MEDICAL GUIDELINES FOR AIRLINE TRAVEL 2nd Edition Aerospace Medical Association Medical Guidelines Task Force Alexandria, VA VOLUME 74 NUMBER 5 Section II, Supplement MAY 2003 Medical Guidelines for Airline Travel, 2nd Edition A1 Introduction A1 Stresses of Flight A2 Medical Evaluation and Airline Special Services A2 Medical Evaluation A2 Airline Special Services A3 Inflight Medical Care A4 Reported Inflight Illness and Death A4 Immunization and Malaria Prophylaxis A5 Basic Immunizations A5 Supplemental Immunizations A5 Malaria Prophylaxis A6 Cardiovascular Disease A7 Deep Venous Thrombosis A8 Pulmonary Disease A10 Pregnancy and Air Travel A10 Maternal and Fetal Considerations A11 Travel and Children A11 Ear, Nose, and Throat A11 Ear A11 Nose and sinuses A12 Throat A12 Surgical Conditions A13 Neuropsychiatry A13 Neurological A13 Psychiatric A14 Miscellaneous Conditions B14 Air Sickness B14 Anemia A14 Decompression Illness A15 Diabetes A16 Jet Lag A17 Diarrhea A17 Fractures A18 Ophthalmological Conditions A18 Radiation A18 References Copyright 2003 by the Aerospace Medical Association, 320 S. Henry St., Alexandria, VA 22314-3579 The paper used in this publication meets the minimum requirements of American National Standard for Information Sciences—Permanence of Paper for Printed Library Materials. ANSI Z39.48-1984. Medical Guidelines for Airline Travel, 2nd ed. Aerospace Medical Association, Medical Guidelines Task Force, Alexandria, VA Introduction smoke, uncomfortable temperatures and low humidity, jet lag, and cramped seating (64). Nevertheless, healthy Each year approximately 1 billion people travel by air passengers endure these stresses which, for the most on the many domestic and international airlines. It has part, are quickly forgotten once the destination is been predicted that in the coming two decades, the reached. In general, passengers with illness (i.e., stable number of passengers will double. A global increase in illness) also usually depart the destination airport none travel, as well as an increasingly aged population in the worse. However, there is always the potential for many countries, makes it reasonable to assume that such passengers to become ill during or after the flight there will be a significant increase in older passengers due to these stresses. and passengers with illness. Patients frequently ask The primary difference between the aircraft environ- their physicians whether or not it is advisable for them ment and the ground environment relates to the atmo- to travel, and if so, what precautions they should take. sphere. Contrary to popular belief, modern aircraft are Consequently, physicians need to be aware of the envi- not pressurized to sea level equivalent. Instead, on most ronmental and physiological stresses of flight in order flights the cabin altitude will be between 5000 and 8000 to properly advise their patients. In addition, because ft (1524 m and 2438 m). This results in reduced baro- international travelers can fly to the four corners of the metric pressure with a concomitant decrease in partial world in just hours, a basic understanding of vaccina- pressure of oxygen (PO ). While the barometric pressure tions is requisite. 2 Two caveats are brought to the attention of the is 760 mm Hg at sea level with a corresponding PaO2 reader. First, if inflight illness or even death has occa- (arterial O2 pressure) of 98 mm Hg, the barometric sionally been reported by the airlines, the event was not pressure at 8000 ft will be 565 mm Hg with PaO2 of about necessarily caused by airline travel or the stresses of 55 mm Hg. If these last data are plotted on the oxyhe- flight. The physician must be mindful that, with so moglobin dissociation curve, we obtain a blood oxygen many passengers spending so many hours inflight, fly- saturation of 90%. Although most healthy travelers can ing and the medical event may be coincidental rather normally compensate for this amount of hypoxemia, than causal. Second, the guidelines described herein are this may not be true for coronary, pulmonary, cerebro- just that–guidelines, and not rigid criteria or hard and vascular, and anemic patients. Because these patients fast rules. Like all patient management, these guidelines may already have a reduced PaO2 on the ground, further must be individualized and tempered by the physi- reduction in aircraft cabin pressure will bring them to cian’s clinical judgment. the steep part of the oxyhemoglobin dissociation curve This publication was prepared by the Aerospace with a resultant very low saturation, which could cause Medical Association Medical Guidelines Task Force. distress and/or exacerbation of their illness (Fig. 1). The information contained herein is for primary care The hazards of cigarette smoking, active and passive, and specialist physicians so they will be better prepared are well known and need not be recounted here. There to advise patients who are contemplating air travel. is a worldwide movement to ban inflight smoking, with (The reader is cautioned that the material applies only the International Civil Aviation Organization (ICAO) to passengers and not to airline crews or cabin atten- having asked all member States to comply. U.S. air dants.) The authors sincerely hope that this publication carriers prohibit smoking on all flights. As a result, will educate the physician and contribute to safe and there has been vast improvement in cabin air quality comfortable flight for passengers. and commensurate crew and passenger comfort. (For passengers with the potential for inflight nicotine with- drawal symptoms, nicotine gum or patch might be Stresses of Flight considered.) Modern commercial aircraft are very safe and, in Today’s aircraft have very low cabin humidity, usu- most cases, reasonably comfortable. However, all ally ranging from 10-20%. This is unavoidable because flights, short or long haul, impose stresses on all pas- the air at high altitude is practically devoid of moisture. sengers. Preflight stresses include airport tumult on the As a result, there can be a drying effect of airway ground such as carrying baggage, walking long dis- passages, the cornea (particularly under contact lenses), tances, and being delayed. Inflight stresses include low- and the skin. ered barometric pressure and partial pressure of oxy- Jet lag or circadian desynchronosis results from the gen, noise, vibration (including turbulence), cigarette desynchronization of the body clock with surrounding Aviation, Space, and Environmental Medicine • Vol. 74, No. 5, Section II • May 2003 A1 MEDICAL GUIDELINES FOR AIRLINE TRAVEL Fig. 1. Oxyhemoglobin Dissocia- tion Curve. environmental cues. It may not only be an annoyance Common medical conditions which should be ad- for healthy passengers, but it can also complicate the dressed in a preflight medical evaluation include car- timing of medications, such as insulin (See Jet Lag and diovascular disease (e.g., angina pectoris, congestive Diabetes sections). heart failure, myocardial infarction), deep venous On commercial flights, regardless of aircraft type, thrombosis, asthma and emphysema, surgical condi- many passengers sit in small, cramped spaces. This is tions, seizure disorder, stroke, mental illness, diabetes, not only uncomfortable, but also reduces the opportu- and infectious diseases. nity to get up, stretch, and walk about the cabin. Sitting The passenger’s health care provider should also con- for long periods is tolerable for most passengers, but for sider vaccination status and the public health aspects of some there is the potential for exacerbating peripheral infectious diseases. Individuals with any contagious edema, cramps, and other circulatory problems. Of par- disease that could be transmitted to other passengers ticular concern are deep venous thrombosis and, even should postpone air travel until they are no longer worse, the potential for pulmonary embolus (See Deep contagious. Of particular concern is tuberculosis. Pro- Venous Thrombosis section). spective passengers who have tuberculosis should have had adequate therapy and be noninfectious prior to Medical Evaluation and Airline Special Services flight. If the physician has fully reviewed the prospective Medical Evaluation traveler’s condition and there is any question regarding The time before a commercial airline flight (preflight) the suitability to fly or any special requests for assis- is the best time to assess fitness of the prospective tance, the airline should be contacted (in many cases, passenger. The private physician should review the this will be the airline medical department). For a pas- passenger’s medical condition, giving special consider- senger with a special medical condition that could lead ation to the dosage and timing of any medications, to inflight illness, injury, or risk to other passengers, contagiousness, and the need for special assistance or some airlines will require a medical certificate from the requests. health care provider stating that the passenger is cur- As a general rule, an individual with an unstable rently stable and fit for air travel. For a contagious medical condition should not fly. Instability combined disease, the certificate should also state that the passen- with the stresses of flight could pose a serious threat to ger is not infectious. the health and well-being of the sick or injured traveler. For the traveling public, “Useful Tips for Airline As mentioned in previous paragraphs, a lowered in- Travel” and “Medical Guidelines for Airline Passen- flight barometric pressure and