Interpretation of Pulmonary Function Tests A Practical Guide Fourth Edition PDF
Book Name : Interpretation of Pulmonary Function Tests PDF
Edition. 4th Edition
Interpretation of Pulmonary Function Tests A Practical Guide Fourth Edition is Pulmonary function tests can provide important clinical information, yet they are vastly underused. They are designed to identify and quantify defects and abnormalities in the function of the respiratory system and answer questions
such as the following: How badly impaired is the patient’s lung function? Is airway obstruction present? How severe is it? Does it respond to bronchodilators? Is gas exchange impaired? Is diffusion of oxygen from alveoli to pulmonary
capillary blood impaired? Is treatment helping the patient? How great is the surgical risk?
Pulmonary function tests can also answer other clinical questions: Is the patient’s dyspnea due to cardiac or pulmonary dysfunction? Does the patient with chronic cough have occult asthma? Is obesity impairing the patient’s pulmonary function? Is the patient’s dyspnea due to weakness of the respiratory muscles?
The tests alone, however, cannot be expected to lead to a clinical diagnosis of, for example, pulmonary fibrosis or emphysema. Test results must be evaluated in light of the history; physical examination; chest radiograph;
computed tomography scan, if available; and pertinent laboratory findings.
Nevertheless, some test patterns strongly suggest the presence of certain con-
ditions, such as pulmonary fibrosis. In addition, the flow–volume loop associated with lesions of the trachea and upper airway is often so characteristic as to be nearly diagnostic of the presence of such a lesion (see Chapter 2).
As with any procedure, pulmonary function tests have shortcomings.
There is some variability in the normal predicted values of various tests. In some studies, this variability is in part due to mixing asymptomatic smokers with nonsmokers in a “normal” population. Some variability also occurs
among laboratories in the ways the tests are performed, the equipment is
used, and the results are calculated.