Interpret these spirometry results and state the type of ventilatory defect indicated: FEV1/FVC = 67% (LLN 70%), FEV1 = 1.34 L (57% pred, LLN 1.73 L), FVC = 1.99 L (67% pred, LLN 2.23 L), FEF25−75 = 0

Here is an interpretation of the spirometry results:

1. FEV1/FVC Ratio: The measured FEV1/FVC ratio is $67\%$. This is below the Lower Limit of Normal (LLN) of $70\%$ and the predicted value of $81\%$. A reduced FEV1/FVC ratio is the primary indicator of an obstructive ventilatory defect.

2. Forced Expiratory Volume in 1 second (FEV1): The measured FEV1 is $1.34 \text{ L}$, which is $57\%$ of the predicted value ($2.37 \text{ L}$) and below the LLN of $1.73 \text{ L}$. This significant reduction in FEV1 further supports the presence of airway obstruction.

3. Forced Vital Capacity (FVC): The measured FVC is $1.99 \text{ L}$, which is $67\%$ of the predicted value ($2.97 \text{ L}$) and below the LLN of $2.23 \text{ L}$. A reduced FVC suggests a restrictive ventilatory defect.

4. Forced Expiratory Flow 25-75% (FEF25-75): The measured FEF25-75 is $0.78 \text{ L/s}$, which is only $32\%$ of the predicted value ($2.41 \text{ L/s}$) and below the LLN of $0.98 \text{ L/s}$. This parameter is a sensitive indicator of small airway obstruction.

5. Forced Expiratory Time (FET): The FET is $12.89 \text{ seconds}$, which is prolonged, consistent with airway obstruction.

Conclusion:
Based on these findings, the spirometry results indicate a mixed ventilatory defect. This is because:

• The FEV1/FVC ratio is reduced ($67\% < 70\% \text{ LLN}$), confirming an obstructive component.
• The FVC is also reduced ($1.99 \text{ L} < 2.23 \text{ L} \text{ LLN}$), confirming a restrictive component.

The preliminary impression on the report also aligns with this, stating "FEV1/VC and VC are reduced indicating Obstruction or a Mixed Obstructive/Restrictive pattern."