Arterial Line - Square Wave Test
The arterial line can measure BP inaccurately unless properly calibrated. Rapidly flushing the line (by pulling the release on the flush device) generates a square wave. Counting oscillations after the square wave indicates if the arterial line is working properly.
Normal = accurate BP
- 1.5 - 2 oscillations
OVERdamped = falsely LOW BP
- <1.5 oscillations
- Absence of dicrotic notch
- Fix: Remove extra tubing & any air bubbles.
UNDERdamped = falsely HIGH BP
- >2 oscillations
- Additional artifactual spikes
- Fix: Adjust filter settings on monitor
Nick Mark MD @nickmmark
#squarewave #test #dampening #damped #arterial #artline #diagnosis
