Managing passengers with stable respiratory disease planning air travel: British Thoracic Society recommendations

Aeromedical Transport for Critically Ill Patients

Aeromedical transport (AMT) is an integral part of healthcare systems worldwide. In this article, the personnel and equipment required, associated safety considerations, and evidence supporting the use of AMT is reviewed, with an emphasis on helicopter emergency medical services (HEMS). Indications for HEMS as guideded by the Air Medical Prehospital Triage Score are presented. Lastly, physiologic considerations, which are important to both AMT crews and receiving clinicians, are reviewed.

Long-term follow-up of patients with congenital diaphragmatic hernia

Neonates with congenital diaphragmatic hernia encounter a number of surgical and medical morbidities that persist into adulthood. As mortality improves for this population, these survivors warrant specialized follow-up for their unique disease-specific morbidities. Multidisciplinary congenital diaphragmatic hernia clinics are best positioned to address these complex long-term morbidities, provide long-term research outcomes, and help inform standardization of best practices in this cohort of patients. This review outlines long-term morbidities experienced by congenital diaphragmatic hernia survivors that can be addressed in a comprehensive follow-up clinic.

Retrospective analysis of referrals for hypoxic challenge testing in children born preterm

INTRODUCTION

Children with a history of bronchopulmonary dysplasia (BPD) may be at risk of hypoxaemia at altitude, such as during air travel. We have performed preflight hypoxic challenge testing (HCT) since 2006, incorporating British Thoracic Society (BTS) guidance since 2011, to determine which children may require oxygen during air travel.

AIMS

We aimed to compare the outcome of HCTs in children with a history of BPD who met the 2011 BTS criteria and those who did not and, in addition to this, to interrogate the data for factors that may predict the outcome of HCT in this population.

METHODS

We performed a retrospective analysis of data from HCTs of children with a history of BPD referred 2006-2020. Cases were excluded if the patient had a respiratory comorbidity, was still on oxygen therapy, if the test was a repeat or if the clinical record was incomplete. Descriptive and univariate analysis of the data was performed, and a binary logistic regression model was fitted.

RESULTS

There were 79 HCTs, of which 24/79 (30%) did not meet BTS 2011 guidelines referral criteria. The analysis showed a greater proportion of desaturation in the group that did not meet criteria: 46% vs 27% (no statistical significance). Baseline oxygen saturations were higher in those who did not require oxygen during HCT and this variable was significant when adjusted for confounders.

CONCLUSIONS

This study found that the current criteria for referral for preflight testing may incorrectly identify those most at risk and highlights the need for further investigation to ensure those most at risk are being assessed prior to air travel.

[Diagnosis and management of idiopathic spontaneous pneumothorax in adolescents]

INTRODUCTION

Due to the absence of consensual definition and agreed-upon pediatric treatment, pneumothorax (PNO) in children and adolescents often remains difficult to properly apprehend.

STATE OF THE ART

While initial diagnostic suspicion is clinical, confirmation necessitates chest imaging, and lung ultrasound has become increasingly prevalent, often at the expense of chest radiography. The goal of treatment is twofold, on the one hand to a fully re-expand the lungs, and on the other hand to forestall PNO recurrence. Depending on PNO severity and clinical tolerance, it may be advisable to envision conservative management, oxygen supplementation, needle exsufflation, or chest tube drainage.

PERSPECTIVES

In order to harmonize clinical practices, guidelines for the precise definition and graduated management of PNO in children and adolescents are highly advisable.

CONCLUSIONS

Idiopathic spontaneous PNO frequently occurs in teenage populations, and its likewise frequent recurrence is not satisfactorily predicted by chest CT findings. It is of paramount importance that patients be fully informed of the risk of recurrence.

Identifying the Causes of Unexplained Dyspnea at High Altitude Using Normobaric Hypoxia with Echocardiography

Exposure to high altitude results in hypobaric hypoxia, leading to physiological changes in the cardiovascular system that may result in limiting symptoms, including dyspnea, fatigue, and exercise intolerance. However, it is still unclear why some patients are more susceptible to high-altitude symptoms than others. Hypoxic simulation testing (HST) simulates changes in physiology that occur at a specific altitude by asking the patients to breathe a mixture of gases with decreased oxygen content. This study aimed to determine whether the use of transthoracic echocardiography (TTE) during HST can detect the rise in right-sided pressures and the impact of hypoxia on right ventricle (RV) hemodynamics and right to left shunts, thus revealing the underlying causes of high-altitude signs and symptoms. A retrospective study was performed including consecutive patients with unexplained dyspnea at high altitude. HSTs were performed by administrating reduced FiO2 to simulate altitude levels specific to patients' history. Echocardiography images were obtained at baseline and during hypoxia. The study included 27 patients, with a mean age of 65 years, 14 patients (51.9%) were female. RV systolic pressure increased at peak hypoxia, while RV systolic function declined as shown by a significant decrease in the tricuspid annular plane systolic excursion (TAPSE), the maximum velocity achieved by the lateral tricuspid annulus during systole (S' wave), and the RV free wall longitudinal strain. Additionally, right-to-left shunt was present in 19 (70.4%) patients as identified by bubble contrast injections. Among these, the severity of the shunt increased at peak hypoxia in eight cases (42.1%), and the shunt was only evident during hypoxia in seven patients (36.8%). In conclusion, the use of TTE during HST provides valuable information by revealing the presence of symptomatic, sustained shunts and confirming the decline in RV hemodynamics, thus potentially explaining dyspnea at high altitude. Further studies are needed to establish the optimal clinical role of this physiologic method.

SPLF/SMFU/SRLF/SFAR/SFCTCV Guidelines for the management of patients with primary spontaneous pneumothorax

INTRODUCTION

Primary spontaneous pneumothorax (PSP) is the presence of air in the pleural space, occurring in the absence of trauma and known lung disease. Standardized expert guidelines on PSP are needed due to the variety of diagnostic methods, therapeutic strategies and medical and surgical disciplines involved in its management.

METHODS

Literature review, analysis of the literature according to the GRADE (Grading of Recommendation, Assessment, Development and Evaluation) methodology; proposals for guidelines rated by experts, patients and organizers to reach a consensus. Only expert opinions with strong agreement were selected.

RESULTS

A large PSP is defined as presence of a visible rim along the entire axillary line between the lung margin and the chest wall and ≥ 2 cm at the hilum level on frontal chest X-ray. The therapeutic strategy depends on the clinical presentation: emergency needle aspiration for tension PSP; in the absence of signs of severity: conservative management (small PSP), needle aspiration or chest tube drainage (large PSP). Outpatient treatment is possible if a dedicated outpatient care system is previously organized. Indications, surgical procedures and perioperative analgesia are detailed. Associated measures, including smoking cessation, are described.

CONCLUSION

These guidelines are a step towards PSP treatment and follow-up strategy optimization in France.

SPLF/SMFU/SRLF/SFAR/SFCTCV Guidelines for the management of patients with primary spontaneous pneumothorax: Endorsed by the French Speaking Society of Respiratory Diseases (SPLF), the French Society of Emergency Medicine (SFMU), the French Intensive Care Society (SRLF), the French Society of Anesthesia & Intensive Care Medicine (SFAR) and the French Society of Thoracic and Cardiovascular Surgery (SFCTCV)

INTRODUCTION

Primary spontaneous pneumothorax (PSP) is the presence of air in the pleural space, occurring in the absence of trauma and known lung disease. Standardized expert guidelines on PSP are needed due to the variety of diagnostic methods, therapeutic strategies and medical and surgical disciplines involved in its management.

METHODS

Literature review, analysis of literature according to the GRADE (Grading of Recommendation Assessment, Development and Evaluation) methodology; proposals for guidelines rated by experts, patients, and organizers to reach a consensus. Only expert opinions with strong agreement were selected.

RESULTS

A large PSP is defined as presence of a visible rim along the entire axillary line between the lung margin and the chest wall and ≥2 cm at the hilum level on frontal chest x-ray. The therapeutic strategy depends on the clinical presentation: emergency needle aspiration for tension PSP; in the absence of signs of severity: conservative management (small PSP), needle aspiration or chest tube drainage (large PSP). Outpatient treatment is possible if a dedicated outpatient care system is previously organized. Indications, surgical procedures and perioperative analgesia are detailed. Associated measures, including smoking cessation, are described.

CONCLUSION

These guidelines are a step towards PSP treatment and follow-up strategy optimization in France.

Hypoxia Altitude Simulation and Reduction of Cerebral Oxygenation in COPD Patients

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is highly prevalent and often associated with chronic hypoxia. Previous studies have shown alterations of cerebral oxygenation and cardiac repolarization in COPD patients (GOLD stage II-IV). Airplane travel is common in patients with COPD; however, the clinical effects of a diminished oxygen partial pressure in aircraft cabin environments at cruising altitude remain elusive. The aim of this study was to assess changes of cerebral oxygenation as well as parameters of cardiac repolarization during a hypoxia altitude simulation combined with mild physical activity in these patients.METHODS: Patients with COPD and healthy subjects (10 per group) randomly selected from the Charité outpatient clinic conducted a hypoxia altitude simulation test which consisted of three phases. The regional cerebral oxygen saturation (rSO₂) of the frontal cortex was measured at rest using near-infrared spectroscopy (NIRS). Furthermore, oxygen saturation (S_pO₂), blood pressure, and heart rate values, as well as a 12-lead-ECG, were recorded. Subsequently, a mild treadmill exercise program (25 W) was divided into 10 min of normoxia (pre-hypoxia), 30 min of mild hypoxia (F_IO₂ = 0.15), followed by a second 10-min period of normoxia (post-hypoxia). Meanwhile, mentioned parameters were recorded in 2-min intervals. P, PQ, QRS, QT, QTc, QTd, T-peak-T-end interval (TpTe), and corrected TpTe (TpTec) were measured on three ECG complexes, each at baseline, at the end of the normoxic phase, and at the end of the hypoxic phase.RESULTS: A total of 10 patients with COPD and 10 control subjects were included in this study. S_pO₂ was significantly lower in COPD patients throughout the whole test. Frontal cerebral rSO₂ was significantly lower in the left hemisphere during hypoxia altitude simulation in COPD patients (59.5 ± 8.5 vs. 67.5 ± 5.7).CONCLUSIONS: We show reduced left frontal cerebral oxygenation during hypoxia and mild exercise in patients with COPD, suggesting diminished altitude resilience and altitude capabilities. Preflight hypoxia assessment might be recommended to patients with severe COPD.Dehe L, Hohendanner F, Gültekin E, Werth G, Wutzler A, Bender TO. Hypoxia altitude simulation and reduction of cerebral oxygenation in COPD patients. Aerosp Med Hum Perform. 2023; 94(3):102-106.

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.

Effects of Acute Hypoxia on Heart Rate Variability in Patients with Pulmonary Vascular Disease

Pulmonary vascular diseases (PVDs), defined as arterial or chronic thromboembolic pulmonary hypertension, are associated with autonomic cardiovascular dysregulation. Resting heart rate variability (HRV) is commonly used to assess autonomic function. Hypoxia is associated with sympathetic overactivation and patients with PVD might be particularly vulnerable to hypoxia-induced autonomic dysregulation. In a randomised crossover trial, 17 stable patients with PVD (resting PaO₂ ≥ 7.3 kPa) were exposed to ambient air (FiO₂ = 21%) and normobaric hypoxia (FiO₂ = 15%) in random order. Indices of resting HRV were derived from two nonoverlapping 5-10-min three-lead electrocardiography segments. We found a significant increase in all time- and frequency-domain HRV measures in response to normobaric hypoxia. There was a significant increase in root mean squared sum difference of RR intervals (RMSSD; 33.49 (27.14) vs. 20.76 (25.19) ms; p < 0.01) and RR50 count divided by the total number of all RR intervals (pRR50; 2.75 (7.81) vs. 2.24 (3.39) ms; p = 0.03) values in normobaric hypoxia compared to ambient air. Both high-frequency (HF; 431.40 (661.56) vs. 183.70 (251.25) ms²; p < 0.01) and low-frequency (LF; 558.60 (746.10) vs. 203.90 (425.63) ms²; p = 0.02) values were significantly higher in normobaric hypoxia compared to normoxia. These results suggest a parasympathetic dominance during acute exposure to normobaric hypoxia in PVD.

Recommandations formalisées d’experts pour la prise en charge des pneumothorax spontanés primaires

Introduction : Le pneumothorax spontané primaire (PSP) est un épanchement gazeux dans la cavité pleurale, survenant hors traumatisme et pathologie respiratoire connue. Des recommandations formalisées d'experts sur le sujet sont justifiées par les pluralités de moyens diagnostiques, stratégies thérapeutiques et disciplines médicochirurgicales intervenant dans leur prise en charge.

Méthodes : Revue bibliographique, analyse de la littérature selon méthodologie GRADE (Grading of Recommendation Assessment, Development and Evaluation) ; propositions de recommandations cotées par experts, patients et organisateurs pour obtenir un consensus. Seuls les avis d'experts avec accord fort ont été retenus.

Résultats : Un décollement sur toute la hauteur de la ligne axillaire et supérieur ou égal à 2 cm au niveau du hile à la radiographie thoracique de face définit la grande abondance. La stratégie thérapeutique dépend de la présentation clinique : exsufflation en urgence pour PSP suffocant ; en l'absence de signe de gravité : prise en charge conservatrice (faible abondance), exsufflation ou drainage (grande abondance). Le traitement ambulatoire est possible si organisation en amont de la filière. Les indications, procédures chirurgicales et l'analgésie périopératoire sont détaillées. Les mesures associées, notamment le sevrage tabagique, sont décrites.

Conclusion : Ces recommandations sont une étape de l'optimisation des stratégies de traitement et de suivi des PSP en France.

2022 Brazilian Thoracic Association recommendations for long-term home oxygen therapy

Some chronic respiratory diseases can cause hypoxemia and, in such cases, long-term home oxygen therapy (LTOT) is indicated as a treatment option primarily to improve patient quality of life and life expectancy. Home oxygen has been used for more than 70 years, and support for LTOT is based on two studies from the 1980s that demonstrated that oxygen use improves survival in patients with COPD. There is evidence that LTOT has other beneficial effects such as improved cognitive function, improved exercise capacity, and reduced hospitalizations. LTOT is indicated in other respiratory diseases that cause hypoxemia, on the basis of the same criteria as those used for COPD. There has been an increase in the use of LTOT, probably because of increased life expectancy and a higher prevalence of chronic respiratory diseases, as well as greater availability of LTOT in the health care system. The first Brazilian Thoracic Association consensus statement on LTOT was published in 2000. Twenty-two years la-ter, we present this updated version. This document is a nonsystematic review of the literature, conducted by pulmonologists who evaluated scientific evidence and international guidelines on LTOT in the various diseases that cause hypoxemia and in specific situations (i.e., exercise, sleep, and air travel). These recommendations, produced with a view to clinical practice, contain several charts with information on indications for LTOT, oxygen sources, accessories, strategies for improved efficiency and effectiveness, and recommendations for the safe use of LTOT, as well as a LTOT prescribing model.

In-Flight Medical Emergencies Management by Anesthetist-Intensivists and Emergency Physicians

BACKGROUND: In-flight medical emergencies (IME) are challenging situations: aircraft cabins are noisy and narrow, medical supplies are scarce, and high-altitude related physiological changes may worsen chronic respiratory or cardiac conditions. The aim of this study was to assess the extent to which anesthetist-intensivists and emergency physicians are aware of IME specificities.METHODS: A questionnaire containing 21 items was distributed to French anesthetist-intensivists and emergency physicians between January and May 2020 using the mailing list of the French Society of Anesthesia and Intensive Care Medicine and the French Society of Emergency Medicine. The following topics were evaluated: high-altitude related physiological changes, medical and human resources available inside commercial aircraft, common medical incidents likely to happen on board, and previous personal experiences.RESULTS: The questionnaire was completed by 1064 physicians. The items corresponding to alterations in the arterial oxygen saturation, respiratory rate, and heart rate at cruising altitude were answered correctly by less than half of the participants (respectively, 3%, 42%, and 44% of the participants). Most responders (83%) were interested in a complementary training on IME management.DISCUSSION: The present study illustrates the poor knowledge in the medical community of the physiological changes induced by altitude and their consequences. In addition to offering specific theoretical courses to the medical community, placing sheets in commercial aircraft summarizing the optimal management of the main emergencies likely to happen on board might be an interesting tool.Diop S, Birnbaum R, Cook F, Mounier R. In-flight medical emergencies management by anesthetist-intensivists and emergency physicians. Aerosp Med Hum Perform. 2022; 93(8):633-636.

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).

Underlying lung disease and exposure to terrestrial moderate and high altitude: personalised risk assessment

Once reserved for the fittest, worldwide altitude travel has become increasingly accessible for ageing and less fit people. As a result, more and more individuals with varying degrees of respiratory conditions wish to travel to altitude destinations. Exposure to a hypobaric hypoxic environment at altitude challenges the human body and leads to a series of physiological adaptive mechanisms. These changes, as well as general altitude related risks have been well described in healthy individuals. However, limited data are available on the risks faced by patients with pre-existing lung disease. A comprehensive literature search was conducted. First, we aimed in this review to evaluate health risks of moderate and high terrestrial altitude travel by patients with pre-existing lung disease, including chronic obstructive pulmonary disease, sleep apnoea syndrome, asthma, bullous or cystic lung disease, pulmonary hypertension and interstitial lung disease. Second, we seek to summarise for each underlying lung disease, a personalized pre-travel assessment as well as measures to prevent, monitor and mitigate worsening of underlying respiratory disease during travel.

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.

Early air transport after thoracic surgery might be safe: A retrospective observational study in the French Caribbean

Objective

The objective of this study was to determine the incidence of early air transport (EAT) morbidity after transpleural surgery. We compared our cohort with our patients not requiring air transport.

Methods

This was a retrospective observational study, in the Thoracic and Cardiovascular Surgery Department of the University Hospital of Martinique over 40 months. We included all of the files (national and local database, and systematic postoperative consultation) of patients operated on for thoracic surgery or distinguished transpleural surgical intervention, whatever their geographical origin. Patients from another French department benefited from EAT. The complications were classified according to Clavien–Dindo before or after the EAT. Diagnostic criteria were chest pain, dyspnea, and abnormal chest radiograph. Continuous variables are presented as mean, median, and SDs. Discrete variables are presented as n (%).

Results

Of 491 patients operated on, 315 were transpleural surgeries, and 99 patients benefited from EAT. There were 55% resections, a percent predicted of forced expiratory volume in 1 second, and an average preoperative Tiffeneau ratio of respectively, 86% and 78. One complication was found: a pneumothorax in an emphysematous patient, 15 days after the flight, who had an index of prolonged air leak >10. The mean time between surgery and flight was 7.2 days (σ = 4.5), and 3.3 days (σ = 2.9) between removal of the last drain and flight. The morbidity of EAT after transpleural surgery was 1%. The 2 cohorts of “EAT” and “Locals” patients were statistically comparable, particularly in morbidity.

Conclusions

EAT appears to be safe after transpleural surgery, following usual criteria for hospital discharge. It would be interesting to study, on a larger scale, the effect of IPAL as an independent risk factor (in case of high IPAL > 10) as well as pathologies that modify transpleural pressures restrictive ventilatory defect.

High altitude simulation testing in patients with congenital diaphragmatic hernia

AIM OF STUDY

Congenital Diaphragmatic Hernia (CDH) is associated with lung hypoplasia and pulmonary hypertension. Many patients receive care in specialty centers requiring air travel upon discharge and for subsequent follow-up care. Premature infants can experience significant hypoxia in flight, but this has not been studied in the CDH population. This report describes our center's experience with simulated altitude testing among CDH patients.

METHODS

In a single center retrospective cohort study, CDH patients who underwent a High Altitude Simulation Test (HAST) from 2006 to 2019 were analyzed. HAST simulates increased altitude by reducing oxygen tension to an FIO2 of 0.15. Patients were tested only when flight was anticipated. Patients requiring oxygen were challenged on their baseline requirement. To pass, patients had to maintain oxygen saturation > 90%, and 94% if diagnosed with pulmonary hypertension. Supplemental oxygen was titrated as needed to achieve this goal.

RESULTS

Of twenty patients tested, only six (30%) passed on their first attempt. Ten (50%) eventually passed, after an average of 3.2 additional attempts over 1.8 years. No patient passed initially who utilized ECMO support, diaphragmatic agenesis, or had elevated right ventricular pressure on echocardiogram. All patients achieved the targeted SpO2 with supplemental oxygen.

CONCLUSION

CDH patients experience hypoxia when exposed to the simulated hypobaric nature of air travel and therefore may become hypoxic in flight, requiring oxygen supplementation. Disease severity seems to correlate with risk of in-flight hypoxia. This data suggests that CDH patients should be screened to assess their need for supplemental oxygen to ensure safe air travel.

LEVEL OF EVIDENCE

Level 4 case series.

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.

Can Patients Travel by Air Less Than 1 Week After Lung Nodulectomy?

Objective: The study objective was to determine empirically based timing recommendations for safe air travel following lung nodulectomy. Methods: All patients who underwent pulmonary nonanatomic resection followed by air travel home immediately after discharge were identified at 2 institutions between 2014 and 2018. These patients were surveyed via telephone regarding any complications they may have experienced during their travel home and within the first week after discharge. These complications included shortness of breath, chest pain, drainage from their surgical sites, and evaluation by a health care provider in the interim, if they required. Results: Our study identified 27 patients who fit the inclusion criteria. The median number of days between surgery and flight home in the studied population was 4 days. The median number of days between chest tube removal and flight home was 2 days. None of the 27 patients reported experiencing shortness of breath, chest pain, drainage from their surgical sites, or need for evaluation by a health care provider within 1 week of discharge. Nine patients (33%) traveled by air with a small (<5%) pneumothorax documented on chest radiography after removal of thoracostomy tube. One (4%) patient successfully traveled without complication with a 10% pneumothorax. Conclusions: The findings of our study support the safety of air travel following lung nodulectomy in patients who have undergone uneventful wedge resection and have no significant pulmonary or cardiac comorbidities. It is not necessary for patients to wait the recommended 7 days prior to traveling.

Management of Pneumothorax

Pneumothorax is a common medical condition encountered in a wide variety of clinical presentations, ranging from asymptomatic to life threatening. When symptomatic, it is important to remove air from the pleural space and provide re-expansion of the lung. Additionally, patients who experience a spontaneous pneumothorax are at high risk for recurrence, so treatment goals also include recurrence prevention. Several recent studies have evaluated less invasive management strategies for pneumothorax, including conservative or outpatient management. Future studies may help to identify who is greatest at risk for recurrence and direct earlier definitive management strategies, including thoracoscopic surgery, to those patients.

Altitude exposure in pediatric pulmonary hypertension-are we ready for (flight) recommendations?

Patients with congenital heart disease are surviving further into adulthood and want to participate in multiple activities. This includes exposure to high altitude by air travel or recreational activities, such as hiking and skiing. However, at an altitude of about 2,500 m, the barometric environmental pressure is reduced and the partial pressure of inspired oxygen drops from 21% to 15% (hypobaric hypoxia). In physiologic response to high-altitude-related hypoxia, pulmonary vasoconstriction is induced within minutes of exposure followed by compensatory hyperventilation and increased cardiac output. Even in healthy children and adults, desaturation can be profound and lead to a significant rise in pulmonary pressure and resistance. Individuals with already increased pulmonary pressure may be placed at risk during high-altitude exposure, as compensatory mechanisms may be limited. Little is known about the physiological response and risk of developing clinically relevant events on altitude exposure in pediatric pulmonary hypertension (PAH). Current guidelines are, in the absence of clinical studies, mainly based on expert opinion. Today, healthcare professionals are increasingly faced with the question, how best to assess and advise on the safety of individuals with PAH planning air travel or an excursion to mountain areas. To fill the gap, this article summarises the current clinical knowledge on moderate to high altitude exposure in patients with different forms of pediatric PAH.

Medical Advice for Travelers

BACKGROUND

In 2019, 1.5 billion international tourist trips were counted worldwide. Germany, with 70.8 million vacations lasting ≥ 5 days, was one of the populations most willing to travel. These days, even elderly and multimorbid persons regularly travel long-distance, which can be associated with significant health risks. By advising travelers and implementing preventive measures, the risk of illness can be reduced significantly.

METHODS

A selective survey of PubMed was performed to identify publications on medical advice for travelers between 2000 and 2020. We included guidelines, studies, and recommendations that mainly deal with the preventive aspects of travel medicine and have a high level of practical relevance and the highest possible level of evidence. Previously published guidelines (based on the GRADE criteria) were adopted, and recommendations not based on the results of scientific studies were characterized as Good Clinical Practice (GCP).

RESULTS

Many medical recommendations for travelers still rely on individualized, experience-based, or consensus-based assessments. Apart from a review of medical history and vaccination status, a risk analysis is performed, travel fitness is evaluated individually, and a prevention plan is designed. Particular attention is devoted to malaria prophylaxis, vector protection, and traveler's diarrhea. Medical advice before travel is especially important for the elderly, children, pregnant women, the chronically ill, long-term and adventure travelers as well as migrants from malaria-endemic areas who are returning home.

CONCLUSION

The health risks associated with travel can be minimized by specialist medical advice. Many recommendations are empirical in nature and require further research.

Is heart failure an obstacle to air travel?

Rapid increasing trend in air travel brings necessity of urgent approach to health situations such as heart failure (HF). The prevalence of HF was projected to be more than 8 million patients ≥18 years of age in 2030; Main factors that contribute to physiological changes to cardiovascular system during a flight are changes in cabin pressure, humidity, stress, prolonged mobility. Identifying patients at risk of pre/post and during air travel along with adequate care by physicians and crew would help in better outcomes and comfortable travel for patients with HF.

Experiences of early air travel with pneumothorax after anterior spinal surgery

Anterior thoracic or thoracolumbar spinal surgery by retropleural approach always carries a risk of pneumothorax as its consequence. Conventionally, the Aerospace Medicine Association and the British Thoracic Society recommend 2 weeks delay of air travel for a patient with resolved postoperative pneumothorax. They also label active pneumothorax as an absolute contraindication for commercial air travel. Such a delay always causes psychological and financial stress to patients and family who are far from home. Here, we report three patients with postoperative pneumothorax, who insisted on early air travel despite being informed of the possible consequences.

Effects of Altitude on Chronic Obstructive Pulmonary Disease Patients: Risks and Care

Air travel and altitude stays have become increasingly frequent within the overall population but also in patients suffering from chronic obstructive pulmonary disease (COPD), which is the most common respiratory disease worldwide. While altitude is well tolerated by most individuals, COPD patients are exposed to some serious complications, that could be life-threatening. COPD patients present not only a respiratory illness but also frequent comorbidities. Beyond oxygen desaturation, it also affects respiratory mechanics, and those patients are at high risk to decompensate a cardiac condition, pulmonary hypertension, or a sleep disorder. Recently, there has been considerable progress in the management of this disease. Nocturnal oxygen therapy, inhaled medications, corticosteroids, inspiratory muscle training, and pulmonary rehabilitation are practical tools that must be developed in the comprehensive care of those patients so as to enable them to afford altitude stays.

Assessing air travel safety in neuromuscular disease: standard versus prolonged hypoxic challenge tests

PURPOSE

The hypoxic challenge test (HCT) is used to evaluate safety for air travel in individuals with respiratory disease by breathing in 15% oxygen for 20 min. Our aim was to determine if a prolonged HCT, lasting 120 min, identified more individuals with neuromuscular disease at potential risk than the standard HCT lasting 20 min.

METHODS

This was a cross-sectional study. All of the clinical testing took place at SickKids, Toronto, Canada. Patients were included in the study if they had a diagnosis of NMD, greater than 6 years of age, resting oxygen saturation ≥ 94%, and partial pressure of carbon dioxide (pCO2) ≤ 45 mmHg. Notable exclusion criteria were left ventricular ejection fraction < 30%, presence of a tracheostomy, and use of non-invasive ventilation for more than 12 h daily. Participants underwent a standard HCT as well as the prolonged HCT on the same day.

RESULTS

Twenty-three patients consented to the study. One patient was withdrawn because he was unable to follow the study procedures. The 22 study participants had a mean age of 14.9 years (standard deviation (SD) of 5 years). Seventeen (77%) participants were male. Two participants were withdrawn on the day of testing due to hypercapnia. Twenty participants completed the standard and prolonged HCTs. None of the participants had a positive standard or prolonged HCT.

CONCLUSION

Our results suggest that performing a standard or prolonged HCT may, in fact, not be of clinical utility in individuals with less severe NMD.

Tuberous sclerosis complex for the pulmonologist

Tuberous sclerosis complex (TSC) is a rare multisystem genetic disorder affecting almost all organs with no sex predominance. TSC has an autosomal-dominant inheritance and is caused by a heterozygous mutation in either the TSC1 or TSC2 gene leading to hyperactivation of the mammalian target of rapamycin (mTOR). TSC is associated with several pulmonary manifestations including lymphangioleiomyomatosis (LAM), multifocal micronodular pneumocyte hyperplasia (MMPH) and chylous effusions. LAM is a multisystem disorder characterised by cystic destruction of lung parenchyma, and may occur in either the setting of TSC (TSC-LAM) or sporadically (S-LAM). LAM occurs in 30–40% of adult females with TSC at childbearing age and is considered a nonmalignant metastatic neoplasm of unknown origin. TSC-LAM is generally milder and, unlike S-LAM, may occur in males. It manifests as multiple, bilateral, diffuse and thin-walled cysts with normal intervening lung parenchyma on chest computed tomography. LAM is complicated by spontaneous pneumothoraces in up to 70% of patients, with a high recurrence rate. mTOR inhibitors are the treatment of choice for LAM with moderately impaired lung function or chylous effusion. MMPH, manifesting as multiple solid and ground-glass nodules on high-resolution computed tomography, is usually harmless with no need for treatment.

Tuberous sclerosis complex is associated with diverse pulmonary manifestations including LAM, multiple micronodular pneumocyte hyperplasia and chylous effusions. LAM occurs in 30–40% of adult females with tuberous sclerosis complex.https://bit.ly/3iLqZ08

Pulmonary Effects of Sustained Periods of High-G Acceleration Relevant to Suborbital Spaceflight

AbstractBACKGROUND: Members of the public will soon be taking commercial suborbital spaceflights with significant G_x (chest-to-back) acceleration potentially reaching up to 6 G_x. Pulmonary physiology is gravity-dependent and is likely to be affected, which may have clinical implications for medically susceptible individuals.METHODS: During 2-min centrifuge exposures ranging up to 6 G_x, 11 healthy subjects were studied using advanced respiratory techniques. These sustained exposures were intended to allow characterization of the underlying pulmonary response and did not replicate actual suborbital G profiles. Regional distribution of ventilation in the lungs was determined using electrical impedance tomography. Neural respiratory drive (from diaphragm electromyography) and work of breathing (from transdiaphragmatic pressures) were obtained via nasoesophageal catheters. Arterial blood gases were measured in a subset of subjects. Measurements were conducted while breathing air and breathing 15 oxygen to simulate anticipated cabin pressurization conditions.RESULTS: Acceleration caused hypoxemia that worsened with increasing magnitude and duration of G_x. Minimum arterial oxygen saturation at 6 G_x was 86 1 breathing air and 79 1 breathing 15 oxygen. With increasing G_x the alveolar-arterial (A-a) oxygen gradient widened progressively and the relative distribution of ventilation reversed from posterior to anterior lung regions with substantial gas-trapping anteriorly. Severe breathlessness accompanied large progressive increases in work of breathing and neural respiratory drive.DISCUSSION: Sustained high-G acceleration at magnitudes relevant to suborbital flight profoundly affects respiratory physiology. These effects may become clinically important in the most medically susceptible passengers, in whom the potential role of centrifuge-based preflight evaluation requires further investigation.Pollock RD, Jolley CJ, Abid N, Couper JH, Estrada-Petrocelli L, Hodkinson PD, Leonhardt S, Mago-Elliott S, Menden T, Rafferty G, Richmond G, Robbins PA, Ritchie GAD, Segal MJ, Stevenson AT, Tank HD, Smith TG. Pulmonary effects of sustained periods of high-G acceleration relevant to suborbital spaceflight. Aerosp Med Hum Perform. 2021; 92(7):633641.

Feasibility of a Hypoxic Challenge Test Under Noninvasive Ventilation Versus Oxygen in Neuromuscular Patients with Chronic Respiratory Insufficiency

Ribeiro Baptista, Bruno, Morgane Faure, Gimbada Benny Mwenge, Capucine Morelot-Panzini, Christian Straus, Thomas Similowski, and Jésus Gonzalez-Bermejo. Feasibility of a hypoxic challenge test under noninvasive ventilation versus oxygen in neuromuscular patients with chronic respiratory insufficiency. High Alt Med Biol. 22: 000-000, 2021. Background: The British Thoracic Society recommendations suggest that all patients with an oxygen saturation (SpO₂) <85% during a hypoxic challenge test (HCT) should receive supplemental oxygen during air travel. However, neuromuscular patients already using ventilatory support are a specific population and noninvasive ventilation (NIV) during a flight could be an alternative to oxygen for hypoxemia correction, through the augmentation of ventilation. Methods: We conducted a comparative, observational study of neuromuscular patients with chronic respiratory failure, requiring nocturnal mechanical ventilation, who were planning to take a flight. HCT was performed with a ventilated canopy placed over the patient's head or the patient's home ventilator. The positive threshold value chosen for the HCT was <90% SpO₂. Results: HCTs were performed on 13 adults with neuromuscular diseases using their home ventilator. Among them, 11 had a positive HCT. For all patients with a positive test, hypoxemia was corrected (SpO₂ to >90%) by oxygen therapy (+9 [6-12]%, p = 0.0029). Patient's home ventilator also significantly increased the SpO₂ by 8 [7-12]% (p = 0.016). Correction of SpO₂ during the HCT was not different between oxygen and NIV. NIV was associated with a significant decrease in pressure, end tidal, carbon dioxide (PetCO₂) (-10 [-16 to -7.5] mmHg, p = 0.04). Conclusions: The performance of an adapted HCT in home-ventilated patients with a neuromuscular pathology may be useful in a personalized treatment plan for air travel. NIV can be a new alternative to oxygen therapy for neuromuscular patients planning to take a flight.

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.

The Impact of Temporary Stay at High Altitude on the Circulatory System

In recent times many people stay temporarily at high altitudes. It is mainly associated with the growing popularity of regular air travel, as well as temporary trips to mountain regions. Variable environmental conditions, including pressure and temperature changes, have an impact on the human body. This paper analyses the physiological changes that may occur while staying at high altitude in healthy people and in people with cardiovascular diseases, such as arterial hypertension, pulmonary hypertension, heart failure, ischemic heart disease, or arrhythmias. Possible unfavourable changes were underlined. Currently recognized treatment recommendations or possible treatment modifications for patients planning to stay at high altitudes were also discussed.

High-altitude Illnesses and Air Travel: Pediatric Considerations

Healthy children may present acute mountain sickness (AMS) within a few hours after arrival at high altitudes. In few cases, serious complications may occur, including high-altitude pulmonary edema and rarely high-altitude cerebral edema. Those with preexisting conditions especially involving hypoxia and pulmonary hypertension shall not risk travelling to high altitudes. Newborn from low altitude mothers may have prolonged time to complete postnatal adaptation. The number of children and adolescents traveling on commercial aircrafts is growing, and this poses a need for their treating physicians to be aware of the potential risks of hypoxia while air traveling.

Are patients with cognitive impairment fit to fly? Current evidence and practical recommendations

BACKGROUND

The worldwide prevalence of dementia is increasing and represents a major public health concern. In the last decades, air travel services have undergone an impressive expansion and one of ten passengers is aged 65 years and older. While air travel can be stressful at all ages and health conditions, older individuals with cognitive impairment carry a greater risk for air-travel-related complications. Consequently, demands to general practitioners for assessing their older patient's fitness to fly are increasing.

METHODS

We conducted a search of the literature in PubMed on the impact of in-flight environmental changes on passengers with cognitive impairment and possible resulting complications. This set the base for a discussion on pharmacological and non-pharmacological interventions aimed at preventing in-flight complications in this vulnerable population.

RESULTS

While our research strategy identified a total of 11 articles related to older age and air travel, only three focused on passengers with cognitive impairment. Our literature review showed that the airplane environment may lead to a large spectrum of symptoms in passengers of all age groups. However, passengers with cognitive impairment due to neurodegenerative diseases are at increased risk for experiencing the most extreme symptoms such as acute confusional state. Non-pharmacological and pharmacological interventions at different stages of the travel process (before, during and after) can help prevent complications in this vulnerable population.

CONCLUSION

The decision to let a patient with cognitive impairment fly requires a solid understanding of the in-flight environmental changes and their impact on older patients with cognitive impairment. Moreover, a sound weighing of the risks and benefits while considering different aspects of the patient's history is demanded. In this regard, the role of the treating physicians and caregivers is essential along with the support of the medical department of the airline.

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.

Assessing Patients for Air Travel

Advising patients before air travel is a frequently overlooked, but important, role of the physician, particularly primary care providers and pulmonary specialists. Although physiologic changes occur in all individuals during air travel, those with underlying pulmonary disease are at increased risk of serious complications and require a specific approach to risk stratification. We discuss the available tools for assessment of preflight risk and strategies to minimize potential harm. We also present a case discussion to illustrate our approach to assessing patients for air travel and discuss the specific conditions that should prompt a more thorough preflight workup.

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.

Assessment of portable oxygen concentrators in infants undergoing hypoxic challenge testing. A randomised controlled crossover trial

AIM

Due to reduced PaO₂ , aircrafts at cruising altitudes are pressurised to a cabin altitude of 2438 m, equivalent to breathing FiO₂ 0.15. Portable oxygen concentrators (POCs) are approved for onboard oxygen supply with lack of evidence, especially in infants. We assessed POCs (continuous-flow cPOC vs. pulsed-flow pPOC) under simulated altitude conditions performing Hypoxic Challenge Testing (HCT).

METHODS

In a randomised controlled crossover trial, we included patients <1 year born prematurely. In incidents of hypoxia (SpO₂  ≤ 85%), oxygen was administered through POC. In patients with a positive hypoxia reversal, HCT was repeated 24 hours later. If hypoxia occurred during the second testing, oxygen was given using the alternative POC.

RESULTS

We randomised 26 patients; 22 patients received allocated intervention (4 dropped out). Mean gestational age 30.4 weeks, mean corrected age 38.2 weeks. Both POCs achieved immediate hypoxia reversal in all cases (SpO₂ cPOC/pPOC 98%/99.4% (95%CI -2.91, 0.01)) without any adverse events. No significant difference was observed in patients with BPD.

CONCLUSION

Both POCs generated sufficient oxygen to reverse HCT induced hypoxia. Although pPOCs are not recommended in paediatric age, our data suggest their effectiveness even in neonates without any associated adverse events. Future research on pPOCs safety is required to establish recommendations for their use.

Exercise-induced hypoxia predicts hypobaric hypoxia during flight in patients after Fontan operation

BACKGROUND

Hypobaric hypoxia (HH) during flight might be more detrimental to pulmonary circulation in Fontan patients compared healthy individuals. This study was designed to clarify whether exercise-induced hypoxia could predict HH during flight in Fontan patients.

METHODS AND RESULTS

Percutaneous oxygen saturation (SpO₂) was analyzed during flight in 11 Fontan patients and eight volunteers. SpO₂ was measured before taking off (S1), at the initial (S2), the end of stabilization (S3), and after landing (S4). The SpO₂-dynamics were compared with SpO₂-dynamics during cardiopulmonary exercise testing (CPX), pulmonary function, and hemodynamics in the Fontan patients. At all measurements, SpO₂ was lower in the Fontan patients than the volunteers during flight. The total SpO₂ decline from S1 to S3 was greater in the Fontan patients than the volunteers. While SpO₂ change from S2 to S3 was negative in the Fontan patients, it was stable in the volunteers. In the Fontan patients, the median value of exercise-induced SpO₂ decline (Ex-dSpO₂), SpO₂ at rest, and SpO₂ at peak was -6%, 93%, and 88%, respectively. In addition to exercise capacity and pulmonary function, the Ex-dSpO₂ was correlated strongly with SpO₂ at all phases during flight (r = 0.75-0.98, p < 0.01 for all). Flight-associated adverse events occurred in two patients with SpO₂ < 80% at S3.

CONCLUSIONS

Both the Fontan patients and the volunteers demonstrated similar SpO₂-dynamics during flight with a greater HH in the Fontan patients. CPX with SpO₂ monitoring is useful in predicting SpO₂-dynamics and adverse events during flight in these patients.

Altitude Travel in Patients With Pulmonary Hypertension: Randomized Pilot-Trial Evaluating Nocturnal Oxygen Therapy

Introduction: Stable patients with pulmonary arterial or chronic thromboembolic pulmonary hypertension (PH) wish to undergo altitude sojourns or air travel but fear disease worsening. This pilot study investigates health effects of altitude sojourns and potential benefits of nocturnal oxygen therapy (NOT) in PH patients. Methods: Nine stable PH patients, age 65 (47; 71) years, 5 women, in NYHA class II, on optimized medication, were investigated at 490 m and during two sojourns of 2 days/nights at 2,048 m, once using NOT, once placebo (ambient air), 3 L/min per nasal cannula, according to a randomized crossover design with 2 weeks washout at <800 m. Assessments included safety, nocturnal pulse oximetry (SpO₂), 6-min walk distance (6 MWD), and echocardiography. Results: At 2,048 m, two of nine patients required medical intervention, one for exercise-induced syncope, one for excessive nocturnal hypoxemia (SpO₂ < 75% for >30 min). Both recovered immediately with oxygen therapy. Two patients suffered from acute mountain sickness. In 6 patients with complete data, nocturnal mean SpO₂ and cyclic SpO₂ dips reflecting sleep apnea significantly differed from 490 to 2,048 m with placebo, and 2,048 m with NOT (medians, quartiles): SpO₂ 93 (91; 95)%, 89 (85; 90)%, 97 (95; 97)%; SpO₂ dips 10.4/h (3.1; 26.9), 34.0/h (5.3; 81.3), 0.3/h (0.1; 2.3). 6 MWD at 490, 2,048 m without and with NOT was 620 m (563; 720), 583 m (467; 696), and 561 m (501; 688). Echocardiographic indices of heart function and PH were unchanged at 2,048 m with/without NOT vs. 490 m. Conclusions: 7/9 PH patients stayed safely at 2,048 m but revealed hypoxemia, sleep apnea, and reduced 6 MWD. Hemodynamic changes were trivial. NOT improved oxygenation and sleep apnea. The current pilot trial is important for designing further studies on altitude tolerance of PH patients.

Management of chronic respiratory complications in children and adolescents with sickle cell disease

Sickle cell disease (SCD) is a life-threatening hereditary blood disorder that affects millions of people worldwide, especially in sub-Saharan Africa. This condition has a multi-organ involvement and highly vascularised organs, such as the lungs, are particularly affected. Chronic respiratory complications of SCD involve pulmonary vascular, parenchymal and airways alterations. A progressive decline of lung function often begins in childhood. Asthma, sleep-disordered breathing and chronic hypoxaemia are common and associated with increased morbidity. Pulmonary hypertension is a serious complication, more common in adults than in children. Although there is a growing attention towards respiratory care of patients with SCD, evidence regarding the prognostic meaning and optimal management of pulmonary issues in children with this condition is limited.This narrative review presents state-of-the-art evidence regarding the epidemiology, pathophysiology and therapeutic options for chronic respiratory complications commonly seen in paediatric patients with SCD. Furthermore, it highlights the gaps in the current knowledge and indicates future directions for studies that aim to improve our understanding of chronic respiratory complications in children with SCD.

Respiratory management of infants with chronic neonatal lung disease beyond the NICU: A position statement from the Thoracic Society of Australia and New Zealand

Chronic neonatal lung disease (CNLD) is defined as continued need for any form of respiratory support (supplemental oxygen and/or assisted ventilation) beyond 36 weeks PMA. Low-flow supplemental oxygen facilitates discharge from hospital of infants with CNLD who are hypoxic in air and is widely used despite lack of evidence on the most appropriate minimum mean target oxygen saturations. Furthermore, there are minimal data to guide the home monitoring, titration or weaning of supplemental oxygen in these infants. The purpose of this position statement is to provide a guide for the respiratory management of infants with CNLD, with special emphasis on role and logistics of supplemental oxygen therapy beyond the NICU stay. Reflecting a variety of clinical practices and infant comorbidities (presence of pulmonary hypertension, retinopathy of prematurity and adequacy of growth), it is recommended that the minimum mean target range for SpO2 during overnight oximetry to be 93-95% with less than 5% of total recording time to be below 90% SpO2 . Safety of short-term disconnection from supplemental oxygen should be assessed before discharge, with majority of infants with CNLD not ready for discharge until supplemental oxygen requirement is ≤0.5 L/min. Sleep-time assessment of oxygenation with continuous overnight oximetry is recommended when weaning supplemental oxygen. Palivizumab is considered safe and effective for the reduction of hospital admissions with RSV infection in this group. This statement would be useful for paediatricians, neonatologists, respiratory and sleep physicians and general practitioners managing children with CNLD.