FIGURE 4.
Algorithm for the assessment of fitness to fly in chronic obstructive pulmonary disease patients. LTOT: long-term oxygen therapy; PaO2: arterial oxygen tension; SpO2: arterial oxygen saturation measured by pulse oximetry; 6MWT: 6-min walk test. #: if dyspnoea on exertion, forced expiratory volume in 1 s <1.5 L or <30% predicted, a pre-existing requirement of oxygen/ventilatory support, bullous lung disease, comorbid conditions that may worsen hypoxaemia like cardiac disease and significant symptoms during previous air travel.