Definition and prevalence
Dyspnoea, or breathlessness, is often described as a subjective sensation of respiratory discomfort, typically manifesting as air hunger, chest tightness, or a feeling of suffocation. Given the multidimensional nature of dyspnoea, it can be challenging to manage effectively, particularly as the disease progresses. It is likely influenced by a combination of physiological factors, such as impaired gas exchange, psychological states like anxiety, and social contexts, such as social isolation. [1,2] Emotional responses, especially anxiety, exacerbate the perception of breathlessness, which can contribute to its complexity in palliative care settings. [3]
The prevalence of dyspnoea varies across advanced illnesses. In cancer patients, particularly those with thoracic malignancies, it is reported in approximately 70% of individuals, especially during the advanced stages. [1] For non-cancer patients, such as those living with chronic obstructive pulmonary disease (COPD) and heart failure, dyspnoea is also common, with estimates ranging from 50% to 100%. [4,5] However, the trajectory of dyspnoea may differ between these groups. In heart failure, for instance, the symptom could fluctuate based on fluid retention or physical exertion, whereas in cancer, it often intensifies gradually as the disease progresses towards the end of life. [2]
In chronic conditions like cystic fibrosis, dyspnoea tends to present earlier and may increase in intensity as lung function declines. [4] Patients with end-stage kidney disease also appear to experience breathlessness, often in the context of coexisting cardiovascular or respiratory conditions, though its prevalence is somewhat variable depending on the specific comorbidities. [5]
Assessment
Assessing dyspnoea in palliative care requires a combination of subjective and objective tools to address the complexity of this symptom. Commonly used subjective tools include the modified Borg Scale, Visual Analogue Scale (VAS), and the modified Medical Research Council (mMRC) Breathlessness Scale. These scales allow patients to rate the severity of their breathlessness, giving clinicians insight into how the symptom affects daily life and functioning. [1,5] The Borg Scale is often employed to quantify breathlessness on a scale from mild discomfort to severe distress, helping clinicians track changes over time. [5]
In addition to subjective assessments, objective measures such as oxygen saturation levels and respiratory rate are commonly used to assess the physiological impact of dyspnoea. [3] However, it is well documented that these physiological measures often do not correlate with the patient’s reported experience of breathlessness. [1] For instance, patients with advanced cancer may report severe dyspnoea even when their oxygen saturation levels remain normal, underscoring the need for a more comprehensive approach to assessment. [2]
Functional assessments, such as the six-minute walk test (6MWT), are sometimes employed to evaluate the impact of dyspnoea on physical activity. This test measures the distance a patient can walk in six minutes, providing insight into their endurance and how breathlessness limits their mobility. [5] However, this test may be unsuitable for many palliative care patients in advanced stages, as their mobility is often severely compromised. [4] In such cases, alternative assessments may be used either singularly or in conjunction with one another, such as evaluating whether the patient can speak in full sentences without difficulty or observing the use of accessory muscles for breathing. These complementary assessments offer a broader understanding of the severity of dyspnoea and can guide more appropriate interventions focused on comfort and symptom management.
Non-pharmacological treatment
Non-pharmacological interventions play a key role in managing dyspnoea in palliative care. Fan therapy involves directing cool air from a fan towards the patient’s face. This movement of air across the face stimulates the trigeminal nerve, reducing the sensation of air hunger. [6] It is a low-cost, non-invasive method that has shown quick effectiveness, with patients reporting relief within minutes of use. [6] This simple intervention is widely accepted and can be easily integrated into both hospital and home settings. [1]
Breathing retraining techniques such as pursed-lip breathing and diaphragmatic breathing are also commonly used. These methods help reduce the respiratory rate and improve breathing efficiency by focusing on controlled breathing patterns. They are often taught to patients to use during episodes of breathlessness, with the goal of reducing the sensation of dyspnoea. [3] These techniques are simple to teach and can be adapted for use in various palliative care settings. [4]
Positioning strategies, such as sitting upright or leaning forward, have also been shown to alleviate breathlessness by improving the mechanics of the diaphragm and reducing the work of breathing. These strategies are practical, require no special equipment, and can provide immediate relief, making them particularly useful in palliative care. [5] Patients and caregivers are often encouraged to experiment with different positions to find those that offer the most relief. [1]
Mindfulness and relaxation techniques, including guided breathing and meditation, are being increasingly integrated into dyspnoea management. These practices help to reduce anxiety, which can worsen the sensation of breathlessness. [7] By promoting a calm and controlled focus on breathing, mindfulness may alleviate patients' perception of dyspnoea. [7] Although more research is needed, these low-risk interventions hold promise when combined with other non-pharmacological approaches such as fan therapy and advanced respiratory support. Despite the varying quality of included studies, emerging evidence from systematic reviews supports the use of acupuncture, acupressure and reflexology for the improvement of breathlessness severity, exercise tolerance and quality of life. [8,9]
Pharmacological treatment
Opioids are widely regarded as the cornerstone for managing dyspnoea in palliative care, particularly when non-pharmacological interventions do not provide sufficient relief. [10] Morphine is the most commonly used opioid, administered either orally or subcutaneously, and works by decreasing the brain's perception of respiratory discomfort. [2] Opioids are thought to alter the central perception of breathlessness by reducing the respiratory drive, even in patients with normal oxygen levels. Starting doses of morphine are typically low and are carefully titrated based on patient response to minimise side effects such as sedation and constipation. [1] Regular reassessment of the dosage is important to ensure optimal symptom relief while mitigating the risk of adverse effects like respiratory depression. [3,11]
Benzodiazepines are often considered when anxiety exacerbates dyspnoea. These medications, such as lorazepam or midazolam, are used primarily for their anxiolytic effects rather than directly relieving breathlessness. While benzodiazepines may help reduce dyspnoea-related anxiety, evidence regarding their direct benefit in alleviating breathlessness is inconsistent, and they are typically used as a secondary option when opioids alone do not provide adequate symptom relief. [11,12] Short-acting benzodiazepines are preferred in the palliative setting due to their reduced risk of long-term sedation and delirium. [1] However, care must be taken to avoid respiratory depression when benzodiazepines are combined with opioids. [5]
Corticosteroids are sometimes employed when inflammation is a key contributor to dyspnoea, such as in cases of airway obstruction or pulmonary conditions. Dexamethasone, for example, can reduce airway oedema and improve airflow, providing symptomatic relief from breathlessness. [4,11] However, their use is usually limited to short-term management due to potential adverse effects like immunosuppression, muscle wasting, and hyperglycaemia. Additionally, oxygen therapy is commonly administered to patients with hypoxaemia but is less effective in those with normal oxygen levels, as studies suggest limited benefit in patients with normal oxygen levels. [11] When used in non-hypoxic palliative patients, the benefits of oxygen therapy such as the alleviation of patient and family distress needs to be considered against drawbacks including practical barriers associated with handling and transporting the oxygen equipment, restricted movement and mobility during use, and potentially increased caregiver load. [13] Anticholinergic agents, such as glycopyrrolate, are also used to manage excessive respiratory secretions contributing to dyspnoea, particularly in the terminal phase. [12]