Adult
Respiratory Distress Syndrome (ARDS) Introduction: This
lung condition is an acute inflammatory condition, which seems to affect the lower
lobes of both lungs more often. It is associated with serious health conditions
such as serious bacterial infections or viral infections with pneumonia, skin
burns and septic shock. Near drowning incidences, fat embolism, inhalation
of toxic gases or pancreatitis are other causes of the adult respiratory distress
syndrome. Signs and symptoms: If within 1 to 2
days following any of the above named conditions the patient starts breathing
rapidly and in a labored fashion (dyspnea), chances are that ARDS has set in. The
inflammatory substances that circulate in the blood release toxic enzymes that
make the capillaries of the lungs leak and secretions appear in the alveoli
and lead to an imbalance between the area of the lungs that are perfused with
blood and that are ventilated by the airways. The end result is that too little
oxygen enters the bloodstream through the lungs, which leads to cyanosis (=bluish
skin discoloration) and dyspnea. Diagnostic
tests: Using the stethoscope the doctor will hear crackles and wheezes
in the lung areas where the problem is located (usually the lower lung lobes). Arterial
blood gases taken at the radial artery will usually show extremely
low partial oxygen pressures in the lab. Chest X-rays show alveolar
infiltrates, which are similar, though different from pulmonary edema
changes found with congestive heart failure. X-ray changes usually lag several
hours behind the clinical condition. Clinical course: Within
2 to 3 days fluid and inflammatory secretions accumulate in the lung tissue that
is affected. This leads to a cellular infiltrate in the affected lung tissue within
2 to 3 weeks, called interstitial fibrosis. If the patient survives, depending
on the severity of this, this infiltrate may resolve completely in time. At the
height of the ARDS there is a danger of bacterial superinfection (pneumonia),
in which case the patient's condition tends to deteriorate. Most of these patients
are treated in an Intensive Care Unit where all the modern equipment is available.
Nevertheless, a high percentage of these very sick patients die as with severe
ARDS there is not enough active lung surface where oxygen can be taken up into
the blood stream. Without oxygen in the system life cannot be sustained. Unfortunately
modern medicine does not have all the answers for these unfortunate patients at
this point in time and more research is needed in this area. Treatment:
The treatment is directed at improving oxygen uptake and at the
same time to prevent the failure of multiple organ systems such as the heart,
the brain, the kidneys, the liver, the gut and the bone marrow. As already indicated
due to the complexity of the treatment, this is usually administered in an Intensive
Care Unit (ICU) setting. With an unconscious patient the first step usually
is intubation and mechanical ventilation with oxygen by positive end expiratory
pressure (PEEP). In order to keep the circulation under control a central
line is usally inserted to be able to administer fluids and possibly
even intravenous nutrition. These patients need around the clock care by highly
trained ICU staff, including respiratory technicians, nurses and doctors. In the
past almost 100% of patients with severe ARDS died. Now with modern ICU techniques
about 60% of patients survive. Most of the patients who survive live a normal
life with no further lung complications. A small percentage of patients who have
been treated with artificial ventilation for several weeks may develop lung fibrosis. |
