Assessment of oxygen supplementation during air travel

Pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a rare and progressive disease characterised by remodelling of the pulmonary arteries and progressive narrowing of the pulmonary vasculature. This leads to a progressive increase in pulmonary vascular resistance and pulmonary arterial pressure and, if left untreated, to right ventricular failure and death. A correct diagnosis requires a complete work-up including right heart catheterisation performed in a specialised centre. Although our knowledge of the epidemiology, pathology and pathophysiology of the disease, as well as the development of innovative therapies, has progressed in recent decades, PAH remains a serious clinical condition. Current treatments for the disease target the three specific pathways of endothelial dysfunction that characterise PAH: the endothelin, nitric oxide and prostacyclin pathways. The current treatment algorithm is based on the assessment of severity using a multiparametric risk stratification approach at the time of diagnosis (baseline) and at regular follow-up visits. It recommends the initiation of combination therapy in PAH patients without cardiopulmonary comorbidities. The choice of therapy (dual or triple) depends on the initial severity of the condition. The main treatment goal is to achieve low-risk status. Further escalation of treatment is required if low-risk status is not achieved at subsequent follow-up assessments. In the most severe patients, who are already on maximal medical therapy, lung transplantation may be indicated. Recent advances in understanding the pathophysiology of the disease have led to the development of promising emerging therapies targeting dysfunctional pathways beyond endothelial dysfunction, including the TGF-β and PDGF pathways.

Hypoxia-altitude simulation test to predict altitude-related adverse health effects in COPD patients

Background/aims

Amongst numerous travellers to high altitude (HA) are many with the highly prevalent COPD, who are at particular risk for altitude-related adverse health effects (ARAHE). We then investigated the hypoxia-altitude simulation test (HAST) to predict ARAHE in COPD patients travelling to altitude.

Methods

This prospective diagnostic accuracy study included 75 COPD patients: 40 women, age 58±9 years, forced expiratory volume in 1 s (FEV1) 40-80% pred, oxygen saturation measured by pulse oximetry (S pO2 ) ≥92% and arterial carbon dioxide tension (P aCO2 ) <6 kPa. Patients underwent baseline evaluation and HAST, breathing normobaric hypoxic air (inspiratory oxygen fraction (F IO2 ) of 15%) for 15 min, at low altitude (760 m). Cut-off values for a positive HAST were set according to British Thoracic Society (BTS) guidelines (arterial oxygen tension (P aO2 ) <6.6 kPa and/or S pO2 <85%). The following day, patients travelled to HA (3100 m) for two overnight stays where ARAHE development including acute mountain sickness (AMS), Lake Louise Score ≥4 and/or AMS score ≥0.7, severe hypoxaemia (S pO2 <80% for >30 min or 75% for >15 min) or intercurrent illness was observed.

Results

ARAHE occurred in 50 (66%) patients and 23 out of 75 (31%) were positive on HAST according to S pO2 , and 11 out of 64 (17%) according to P aO2 . For S pO2 /P aO2 we report a sensitivity of 46/25%, specificity of 84/95%, positive predictive value of 85/92% and negative predictive value of 44/37%.

Conclusion

In COPD patients ascending to HA, ARAHE are common. Despite an acceptable positive predictive value of the HAST to predict ARAHE, its clinical use is limited by its insufficient sensitivity and overall accuracy. Counselling COPD patients before altitude travel remains challenging and best focuses on early recognition and treatment of ARAHE with oxygen and descent.

Transport aérien de l’oxygène en cabine et en soute : risques, réglementation et pratiques en situation de crise

Jamais autant que dans la crise COVID-19 actuelle l’oxygène (O₂) n’a joué un si grand rôle, sous toutes ses formes de production. Il était donc tout naturel que ce gaz, commun mais précieux en situation de crise, soit à la fois un élément clef et une contrainte forte au transport en avion de patients contaminés par la COVID-19. L’O₂ est en effet considéré par l’industrie du transport aérien comme un « dangerous good » du fait de ses propriétés comburantes pouvant favoriser un incendie en vol, ainsi que par son conditionnement sous pression, avec les risques associés. Il est donc tout naturel que, depuis l’essor massif du transport aérien au milieu du 20^e siècle, des normes, réglementations et recommandations, plus ou moins contraignantes, aient été mises en place. Ceci n’est pas sans amener des contraintes et limitations importantes à la capacité de transporter en avion simultanément un grand nombre de patients oxygéno-requérants, mais est également un élément important de garantie de sécurité afin d’éviter que, poussées par le besoin médical ou logistique, des équipes médicales ne soient tentées de sortir du cadre, au risque d’aller vers un incident en vol pouvant s’avérer dramatique. Pour le futur, certaines pistes prometteuses seraient à explorer, en particulier les concentrateurs d’oxygène de forte capacité.

Differences in Tolerance to Hypoxia: Physiological, Biochemical, and Molecular-Biological Characteristics

Hypoxia plays an important role in the development of many infectious, inflammatory, and tumor diseases. The predisposition to such disorders is mostly provided by differences in basic tolerance to oxygen deficiency, which we discuss in this review. Except the direct exposure of different-severity hypoxia in decompression chambers or in highland conditions, there are no alternative methods for determining organism tolerance. Due to the variability of the detection methods, differences in many parameters between tolerant and susceptible organisms are still not well-characterized, but some of them can serve as biomarkers of susceptibility to hypoxia. At the moment, several potential biomarkers in conditions after hypoxic exposure have been identified both in experimental animals and humans. The main potential biomarkers are Hypoxia-Inducible Factor (HIF)-1, Heat-Shock Protein 70 (HSP70), and NO. Due to the different mechanisms of various high-altitude diseases, biomarkers may not be highly specific and universal. Therefore, it is extremely important to conduct research on hypoxia susceptibility biomarkers. Moreover, it is important to develop a method for the evaluation of organisms' basic hypoxia tolerance without the necessity of any oxygen deficiency exposure. This can contribute to new personalized medicine approaches' development for diagnostics and the treatment of inflammatory and tumor diseases, taking into account hypoxia tolerance differences.

A comprehensive and practical approach to the management of idiopathic pulmonary fibrosis

Introduction: Idiopathic pulmonary fibrosis (IPF) is a debilitating, progressive, and fatal fibrotic pulmonary disease with a prognosis comparable to that of lung cancer. IPF management is a complex process that involves pharmacological and nonpharmacological interventions, extensive patient education, and addressing patient needs that change through the course of the illness. Areas covered: This review summarizes the key aspects of a multifaceted, multidisciplinary, individualized approach to IPF care that incorporates available treatment options, strategies to improve compliance with antifibrotic therapies, pulmonary rehabilitation, and the integration of palliative care for symptom management. Aspects of care discussed include the use of antifibrotic therapy and nonpharmacological treatments, targeted education and psychosocial support, evaluation and management of comorbidities, and early integration of palliative care. Expert opinion: By incorporating this comprehensive approach to disease management, physicians can address most aspects of care for a patient with IPF to optimize survival and quality of life.

In-Flight Medical Emergencies: A Review

IMPORTANCE

In-flight medical emergencies (IMEs) are common and occur in a complex environment with limited medical resources. Health care personnel are often asked to assist affected passengers and the flight team, and many have limited experience in this environment.

OBSERVATIONS

In-flight medical emergencies are estimated to occur in approximately 1 per 604 flights, or 24 to 130 IMEs per 1 million passengers. These events happen in a unique environment, with airplane cabin pressurization equivalent to an altitude of 5000 to 8000 ft during flight, exposing patients to a low partial pressure of oxygen and low humidity. Minimum requirements for emergency medical kit equipment in the United States include an automated external defibrillator; equipment to obtain a basic assessment, hemorrhage control, and initiation of an intravenous line; and medications to treat basic conditions. Other countries have different minimum medical kit standards, and individual airlines have expanded the contents of their medical kit. The most common IMEs involve syncope or near-syncope (32.7%) and gastrointestinal (14.8%), respiratory (10.1%), and cardiovascular (7.0%) symptoms. Diversion of the aircraft from landing at the scheduled destination to a different airport because of a medical emergency occurs in an estimated 4.4% (95% CI, 4.3%-4.6%) of IMEs. Protections for medical volunteers who respond to IMEs in the United States include a Good Samaritan provision of the Aviation Medical Assistance Act and components of the Montreal Convention, although the duty to respond and legal protections vary across countries. Medical volunteers should identify their background and skills, perform an assessment, and report findings to ground-based medical support personnel through the flight crew. Ground-based recommendations ultimately guide interventions on board.

CONCLUSIONS AND RELEVANCE

In-flight medical emergencies most commonly involve near-syncope and gastrointestinal, respiratory, and cardiovascular symptoms. Health care professionals can assist during these emergencies as part of a collaborative team involving the flight crew and ground-based physicians.

Should I stay or should I go? COPD and air travel

Chronic obstructive pulmonary disease (COPD) is a challenging respiratory problem throughout the world. Although survival is prolonged with new therapies and better management, the magnitude of the burden resulting from moderate-to-severe disease is increasing. One of the major aims of the disease management is to try to break the vicious cycle of patients being homebound and to promote an active lifestyle. A fundamental component of active daily life is, of course, travelling. Today, the world is getting smaller with the option of travelling by air. Air travel is usually the most preferred choice as it is easy, time saving, and relatively inexpensive. Although it is a safe choice for many passengers, the environment inside the aeroplane may sometimes have adverse effects on health. Hypobaric hypoxaemia due to cabin altitude may cause health risks in COPD patients who have limited cardiopulmonary reserve. Addressing the potential risks of air travel, promoting proactive strategies including pre-flight assessment, and education of COPD patients about the "fitness to fly" concept are essential. Thus, in this narrative review, we evaluated the current evidence for potential risks of air travel in COPD and tried to give a perspective for how to plan safe air travel for COPD patients.

In-flight angina pectoris; an unusual presentation

BACKGROUND

An unusual case of typical angina which occurred on a long haul flight is presented. This case is notable as this was the index presentation, with no previous symptoms prior to this. Physiological changes at altitude can be marked, and include hypoxia, tachycardia and an increase in cardiac output. These changes were enough to expose underlying angina in our patient.

CASE PRESENTATION

A 68 year old man presented with typical cardiac chest pain on a long haul flight. His symptoms first started 10-15 min after take-off and resolved on landing. This was his index presentation, and there were no similar symptoms in the past. Background history included hypercholesterolaemia and benign prostatic hypertrophy only. He led a rather sedentary lifestyle. A CT coronary angiogram showed significant disease in the proximal left anterior descending artery and proximal right coronary artery. He went on to have a coronary angiogram with invasive physiological measurements, which determined both lesions were physiologically significant. Both arteries were treated with drug eluting stents. Since treatment, he once again embarked on a long haul flight, and was completely asymptomatic.

CONCLUSION

The presentation of symptoms in this individual was rather unusual, but clearly caused by significant coronary artery disease. Potentially his sedentary lifestyle was not enough in day-to-day activities to promote anginal symptoms. When his cardiovascular system was physiologically stressed during flight, brought about by hypoxia, raised sympathetic tone and increased cardiac output, symptoms emerged. In turn, when landing, with atmospheric conditions normalised, physiological stress was removed, and symptoms resolved. Clinically therefore, one should not exclude symptoms that occur with differing physiological states, such as stress and altitude, as they are also potential triggers for myocardial ischaemia, despite absence of day-to-day symptoms.

Hypoxic Challenge Testing (Fitness to Fly) in children with complex congenital heart disease

Objective

Commercial airplanes fly with an equivalent cabin fraction of inspired oxygen of 0.15, leading to reduced oxygen saturation (SpO2) in passengers. How this affects children with complex congenital heart disease (CHD) is unknown. We conducted Hypoxic Challenge Testing (HCT) to assess need for inflight supplemental oxygen.

Methods

Children aged <16 years had a standard HCT. They were grouped as (A) normal versus abnormal baseline SpO2 (≥95% vs <95%) and (B) absence versus presence of an actual/potential right-to-left (R–L) shunt. We measured SpO2, heart rate, QT interval corrected for heart rate and partial pressure of carbon dioxide measured transcutaneously (PtcCO2). A test failed when children with (1) normal baseline SpO2 desaturated to 85%, (2) baseline SpO285%–94% desaturated by 15% of baseline; and (3) baseline SpO275%–84% desaturated to 70%.

Results

There were 68 children, mean age 3.3 years (range 10 weeks–14.5 years). Children with normal (n=36) baseline SpO2 desaturated from median 99% to 91%, P<0.0001, and 3/36 (8%) failed the test. Those with abnormal baseline SpO2 (n=32) desaturated from median 84% to 76%, P<0.0001, and 5/32 (16%) failed (no significant difference between groups). Children with no R–L shunt (n=25) desaturated from median 99% to 93%, P<0.0001, but 0/25 failed. Those with an actual/potential R–L shunt (n=43) desaturated from median 87% to 78%, P<0.0001, and 8/43 (19%) failed (difference between groups P<0.02). PtcCO2, heart rate and QT interval corrected for heart rate were unaffected by the hypoxic state.

Conclusions

This is the first evidence to help guide which children with CHD need a preflight HCT. We suggest all children with an actual or potential R–L shunt should be tested.

Physiological predictors of Hypoxic Challenge Testing (HCT) outcomes in Interstitial Lung Disease (ILD)

BACKGROUND

Pre-flight risk assessments are currently recommended for all Interstitial Lung Disease (ILD) patients. Hypoxic challenge testing (HCT) can inform regarding the need for supplemental in-flight oxygen but variables which might predict the outcome of HCT and thus guide referral for assessment, are unknown.

METHODS

A retrospective analysis of ILD patients attending for HCT at three tertiary care ILD referral centres was undertaken to investigate the concordance between HCT and existing predictive equations for prediction of in-flight hypoxia. Physiological variables that might predict a hypoxaemic response to HCT were also explored with the aim of developing a practical pre-flight assessment algorithm for ILD patients.

RESULTS

A total of 106 ILD patients (69 of whom (65%) had Idiopathic Pulmonary Fibrosis (IPF)) underwent HCT. Of these, 54 (51%) patients (of whom 37 (69%) had IPF) failed HCT and were recommended supplemental in-flight oxygen. Existing predictive equations were unable to accurately predict the outcome of HCT. ILD patients who failed HCT had significantly lower resting SpO₂, baseline PaO_2, reduced walking distance, FEV1, FVC and TLCO, but higher GAP index than those who passed HCT.

CONCLUSIONS

TLCO >50% predicted and PaO₂ >9.42 kPa were independent predictors for passing HCT. Using these discriminators, a novel, practical pre-flight algorithm for evaluation of ILD patients is proposed.

Short-term exposure to hypoxia for work and leisure activities in health and disease: which level of hypoxia is safe?

INTRODUCTION

Exposures to natural and simulated altitudes entail reduced oxygen availability and thus hypoxia. Depending on the level of hypoxia, the duration of exposure, the individual susceptibility, and preexisting diseases, health problems of variable severity may arise. Although millions of people are regularly or occasionally performing mountain sport activities, are transported by airplanes, and are more and more frequently exposed to short-term hypoxia in athletic training facilities or at their workplace, e.g., with fire control systems, there is no clear consensus on the level of hypoxia which is generally well tolerated by human beings when acutely exposed for short durations (hours to several days).

CONCLUSIONS

Available data from peer-reviewed literature report adaptive responses even to altitudes below 2,000 m or corresponding normobaric hypoxia (F(i)O(2) > 16.4%), but they also suggest that most of exposed subjects without severe preexisting diseases can tolerate altitudes up to 3,000 m (F(i)O(2) > 14.5%) well. However, physical activity and unusual environmental conditions may increase the risk to get sick. Large interindividual variations of responses to hypoxia have to be expected, especially in persons with preexisting diseases. Thus, the assessment of those responses by hypoxic challenge testing may be helpful whenever possible.

Suicide by oxygen deprivation with helium: a preliminary study of British Columbia coroner investigations

This article researches a relatively new suicide method advanced by right-to-die organizations: oxygen deprivation by breathing helium inside a plastic hood. The article begins with a review of the role of the coroner and the history of oxygen deprivation with helium; it then examines 20 Judgements of Inquiry (JOI) by British Columbia coroners into this form of suicide. The JOI were obtained through the Freedom of Information and Protection of Privacy Act and cover the period of 1999 to 2007. Findings raise concerns about the coding system used by coroners as well as adherence to internal documentation guidelines. The British Columbia Coroners Service (BCCS) has a public safety mandate to investigate all unnatural deaths and to make recommendations to prevent deaths in similar circumstances. It is a concern that BCCS has no recommendations to prevent suicides by oxygen deprivation with helium. More in-depth, systematic research is recommended to determine the prevalence of suicide by oxygen deprivation and to develop strategies to benefit public health and safety.

COPD and air travel: oxygen equipment and preflight titration of supplemental oxygen

BACKGROUND

Patients with COPD may need supplemental oxygen during air travel to avoid development of severe hypoxemia. The current study evaluated whether the hypoxia-altitude simulation test (HAST), in which patients breathe 15.1% oxygen simulating aircraft conditions, can be used to establish the optimal dose of supplemental oxygen. Also, the various types of oxygen-delivery equipment allowed for air travel were compared.

METHODS

In a randomized crossover trial, 16 patients with COPD were exposed to alveolar hypoxia: in a hypobaric chamber (HC) at 2,438 m (8,000 ft) and with a HAST. During both tests, supplemental oxygen was given by nasal cannula (NC) with (1) continuous flow, (2) an oxygen-conserving device, and (3) a portable oxygen concentrator (POC).

RESULTS

PaO(2) kPa (mm Hg) while in the HC and during the HAST with supplemental oxygen at 2 L/min (pulse setting 2) on devices 1 to 3 was (1) 8.6 ± 1.0 (65 ± 8) vs 12.5 ± 2.4 (94 ± 18) (P < .001), (2) 8.6 ± 1.6 (64 ± 12) vs 9.7 ± 1.5 (73 ± 11) (P < .001), and (3) 7.7 ± 0.9 (58 ± 7) vs 8.2 ± 1.1 (62 ± 8) (P= .003), respectively.

CONCLUSIONS

The HAST may be used to identify patients needing supplemental oxygen during air travel. However, oxygen titration using an NC during a HAST causes accumulation of oxygen within the facemask and underestimates the oxygen dose required. When comparing the various types of oxygen-delivery equipment in an HC at 2,438 m (8,000 ft), compressed gaseous oxygen with continuous flow or with an oxygen-conserving device resulted in the same PaO(2), whereas a POC showed significantly lower PaO(2) values.

TRIAL REGISTRY

ClinicalTrials.gov; No.: Identifier: NCT01019538; URL: clinicaltrials.gov.

Oxygen therapy in chronic obstructive pulmonary disease

Since the introduction of oxygen as a therapeutic agent 70 years ago, much has been learned regarding the detrimental effects of hypoxemia and the beneficial impact of oxygen therapy. It is projected that there are close to 800,000 patients receiving long-term oxygen therapy (LTOT) in the United States, at a cost of approximately $1.8 billion annually. The large numbers of patients receiving supplemental oxygen as treatment and the high costs incurred in providing oxygen therapy necessitate the practitioner to know the indications for LTOT as well its effects on survival, pulmonary hemodynamics, sleep, and exercise capacity. It is now recognized that the basis for LTOT prescription for all patients is founded on data that are over 25 years old and that only involve a very select cohort of patients. It is clear that further studies are required to assess the effects of oxygen on patients with chronic obstructive pulmonary disease with only mild hypoxemia, not only survival but also on neurocognitive function, quality of life, exercise physiology, and sleep quality. In addition, although proven to be safe when prescribed long term to individuals with lung disease, there are some concerns about worsening carbon dioxide retention and increased oxidant injury. The goals of this article are to briefly describe the indications for chronic oxygen administration, the physiologic effects of treatment, and potential toxicities, as well as its effect on morbidity and mortality.

Using laboratory measurements to predict in-flight desaturation in respiratory patients: are current guidelines appropriate?

In an attempt to guide physicians asked by respiratory patients for advice on flight fitness, the British Thoracic Society (BTS) have published guidelines on fitness to fly. The main potential hazard is hypobaric hypoxia, and efforts have focused on the prediction of hypoxia in individuals. The present study examines 10 years' experience of hypoxic challenge (HC) of respiratory patients to evaluate if the guidelines recommended by the BTS are appropriate. One hundred and eighteen patients (67 female, mean age 65.6+/-11.4 (SD) years) were referred for assessment. Patients underwent HC using a 40% Venturi mask supplied with 100% N(2) which lowered the F(i)O(2) to 15.1%. A further 13 patients on long-term oxygen therapy also underwent HC whilst receiving supplemental oxygen. In agreement with the BTS guidelines, all patients with a sea level SpO(2) of over 95% maintained their SpO(2) > or = 90% during HC. One third of patients with sea level SpO(2) of 92-95%, but no other risk factor (as defined by the guidelines) also desaturated below 90% during HC. Thirty-two patients were assessed as fit to fly with supplemental oxygen. Our results support the BTS guidelines for patients with a sea level SpO(2) > 95% but suggest that some revision is required for patients with a sea level SpO(2) of 92-95%. It was not possible to predict from either initial SpO(2) or spirometry which individuals were at risk of desaturation below 90% during hypoxic challenge.

Definition of Cutoff Values for the Hypoxia Test Used for Preflight Testing in Young Children With Neonatal Chronic Lung Disease

BACKGROUND

The hypoxia test can be performed to identify potential hypoxia that might occur in an at-risk individual during air travel. In 2004, the British Thoracic Society increased the hypoxia test cutoff guideline from 85 to 90% in young children. The aim of this study was to investigate how well the cutoff values of 85% and 90% discriminated between healthy children and those with neonatal chronic lung disease (nCLD).

METHODS

We performed a prospective, interventional study in young children with nCLD who no longer required supplemental oxygen and healthy control subjects. A hypoxia test (involving the administration of 14% oxygen for 20 min) was performed in all children, and the nadir in pulse oximetric saturation (Spo(2)) recorded.

RESULTS

Hypoxia test results were obtained in 34 healthy children and 35 children with a history of nCLD. Baseline Spo(2) in room air was unable to predict which children would "fail" the hypoxia test. In those children < 2 years of age, applying a cutoff value of 90% resulted in 12 of 24 healthy children and 14 of 23 nCLD children failing the hypoxia test (p = 0.56), whereas a cutoff value of 85% was more discriminating, with only 1 of 24 healthy children and 6 of 23 nCLD children failing the hypoxia test (p = 0.048).

CONCLUSION

In the present study, using a hypoxia test limit of 90% did not discriminate between healthy children and those with nCLD. A cutoff value of 85% may be more appropriate in this patient group. The clinical relevance of fitness to fly testing in young children remains to be determined.

Is this baby fit to fly? Hypoxia in aeroplanes

During air flight, cabin pressurisation results in a reduced fraction of inspired oxygen to 0.15. Healthy children desaturate by around 4% and remain asymptomatic. However children under the age of 1 year are more susceptible to hypoxia, especially if they were born preterm, and even more so if they are survivors of chronic neonatal lung disease. Pre-flight testing with a 'fitness to fly' test is available in some tertiary respiratory centres. The British Thoracic Society 2004 guideline currently recommends supplemental oxygen be given if the child's oxygen saturation falls below 90% during the test, although 85% may be a more appropriate cut off level.

Predictors of acute lung injury and severe hypoxemia in patients undergoing operative talc pleurodesis

BACKGROUND

Acute lung injury (ALI) is a life-threatening complication of talc pleurodesis. This study defines characteristics that predispose patients to ALI and severe hypoxemia in patients after video-assisted thoracoscopic surgery (VATS) talc pleurodesis.

METHODS

Charts of patients who underwent talc pleurodesis at Northwestern Memorial Hospital between January 1, 1997 and December 31, 2003 were retrospectively reviewed. We sought variables associated with the development of postoperative ALI or severe hypoxemia, defined as an increase in fraction of the inspired oxygen by more than 0.15 within 24 hours after the surgery. The analysis included 84 patients (58 women, 26 men) who underwent VATS talc pleurodesis for malignant (n = 74) or benign (n = 10) indications.

RESULTS

ALI developed in 5 patients (5.9%), severe hypoxemia developed in 25 (29.8%), and 54 (64.3%) did not have postoperative complications. In multivariate analysis, the presence of peripheral edema before pleurodesis (p = 0.005), any preoperative requirement for supplemental oxygen (p = 0.032), and chemotherapy within 14 days before pleurodesis (p = 0.04) were identified as predictors of ALI or severe postoperative hypoxemia.

CONCLUSIONS

Oxygen supplementation, recent chemotherapy, and presence of peripheral edema were independent predictors of a combined outcome of ALI or severe hypoxemia after VATS talc pleurodesis. Patients with these characteristics might be at risk for adverse outcomes of talc pleurodesis and should be considered for alternative therapy for their effusions.

Pulmonary function testing and extreme environments

Millions of people worldwide engage in leisure or occupational activities in extreme environments. These environments entail health risks even for normal subjects. The presence of lung disease, or other conditions, further predisposes to illness or injury. Patients who have lung conditions should, but often do not, consult with their pulmonary clinicians before traveling. Normal subjects, including elderly or deconditioned adults, may be referred to pulmonologists for evaluation of risk prior to exposure. Other patients may present for consultations after complications occur. Pulmonary function testing before or after exposure can assist physicians counseling patients about the likelihood of complications.

The effects of flight and altitude

Increasing numbers of infants and children journey by aeroplane, or travel to high altitude destinations, for example, on holiday or as part of a population migration. Most are healthy, although increasingly children may be transported by aeroplane or helicopter specifically to obtain treatment for severe illness or injury. It is therefore useful to review the effects of altitude, and their relevance to children who undertake flights or travel to, or at high altitudes, particularly those with acute and chronic medical conditions.

Oxygen therapy for cystic fibrosis

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A practical approach to oxygen therapy in cystic fibrosis

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