What is a flow-volume loop?

Typically, when one thinks of flow-volume loops, one refers to the classical loops of forced expiratory spirometry. Most of what is written about flow-volume loops refers to these.

Should the flow-volume loop associated with the selected FEV1 be reported?

There are however, no guidelines for selecting the most appropriate flow-volume loop. It would seem that the flow-volume loop associated with the selected FEV1 should be reported since the FEV1 is primarily associated with flow rates.

What causes a sawtooth profile in a flow-volume loop?

A flow-volume loop can have a sawtooth profile. This can occur during exhalation or inhalation. The sawtooth pattern is usually generated either by airflow disturbances in the upper airway or from tremors of the respiratory muscles.

What is the difference between The spirogram and the flow-volume loop?

In contrast to the spirogram, which displays airflow (in L) over time (in sec), the flow-volume loop (see Figure: Flow-volume loops ) displays airflow (in L/second) as it relates to lung volume (in L) during maximal inspiration from complete exhalation (residual volume [RV]) and during maximum expiration from complete inhalation (TLC).