Dyspnea

Dyspnea (breathlessness) can range from shortness of breath on exertion to frank air hunger when severe.  This can be one of the most frightening and distressing symptoms for patients, families, and health care providers. It has been reported to occur in approximately 30-70% of palliative cancer patients. Since the dying person's respiratory pattern may noticeably change as their illness progresses and especially in the last hours of living, his/her loved ones should be informed that these changes do not necessarily mean the patient is experiencing dyspnea. Open discussion with the dying person about his/her experiences should be encouraged since they may not only alleviate anxiety but will also strengthen his/her relationships with loved ones.

COMMON CAUSES
Multiple factors often coexist, including:

  • pre-existing lung disease;
  • primary lung cancers;
  • metastasis to lung;
  • pleural effusion;
  • infection;
  • pulmonary embolism;
  • tumor related atelectases or airway obstruction;
  • fibrosis secondary to radiation or chemotherapy;
  • elevated diaphragm secondary to ascites, hepatomegaly, or phrenic nerve lesion;
  • anxiety;
  • anemia;
  • cardiac causes (i.e. congestive heart failure);
  • profound muscle weakness.

ASSESSMENT
It is important to emphasize that dyspnea is a subjective experience.  Respiratory symptoms are one of the most poorly understood areas of palliative care medicine. The patient's experience may not correlate with any measurable value of function such as O2 Sat or pO2, respiratory rate, or, for that matter, professional and family members' perceptions. Dyspnea has a multidimensional nature. It can provoke significant anxiety that will exacerbate its severity.

MANAGEMENT

Non-Pharmacological Interventions
Education about the causes of dyspnea, discussion of and planning to avoid exacerbating activities as well as normalizing effects of emotions on symptom severity may help the person achieve a sense of control over his/her breathlessness.

Family, loved ones and other members of the multidisciplinary team can help minimize sense of isolation that may occur when previously enjoyed activities are decreased and exploring spiritual and religious issues may also decrease sense of loneliness.

Arranging for legal or financial counseling may also help alleviate anxiety that may be contributing to worsening dyspnea.

Other practical aspects are to:

  • limit the number of people in the patient's room;
  • reduce the room temperature, and maintain humidity;
  • open a window and allow the dying person to see outside;
  • use of a fan to blow cool air across the dying person's face (may work);
  • eliminate environmental irritants such as smoke;
  • reposition the patient by elevating the head of his or her bed, or positioning from  one side to another;

Chest physiotherapy: may be helpful if helps increase sputum clearance however may be physically draining and painful for dying patients. Use is limited and depends on individual situation.

Suctioning: never pleasant to undergo and may be very distressing to the dying person especially if in the last hours of life. Anticholinergic drugs such as scopolamine and glycopyrrolate to decrease sputum production are kinder and gentler. Use of suctioning should be individualized.

Relaxation therapy including distraction, or hypnotic therapy may allow the dying person to control or decrease his/her dyspnea. Other complementary therapies may also help some patients.

Pharmacological Interventions
A combination of non-pharmacological and pharmacological therapies is usually needed.  Treat the underlying cause if appropriate.

Oxygen
If a patient is breathless, a therapeutic trial of supplemental oxygen may help even if pO2 or O2Sats do not indicate a need for oxygen therapy.
Home O2 is expensive. However, it may be covered under existing provincial payment programs even if the patient does not meet the usual criteria of pO2, O2 Sat or exercise induced hypoxemia if the oxygen therapy is deemed palliative.

There is usually a time limit for using home O2 as a palliative intervention (3-6months), so if the dying person qualifies for home O2 using the standard criteria, these should be used in the application for financial coverage since the need to apply for renewals is eliminated.

Opioids
The mechanisms by which opioids alleviate dyspnea are not entirely clear but they have been shown to decrease the perception of dyspnea.

Opioids do not decrease respiratory rate unless they are used inappropriately, e.g. very large doses of morphine are used or repeated large doses are given in very short amount of time.

If titrated to alleviate dyspnea, opioids will not hasten death.

If dyspnea is intermittent, opioids may be used intermittently. Treating dyspnea is different than treating pain since dyspnea will not necessarily be worse or more difficult to control if not prevented. Intermittent therapy may also have added benefit of decreasing side effects such as drowsiness.
In the opioid-naive patient, low doses of opioids may be all that is needed.  Pharmacological tolerance usually does not occur. If dyspnea progresses, it is likely due to a complication or progression of the illness.

Nebulized morphine initially showed promise but recent studies have not supported its use. In fact it may increase or provoke bronchospasm due to its ability to cause histamine release.

Benzodiazepines/Anxiolytics
Benzodiazepines decrease dyspnea by depressing ventilation by decreasing thoracoabdominal muscle response peripherally and by decreasing central sensitivity to increasing pCO2.

Since dyspnea is accompanied by anxiety and even in some cases by panic, benzodiazepines are used as first line therapy, often in combination with opioids.
Remember that tolerance to opioid-induced anxiolysis occurs so if anxiety is a problem, should add benzodiazepine.

As with opioids, use low doses of benzodiazepines and increase as needed. Once stable, change to longer acting drugs to ensure ease of administration. 

Cannabinoids - Nabilone
Nabilone may help dyspnea by acting as a bronchodilator and a sedative.
Its psychotropic effects may lead to euphoria.

Side effects include hypotension, reflex tachycardia, dysphoria, especially in elderly, and increased ventilatory response to CO2 bronchodilator and increased ventilatory response to CO2 which, interestingly, is not perceived as increasing dyspnea.

Good for continuously dyspneic, anxious CO2 retainer.  Avoid if in atrial fibrillation or CHF (congestive heart failure).

Steroids
Are not helpful in all causes of dyspnea. Greatest benefit is in cases of bronchospasm, SVC obstruction, lymphangitic carcinomatosis and tracheal obstruction.

Adverse effects may be distressing: hyperglycemia, sleep disturbances, mood swings, fluid retention, candidiasis and myopathy.

Phenothiazines/ Butyrophenones
Chlorpromazine has been reported to improve breathlessness, particularly when combined with opioids.

Watch out for drowsiness and hypotension.

Haldol used regularly as an antiemetic has not really been studied regarding dyspnea.

Heliox
Decreases dyspnea in cases of bronchospasm or obstruction by increasing laminar flow, therefore bypassing obstruction.
Only works if O2 requirements are low and only available in hospital setting.
Oxygen mixed with helium: concentrations of 70: 30, 80:20, 60:40 (helium/oxygen).

Heliox does not affect character of voice.

Racemic Epinephrine
Generally difficult to obtain outside of the hospital setting.  Can decrease dyspnea in cases of upper airway obstruction.

Side effects include: palpitations, tachycardia, hypertension, and anxiety.

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This page was last updated: March 9th, 2005 at 1:01pm.