HOUSTON--More than half of the patients who present to M.D. Anderson
Cancer Centers emergency room have a complaint of dyspnea,
Sandra Henke, RN, a thoracic oncology nurse at M.D. Anderson, said at
the Centers 2nd Annual Nursing Conference. "Even when
there are other emergency symptoms, breathing difficulties are the
most pronounced because they cause the most distress for the
patient," Ms. Henke said.
Dyspnea can also be problematic for the medical staff because it is
difficult to determine its direct cause. "The mechanisms that
cause dyspnea are complex, which may prevent us from immediately
determining its underlying cause," she said.
The cancer patients most likely to present with dyspnea are those
with lung cancer, though often not until the later stages of the
"There is a prevailing but false assumption that patients with
lung cancer instantly suffer from shortness of breath, hemoptysis,
and coughing," Ms. Henke said. "In fact, patients rarely
complain of breathing problems in the early stages of lung cancer,
because at this point, the lesions are peripheral and not near a
major airway, so there is no blockage that would cause breathlessness."
Dyspnea is more often a symptom of later-stage lung cancer. Studies
have shown that when patients with lung cancer begin to complain of
dyspnea that is severe enough to require medical evaluation, they
usually have a life expectancy of only 2 to 3 weeks. "These are
cases in which there is clearly an obstruction to the airway,"
Ms. Henke said.
The second tumor group in which dyspnea most commonly occurs is
breast cancer. In this group, breathing problems are caused by
pleural effusions rather than by a blockage in the lungs.
"When determining the cause of dyspnea in the cancer setting, it
is important to consider which cancer treatments the patient has
undergone," Ms. Henke stressed. Chemotherapy drugs can cause
pulmonary toxicity and produce dyspnea. Bleomycin (Blenoxane) may be
particularly harmful because it can infiltrate interstitial tissues
and lead to pulmonary fibrosis.
Biologic response modifiers (such as interleukin-2) can cause a shift
in the pulmonary fluids, which can lead to dyspnea.
Radiation delivered to the chest can cause pulmonary compromise,
which is most problematic for patients with lung cancer. Surgical
dissection for lung cancer places patients at substantial risk for
dyspnea, particularly when it is performed on patients with other
"Patients with a long-term smoking history, for example, will
likely present with preexisting pulmonary compromise," Ms. Henke
said. "When a smoker undergoes lung resection, the risk of
dyspnea is increased."
Another common cause of dyspnea is pulmonary embolism, she said. This
condition can be the result of surgery or long-term immobility and is
characterized by a slow, gradual collection of fluid. These patients
report feeling like they are choking or smothering.
Patients with adenocarcinoma of the lung very often present with
thrombosis, which can result from pulmonary embolism. Because it is
difficult to detect, pulmonary embolism is commonly missed on
diagnosis. "Clinical findings are inclusive for pulmonary
embolism," Ms. Henke said. "You really need a ventilation
scan for a more accurate diagnosis."
The first steps in assessing the cause of dyspnea are the physical
examination and medical history. "In the cancer setting, it is
particularly important to document the tumor history and cancer
treatment background," Ms. Henke said.
The next step is the pulmonary assessment. "Make a visual
inspection to see if the chest is rising and falling
symmetrically," she suggested. "If it is not, there may be
a blockage in a major airway."
Also, because the heart and lungs work so closely together, a
complete pulmonary and cardiac evaluation is recommended. In many
cases, these evaluations may point to a problem other than dyspnea.
"If jugular vein distention is detected, the problem may be
congestive heart failure rather than dyspnea," Ms. Henke said.
The third step is evaluation of the patients breathing sounds.
Some breathing disorders are noticeable without a stethoscope because
they are characterized by marked distress or unnatural breathing
"The patient may be struggling to catch his or her breath, or
normal breaths may be replaced by a wheezing or crackling sound,"
Ms. Henke said. "These are clear signs of an obstruction in the
trachea, main bronchus, or another airway."
The final and key step in determining the cause of dyspnea is the
chest x-ray. "Ninety percent of cases of dyspnea are confirmed
on chest x-ray," she said. "The x-ray helps us determine
whether we are dealing with some other ailment that could cause breathlessness."
Dyspnea is typically treated with medications, such as albuterol,
administered through a bronchial dilator. "Albuterol can cause
agitation and irritability, however, so patients who receive this
prescription should be monitored closely," Ms. Henke warned.
Steroids are the easiest to use and most effective drugs for
relieving dyspnea, and have been used extensively in terminal
patients and patients who have undergone radiotherapy, but there are long-term
complications associated with this family of drugs. Other drugs that
may be used include cough medicines, certain pain medications,
diazepam, hydromor-phone, morphine, and oxygen.
It is important to remember that dyspnea is a complex symptom and
that in assessing this problem, the care team must take into
consideration more than the physical symptoms, Ms. Henke said.
"Just because a person reports shortness of breath, it is not an
immediate sign that their oxygen level is low. A chest x-ray is
vital, and other scans may be needed," she said.
Also, the care team must remember that dyspnea may have a
psychological component. Breathlessness can induce anxiety, and the
more anxious patients become, the more breathless they will become,
she said, "so a manageable situation can easily and quickly
evolve into an emergency."