Air travel in women with lymphangioleiomyomatosis

Stacey Pollock‐BarZiv

Marsha Cohen

Gregory Downey

Simon Johnson

Eugene Sullivan

Francis McCormack

Stacey Pollock‐BarZiv, Women's College Research Institute, Women's College Hospital, Toronto, Ontario, Canada

Marsha M Cohen, Department of Health Policy, Management and Evaluation, The University of Toronto, Toronto, Ontario, Canada

Gregory P Downey, Division of Respirology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada

Simon R Johnson, Division of Therapeutics and Molecular Medicine, The University of Nottingham, Nottingham, UK

Eugene Sullivan, Chief Medical Officer, Lung Rx, Silver Spring, Maryland, USA

Francis X McCormack, Division of Pulmonary & Critical Care Medicine, University of Cincinnati Medical Center, Cincinnati, Ohio, USA

Correspondence to: Dr S Pollock‐BarZiv
Division of Cardiology, Cardiac Transplant, Room 6429, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, Canada M5G 1X8; s.pollock. barziv@utoronto.ca

Stacey Pollock‐BarZiv, Women's College Research Institute, Women's College Hospital, Toronto, Ontario, CanadaMarsha M Cohen, Department of Health Policy, Management and Evaluation, The University of Toronto, Toronto, Ontario, CanadaGregory P Downey, Division of Respirology, Department of Medicine, University of Toronto, Toronto, Ontario, CanadaSimon R Johnson, Division of Therapeutics and Molecular Medicine, The University of Nottingham, Nottingham, UKEugene Sullivan, Chief Medical Officer, Lung Rx, Silver Spring, Maryland, USAFrancis X McCormack, Division of Pulmonary & Critical Care Medicine, University of Cincinnati Medical Center, Cincinnati, Ohio, USACorrespondence to: Dr S Pollock‐BarZiv
Division of Cardiology, Cardiac Transplant, Room 6429, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, Canada M5G 1X8; s.pollock. barziv@utoronto.ca

Received 2006 Jan 4; Accepted 2006 Aug 31.

Abstract

Background and objective

The safety of air travel in patients with pneumothorax‐prone pulmonary diseases, such as lymphangioleiomyomatosis (LAM), has not been studied to any great extent. A questionnaire‐based evaluation of air travel in patients with LAM was conducted to determine experiences aboard commercial aircraft.

Methods

A survey was sent to women listed in the US LAM Foundation registry (n = 389) and the UK LAM Action registry (n = 59) to assess air travel, including problems occurring during flight. Women reporting a pneumothorax in flight were followed up to ascertain further details about the incident.

Results

327 (73%) women completed the survey. 308 women answered the travel section, of whom 276 (90%) had “ever” travelled by aeroplane for a total of 454 flights. 95 (35%) women had been advised by their doctor to avoid air travel. Adverse events reported included shortness of breath (14%), pneumothorax (2%, 8/10 confirmed by chest radiograph), nausea or dizziness (8%), chest pain (12%), unusual fatigue (11%), oxygen desaturation (8%), headache (9%), blue hands (2%), haemoptysis (0.4%) and anxiety (22%). 5 of 10 patients with pneumothorax had symptoms that began before the flight: 2 occurred during cruising altitude, 2 soon after landing and 1 not known. The main symptoms were severe chest pain and shortness of breath.

Discussion and conclusion

Adverse effects occurred during air travel in patients with LAM, particularly dyspnoea and chest pain. Hypoxaemia and pneumothorax were reported. The decision to travel should be individualised; patients with unexplained shortness of breath or chest pain before scheduled flights should not board. Patients with borderline oxygen saturations on the ground should be evaluated for supplemental oxygen therapy during flight. Although many women had been advised not to travel by air, most travelled without the occurrence of serious adverse effects.

Abstract

Pulmonary lymphangioleiomyomatosis (LAM) is a progressive lung disease that affects young women, and is characterised by diffuse proliferation of abnormal smooth‐muscle cells and cystic destruction of the lung parenchyma.¹²³⁴⁵ LAM occurs in about 30% of women with neurocutaneous syndrome, tuberous sclerosis (TSC) and also in those without heritable disease (sporadic LAM). Clinically, LAM is characterised by progressive dyspnoea with exertion, fatigue, pneumothorax (in as many as 70% of patients), chronic cough, wheezing and chest pain, chylothorax, and an obstructive or mixed restrictive and obstructive pattern on pulmonary function tests.¹²³⁴⁵ The rate of advancement varies considerably; however, as the disease progresses, patients often require supplemental oxygen. No definitive treatment for LAM currently exists, and lung transplantation remains the only therapeutic option for patients with advanced disease.

The exact prevalence of LAM is not known. In the UK, a minimum prevalence of 1/373 000 women aged 16–65 years was reported,³ and the minimal prevalence rate worldwide is estimated at 2.6 cases per 1 million women.⁶⁷ The incidence of TSC LAM is currently estimated at about 30–40% of women with TSC⁸; TSC occurs as 1/6000 births, suggesting there may be as many as 8000–10 000 women with TSC LAM in North America, and almost 250 000 worldwide.⁸

Rajjoub et al⁹ reported on a 21‐year‐old woman who experienced acute, severe dyspnoea during air travel, requiring immediate transport to hospital where a chest radiograph disclosed a pneumothorax. Further anecdotal reports suggest air travel may predispose patients with LAM to pneumothorax¹⁹ (Dr McCormack, US LAM Foundation, personal communication, 2003). Therefore, doctors are often asked about the risk to patients when flying. Despite this, there has been little study on the safety of commercial air travel in patients with LAM. During flight, the cabin pressure is generally adjusted to be equivalent to that at an altitude of 1524–2438 m (5000–8000 feet) above sea level, which typically results in a 40% decrease in arterial oxygen pressure (PaO₂), from 95 to about 56 mm Hg (from 12.7 to about 7.5 kPa) in healthy people.¹⁰ Clinically significant hypoxia may occur in some patients with reduced baseline PaO₂ at sea level.¹⁰¹¹ Further, given the sinusoidal shape of the oxyhaemoglobin saturation curve, these individuals may experience precipitous declines in their oxygen levels during flight.¹⁰ The falling PaO₂ with increasing altitude may in turn result in several physiological adaptations, including hyperventilation, pulmonary vasoconstriction, altered ventilation/perfusion matching and increased sympathetic tone.¹¹¹²

The British Thoracic Society¹³ has published recommendations for passengers with respiratory disease planning air travel (http://www.brit‐thoracic.org.uk/page246.html). They note that physiological compensations for acute hypoxaemia at rest include mild to moderate hyperventilation and a moderate tachycardia. In those with pulmonary disease, these compensatory mechanisms may be insufficient to offset the risk of hypoxaemia and concurrent adverse effects, especially during air travel. Similarly, the Canadian and American Thoracic Societies have published guidelines for air travel for patients with chronic obstructive pulmonary disease.¹⁴¹⁵ Both warn of the risks of altitude‐related hypoxaemia and provide recommendations for pre‐travel assessment. Nonetheless, patients with chronic obstructive pulmonary disease with arterial oxygen tensions above the recommended “safe” level of 7.3 kPa (55 mm Hg) may still develop severe hypoxaemia in flight.¹⁶ Christensen et al¹⁶ reported that of 15 stable patients with chronic obstructive pulmonary disease (resting PaO₂ >9.3 kPa; forced expiratory volume in 1 s <50% predicted), three patients developed marked hypoxaemia during simulated air travel at 2438 m (8000 feet), and that light exercise (such as walking along the aisle) led to severe hypoxaemia in 13 of the 15 patients.

The availability of in‐flight oxygen may help to alleviate problems with hypoxaemia in flight. Many commercial airlines offer in‐flight oxygen to passengers, but some smaller airlines do not. There is usually a substantial fee for oxygen for each in‐flight segment and there are often restrictions on the type of aircraft that will accommodate the oxygen cylinders. New Federal Aviation Authority regulations allow certain portable oxygen concentrators but these are expensive and not yet practical for most travellers. These factors may limit the accessibility of air travel to patients with lung disease.

In addition to the risk of hypoxaemia, patients with cystic lung diseases such as LAM may be particularly vulnerable to other flight‐related complications such as pneumothorax. During ascent, there is a decrease in cabin pressure and a consequent increase in the volume of gases contained in closed body cavities, such as within non‐communicating airspaces in the lungs of patients with LAM.¹⁰¹¹ Pressure fluxes during ascent and descent pose the greatest risk for expansion of an existing pneumothorax and, in theory, for the occurrence of a new pneumothorax. The British Thoracic Society¹³ air travel guidelines for those with a history of pneumothorax were updated in 2004 (http://www.brit‐thoracic.org.uk/page246.html), and include the following recommendations:

Minimum 1 week after full radiographic resolution on chest x ray prior to air travel
Minimum of 2 weeks prior to air travel for traumatic pneumothorax or thoracic surgery
Patients with current closed pneumothorax should not travel by commercial air
Risk of recurrence is higher in those with coexisting lung disease up to a year, particularly in those not undergoing surgical treatment of the initial pneumothorax.

Patients with LAM may be at increased risk for pneumothorax in general. Almoosa et al¹⁷ reported that 66% of patients had at least one spontaneous pneumothorax, and 77% of those had at least one subsequent pneumothorax. Although anecdotal reports of in‐flight pneumothorax have led many doctors to advise patients not to fly, no published guidelines exist for air travel in women with LAM⁹ (US LAM Foundation, personal communication). Moreover, excess costs and limited access to medical assistance and supplemental oxygen are potential barriers to air travel in these women. To better understand the experiences of air travel and the occurrence of in flight adverse events, we surveyed a large population of women with LAM.

Abbreviations

LAM - lymphangioleiomyomatosis

PaO₂ - arterial oxygen pressure

TSC - tuberous sclerosis

Abbreviations

Footnotes

Funding: The US LAM Foundation and the Social Sciences and Humanities Research Council of Canada provided a doctoral fellowship to SP‐B.

Competing interests: GPD currently holds the R Fraser Elliott Chair in transplantation research from the Toronto General Hospital and is a tier 1 Canada Research Chair.

Footnotes

References

1. Sullivan E JLymphangioleiomyomatosis: a review. Chest 19981141689–1703. [[PubMed][Google Scholar]
2. Johnson S RLymphangioleiomyomatosis: clinical features, management and basic mechanisms. Thorax 199954254–264. [Google Scholar]
3. Johnson S R, Tattersfield A EClinical experience of lymphangioleiomyomatosis in the UK. Thorax 2000551052–1057. [Google Scholar]
4. Taylor J R, Ryu J, Colby T V. et al Lymphangioleiomyomatosis: clinical course in 32 patients. N Engl J Med 19903231254–1260. [[PubMed]
5. Cohen M M, Pollock‐BarZiv S M, Johnson S REmerging clinical picture of lymphangioleiomyomatosis. Thorax 200560875–879. [Google Scholar]
6. Urban T, Lazor R, Lacronique J. et al Pulmonary lymphangioleiomyomatosis. A study of 69 patients. Medicine 199978321–337. [[PubMed]
7. Glassberg M KLymphangioleiomyomatosis. Clin Chest Med 200425573–582. [[PubMed][Google Scholar]
8. Costello L C, Hartman T E, Ryu J HHigh frequency of pulmonary lymphangioleiomyomatosis in women with tuberous sclerosis complex. Mayo Clin Proc 200075591–594. [[PubMed][Google Scholar]
9. Rajjoub S, Blatt M V, Ritterspach JResponse to treatment with progesterone in a patient with pulmonary lymphangioleiomyomatosis. W V Med J 199591322–323. [[PubMed][Google Scholar]
10. Gendreau M A, DeJohn CResponding to medical events during commercial airline flights. N Engl J Med 20023461067–1072. [[PubMed][Google Scholar]
11. Cottrell J JAltitude exposures during aircraft flight: flying higher. Chest 19889381–84. [[PubMed][Google Scholar]
12. Mortazavi A, Eisenberg M J, Langleben D. et al Altitude‐related hypoxia: risk assessment and management for passengers on commercial aircraft. Aviat Space Environ Med 200374922–927. [[PubMed]
13. British Thoracic Society Standards of Care Committee Managing passengers with respiratory disease planning air travel: British Thoracic Society recommendations. Thorax 200257289–304.
14. Celli B RATS standards for the optimal management of chronic obstructive pulmonary disease. Respirology 19972S1–S4. [[PubMed][Google Scholar]
15. Lien D, Turner MRecommendations for patients with chronic respiratory disease considering air travel: a statement from the Canadian Thoracic Society. Can Respir J 1998595–100. [[PubMed][Google Scholar]
16. Christensen C C, Ryg M, Refyem O K. et al Development of severe hypoxaemia in chronic obstructive pulmonary disease patients at 2438 m (8000 ft) altitude. Eur Respir J 200015635–639. [[PubMed]
17. Almoosa K F, Ryu J H, Medez J. et al Management of pneumothorax in lymphangioleiomyomatosis: effects of recurrence and lung transplantation. Chest 20061291274–1281. [[PubMed]
18. American Thoracic Society Dyspnea: mechanisms, assessment, and management: a consensus statement. Am J Respir Crit Care Med 1999159321–341. [[PubMed]
19. Stoller J KOxygen and air travel. Respir Care 200045214–221. [[PubMed][Google Scholar]
20. Seccombe L M, Kelly P T, Wong C K. et al Effect of simulated commercial flight on oxygenation in patients with interstitial lung disease and chronic obstructive pulmonary disease. Thorax 200459966–970.
21. Johnson A O CChronic obstructive pulmonary disease: fitness to fly with COPD. Thorax 200358729–732. [Google Scholar]
22. Dilliard T A, Moores L K, Bilello K L. et al The pre‐flight evaluation. A comparison of hypoxia inhalation test with hypobaric exposure. Chest 1995107352–357. [[PubMed]