CLEVELANDCommon respiratory symptoms of advanced cancer
include dyspnea, wheezing and broncho-spasm, cough, and pleural
effusion. Shortness of breath is the symptom cancer patients fear
most, with the exception of pain, Susan B. LeGrand, MD, said at a
conference on Palliative Medicine held at the Cleveland Clinic
Dyspnea a Subjective Symptom
Patients with dyspnea, defined as the sensation of difficulty
breathing, not necessarily related to exertion, feel as if they
are suffocating, said Dr. LeGrand, of the Cleveland Clinics
Harry R. Horvitz Center for Palliative Medicine. Dyspnea is a very
subjective symptom and one that is difficult to measure, since it
doesnt correspond with blood oxygen levels. In the literature,
dyspnea is described as present in 24% to 79% of palliative care
patients, she said.
Unfortunately, the pathophysiology of dyspnea is not well known.
Our understanding of dyspnea is about where we were 10 to 15
years ago with pain, Dr. LeGrand said. It is possible that when
respiratory muscles deteriorate, patients suffer from dyspnea,
although no existing lab test can measure this kind of muscle
deterioration, she said.
Dyspnea in palliative care patients can result from direct effects of
the cancer or its treatment. Cancer patients may have preexisting
asthma, chronic obstructive pulmonary disease, or congestive heart
failure. For this reason, identifying the cause of dyspnea is
When trying to determine the cause of dyspnea, it can be helpful to
think in terms of organ involvement. Consider which organ is
affecting the symptom, Dr. LeGrand suggested. Is it the lung?
Pulmonary causes of dyspnea include asthma, chronic obstructive
pulmonary disease, pleural disease, interstitial fibrosis, emboli,
lymphangitic carcinomatosis, or tumor in the airway. Pulmonary
infection is a major cause of dyspnea in patients with advanced
cancer, Dr. LeGrand said.
In addition to congestive heart failure, cardiac causes of dyspnea
include pericardial effusion and arrhythmia. Although
pericardial effusion is devastating, she said, its
also easy to fix. Textbooks dont mention arrhythmia as a
cause of dyspnea, but Dr. LeGrand sees it fairly often. Arrhythmia is
also easy to address, she said.
There is a growing recognition that cachexia and weakness contribute
to dyspnea. Ascites and hepatomegaly may prevent the diaphragm from
moving correctly. Another cause of dyspnea to consider is anemia,
although its contribution to dyspnea is hard to determine. Anxiety,
too, may contribute, she said.
When evaluating the cause of dyspnea, taking a good history is very
important, Dr. LeGrand said. Determine the time course of the
symptom: Did it come on suddenly (embolism) or gradually (infection)?
Is it worse in certain positions or with exercise? What treatment is
the patient receiving for cancer?
A physical exam is necessary, she said. Tests, including a chest
x-ray, hemoglobin testing, or digital oximetry, may be appropriate.
Dr. LeGrand said she prefers digital oximetry to measuring blood
gases because it is less painful to the patient and generally
provides all the needed information.
Treating the Symptoms
Ideally, the physician should treat dyspnea by treating the
underlying disease. However, with advanced cancer, or while waiting
to treat the underlying disease, it is appropriate to begin treating
Systemic opioids remain the mainstay of symptom relief, she said.
There is some clinical interest in nebulized narcotics; however,
there are few controlled studies in the literature that demonstrate
their superiority to systemic narcotics.
Supplemental oxygen is often used to treat dyspnea. Although some
physicians believe it is overprescribed in the United States and that
its benefit is primarily the result of placebo effect, Dr. LeGrand
said that she was comfortable offering it to end-stage patients.
Methylxanthines can augment respiratory muscle function, particularly
the diaphragm, but there are no studies in this population.
Bronchodilators, often underutilized, are helpful, she said.
Corticosteroids and anxiolytics also can play a role in symptomatic treatment.
Wheezing and Bronchospasm
Wheezing and bronchospasm are common causes of dyspnea and may be
pulmonary or cardiac in origin. Wheezing is a frequent premorbid
condition. It can be differentiated from stridor by its pitch and
The pulmonary function tests needed to diagnose the cause of wheezing
are tiring, and Dr. LeGrand recommended avoiding such tests for weak
patients. Instead, the physician can initiate a therapeutic trial of
bronchodilators. Patients often benefit from bronchodilators thus
obviating pulmonary function tests.
Cough Common in Lung Cancer
Coughing contributes to dyspnea, nausea and vomiting, and pain. A
patient who coughs hard enough can break ribs. This symptom is
present in 79% of patients who present with lung cancer.
Cough in palliative care patients can have many causes, Dr. LeGrand
said. Gastroesophageal reflux is a common cause. Patients with
cardiopulmonary disease will cough. Some medications, particularly
angiotensin-converting enzyme (ACE) inhibitors given for congestive
heart failure, can cause cough. A weak patient who is swallowing
ineffectively may aspirate food and cough. Finally, a patient may
have a cold or sinus infection that is responsible for the cough.
A cough should be addressed by treating the underlying disease, if
possible. With palliative care patients, however, Dr. LeGrand said,
it may only be possible to treat the symptom.
Opioids are effective cough sup-pressants, she said. No advantage has
been shown for using one type of opioid over another, so there is no
advantage for switching drugs. Dextromethorphan, present in many
over-the-counter medications, may be useful.
There is some support in the literature for giving an elixir rather
than a pill because it is more soothing. The literature also shows
that the nonopioid benzo-natate (Tessalon Perles) is effective.
Although nebulized anesthetics have been shown to provide prolonged
relief from an uncontrolled cough, Dr. LeGrand said she would like to
see more controlled trials. One drawback to nebulized anesthetics is
that the patient is required to fast after their use because the
inhaled anesthetics eliminate the gag reflex and cause a local
anesthesia of the buccal mucosa.
Pleural effusion should be suspected if the patient reports dyspnea
that started with exertion and then was present even at rest. Dyspnea
is often better when the patient sits up. Cough and chest pain may
also be present. In 10% to 50% of patients, pleural effusion may
signal the initial manifestation of tumor.
Pleural effusion can be diagnosed by chest x-ray and decubitus films.
If the etiology is in question, a diagnostic tap is appropriate, but
is not necessary if the patient is already known to have metastatic
cancer. A detailed evaluation of fluid is not helpful in advanced cancer.
Treatment for pleural effusion very much depends on where the
patient is in his or her life, Dr. LeGrand said. Tube
thoracostomy with sclerosis is the predominant treatment and is
successful in about 70% of patients. Pleurectomy is usually
inappropriate for a patient with advanced cancer. With very short
life expectancy, periodic thoracentesis might be appropriate.
Treatment may also include thorascopic pleurodesis.