Breathlessness in Palliative Care

Introduction

Breathlessness is the symptom patients and families find most frightening, and it is the one where the intuitive response is most often wrong. The instinct is to reach for oxygen; the evidence supports reaching for a fan, a chair, a breathing technique and, if needed, a very small dose of morphine.

It affects 50 to 70% of people with advanced cancer, over 90% of those dying with chronic obstructive pulmonary disease, and a similar proportion in advanced heart failure and motor neurone disease.⁵ Prevalence and severity both rise as death approaches, and breathlessness at rest is an adverse prognostic sign.

Chronic breathlessness syndrome is the term for breathlessness that persists despite optimal treatment of the underlying disease. Naming it matters, because it makes clear that the symptom needs treating in its own right rather than being accepted as the inevitable consequence of an untreatable illness - which is what happens when clinicians run out of disease-directed options.

Why breathlessness feels the way it does

Breathlessness is a conscious sensation generated in the brain, not a direct readout of blood gases. It arises when there is a mismatch between the respiratory drive being generated and the ventilation actually achieved - sometimes called neuromechanical dissociation. The brain expects a certain amount of movement and airflow for the effort it has commanded, and the discrepancy is experienced as air hunger.

• Chemoreceptors - central medullary receptors responding to CO2 and pH, and peripheral carotid body receptors responding to hypoxia, generate respiratory drive
• Mechanoreceptors - in the lung, chest wall, respiratory muscles and diaphragm, signalling how much movement has actually occurred
• Upper airway and facial receptors - cold airflow over the trigeminal nerve territory reduces the sensation of breathlessness. This is the physiological basis of the handheld fan.
• Cortical and limbic processing - the sensation is interpreted, and fear, memory and context amplify it. Functional imaging shows breathlessness activates the same limbic regions as pain and fear.

Causes

Most patients have several contributing causes, and it is worth listing them explicitly rather than assuming the cancer explains everything.

Assessment

• Onset and pattern - sudden or gradual, constant or episodic, and what brings it on
• Functional impact - what can they no longer do? "How far can you walk before you have to stop" and "can you get to the bathroom" are more useful than a score
• Positional and nocturnal features - orthopnoea and paroxysmal nocturnal dyspnoea suggest heart failure; platypnoea suggests a shunt; breathlessness lying on one side suggests a large effusion
• Associated symptoms - cough, sputum, haemoptysis, chest pain, wheeze, fever, ankle swelling
• The fear - ask directly what they think is happening and what they are afraid of. Many patients believe they will suffocate to death, and addressing that explicitly relieves a great deal of distress.
• Impact on the family - carers find breathlessness frightening and often call an ambulance because no one has told them what to do
• Severity - the modified MRC dyspnoea scale for functional limitation, or a simple 0 to 10 numerical rating scale for tracking response

The scale is useful for documenting change over time, but it measures what the patient can do rather than how bad the sensation is - and the two diverge. A patient at grade 4 who has learned to pace themselves and use a fan may be far less distressed than one at grade 2 who panics with every episode, which is why mastery matters as much as severity.⁶

Examination covers respiratory rate and pattern, use of accessory muscles, ability to speak in full sentences, oxygen saturation, chest signs, cardiovascular examination for heart failure and effusion, signs of SVC obstruction, and the calves for deep vein thrombosis. Look also for cachexia, anaemia and oral candidiasis.

Investigations should be proportionate: request them if the result would change management. In a patient with weeks to live who would not tolerate or want treatment, a CT pulmonary angiogram achieves nothing. In a patient with months of good function, finding and treating a pulmonary embolism or an effusion transforms their quality of life. Chest radiograph, FBC, and bedside saturations are usually reasonable; echocardiography, CTPA and pleural ultrasound are used selectively.

Management

1. Treat what is reversible

• Pleural effusion - therapeutic aspiration, then pleurodesis or an indwelling catheter if it recurs
• Infection - antibiotics remain appropriate for most patients; the decision changes only in the last days of life
• Pulmonary embolism - low molecular weight heparin or a DOAC; cancer-associated thrombosis is common and often missed
• Anaemia - transfuse if symptomatic, but review whether the benefit lasted; repeated transfusion with only a day or two of benefit is not helpful
• Bronchospasm - bronchodilators, and a trial of these is worthwhile even without a formal COPD diagnosis
• Heart failure - diuretics, and optimise disease-modifying therapy where the patient can tolerate it
• SVC obstruction - dexamethasone and urgent stenting, with radiotherapy or chemotherapy depending on the tumour
• Lymphangitis carcinomatosa or airway obstruction - high-dose dexamethasone, and consider radiotherapy or airway stenting
• Pericardial effusion - pericardiocentesis or a pericardial window

2. Non-pharmacological measures - the first-line treatment

These are not an afterthought to be tried when drugs fail. They have the best evidence base of anything in this topic, they have no side effects, and they give the patient a sense of control over a symptom that otherwise feels uncontrollable.

• Breathing control - slow, relaxed breathing using the lower chest, taught by a physiotherapist. Pursed-lip breathing reduces dynamic airway collapse and hyperinflation in COPD, and gives immediate relief.
• Positioning - sitting upright and leaning forward with arms braced on a table or on the knees fixes the shoulder girdle and improves the mechanical advantage of the accessory muscles
• Pacing and activity planning - breaking tasks up, sitting to wash and dress, planning the day around energy levels
• Walking aids - a rollator improves walking distance in COPD by allowing arm bracing
• Cool air - an open window, a cool room, avoiding hot stuffy environments
• Anxiety management - relaxation, mindfulness, cognitive behavioural techniques, and simply naming and normalising the panic cycle
• A written crisis plan - so the patient and family know what to do during an episode, which reduces emergency calls and admissions
• Breathlessness support services - multidisciplinary clinics combining physiotherapy, occupational therapy and palliative care, which improve mastery of breathlessness and are cost-effective²

3. Opioids

Low-dose opioids reduce the sensation of breathlessness, probably by reducing central respiratory drive, reducing the ventilatory response to hypercapnia and hypoxia, and altering the central perception of the sensation. A Cochrane review supports oral and parenteral opioids for breathlessness, though nebulised opioids are not effective.⁴

• In an opioid-naive patient, start immediate-release morphine 2.5 to 5 mg as required, or modified-release morphine 5 mg twice daily, and titrate slowly against symptom and side effects
• In a patient already on opioids for pain, use a dose for breathlessness that is typically smaller than their breakthrough analgesic dose, and titrate
• Co-prescribe a laxative and an as-required antiemetic, exactly as for pain
• In renal impairment, use oxycodone, or alfentanil or buprenorphine if severe
• Reassure the patient and family that these doses do not depress breathing or hasten death - the fear that morphine will "finish them off" is widespread and a major barrier to treatment

4. Benzodiazepines

Evidence for benzodiazepines in breathlessness is weaker than for opioids, and a Cochrane review found no significant benefit over placebo overall.⁷ They remain useful where anxiety and panic are a prominent component, and in the last days of life. Lorazepam 0.5 mg sublingually as required is the usual choice; midazolam subcutaneously or in a syringe driver is used in the dying phase, often combined with an opioid.

5. Oxygen

6. Other measures

• Corticosteroids - dexamethasone for lymphangitis carcinomatosa, SVC obstruction, airway obstruction and radiation pneumonitis; give as a time-limited trial and stop if there is no benefit
• Treat cough separately - simple linctus, codeine or low-dose morphine, and treat reflux and postnasal drip
• Secretions - carbocisteine or nebulised saline to loosen sputum where the patient can still clear it
• Non-invasive ventilation - has a defined role in motor neurone disease, where it improves both survival and quality of life, and occasionally for symptom control in other conditions
• Referral to specialist palliative care for refractory breathlessness, and to physiotherapy and occupational therapy early rather than late

In the last days of life

The aim shifts entirely to comfort. Anticipatory medicines are prescribed subcutaneously - an opioid for breathlessness and pain, midazolam for agitation and distress, and an antimuscarinic for noisy respiratory secretions. It is worth telling families explicitly that the rattling sound of retained secretions distresses observers far more than the patient, who is usually deeply unconscious; repositioning and reassurance often matter more than the drug.¹

Complications

• Progressive deconditioning - avoidance of activity leads to muscle loss, which lowers the threshold for breathlessness further
• Social isolation and loss of role - patients stop going out, and breathlessness on speaking makes conversation exhausting
• Anxiety and depression, which are both consequences and amplifiers of the symptom
• Carer distress and burnout - watching someone struggle to breathe is one of the most distressing experiences relatives describe, and is a common reason for a crisis admission in the last weeks of life
• Falls, from breathlessness on exertion combined with sedating medication
• Repeated hospital admissions where no crisis plan exists

Red flags

Outcomes

Breathlessness cannot usually be abolished, but the great majority of patients can be helped substantially - the realistic goal is improved mastery, meaning the patient feels able to manage episodes rather than being at their mercy. Trials of breathlessness support services show improvement in mastery and in carer distress even where the measured intensity of breathlessness changes little, which tells you something important about what patients value.²

Breathlessness at rest in advanced disease is an adverse prognostic marker, and worsening breathlessness over days is one of the features suggesting a patient is entering the last weeks or days of life. It should therefore prompt review of the overall plan, anticipatory prescribing, and a conversation about preferred place of care.

The message worth taking into an exam and onto a ward is the inversion of the intuitive order. Look for what is reversible, then use a fan, positioning and breathing control, then low-dose morphine, then a benzodiazepine if anxiety dominates - and use oxygen only if the patient is hypoxaemic. Doing it in that order helps more patients than doing it in the order instinct suggests.