Managing patients with stable respiratory disease planning air travel: a primary care summary of the British Thoracic Society recommendations

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.

Impact of simulated flight conditions on supraventricular and ventricular ectopy

Though billions of passengers and crew travel by air each year and are exposed to altitude equivalents of 7000-8000 feet, the health impact of cabin oxygenation levels has not been well studied. The hypoxic environment may produce ectopic heartbeats that may increase the risk of acute in-flight cardiac events. We enrolled forty older and at-risk participants under a block-randomized crossover design in a hypobaric chamber study to examine associations between flight oxygenation and both ventricular (VE) and supraventricular ectopy (SVE). We monitored participant VE and SVE every 5 min under both flight and control conditions to investigate the presence and rate of VE and SVE. While the presence of VE did not differ according to condition, the presence of SVE was higher during flight conditions (e.g. OR ratio = 1.77, 95% CI: 1.21, 2.59 for SVE couplets). Rates of VE and SVE were higher during flight conditions (e.g. RR ratio = 1.25, 95% CI: 1.03, 1.52 for VE couplets, RR ratio = 1.76, 95% CI: 1.39, 2.22 for SVE couplets). The observed higher presence and rate of ectopy tended to increase with duration of the flight condition. Further study of susceptible passengers and crew may elucidate the specific associations between intermittent or sustained ectopic heartbeats and hypoxic pathways.

Cardiorespiratory Adaptation to Short-Term Exposure to Altitude vs. Normobaric Hypoxia in Patients with Pulmonary Hypertension

Prediction of adverse health effects at altitude or during air travel is relevant, particularly in pre-existing cardiopulmonary disease such as pulmonary arterial or chronic thromboembolic pulmonary hypertension (PAH/CTEPH, PH). A total of 21 stable PH-patients (64 ± 15 y, 10 female, 12/9 PAH/CTEPH) were examined by pulse oximetry, arterial blood gas analysis and echocardiography during exposure to normobaric hypoxia (NH) (FiO2 15% ≈ 2500 m simulated altitude, data partly published) at low altitude and, on a separate day, at hypobaric hypoxia (HH, 2500 m) within 20−30 min after arrival. We compared changes in blood oxygenation and estimated pulmonary artery pressure in lowlanders with PH during high altitude simulation testing (HAST, NH) with changes in response to HH. During NH, 4/21 desaturated to SpO2 < 85% corresponding to a positive HAST according to BTS-recommendations and 12 qualified for oxygen at altitude according to low SpO2 < 92% at baseline. At HH, 3/21 received oxygen due to safety criteria (SpO2 < 80% for >30 min), of which two were HAST-negative. During HH vs. NH, patients had a (mean ± SE) significantly lower PaCO2 4.4 ± 0.1 vs. 4.9 ± 0.1 kPa, mean difference (95% CI) −0.5 kPa (−0.7 to −0.3), PaO2 6.7 ± 0.2 vs. 8.1 ± 0.2 kPa, −1.3 kPa (−1.9 to −0.8) and higher tricuspid regurgitation pressure gradient 55 ± 4 vs. 45 ± 4 mmHg, 10 mmHg (3 to 17), all p < 0.05. No serious adverse events occurred. In patients with PH, short-term exposure to altitude of 2500 m induced more pronounced hypoxemia, hypocapnia and pulmonary hemodynamic changes compared to NH during HAST despite similar exposure times and PiO2. Therefore, the use of HAST to predict physiological changes at altitude remains questionable. (ClinicalTrials.gov: NCT03592927 and NCT03637153).

COPD patients’ pre-flight check: A narrative review

 For most of the people with stable and well-controlled chronic obstructive pulmonary disease (COPD), air travel is safe and comfortable, but the flight environment may pose clinical challenges. This narrative review aims to update the requirements for allowance to fly of people with COPD without chronic respiratory failure.  A literature review was performed on platforms: Pubmed, Scopus and Ovid, for citations in English from 2000 to 2021. The following key words were used: COPD AND: air-travel, in-flight hypoxemia, fitness to air travel.  Official regulatory documents and guidelines were also examined. Current air travel statements recommend supplemental oxygen when in flight arterial oxygen tension (PaO2) is expected to fall below 6.6 or 7.3 kPa. Several lung function variables, prediction equations and algorithms have been proposed to estimate in-flight PaO2, the need for in-flight supplemental oxygen, and to select individuals needing more advanced pre-flight testing, such as the hypoxia-altitude simulation test. Exercise induced desaturation and aerobic capacity correlate significantly with in-flight PaO2. COPD patients with late intensification of disease, new changes in medications, recent acute exacerbation/ hospitalization or anticipated emotional and physical stress during the proposed air-travel should be carefully evaluated by the caring family or specialist physician.

Consensus guidelines for improving patients' understanding of invasive fungal disease and related risk prevention in the haematology/oncology setting, 2021

Patients with invasive fungal disease (IFD) are at significant risk of morbidity and mortality. A productive partnership between patients, their carers/families, and the multidisciplinary team managing the infection and any underlying conditions, is essential. Sharing information and addressing knowledge gaps are required to ensure those at risk of IFD avoid infection, while those with suspected or confirmed infection optimise their therapy and avoid toxicities. This new addition to the Australian and New Zealand consensus guidelines for the management of IFD and antifungal use in the haematology/oncology setting outlines the key information needs of patients and their carers/families. It specifically addresses risk factor reduction, antifungal agents and adherence, and the risks and benefits of complementary and alternative therapies. Knowledge gaps are also identified to help inform the future research agenda.

Aeromedical Transport of Critically Ill Patients: A Literature Review

The aeromedical transport of critically ill patients has become an integral part of practicing medicine on a global scale. The development of reliable portable medical equipment allows physicians, emergency medical technicians, and nurses to transport wounded and diseased patients under constant critical care attention. Air transportation involves utilizing a fixed-wing (airplane) or rotor-wing (helicopter) aircraft to accomplish different types of transports ranging from scene responses to international transfers. The proper preparation and management of patients undergoing aeromedical transport require a basic understanding of the physiological changes and unique challenges encountered within the aircraft environment at 8,000 ft above sea level. The purpose of this paper is to review the literature and provide guidelines for approaching the aeromedical transportation of critically ill patients.

Traveling With Cancer: A Guide for Oncologists in the Modern World

PURPOSE

Travel for patients with cancer has become more achievable because of gains in quality of life and overall survival. The risk assessment of these patients is complex, and there is a paucity of data to which clinicians can refer. We present the challenges of traveling with cancer and a review of the literature.

METHODS

A review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed. A search using the terms "cancer," "advanced cancer," "metastases," "brain edema," "lymphoedema," "pneumothorax," "pleural effusion," "pericardial effusion," pneumonitis," "hypoxia," "end-of-life," and "shunt," combined with "flying" and "air travel," was conducted. The PubMed and Cochrane databases were searched for English-language studies up to December 2018. Studies, case reports, or guidelines referring to travel in the context of adult patients with malignancies were included. A total of 745 published articles were identified; 16 studies were included. An inclusive approach to data extraction was used.

RESULTS

There were no specific criteria to deem a patient with cancer fit to travel. Neurologic, respiratory, and cardiac implications, and time from recent surgery or procedure need to be considered There was a lack of high-quality studies to inform decisions, but the British Thoracic Society and Aerospace Medical Association Medical Guidelines included recommendations for fitness to fly for patients with cancer.

CONCLUSION

In the absence of large prospective studies, individual fitness to travel should be assessed on a case-by-case basis, bearing in mind that maximizing a patient's ability to safely travel is an important goal for many individuals with cancer.

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.

COPD patients should be informed about the “fitness to fly” concept and patients with moderate-to-severe disease need to be assessed with clinical and functional parameters for possible risk factors for in-flight hypoxaemia before flyinghttp://ow.ly/Yd4A30k41Hq

Travel During Pregnancy: Considerations for the Obstetric Provider

Importance

Travel among US citizens is becoming increasingly common, and travel during pregnancy is also speculated to be increasingly common. During pregnancy, the obstetric provider may be the first or only clinician approached with questions regarding travel.

Objective

In this review, we discuss the reasons women travel during pregnancy, medical considerations for long-haul air travel, destination-specific medical complications, and precautions for pregnant women to take both before travel and while abroad. To improve the quality of pretravel counseling for patients before or during pregnancy, we have created 2 tools: a guide for assessing the pregnant patient's risk during travel and a pretravel checklist for the obstetric provider.

Evidence Acquisition

A PubMed search for English-language publications about travel during pregnancy was performed using the search terms "travel" and "pregnancy" and was limited to those published since the year 2000. Studies on subtopics were not limited by year of publication.

Results

Eight review articles were identified. Three additional studies that analyzed data from travel clinics were found, and 2 studies reported on the frequency of international travel during pregnancy. Additional publications addressed air travel during pregnancy (10 reviews, 16 studies), high-altitude travel during pregnancy (5 reviews, 5 studies), and destination-specific illnesses in pregnant travelers.

Conclusions and Relevance

Travel during pregnancy including international travel is common. Pregnant travelers have unique travel-related and destination-specific risks. We review those risks and provide tools for obstetric providers to use in counseling pregnant travelers.

Bench Evaluation of Four Portable Oxygen Concentrators Under Different Conditions Representing Altitudes of 2438, 4200, and 8000 m

Bunel, Vincent, Amr Shoukri, Frederic Choin, Serge Roblin, Cindy Smith, Thomas Similowski, Capucine Morélot-Panzini, and Jésus Gonzalez. Bench evaluation of four portable oxygen concentrators under different conditions representing altitudes of 2438, 4200, and 8000 m. High Alt Med Biol. 17:370-374, 2016.-Air travel is responsible for a reduction of the partial pressure of oxygen (O₂) as a result of the decreased barometric pressure. This hypobaric hypoxia can be dangerous for passengers with respiratory diseases, requiring initiation or intensification of oxygen therapy during the flight. In-flight oxygen therapy can be provided by portable oxygen concentrators, which are less expensive and more practical than oxygen cylinders, but no study has evaluated their capacity to concentrate oxygen under simulated flight conditions. We tested four portable oxygen concentrators during a bench test study. The O₂ concentrations (FO₂) produced were measured under three different conditions: in room air at sea level, under hypoxia due to a reduction of the partial pressure of O₂ (normobaric hypoxia, which can be performed routinely), and under hypoxia due to a reduction of atmospheric pressure (hypobaric hypoxia, using a chamber manufactured by Airbus Defence and Space). The FO₂ obtained under conditions of hypobaric hypoxia (chamber) was lower than that measured in room air (0.92 [0.89-0.92] vs. 0.93 [0.92-0.94], p = 0.029), but only one portable oxygen concentrator was unable to maintain an FO₂ ≥ 0.90 (0.89 [0.89-0.89]). In contrast, under conditions of normobaric hypoxia (tent) simulating an altitude of 2438 m, none of the apparatuses tested was able to achieve an FO₂ greater than 0.76. (0.75 [0.75-0.76] vs. 0.93 [0.92-0.94], p = 0.029). Almost all portable oxygen concentrators were able to generate a sufficient quantity of O₂ at simulated altitudes of 2438 m and can therefore be used in the aircraft cabin. Unfortunately, verification of the reliability and efficacy of these devices in a patient would require a nonroutinely available technology, and no preflight test can currently be performed by using simple techniques such as hypobaric hypoxia.

Prevention of Medical Events During Air Travel: A Narrative Review

Prior to traveling, and when seeking medical pretravel advice, patients consult their personal physicians. Inflight medical issues are estimated to occur up to 350 times per day worldwide (1/14,000-40,000 passengers). Specific characteristics of the air cabin environment are associated with hypoxia and the expansion of trapped gases into body cavities, which can lead to harm. The most frequent medical events during air travel include abdominal pain; ear, nose, and throat pathologies; psychiatric disorders; and life-threatening events such as acute respiratory failure or cardiac arrest. Physicians need to be aware of the management of these conditions in this unusual setting. Chronic respiratory and cardiovascular diseases are common and are at increased risk of acute exacerbation. Physicians must be trained in these conditions and inform their patients about their prevention.

Patients' perspective of barriers and facilitators to taking long-term controller medication for asthma: a novel taxonomy

Background

Although asthma morbidity can be prevented through long-term controller medication, most patients with persistent asthma do not take their daily inhaled corticosteroid. The objective of this study was to gather patients’ insights into barriers and facilitators to taking long-term daily inhaled corticosteroids as basis for future knowledge translation interventions.

Methods

We conducted a collective qualitative case study. We interviewed 24 adults, adolescents, or parents of children, with asthma who had received a prescription of long-term inhaled corticosteroids in the previous year. The one-hour face-to-face interviews revolved around patients’ perceptions of asthma, use of asthma medications, current self-management, prior changes in self-management, as well as patient-physician relationship. We sought barriers and facilitators to optimal asthma management. Interviews were transcribed verbatim and transcripts were analyzed using a thematic approach.

Results

Patients were aged 2–76 years old and 58% were female. Nine patients were followed by an asthma specialist (pulmonologist or allergist), 13 patients by family doctors or pediatricians, and two patients had no regular follow-up. Barriers and facilitators to long-term daily inhaled corticosteroids were classified into the following loci of responsibility and its corresponding domains: (1) patient (cognition; motivation, attitudes and preferences; practical implementation; and parental support); (2) patient-physician interaction (communication and patient-physician relationship); and (3) health care system (resources and services). Patients recognized that several barriers and facilitators fell within their own responsibility. They also underlined the crucial impact (positive or negative) on their adherence of the quality of patient-physician interaction and health care system accessibility.

Conclusions

We identified a close relationship between reported barriers and facilitators to adherence to long-term daily controller medication for asthma within three loci of responsibility. As such, patients’ adherence must be approached as a multi-level phenomenon; moreover, interventions targeting the patient, the patient-physician interaction, and the health care system are recommended. The present study offers a potential taxonomy of barriers and facilitators to adherence to long-term daily inhaled corticosteroids therapy that, once validated, may be used for planning a knowledge translation intervention and may be applicable to other chronic conditions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-015-0044-9) contains supplementary material, which is available to authorized users.