Dyspnea is defined as a subjective sensation of difficulty breathing.

Etiology
The causes of dyspnea near the end-of-life include a wide spectrum of serious lung or heart conditions, anemia, anxiety, chest wall pathology, electrolyte disturbances or even urinary retention or constipation.

Assessment
Looking for simple problems is always warranted. Is the oxygen turned on? Is the tubing kinked? Is there fluid overload from IV fluids or TPN? Is dyspnea part of an acute anxiety episode, severe pain, constipation or urinary retention? Is there a new pneumothorax or worsening pleural effusion?

Understanding 1) where patients are at in the dying trajectory, and 2) their identified goals of care, is essential to guide the extent of workup to discover reversible causes.
If the patient is clearly dying, and the goals of care are comfort, then pulse oximetry, blood gas, EKG, CXR are not indicated.

Treatment
General measures: Positioning (sitting up), increasing air movement via a fan or open window, and use of bedside relaxation techniques are all helpful.
In the imminently dying patient, discontinuing parenteral fluids is appropriate.

Treatment with opioids: Opioids are the drugs of choice for dyspnea. In the opioid naive patient, low doses of oral (10-15 mg) or parenteral morphine (2-5 mg), will provide relief for most patients; higher doses will be needed for patients on chronic opioids. When dyspnea is acute and severe, parenteral is the route of choice: 2-5 mg IV every 5-10 minutes until relief. In the inpatient setting, a continuous opioid infusion, with a PCA dose that patients, nurses or families can administer, will provide the most timely relief.
Nebulized morphine has been reported to provide benefit in uncontrolled case reports. Controlled trials have not demonstrated any benefit compared to placebo, confirming the low bioavailability of nebulized opioids.

Treatment with oxygen: Oxygen is often, but not universally, helpful. When in doubt, a therapeutic trial, based on symptom relief, not pulse oximetry, is indicated. Patients generally prefer nasal cannula administration than a mask, especially in setting of imminent death when agitation from the mask is commonly seen. There is little reason to go beyond 4-6 L/min of oxygen via nasal cannula in the actively dying patient. Request a face-tent for patients whose claustrophobia is exacerbated when using a mask.

Treatment with other drugs: Antitussives can help with cough, anticholinergics (e.g. scopolamine) will help reduce secretions, anxiolytics (e.g. lorazepam) can reduce the anxiety component of dyspnea.
Other agents that may have specific disease-modifying effects include diuretics, bronchodilators, and corticosteroids.

Family / team discussions: While there is no evidence that proper symptom management for terminal dyspnea hastens death, the course and management of terminal dyspnea, especially when opioids are used, should be fully discussed with family members, nurses, and others participating in care to avoid confusion about symptom relief vs. fears of euthanasia or assisted suicide.

See reference for more information.

Adapted from Weissman DE. Palliative Care Network of Wisconsin. Fast facts and concepts #27. Dyspnea at the end of life. Internet. Accessed on June 22, 2016.