The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
-
The lungs and heart are irrevocably linked in their oxygen (O2) and carbon dioxide (CO2) transport functions. Functional impairment of the lungs often affects heart function and vice versa The steepness with which ventilation (V'E) rises with respect to CO2 production (V'CO2 ) (i.e. the V'E/V'CO2 slope) is a measure of ventilatory efficiency and can be used to identify an abnormal ventilatory response to exercise. ⋯ An altered PaCO2 set-point and chemosensitivity are present in many cardiopulmonary diseases, which influence V'E/V'CO2 by affecting PaCO2 Increased ventilation-perfusion heterogeneity, causing inefficient gas exchange, also contributes to the abnormal V'E/V'CO2 observed in cardiopulmonary diseases by increasing VD/VT During cardiopulmonary exercise testing, the PaCO2 during exercise is often not measured and VD/VT is only estimated by taking into account the end-tidal CO2 partial pressure (PETCO2 ); however, PaCO2 is not accurately estimated from PETCO2 in patients with cardiopulmonary disease. Measuring arterial gases (PaO2 and PaCO2 ) before and during exercise provides information on the real (and not "estimated") VD/VT coupled with a true measure of gas exchange efficiency such as the difference between alveolar and arterial O2 partial pressure and the difference between arterial and end-tidal CO2 partial pressure during exercise.
-
What is the experience of people living with breathlessness due to medical conditions, those caring for them and those treating them, with regard to quality of life and the nature of clinical interactions?Electronic databases (Ovid MEDLINE, Embase, CINAHL Plus and PsycINFO) were searched (January 1987 to October 2017; English language), for qualitative studies exploring the experience of chronic breathlessness (patients, carers and clinicians). Two independent reviewers screened titles, abstracts and papers retrieved against inclusion criteria. Disagreements were resolved with a third reviewer. ⋯ The themes were combined to form the concept of "breathing space", to show how engaged coping and appropriate help-seeking (patient) and attention to symptom (clinician) helps maximise the patient's quality of living with breathlessness. Breathlessness has widespread impact on both patient and carer and affects breathing space. The degree of breathing space is influenced by interaction between the patient's coping style, their help-seeking behaviour and their clinician's responsiveness to breathlessness itself, in addition to managing the underlying disease.