Breathlessness in advanced disease

Breathlessness is a distressing symptom that arises in many diseases. It has several pathophysiological causes, involving the interplay between peripheral and central chemoreceptors, pulmonary and bronchial receptors, chest wall and diaphragmatic muscles, and cortical processing. Older people and patients with cachexia are more susceptible to breathlessness on exertion. Most patients can be assessed by physical examination and simple investigations including haemoglobin, oxygen saturation, ECG, and imaging (X-ray and ultrasound). Research has shown that opioid receptors are important in the central medullary chemoreceptors but also in the cortical areas, and that careful use of opioids can reduce the sensation of breathlessness without compromising ventilatory control. Benzodiazepines also reduce breathlessness, probably by their anxiolytic and sedative actions. The combination of opioid and short-acting benzodiazepine is especially useful. Nebulized furosemide is a new approach that requires further research. Oxygen is indicated if the saturation falls, but increased airflow around the face (e.g. with a fan) can also help. The combination of helium with oxygen may be more effective than oxygen alone. Non-invasive ventilation may be necessary in severe cases, such as neuromuscular disease. Non-medical approaches, including breathing training and relaxation, can also help. Infusions of carefully titrated opioid and midazolam can be used in the dying patient, together with an anticholinergic agent if upper airways secretions are causing 'death rattle'.