FVC Tracing: FEF200–1200 Calculator

Calculates the flow slope for the initial 200–1200 mL segment from graph readings one second apart.

Inputs

Color mode links each input to the matching equation term and solving arithmetic.

Equation and Work

Equation:
Solving steps:
FEF200–1200
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L/sec
Volume difference
—
L
Reference status
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8.7 L/sec adult example
Normal/reference: FEF200–1200 reference example in the book: 8.7 L/sec for a 70-inch, 20-year-old male; use appropriate predicted tables for formal interpretation.

Clinical Significance

FEF200–1200 is the flow slope for the first measured 200 to 1200 mL segment of an FVC maneuver. The 200 and 1200 terms identify the graph-volume points used to calculate the one-second slope.

Used to assess large-airway flow, along with early timed expiratory volumes.

Requires accurate plotting and graph reading; patient effort can affect results.

References (APA 7th Edition)

  1. Chang, D. W. (2020). Respiratory Care Calculations (Revised 4th ed.). Jones & Bartlett Learning. Formula content adapted from the uploaded text/reference packet.