation-health.org
• Telephone [phone] - Fax [phone]
• E-mail fkahn_at_aviation-health.org
• Address 17C Between Towns Road, Oxford, OX1 4HL