Procedure
The child is seated alone in the box with the door closed. The childs breathing should aim for a frequency of 30-45.
- An adult may accompany the child in the box and should then perform one slow exhalation during the measurement. Such slow exhalation willl not interfer in the measurement of the rapid pressure swings by the child.
- "Loops" on the screen shows the relation between pressure (or volume) (x-axis) and flow (y-axis). That is the pressure driving the flow in and out of the lungs. sRaw is the inclination of these loops.
- Technically acceptable loops are chosen as those which are "closed" in the middle "Open" loops normally indicate insufficient BTPS correction. The loops should assume a straight line with a tendency to s-shaped, and should be symmetric around the inclination.
- BTPS correction is done automatically when the result is analyzed, or may be done manually by "Automatic ASC optimization" or F4
- sRaw from one run is calculated as the median value of five technically satisfactory loops with similar configuration and inclination.
- It is recommended to calculate the mean sRaw of duplicate measurements. Such two measurements should not differ more than + 0,3 [kPa*s]
- If a seconds person has accompanied the child in the box sRaw should be adjusted by the factor (810-adults weight)/810).
COPSAC • Faculty of Health Sciences • University of Copenhagen • Denmark
Danish Pediatric Asthma Center • Copenhagen University Hospital
Ledreborg Alle 34 • 2820 Gentofte • phone +45 3977 7360 • contact@copsac.com
© 2011
