The Airway and Lungs

Extremely useful and relevant information can be obtained when analysing the position assumed by patients with dyspnoea. Relief of breathlessness in a sitting or standing position compared to the recumbent position is referred to as orthopnoea. While increased venous return in the supine patient is well tolerated in individuals with a preserved heart function, this leads to pulmonary venous congestion, an increase in interstitial lung water and a subsequent reduction of lung capacities with resultant shortness of breath in patients with impaired heart function. Accordingly, patients with heart failure prefer to sit upright (e.g. supporting their back with pillows to achieve a maximum upright position) (Fig. 5.1). Conversely, placing the patient into a supine position may be used as a stress test to exclude respiratory distress due to heart failure or (pulmonary) fluid overload. A history of paroxysmal nocturnal dyspnoea characterized by repeated awakening due to breathlessness while sleeping in the recumbent position is a typical symptom of heart failure.