Hypoxia During Air Travel in Adults With Pulmonary Disease

Oxygen Therapy Part 2 - Indications and Toxicity

Oxygen Therapy Part 2: Indications and ToxicityWemple et al. continue their review of oxygen therapy, discussing the acute and chronic indications for oxygen and the delivery of supplemental oxygen (and its potential adverse effects and toxicity).

Loss of consciousness during air travel: A case of lung bullae

A giant lung bulla occupies at least a third of the lung space. We present a middle-aged man who lost consciousness during an air flight for 30 minutes, without any respiratory symptoms. An incidental finding on chest x-ray revealed a giant bulla and a chest computed tomography imaging confirmed the diagnosis and ruled out a tension pneumothorax. A giant lung bulla is an uncommon cause of loss of consciousness and may be suspected if it occurs during air travel.

Can a patient with pulmonary hypertension travel safely by plane?

Air travel is known as the safest way of transportation. Therefore, patients with health problems prefer to travel by air; however, those with heart or lung issues, who do not have any problems under normal conditions, may experience some problems in high altitude and different environmental conditions. In this review, we have described the points to be considered during air travel in patients with pulmonary hypertension.

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.

Commercial Air Travel for Passengers With Cardiovascular Disease: Recommendations for Less Common Conditions, Considerations for Venous Thromboembolism, and General Guidance

The accelerated growth of commercial flights has resulted in a huge upswing of air travelers over the last few decades, including passengers with a wide range of cardiovascular conditions. Notwithstanding the ongoing COVID-19 pandemic that has set back the aviation industry for the next 1-2 years, air travel is expected to rebound fully by 2024. Guidelines and evidence-based recommendations for safe air travel in this group vary, and physicians often encounter situations where opinions and assessments on fitness for flights are sought. This article aims to provide an updated suite of recommendations for the aeromedical disposition of passenger with uncommon cardiovascular conditions, such as congenital heart diseases, inflammatory cardiac conditions (endocarditis/pericarditis/myocarditis), pulmonary hypertension, and venous thromboembolism. In addition, the article also aims to provide practical general guidance for the aeromedical examiner in evaluating, preparing, and optimizing the cardiac status of the patient with cardiovascular ailments for air travel.

Commercial Air Travel for Passengers With Cardiovascular Disease: Stressors of Flight and Aeromedical Impact

The exponential growth of commercial flights has resulted in a sharp rise of air travellers over the last 2 decades, including passengers with a wide range of cardiovascular conditions. Notwithstanding the ongoing COVID-19 pandemic that had set back the aviation industry for the next 1 to 2 years, air travel is expected to rebound fully by 2023-2024. Guidelines and evidence-based recommendations for safe air travel in this group vary, and physicians often encounter situations where opinions and assessments on fitness for flights are sought. This article aims to provide an overview of the stressors of commercial passenger flights with an impact on cardiovascular health for the general cardiologist and family practitioner, when assessing the suitability of such patients for flying fitness.

Transthoracic Needle Biopsy of Pulmonary Nodules: Meteorological Conditions and the Risk of Pneumothorax and Chest Tube Placement

The purpose of this paper is to evaluate whether meteorological variables influence rates of pneumothorax and chest tube placement after percutaneous transthoracic needle biopsy (PTNB) of pulmonary nodules. A retrospective review of 338 consecutive PTNBs of pulmonary nodules at a single institution was performed. All procedures implemented a coaxial approach, using a 19-gauge outer guide needle for access and a 20-gauge core biopsy gun with or without a small-gauge aspiration needle for tissue sampling. Correlation between age, sex, smoking history, lesion size, meteorological variables, and frequency of complications were evaluated. Fisher exact, trend and t tests were used to evaluate the relationship between each factor and rates of pneumothorax and chest tube placement. A p value of less than 0.05 was considered to indicate a statistically significant difference. Pneumothorax occurred in 115 of 338 patients (34%). Chest tube placement was required in 30 patients (8.9%). No significant relationship was found between pneumothorax rate and age (p = 0.172), sex (p = 0.909), smoking history (p = 0.819), or lesion location (p = 0.765). The presence or absence of special weather conditions did not correlate with the rate of pneumothorax (p = 0.241) or chest tube placement (p = 0.213). The mean atmospheric temperature (p = 0.619) and degree of humidity (p = 0.858) also did not correlate with differences in the rate of pneumothorax. Finally, mean atmospheric pressure on the day of the procedure demonstrated no correlation with the rate of pneumothorax (p = 0.277) or chest tube placement (p = 0.767). In conclusion, no correlation is demonstrated between the occurrence of pneumothorax after PTNB of pulmonary nodules and the studied meteorological variables.

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.

Postobstructive pulmonary edema in the setting of aspiration and air travel

BACKGROUND

Postobstructive pulmonary edema (POPE)-also referred to as negative pressure pulmonary edema-occurs with deep inspiration against a closed glottis or obstructed airway. The result can be life threatening, however, most cases have a self-limited presentation and resolve with supportive care.

OBJECTIVE

Our aim was to critically evaluate a previously unreported mechanism in the exacerbation of POPE.

CASE REPORT

This is a report of a 50-year-old woman who experienced an acute episode of hypoxia and altered mental status aboard a transcontinental flight. Her presentation was suggestive of pulmonary embolus. However, a detailed history yielded an episode of preflight choking relieved by the Heimlich maneuver. After 2 days of supportive care she was discharged with a complete return to baseline.

CONCLUSIONS

Subclinical cases of POPE can be exacerbated by the low atmospheric pressure experienced on commercial airlines. With early recognition and supportive treatment, the patient returned to baseline before her discharge 2 days later. Making the diagnoses of POPE is not always straightforward for the practitioner and necessitates a broad differential. Initial supportive care focusing on maximizing respiratory support is critical.

Commercial air travel after pneumothorax: a review of the literature

Because of the physiological stresses of commercial air travel, the presence of a pneumothorax has long been felt to be an absolute contraindication to flight. Additionally, most medical societies recommend that patients wait at least 2 weeks after radiographic resolution of the pneumothorax before they attempt to travel in a nonurgent fashion via commercial air transport. This review sought to survey the current body of literature on this topic to determine if a medical consensus exists; furthermore, this review considered the scientific support, if any, supporting these recommendations. In this review, we found a paucity of data on the issue and noted only a handful of prospective and retrospective studies; thus, true evidence-based recommendations are difficult to develop at this time. We have made recommendations, when possible, addressing the nonurgent commercial air travel for the patient with a recent pneumothorax. However, more scientific research is necessary in order to reach an evidence-based conclusion on pneumothoraces and flying.

Guidelines for diagnosis and management of chronic obstructive pulmonary disease: Joint ICS/NCCP (I) recommendations

Chronic obstructive pulmonary disease (COPD) is a major public health problem in India. Although several International guidelines for diagnosis and management of COPD are available, yet there are lot of gaps in recognition and management of COPD in India due to vast differences in availability and affordability of healthcare facilities across the country. The Indian Chest Society (ICS) and the National College of Chest Physicians (NCCP) of India have joined hands to come out with these evidence-based guidelines to help the physicians at all levels of healthcare to diagnose and manage COPD in a scientific manner. Besides the International literature, the Indian studies were specifically analyzed to arrive at simple and practical recommendations. The evidence is presented under these five headings: (a) definitions, epidemiology, and disease burden; (b) disease assessment and diagnosis; (c) pharmacologic management of stable COPD; (d) management of acute exacerbations; and (e) nonpharmacologic and preventive measures. The modified grade system was used for classifying the quality of evidence as 1, 2, 3, or usual practice point (UPP). The strength of recommendation was graded as A or B depending upon the level of evidence.

[Preparing patients with chronic pulmonary disease for air travel]

Flying is the most important way of travelling in the continually growing international tourism. Number of passengers and those with preexisting diseases, mainly with cardiopulmonary problems, is increasing over years. One of the main tasks of the pre-travel advice is to assess tolerance to hypoxia of the traveler, and specify the necessity, as well as the type and volume of supplementary oxygen therapy. It is indispensable to know the cabin-environment and impact of that on the travelers' health. Travel medicine specialist has to be aware of the examinations which provide information for the appropriate decision on the fit-to-fly condition of the patient. The physician who prepares the patient with chronic obstructive pulmonary disease for repatriation by regular flight and the escorting doctor have to be fully aware of the possibilities, modalities, advantages and contraindications of the on-board oxygen supply and therapy. In this review, the authors give a summary of literature data, outline the tools of in-flight oxygen therapy as well as discuss possibilities for the preflight assessment of patients' condition including blood gas parameters required for safe air travel, as recommended in international medical literature. The preparation process for repatriation of patients with chronic obstructive pulmonary disease is also discussed.

Treatment of pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a chronic progressive disease of the pulmonary vasculature characterized by elevated pulmonary arterial pressure and secondary right ventricular failure. PAH is considered a life-threatening condition unless treated. This article provides a comprehensive review of controlled and uncontrolled trials to define the risk-benefit for different therapeutic options of this clinical disorder. Relevant published articles were identified through searches of the National Center for Biotechnology PubMed database. All therapeutic measures for PAH were discussed. Six drugs have been approved in the United States for the treatment of PAH. Extensive medical advancement has been achieved in treatment of PAH. However, none of the approved therapies have shown ability to cure the disease. New research should be performed to develop promising new therapies.

Air travel can be safe and well tolerated in patients with clinically stable pulmonary hypertension

Our aim was to determine what proportion of patients with pulmonary hypertension (PH) has undertaken air travel contrary to the general medical advice and to characterize these patients according to disease severity and medical treatment. In cooperation with Pulmonale Hypertonie e.V., the German patient organization, a questionnaire was distributed. In total, 430 of 720 questionnaires were returned completed. Of the 179 patients who travelled at least once by air, the distribution of New York Heart Association functional classes I/ II/ III/ IV was 2/ 77/ 74/ 8, respectively; 83 patients were receiving monotherapy; 58 patients were receiving a combination of two or more therapies; 57 patients were on long-term ambulatory oxygen treatment; and 29 patients used supplemental oxygen while travelling. Overall, 20 adverse events were reported, mostly of mild to moderate severity (i.e., peripheral edema, dyspnea), with need of medical intervention in only 7 cases. The 251 patients who did not travel by air were, on average, in more advanced stages of disease and/or clinically unstable. In conclusion, a majority of patients (159 out of 179) did not experience any complications during or directly after the flight even though no special precautions were taken. Thus we conclude that for patients with PH in a stable clinical condition, air travel can be safe and well tolerated.

Treatment of pulmonary arterial hypertension with targeted therapies

Pulmonary arterial hypertension (PAH) is a rare disorder characterized by progressive obliteration of the pulmonary microvasculature that results in elevated pulmonary vascular resistance and premature death. Although no cure exists for PAH, improved understanding of the pathobiological mechanisms of this disease has resulted in the development of effective therapies that target specific aberrant pathways. Agents that modulate abnormalities in the prostacyclin, endothelin, and nitric oxide pathways have been shown in randomized, controlled studies to confer improvements in functional status, pulmonary hemodynamics, and possibly even slow disease progression. Several additional pathways believed to play an important role in the pathogenesis of PAH have been identified as potentially useful therapeutic targets and a number of investigative approaches focusing on these targets are in active development. In this Review, we highlight the pharmacological agents currently available for the treatment of PAH and discuss potential novel strategies.

[Physical exposure by travelling]

Approximately 40 million Germans travel abroad every year. Air travel is the most frequently used mean of transportation followed by the automobile. During airplane flights rheumatic patients are subjected to numerous physical, biological and climatic factors which can cause stress and adverse effects on general health. Therefore, preventive strategies are helpful to protect against health damage, provided that there is general fitness for air travel. The present article focuses on physical and biological stress as well as psychological aspects during air travel and reviews prophylactic measures.

Air travel and the risk of thromboembolism

Almost two billion people use commercial aircraft annually. Long-haul flights are taken by over 300 million people. A serious complication of long-distance travel (or prolonged time of flight) is thromboembolism. The real incidence of the problem is difficult to evaluate since there is no consensus about the diagnostic tests or limitation of time after landing connected to the VTE complication. A direct relation between VTE incidence and long-distance flights has been documented. The risk for DVT is 3-12% in a long-haul flight. The pathophysiologic changes that increase VTE risk at flight are stasis (sitting in crowded condition), hypoxia in the airplane cabin, and dehydration. Individual risk factors for air travel-related VTE include age over 40 years, gender (female), women who use oral contraceptives, varicose veins in lower limbs, obesity and genetic thrombophilia. Prevention measures include environmental protection such as keeping the pressure inside the airplane cabinet in hypobaric condition, avoiding dehydration and prolonged sitting. For individuals at increased risk, venous blood stasis can be reduced by wearing elastic stockings and prophylactic use of low-molecular-weight heparin.

[Recommendations for management of patients with lung disease planning a flight or high altitude travel]

Every year a large number of children travel by plane and/or to places with high altitudes. Most of these journeys occur without incident. Immigration and recent socioeconomic changes have also increased the number of patients with cardiopulmonary disease who travel. Environmental changes in these places, especially lower oxygen, can lead to a risk of significant adverse events. The paediatrician must be aware of the diseases that are susceptible to complications, as well as the necessary preliminary studies and recommendations for treatment in these circumstances. The Techniques Group of the Spanish Society of Paediatric Chest Diseases undertook to design a document reviewing the literature on the subject, providing some useful recommendations in the management of these patients.

Current therapeutic approaches to pulmonary arterial hypertension

Pulmonary hypertension is a heterogeneous hemodynamic and pathophysiological state that is observed in a number of clinical conditions, which have been divided into six diagnostic groups. Although the increase in pulmonary pressure observed in these clinical groups may be similar, underlying disease mechanisms, diagnostic methods, and prognostic and therapeutic consequences are completely different. Pulmonary arterial hypertension is associated with several rare conditions that have comparable clinical and hemodynamic characteristics and exhibit virtually identical anatomical and pathological alterations in the lung microcirculation. These conditions include idiopathic and familial forms of the disease and disease forms associated with connective tissue disease, congenital heart defects involving systemic-to-pulmonary arterial shunts, portal hypertension, and HIV infection. It has been shown that treatment with specific drugs (e.g. prostanoids, endothelin-receptor antagonists and phosphodiesterase type-5 inhibitors) is effective in these patients and that these drugs can also be administered in various combinations. An evidence-based treatment algorithm has been developed for these patients. In patients with pulmonary hypertension due to left heart disease or lung disease, treatment focuses on the underlying condition and there is no convincing evidence that agents approved for pulmonary arterial hypertension are effective. For patients with chronic thromboembolic pulmonary hypertension, the treatment of choice is pulmonary endarterectomy. However, drugs intended specifically for the treatment of pulmonary arterial hypertension may be considered in inoperable cases or after suboptimal surgery.

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.

[Is there a doctor on board?]

Medical problems during flight have become an important issue as the number of passengers and of miles flown continue to rise. Cabin pressurization causes hypoxia, hypobaria and decreased humidity, which are responsible for most medical incidents occurring during flight. Worldwide daily medical incidents are estimated at 350, i.e., one per 14,000 to 39,600 passengers. Medical advice is obtained in 69% of cases, from physicians (40%), nurses (25%), or paramedics (4%) on board the plane. The leading causes of medical incidents are gastrointestinal (25%), cardiac (10%), and neurological (10%) diseases. The incidence of cardiac arrest in flight is 1000 cases a year, worldwide. Since 1992, airlines have progressively equipped their planes with automated external defibrillators, and crew members are trained to use them. Passenger flights carry medical equipment and drugs, determined according to number of passengers and the flight distance. The conditions of intervention are codified: "good Samaritan" laws protect professionals from liability when they choose to aid others who are injured or ill. Current recommendations call for physicians to identify themselves, request an interpreter when necessary, obtain the patient's consent, conduct out examination, inform the patient, family members and crew members of the situation, contact ground medical staff, use well-known procedures, consider flight diversion, and write up a case report.

Prophylaxis of travel-related thrombosis in women

Travel-related thrombosis occurs in 1/6,000 individuals who fly long-haul flights. The risk is increased significantly in passengers with thrombophilia and during hormonal therapy. Pregnancy is a hypercoagulable state with 5-10-fold increase in VTE risk. Mechanisms for hypercoagulation on air are related to cabin atmospheric conditions, with immobility and flight duration playing a major role. Prophylactic measures include frequent exercise in all passengers, elastic stockings and LMWH in travelers at high risk.