Flow Volume Loops




Fig. 70.1 A normal FVL





Questions


  1. 1.


    Draw a normal flow volume loop. Label the x- and y-axes. Where is the residual volume and total lung capacity located? Show where expiration and inspiration are represented.

     

  2. 2.


    Regarding patient effort, what is required from the patient for a flow volume loop to be accurate? What type of patients might have difficulty with a FVL?

     

  3. 3.


    Where is the peak expiratory flow rate (PEFR) located on the FVL? What are the normal values for PEFR for adult females and males? Besides a respiratory problem, what are major influences on the PEFR?

     

  4. 4.


    Where does an FVL start? What direction does the FVL follow?

     

  5. 5.


    Draw an FVL for a patient with mild COPD. Describe some key characteristics. Explain what happens to the FVL whenever there is severe COPD.

     

  6. 6.


    Draw an FVL for a patient with vocal cord paralysis.

     

  7. 7.


    Explain what an FVL for a patient with a fixed obstruction such as a goiter looks like.

     

  8. 8.


    What does an FVL typically look like for restrictive lung disease?

     


A371567_1_En_70_Figb_HTML.jpg



Fig. 70.1a Normal flow volume loop with labels



Answers


  1. 1.


    Refer to Fig. 70.1a. The y-axis represents the flow rate. On this same axis exhalation is found in the area above the x-axis, and inhalation is represented below the x-axis. The lung volume is plotted on the x-axis and the value decreases from left to right. In other words, the x-axis starts at total lung capacity at the left end, and the volume decreases progressively until residual volume is reached at the far right.

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Sep 23, 2017 | Posted by in Uncategorized | Comments Off on Flow Volume Loops

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