What conclusions can you draw from the following data, obtained on a 67-year-old, 76-kg man admitted for pulmonary complications arising from silicosis?
A) Results indicate generalized airway obstruction.
B) Results indicate normal pulmonary function.
C) Results indicate a combined disease process.
D) Results indicate a restrictive lung disorder.

Question

What conclusions can you draw from the following data, obtained on a 67-year-old, 76-kg man admitted for pulmonary complications arising from silicosis? 
A) Results indicate generalized airway obstruction. 
B) Results indicate normal pulmonary function. 
C) Results indicate a combined disease process. 
D) Results indicate a restrictive lung disorder.

Quizplus · Accepted Answer

Interpretation of the pulmonary function report: Interpretive strategies for pulmonary function testing abound. Most computer-based pulmonary function testing systems have algorithms in their software programs for computer-assisted interpretations of the pulmonary function report. A consensus for interpreting test results is growing. Table 20-8 summarizes pulmonary function changes that may occur in advanced obstructive and restrictive patterns of lung diseases, and Figure 20-16 presents a simple algorithm to assess pulmonary function test results in clinical practice. When considering a pulmonary function report, the %FEV₁/VC ratio is a good place to start, because it provides an initial focus as normal, restrictive, or obstructive impairment. When the %FEV₁/FVC is less than the limit of normal (LLN), there is airway obstruction. When the %FEV₁/FVC is greater than the LLN, there is no airway obstruction. The LLN %FEV₁/FVC can be determined directly for various population using regression equations in Table 20-9 or simply estimated at 70%. If the %FEV₁/FVC ratio is greater than the LLN or 70% and if the TLC is less than the LLN, often defined as less than 80% predicted normal, the patient has a restrictive impairment, according to this algorithm. The severity of the restriction is based on the percent predicted or on the number of standard deviations below the LLN TLC according to Table 20-2. If the %FEV₁/FVC ratio is less than 70%, the patient likely has an obstructive impairment; the severity of the obstruction is based on the percent predicted normal FEV₁ according to Table 20-2. If the percent predicted normal DLCO is less than 80%, the patient has a diffusion impairment. Some laboratories also report the DLCO/V_A ratio, which indexes the DLCO for lung volume measured during the single breath test. If the DLCO/V_A ratio is also less than 80% of the indexed value, the cause of the diffusion impairment is considered within the lung, and if the DLCO/V_A ratio is greater than 80% of the indexed value, the cause of the diffusion impairment is considered due to small lung volume.

What Conclusions Can You Draw from the Following Data, Obtained