Updated recommendations on respiratory specialist referral and the need for in-flight oxygen are made in a new clinical statement on air travel for passengers with respiratory disease.
Published in Thorax, the statement developed by the British Thoracic Society (BTS) says several developments have taken place in the area of air travel-related hypoxia since the last guidelines were published in 2011, “requiring a new look at the advice for healthcare professionals”.
As such, the new guidance compiled by an expert group of secondary and primary healthcare professionals spanning paediatrics, nursing, respiratory physiology, and physiotherapy, focuses on three key areas: the role of the hypoxic challenge test (HCT) to predict hypoxaemia during flight; how respiratory conditions respond differently to altitude; and logistics of air travel with equipment such as portable oxygen concentrators (POCs).
The guidelines stress that all patients should undergo careful initial evaluation – with history and physical examination – by a competent clinician, who should review symptoms, baseline exercise capacity, recent exacerbation history, treatments and previous experience of air travel.
Those whose screening raises concerns should be referred to a respiratory specialist, who might advise HCT if appropriate. While HCT is not able to predict respiratory symptoms during air travel, limited evidence does suggest that those who desaturate during the test, in-flight oxygen can help to alleviate symptoms.
According to the guidelines, patients who shouldn’t need HCT include: those with stable disease who have previously undergone the test; COPD patients with baseline SpO2 ≥95% and either MRC score 1-2 or desaturation to no less than 84% during walking tests; those previously unable to tolerate air travel; and preterm infants who have not reached their due date at the time of travel.
Those is should be considered include: COPD patients with resting SpO2 of ≤95%, MRC score 3 or greater, or desaturation to <84% walking tests; infants and children with a history of neonatal respiratory problems; adults and children with severe asthma; ILD patients whose SpO2 drops to less than 95% on exercise, and whose resting sea level arterial oxygen tension (PaO2) is ≤9.42 kPa or whose TLCO is ≤50%; those with severe respiratory muscle weakness or chest wall deformity in whom forced vital capacity (FVC) is less than 1 L; patients with existing or previous hypercapnia and those at risk of hypercapnia; and patients with a history of type 2 respiratory failure already on long-term oxygen therapy at sea level.
In-flight oxygen is then only recommended if HCT results show a PaO2 of less than 6.6 kPa (<50 mm Hg) or SpO2 of less than 85%.
Several statements were made regarding the management of patients with different respiratory conditions. Common themes were that these should be optimised before travel, that medicines should be carried on board, that acute exacerbations are treated with patients’ own inhalers, and that those with more severe forms carry copies of their management plans and other relevant clinical information.
For asthma, the expert group noted that HCT should be considered for those with severe illness, regardless of baseline sea level oxygen saturation, and stressed that appropriate precautions, such as not eating during flights, should be taken for those who also have food allergy given that they are at greater risk of anaphylaxis.
For COPD, aside from HCT in those meeting the testing threshold recommendations included advising patients of their greater risk of VTE, and ensuring that those requiring long-term oxygen therapy also plan for this at their destination.
For those with cystic fibrosis, HCT is recommended in those old enough for spirometry and whose FEV1 is less than 50% predicted, and in-flight oxygen recommended for those whose SpO2 falls under the 90% threshold. HCT should also be considered in children able to undertake spirometry with chronic lung disease whose FEV1 is consistency under 50% predicted, the group noted.
Patients with non-CF bronchiectasis should seek advice from a respiratory physiotherapist on adapting airway clearance techniques for long-haul flights, and while portable nebulisers and positive expiratory pressure (PEP) devices can be considered for in-flight use, the authors stressed that they would need pre-flight approval from the airline.
The clinical statement also offers advice on how to manage patients with non-CF bronchiectasis, interstitial lung disease, thoracic surgery and other interventional procedures, trapped lung, bronchoscope procedures, pneuomothorax, upper respiratory infections, viral infections, tuberculosis, pneumonia, Obstructive Sleep Apnoea (OSAS) and Obesity Hypoventilation Syndrome (OHS), respiratory muscle and chest wall disorders, prevention of VTE during air travel and air travel after VTE, pulmonary hypertension, lung cancers and mesothelioma, and hyperventilation and dysfunctional breathing.
Read the comprehensive recommendations in full here