January '99
by Larissa Podilsky
Palliative Care Consult Nurse, Edmonton Regional Palliative Care Program

Dyspnea is an uncomfortable awareness of breathing that occurs in approximately 30-75 % of terminal cancer patients. It is one of the most distressing symptoms for both patient and family members and can seriously impact quality of life. Dyspnea is similar to pain in that it is a subjective sensation involving the person's perception of breathlessness and his/her reaction to it.

Cause of dyspnea
There are numerous underlying causes of dyspnea which include:

1. Direct effect of the tumour ie. primary or metastatic tumour, pleural effusion, superior vena cava syndrome, airway obstruction.
2. Secondary to cancer therapies ie. post pneumonectomy, fibrosis secondary to radiation or chemotherapy.
3. Not directly due to tumour or therapies ie. anemia, COPD, elevated diaphragm due to ascites or hepatomegaly, pulmonary embolism, cardiac causes (ie CHF), infection, cachexia and profound muscle weakness.

Assessment of Dyspnea
A thorough physical exam and history is essential as the management of dyspnea will be based on it's cause. On exam, note any increase in respiratory rate, nasal flaring, intercostal in drawing and use of accessory muscles of respiration, restlessness, coughing, cyanosis, decreased air entry or adventitious breath sounds on auscultation. Review results of investigations, chest x-ray, CBC (Hgb &WBC). Check oxygen saturation, keeping in mind that in anemic patients even though the saturation level may be adequate they may still be hypoxic.

It is essential to ask patients specifically about their perceived level of breathlessness. For example, on exam a patient may be tachypneic and appear distressed but when specifically asked, will deny feeling SOB or distressed. Often the opposite holds true in that a patient may not exhibit obvious signs of dyspnea but may rate it very high on assessment.

Management of dyspnea

1. Specific treatment of underlying reversible cause if appropriate. For example:
   • Lymphangitis carcinomatosis-->corticosteroids,
   • pleural effusion--> thoracentesis,
   • airway obstruction--> radiation, corticosteroids,
   • superior vena cava -->radiation, corticosteroids,
   • COPD --> bronchodilators,
   • infection --> antibiotics,
   • anemia --> transfusion of packed cells,
   • massive ascites--> paracentes
2. Symptomatic treatment for irreversible cause.
• i) Oxygen therapy -may help to reduce the perception of breathlessness and improve patient comfort irregardless of normal oxygen saturation levels. Patients and family members may associate dyspnea and the need for oxygen as a terminal event, which it may be. It is important they understand that the oxygen is not being used to extend life, but for comfort and decrease distress.
• ii) Opioid use -is believed to work on centrally located opioid receptors and act by decreasing the perception of dyspnea. If the patient is already taking regular opioids for pain, the breakthrough dose needs to be ordered for breakthrough dyspnea as well as pain. Patients and families need to be aware of opioid use for dyspnea as well.
• iii) Sedation -rarely needed, however, with intractable dyspnea Midazolam may be indicated.

3. Supportive measures.

• assist in ADLs and minimize energy expenditure, maintain good oral hygiene, maximize patient positioning with raising the head of the bed or wedge.
• ensure a calm environment, utilize distraction and relaxation exercises, supportive teaching and reassurance.
• promote air circulation with an open window or fan, teach breathing control techniques.

Reevaluation of dyspnea
It is essential to reevaluate the effectiveness of the interventions and how the symptom is perceived by the patient. With ongoing assessments symptom management can be maximized.

References

• Cantwell, P., Mackay, S., Macmillan, K., Turco, S., Mckinnon, S., Read-Paul, L. (1997). 99 questions and answers about palliative care: a nurse's handbook. Regional Palliative Care Program, Capital Health Authority, Edmonton, Alberta, Canada.
• Doyle, D., Hanks, G., MacDonald, N. (Eds.) (1998). Oxford textbook of palliative medicine. Oxford: Oxford University Press.
• Pereira, J., Bruera, E. (1996). The Edmonton aid to palliative care. University of Alberta, Edmonton, Alberta, Canada. First Edition.