The Impact of Severe Kyphoscoliosis on Lung Function

What is the expected effect of severe kyphoscoliosis on lung function?

A. Decreased FEV1/FVC and vital capacity

B. Unchanged FEV1/FVC and decreased vital capacity

C. Increased FEV1/FVC and vital capacity

D. Decreased FEV1/FVC and unchanged vital capacity

E. Unchanged FEV1/FVC and vital capacity

Final answer:

Option B (Unchanged; decreased) is correct.

Answer:

In severe kyphoscoliosis, which is associated with restrictive lung disease, the FEV1/FVC ratio is typically unchanged while the forced vital capacity is decreased due to limited lung expansion.

Individuals with severe kyphoscoliosis may experience a significant impact on their lung function. Kyphoscoliosis is a condition characterized by an abnormal curvature of the spine in both the sagittal and coronal planes, leading to a combination of kyphosis (forward rounding of the upper back) and scoliosis (sideways curvature of the spine).

When it comes to lung function, severe kyphoscoliosis can result in restrictive lung disease. In this scenario, the lungs are restricted in their ability to fully expand, leading to decreased vital capacity. Vital capacity refers to the maximum amount of air a person can exhale after taking a deep breath. Due to the limited expansion of the lungs in individuals with severe kyphoscoliosis, their vital capacity is expected to be decreased.

The FEV1/FVC ratio, which represents the percentage of the forced expiratory volume in one second to the forced vital capacity, is used to assess lung function. In severe kyphoscoliosis, this ratio is typically unchanged. This means that despite the reduced vital capacity, the expiratory flow rates remain relatively normal. The lungs are still able to expel air reasonably fast, even though the total volume that can be forcefully exhaled is compromised.

It's important to differentiate this pattern from other conditions like lung fibrosis, where the lungs become stiff and less pliable, leading to a high FEV1/FVC ratio. In kyphoscoliosis, the lungs decrease in size but the FEV1/FVC ratio remains unchanged or even higher than normal.

Overall, individuals with severe kyphoscoliosis may exhibit a combination of unchanged FEV1/FVC ratio and decreased vital capacity, highlighting the impact of this condition on their lung function.